Thank you for your attention.

	DR. NELSON:  Thank you.

	Celso.

Celso Bianco, M.D.

	DR. BIANCO:  I am Celso Bianco.  I am speaking for America's Blood
Centers.

	America's Blood Centers (ABC) is a national network of
locally-controlled, not-for-profit community blood centers that provide
nearly half of the U.S. blood supply from volunteer donors.

	Collectively, America's Blood Centers' total blood collections exceeded
7 million donations in 2001.  ABC members operate in 45 states and in
Quebec, Canada, and serve more than half of the 6,000 hospitals in the
U.S.

	Members of America's Blood Centers thank the FDA for the opportunity to
participate in this public discussion about the reduction of the
incidence of bacterial contamination of blood components.  Bacterial
contamination is the second cause of transfusion-related fatalities
reported to FDA, representing 10 percent of the cases with an average of
five reports a year.

	Only hemolytic reactions due to errors cause more fatalities--an
average of 18 a year and half of the reported transfusion-associated
fatalities (Jong-Hoon Lee, M.D., CBER, FDA September 1999).

	ABC members also agree that measures to reduce the incidence of
bacterial contamination of blood components should be implemented.
However, they believe that a number of unresolved issues must be
considered by this committee and by FDA before the agency issues any
specific requirements.

	Bacterial contamination of blood components is a far more complex
problem than viral contamination.  Substantial reduction of transmission
of HBV, HCV, and HIV by transfusion has been achieved by screening
assays that are specific for each virus,  as well s by donor history
questions and donor deferrals.

	Viruses do not replicate during component storage; what is in the donor
is in the blood sample collected for testing and is in the blood bag.

	Bacteria, on the other hand, are everywhere.  There are thousands of
species that may contaminate blood products, and they replicate during
storage.  They may be present in minuscule amounts in the donor's
circulation, they may survive skin disinfection, and there are no
specific tests.

	The sensitivity of disinfection and detection systems varies according
to the type of bacterium.  Thus, while everyone agrees that something
should be done, there is no clear agreement about what should be done.

	The American Association of Blood Banks' Standards Committee is
proposing new standards for skin disinfection in the next edition of
AABB's Standards.  The Standards Committee has also proposed the
implementation of bacterial detection systems (without specifying how
this should be done).

	We all agree that disinfection of the venipuncture site should be
performed using the most effective method possible.  Recent studies
suggest that tincture of iodine would be better than current methods.

	A second approach to reducing the incidence of bacterial contamination
adopted in some European countries, e.g., The Netherlands, is attaching
a diversion pouch to the collection bag.  The first several ml of
collected blood are diverted to the pouch and used for testing.

	This prevents skin contaminants and the skin plug often generated by
penetration of the needle from entering the collection bag.  These
diversion pouches are available in some apheresis sets, but are not yet
approved for whole blood collection systems.

	Unfortunately, skin disinfection and diversion pouches only reduce skin
and environmental contaminants. Several bacteria of importance are in
the donor's circulation and are not affected by these measures.
Detection systems appear, at first sight, to be the solution.

	In theory, bacterial culture and detection of bacterial growth could
resolve the problem of bacterial contamination of blood components, and
FDA has approved two such systems in recent months.  However, the
approval is specific for quality control, not for release of blood
components as free of bacterial contamination.

	Concerned about bacterial contamination, European blood agencies have
decided to adapt clinical laboratory culture systems to their
operations.  In The Netherlands, platelets from whole blood are prepared
by the buffy coat method, pooled, and a sample from the pool is placed
in a culture system with automated detection of bacterial growth.

	After 24 hours, if the culture is negative, the platelets are released
to hospitals.  If growth is observed in subsequent days, the hospital
and physicians are notified.  This method for the preparation of pools
of platelets from whole blood is not approved in the U.S.

	Hema-Quebec, our Canadian member, has implemented bacterial detection
systems for platelets collected by apheresis and is studying the
adoption of the buffy coat method for preparation of platelets from
whole blood.

	Among the 75 ABC member centers, 8 have decided to implement bacterial
detection systems in the near future.  They plan to use he ones
currently approved for QC of apheresis platelets, in a way similar to
that used by the Dutch.  These systems are complex and expensive;
moreover,  they cannot be applied in a practical manner to platelets
derived from whole blood.

	Current FDA regulations prevent us from pre-pooling platelets from
whole blood.  When pooled, they must be transfused within four hours,
even if the pooling is performed in a closed system, using sterile
connecting devices.

	For this reason, the implementation of bacterial detection systems
threatens the survival of platelets from whole blood.  Members of this
committee should be aware that there aren't enough platelets collected
by apheresis to supply the needs of the U.S. healthcare system.

	Last year, ABC members distributed about 550,000 platelets by apheresis
and 1.5 million units of platelets derived from whole blood, and it
would take several years to reach sufficiency if we were to convert
entirely to platelets by apheresis.

	In addition, many hospitals are resistant to the conversion, because of
the substantial cost differential between the two components.

	Some less cumbersome and less expensive approaches have been proposed
for the screening of random donor platelets for bacterial contamination.
 One is the use of a reagent dipstick for pH and glucose; a pH lower
than 7 and/or a glucose level of less than 250 mg/dl would be considered
indicators of bacterial contamination.

	The sensitivity and specificity of dipsticks is not yet fully assessed.
 In the past, some centers have screened platelets with a Gram stain
immediately before transfusion.  However, we know that these two methods
are much less sensitive than systems based on bacterial culture.

	In our opinion, a number of practical issues need to be dealt with
before restrictive standards or regulatory mandates are issued for
interventions designed to reduce the incidence of bacterial
contamination.

	The mode of application of the systems approved for quality control is
still unclear for us.  What would be the corrective actions triggered by
the finding of an occasional component with bacterial growth?  We can
think of personnel retraining and very little else.  How should we
interpret these findings from the QC point of view?

	Where should bacterial detection be performed?  At the blood center
where the components are prepared, or at the hospital, closer to the
transfusion event?  The requirements for the two approaches are quite
different.

	Detection at the collection facility requires high sensitivity, and
results obtained at the time of release of the platelets (consider the
five-day out-date) may not be predictive of the bacterial load at
expiration.  On the other hand, there are no reliable systems for
testing close to the transfusion event, when platelet concentrates are
pooled.

	One of the approved systems (Pall) focuses mainly on aerobes; the
manufacturer of the other is recommending cultures for aerobes and
anaerobes (BioMerieux).  Are cultures for anaerobes warranted,
considering that platelets are stored in gas permeable bags in an
oxygen-containing atmosphere?

	Recognizing that anaerobes are rare causes of clinical bacterial
contamination, and sometimes not detected in vitro until beyond the
expiration of the product, we do not think that use of anaerobic media
is a key initial part of this initiative.

	What inoculation systems should we use to prevent false positive
results?  Do we need to use laminar flow hoods?  How do we deal with
false positives?

	The Pall BDS is an endpoint system.  Specimens are inoculated 24 hours
after collection and the cultures read at least 24 hours later.  In
contrast, the BioMerieux bacT/ALERT is a continuous system, raising the
question of when cultures should be considered negative.

	Then the BioMerieux system is used and the cultures continue to be
followed after release of the platelets to a hospital, if subsequently
positive, what should physicians be told (since in many cases the
platelets will have been transfused)?

	To what level should centers or contract microbiology services identify
positives?  Is there a need for performance of antimicrobial
susceptibility assays? Probably yes.

	Could cultures be inoculated at the collection facility and read at the
hospital that received the component?  If so, how would specimens be
identified?  What software modifications are needed to assure
correlation between components and culture results?  In this case,  how
should reports of positive results be handled?

	How do we validate these systems?  What are the positive controls?  How
can we measure the efficacy of the detection procedures in light of the
low frequency of events?

	Finally, should a recommendation be made for implementing these very
expensive new procedures, there should be a consistent message to
hospitals and insurers explaining that their benefit far exceeds their
cost.

	Considering these and many other issues that need to be reviewed, we
respectfully request that this committee and FDA consider the following:

	Support collection facilities that implement methods to reduce the risk
of bacterial contamination by skin contaminants in blood and blood
components.

	Facilitate the licensure of bacterial detection systems for component
release, allowing claims such as "negative for bacteria at time of
release."

	Support collection facilities that decide to implement 100 percent
Quality Control for their apheresis platelets.  Their experience will be
invaluable for progress in this area.  Regulatory actions could have
serious inhibitory effects and delay the implementation of procedures
that will certainly increase the safety of transfusion.

	Encourage the development of alternative technologies for bacterial
detection that are less laborious, less expensive, and can be applied at
the hospital level, closer to the transfusion event.  This is essential
for the survival of whole blood derived platelets and for the
fulfillment of patient needs.

	Speed the regulatory process for the extension of the expiration date
of platelets to seven days if negative for contamination.

	Allow pre-pooling of platelets from whole blood using approved sterile
connecting devices, based on the long and successful European experience
with buffy coat platelets.

	We strongly believe that these actions will encourage the
implementation of means to reduce bacterial contamination of platelets
and hence increase the availability of safer platelets for transfusion.
When we reach this stage of development, we will welcome FDA regulation.

	Thank you very much for the opportunity to present our point of view.

	DR. NELSON:  Thanks, Celso.

	T.J. Smith?

	MS. CROSBY:  T.J. Smith has asked me to give the presentation.

Cynthia Crosby

	MS. CROSBY:  I am Cynthia Crosby.

	As we go forward, I am going to skip through these slides really fast,
but I want to challenge the FDA Advisory Committee to understand the
modes and mechanisms of antimicrobial solutions in choosing what I am
hearing a plea from your Red Cross, the ABC to adequately assess skin
preparation prior to the venipuncture.

	[Slide.]

	Understanding antiseptic agents is very easy and readily available in
the texts that are out there.  I am with Medi-Flex.  We have been in the
business for 17 years of providing aseptic tools to deliver antiseptic
products to the donor site.

	Our bread and butter is in the donor prep market outside the United
States by them using alcohol followed by tincture of iodine.  Our bread
and butter in the United States is blood culture kits that provide
alcohol followed by tincture of iodine.

	[Slide.]

	Why is tincture of iodine superior to your current AABB recommendation
of povidone-iodine?  Povidone-iodine is complex with an inert polymer
that must dry for the polymer, must dry for the iodine to decomplex, to
have a kill mode.

	[Slide.]

	With tincture of iodine, you have readily available iodine.  It is
there in the position to have an immediate effect prior to your
venipuncture.

	[Slide.]

	We have had great demand from the blood donation facilities for a
chlorhexidine type based product whether it be tincture or aqueous.  We
are hearing that every day if this product has been approved by the FDA
to be used for blood donation.

	Right now we have several facilities that are running validations.  The
National Blood Authority in the UK is in the mode right at this time of
implementing a chlorhexidine/alcohol/tincture for blood donation.

	Carl McDonald presented at the International Blood Banking Conference
in Canada that stated that there was an equivalence to the tincture of
iodine two-step procedure, alcohol followed by tincture of iodine.

	In this, there was 2.76 log reduction with tincture of iodine versus a
2.6 log reduction with the chlorhexidine/tincture.  Over 99 percent of
the bacteria were killed at the time of the venipuncture.

	[Slide.]

	What makes chlorhexidine ideal is its affinity to bind to the skin
surface.  Ideal antiseptics should be broad spectrum, they have to be
rapid.

	[Slide.]

	They have to be rapid because of one key component, and that is
convenience and compliance to protocol.  As our staffing nurses are
reduced, our average age nurse is now 47 years old in our facilities,
and as phlebotomy teams are reduced, compliance and convenience to
protocol is necessary.

	Industry has met that demand by combining products that will have a
quick dry time, a quick kill.

	[Slide.]

	As of July 2000, there was an NDA approval for a new
chlorhexidine/tincture product, 2 percent chlorhexidine and 70 percent
isopropyl.  It has been demanded from the health care worker or
clinician for the care of catheter insertion and catheter lines.

	In 10 years, we have heard the data over and over again in the 50
percent reduction to catheter-related bloodstream infections.  We see it
now in the studies that are followed in the data that I gave you as a
package that shows the 50 percent reduction by going to use a
chlorhexidine/tincture prior to a vascular procedure.

	[Slide.]

	Povidone-iodine is your current prep.  It's a two-step procedure.
Tincture of iodine and CHD are far superior in the clinical and in the
in vitro data to povidone-iodine. Tincture of iodine is a two-step
procedure.  It is proposed for the standards of blood banking and
transfusion.

	Two percent chlorhexidine based products that are currently available,
which only happens to be one, is a one-step procedure.  It is equivalent
to the two-step tincture of iodine.  It is proposed as an alternate
prep.

	One thing I can state is that we see huge compliance to protocol in the
hospital community.  New CDC guidelines for the prevention speaks I
think, and I am going to go out on a limb here, to your donation
facilities, that is, educated and dedicated resources are necessary to
reduce your contaminations.

	Maximal barriers and the understanding of maximal barriers are
necessary in reducing contamination, and 2 percent chlorhexidine-based
antiseptics are preferred, they are the preferred antiseptic of choice
by the CDC, and they have superior efficacy compared to povidone-iodine.

	[Slide.]

	Preventative measures are the highest quality in medical treatment and
the most cost efficient.  They are simple.  We just have to make the
decision to use those preventative measures.

	Thank you.

	DR. NELSON:  Thank you very much.

	Pall Corporation also had a statement to make, but they have decided to
submit it for the record rather than to read it or present it at the
meeting at this time.

	We are no longer in the open public hearing.

	Maybe we can go to the questions.  John.

Questions for the Committee

	DR. LEE:  I guess I will just read the question one more time regarding
donor arm prep.

	Do available scientific data support preferential use of an
isopropanol/tincture of iodine procedure for preparation of the donor's
phlebotomy site?

	I guess I would just comment that some of the comments we heard during
open public hearing session just now didn't really refer back to some of
the material that I presented in the morning.  The fact that
isopropanol/tincture of iodine is proven to be superior in the donor
setting seems a bit of an overclaim in view of what I presented.

	DR. SIMON:  Is it appropriate to start the discussion?  I guess it is
an interesting topic because I have a long-standing interest in it, and
actually, data that were not presented here, but there was a study done,
the United Blood Services in 1993-94.  It was only presented in abstract
form and it is referred to in the Goldman paper, and it showed that
tincture of iodine was superior in eradicating organisms from the skin.

	I actually wrote the AABB at that time and proposed that we make the
change then, and that obviously did not occur.  So, I think that there
is data and I think there is data in the blood culture literature, as
well, to indicate that looking strictly at data, it would appear that
tincture of iodine is superior to the povidone and that, in addition,
chlorhexidine is also superior.

	Actually, we use chlorhexidine in our laboratory for our blood
cultures, but when I questioned our microbiologist on why we made that
choice instead of tincture of iodine, it was because we have a lot of
these cultures drawn by non-dedicated personnel, not personnel that we
control, intensive care, emergency room nurses, and so one-step
procedure, which the chlorhexidine is, is superior or we feel we get
superior compliance and went with that instead.

	I think there is data to support the change as AABB plans.  I must say
that I was impressed with your presentation and I think from the common
sense point of view, one could well raise the question, does it really
make a difference in the donor setting where you have so many other
things going on, and you have sort of a multifactorial situation.

	But I would guess if we are this concerned about this subject to be
willing to move to some of these other steps that we are going to
discuss, I would think, as a first step, that we would want to have the
most effective removal of organisms from the arm to begin with when the
unit is drawn.

	I think that the tincture of iodine, as AABB has proposed, with the
chlorhexidine as the backup for iodine-sensitive individual, that would
be the step to go, so I would support this.

	I would put into that statement, however, that I don't think the plasma
industry should be required to go this direction because none of their
products are stored are either refrigeration or room temperature.  They
are frozen,  and they have not had a problem with bacterial infection in
that industry.

	So, I would think that they should be okay to go with either one, but I
would support the AABB position at this time.

	DR. ALLEN:  Thank you, Toby.  I think that is a good introduction to
the discussion.  I have been mulling over,  given the way in which the
question is worded, whether I would vote yes or abstain.

	My feeling is that there is some evidence that tends to lean towards
tincture of iodine in isopropanol, or the combination, the two step, as
clearly the preferred way to go although I would have real trouble given
the broader view of 2 percent chlorhexidine in isopropanol as an equal
alternative.

	I guess my question is what is the implication of voting yes for this
in terms of action that the FDA might take given that the AABB already
has revised proposed standards out that use this with the chlorhexidine
as an alternative.

	So, if we vote yes for this, what are the implications in terms of how
the FDA is going to use this information?

	DR. LEE:  That's a million dollar question.  Dr. Epstein, would you
like to field that question?

	DR. EPSTEIN:  The question before the agency is whether we should issue
a regulatory guidance recommending preferred use of isopropanol/tincture
of iodine.  It has occurred from time to time that we disagree with an
industry voluntary standard, and then we may take a regulatory position
to override it.

	So, in this case, our options would be to remain neutral and let the
preference be voluntary or to endorse it through a regulatory
recommendation.

	DR. ALLEN:  I would certainly feel comfortable and I would vote yes if
it is to be a voluntary recommended standard.  I am much less
comfortable I think to take it to the regulatory level.

	DR. EPSTEIN:  Well--okay.

	[Laughter.]

	DR. NELSON:  Actually, this committee doesn't exactly make regulations.
 We are supposed to help the FDA evaluate data and evaluate what is
there and what is missing.  So, I don't think you need to consider
yourself a judge or a congressman at this point, I guess.

	DR. KLEIN:  I appreciated Dr. Lee's very thorough review, but I must
say I sort of discounted the studies that simply showed that you can't
culture something or you culture something less frequently from the
site, because that really isn't a good demonstration of what might be
the risk in the bag.

	Actually, I think you could be fairly badly misled by those studies.
What you really want to know is what the risk is of contaminating the
component.  We don't have those studies unfortunately, and I think the
best that we have are the blood culture studies which by and large show
that all of these preps are just about the same, I guess, with the
exception of soap, which I don't think anyone supports.

	The problem with those studies, of course, is that the background level
is so high that it could mask slight differences between different arm
preps.

	So, I don't have any problem with saying that this is a good
preparation, I guess as the AABB is suggesting in its standard.  I would
hate to see anything regulated based on that, however.  I don't think
the data support it.

	DR. NELSON:  In these studies, apparently what happened, the way they
did it is they cultured before the preparation and then they applied the
material and then recultured.  It was stated as a percent reduction of
flora.

	DR. LEE:  Well, many of the blood culture studies were comparisons.

	DR. NELSON:  Not the blood cultures, the McDonald.

	DR. LEE:  The blood collection studies, yes, it was cultured before and
after.  Again, when represented as percent reduction, the values don't
strike out at you as much, the difference between 99 and 98, I don't
know what that really means.

	DR. NELSON:  Mary.

	DR. CHAMBERLAND:  I guess I am puzzling over this, too, because I guess
what are the criteria, what is the level or rigor that is going to
demonstrate that one of these preparations is "preferential."

	I agree with Dr. Klein's comments that log reduction of bacteria skin
contaminants is not necessarily at all the whole story.  I just wanted
to make sure because it was a quite a load of literature that the
committee was given to review in advance, in a relatively short period
of time, so I think it is really hard for us to basically digest all of
this.

	I do want to commend you because I think you did really put together a
really nice, critical review.  As I understand it, there are no data for
this proposed prep that look at contamination rates in bags of
platelets, that is correct, it is just all skin studies.

	DR. LEE:  That is my understanding.  The thing that comes closest is
the third study that I described, within which cultures of actual
platelet units were done, but that study did not include the tincture of
iodine/isopropanol method.

	DR. CHAMBERLAND:  So, as a surrogate, then, you brought up in some of
your slides some reviews of literature that is available on looking at
blood culture data.

	DR. LEE:  Right.

	DR. CHAMBERLAND:  And the various preps.  Again, I want to make sure I
have got the bottom line here straight, but in looking at the blood
culture data, were there any clear winners here?  This
isopropanol/tincture of iodine did not emerge in the blood culture
studies as showing a preferential--

	DR. LEE:  No, it did not.  There are some conflicting results.  Some
showed marginally better performance, but there were many others,
equally as many, that showed no difference.

	DR. CHAMBERLAND:  I think it comes down to--again, this is what I am
struggling with--if FDA is signaling that they are potentially
considering guidance, then, you usually have to put forward what your
criteria are that you are going to evaluate.

	I guess a fair question is if the only data for this new prep are skin
culture data, is that adequate, is that the whole story, would you
require more rigorous data.

	In the end, at the end of the day, how much of a difference is it going
to make.

	DR. LEE:  I see Dr. Epstein at the mike.

	DR. EPSTEIN:  Maybe I can shed some light.  I think Dr. Lee said this
earlier.  What has happened here is we have had a series of workshops
over a period of years.  At every single workshop or symposium, someone
shows the studies on the isopropanol alcohol/tincture of iodine prep and
says, look, this reduces bacterial contamination of the skin.

	We all agree that we don't have a good endpoint study in platelets, and
the FDA has not come forward in the face of that with a recommendation
for preferred use of that procedure because we keep taking a look at the
larger literature and scratching our heads and saying we are not ready
to do this.

	On the other hand, the AABB has now, listening to the same workshops,
the symposiums, reading the same literature, has decided to make this a
voluntary standard.

	Now, there are two positions that the FDA could take.  One is we agree,
so we will make it a regulatory standard, or we are not so sure, but we
are not opposed to the industry voluntary standard.

	Again, and I guess this comes back to you, Jim, we are not asking you
to decide the regulatory position.  We are just asking you whether you
are, in effect, in agreement with the FDA that the science is too soft
for us to take a regulatory position, because after all, the pressure on
us has been to do just that.

	DR. SIMON:  I just will say a few more words in support of my position,
I guess, for a yes vote on the question.  I think we have to remember
that what we used to cleanse the skin was based on this kind of
analysis.  That is, we wouldn't have any prep at all as far as I know if
we had as an endpoint, the desired one, of the infection of the unit.

	So, we have sort of empirical choice of agents that remove bacteria
from the skin, because that is what we want to do with this step of the
procedure, and the data would indicate that tincture may be superior.

	I was a little surprised at the skepticism about the blood culture
studies because the reason we did the study at UBS back in 1994 was the
literature on the blood culture studies, which indicated that povidone
was inferior.

	I might be somewhat influenced by this 1999 study by my former mentor
at medical school from Barnes-Jewish, which showed tincture of iodine to
be superior, and I don't believe that we would use povidone in our
laboratory for blood cultures at this time.  We would use either
chlorhexidine or tincture of iodine.

	So, I think that there is enough data there given that what our
objective is with this step of the procedure is to remove bacteria from
the arm.  We may have to do other procedures to make sure that the
platelets are absolutely sterile, but that would seem to be the most
reasonable first step.

	DR. FITZPATRICK:  I would agree with Toby, but prior to making
regulation, because really the only data we have for regulation is from
the Vox Sang article, and since the tincture of iodine wasn't in that,
there isn't a comparison to use, so you would need a comparison.

	But as far as just surface contamination, I think there is ample
evidence, and we did used to use tincture of iodine, and the biggest
complaint was that techs and nurses were getting cut in their fingers
when they broke the ampule initiative the tincture of iodine swab that
was used to prepare the arm, and now there is a method where you don't
have to break a glass ampule to do that.

	Since it just says preferential, it is pretty soft as it is.

	DR. LEW:  I think maybe to be fair, to be more specific, though,
because everyone is struggling with the fact, I think, that there is no
good studies looking at many different types of preparations and saying
that this is The superior with a capital T.

	But if you can just say preferential, the tincture compared to what is
used now as a recommended standard, I don't think anyone would have a
major problem with that.  It is just trying to imply this is the best
overall.  The data is not there, and it is not appropriate to I think
regulate based on no data.

	DR. NELSON:  Are we ready to vote on this?  It is now an open public
hearing, but if you have got something critical that we haven't
considered.

	DR. WAGNER:  Just a cautionary note, and that is of placing too much
emphasis on whole blood cultures done at hospitals on patients who may
already, some fraction of which would be bacteremic, to compare two
different skin preparation methods.

	The bacteremia in the population may overwhelm the differences.

	DR. NELSON:  The difference of differentiating a contaminant from a
real infection.  We have recorded that.

	DR. ALLEN:  Would the FDA consider an amendment, if we add at the end
of this, the sentence as written, "for preparation of the donor's
phlebotomy site compared with the current procedure using
povidone-iodine"?

	That compares this one versus that one without making a statement about
any other preparation.

	DR. LEE:  We could do that, interpret the question in that light.

	DR. NELSON:  Right, since that is what is used, I guess.  Okay.

	DR. SMALLWOOD:  Would you repeat that?

	DR. ALLEN:  Do available scientific data support preferential use of an
isopropanol/tincture of iodine procedure for preparation of the donor's
phlebotomy site compared with the current standard procedure based on
povidone-iodine preparation?

	DR. SMALLWOOD:  Voting will be by roll call as required.

	The question as amended reads:  Do available scientific data support
preferential use of an isopropanol/tincture of iodine procedure for
preparation of the donor's phlebotomy site compared with the current
standard procedure based on povidone-iodine preparation?

	Allen.

	DR. ALLEN:  I vote yes and I think we need to look at other
preparations, and we need to study the donor acceptability of the
tincture of iodine.

	DR. SMALLWOOD:  Chamberland.

	DR. CHAMBERLAND:  I am going to vote no.

	DR. SMALLWOOD:  Davis.

	DR. DAVIS:  No.

	DR. SMALLWOOD:  DiMichele.

	DR. DiMICHELE:  No.

	DR. SMALLWOOD:  Doppelt.

	DR. DOPPELT:  Yes.

	DR. SMALLWOOD:  Fitzpatrick.

	DR. FITZPATRICK:  Yes.

	DR. SMALLWOOD:  Klein.

	DR. KLEIN:  No.

	DR. SMALLWOOD:  Lew.

	DR. LEW:  Yes.

	DR. SMALLWOOD:  Schmidt.

	DR. SCHMIDT:  Yes.

	DR. SMALLWOOD:  Stuver.

	DR. STUVER:  No.

	DR. SMALLWOOD:  Fallat.

	DR. FALLAT:  No.

	DR. SMALLWOOD:  Harvath.

	DR. HARVATH:  No.

	DR. SMALLWOOD:  Nelson.

	DR. NELSON:  Yes.

	DR. SMALLWOOD:  Dr. Simon, you would--

	DR. SIMON:  Yes.

	DR. SMALLWOOD:  The results of the voting.  There are 6 yes votes, 7 no
votes, no abstentions, the acting non-voting industry representative
agrees with the yes vote.

	DR. NELSON:  Now that we have solved that, do we have a second
question?

	DR. WILLIAMS:  Just a very brief clarification.  Like this question,
several of the other questions deal with issues in which there is a
developing industry standard, as well as a potential developing
regulatory policy.

	Several of these initiatives are draft standards. They need to go
through a membership comment period and final acceptance, so just to
clarify, these are not existing industry standards at this time.

	Committee Question 2.  Do available data on the sterility of the
sterile connecting device procedure support the use of this procedure to
collect samples for bacterial detection from in-date platelet products?

	DR. NELSON:  Discussion?  Yes.

	DR. SIMON:  I think the data were fairly overwhelming to answer this
yes, however, just with the caveat that we are introducing another
complexity into the system, which at a breakdown at some point, could
lead to more bacterial infections than what we have now, but I think
certainly the data we are presented support it and obviously, the FDA
has approved this for products that remain in-date and can be infused.

	So, I would think that we would vote yes on this one.

	DR. NELSON:  When it breaks down, that will lead to another question
later on.

	Are we ready to vote?

	DR. SMALLWOOD:  Question No. 2.  Do available data on the sterility of
the sterile connecting device procedure support the use of this
procedure to collect samples for bacterial detection from in-date
platelet products?

	Allen?

	DR. ALLEN:  Yes.

	DR. SMALLWOOD:  Chamberland.

	DR. CHAMBERLAND:  Yes.

	DR. SMALLWOOD:  Davis.

	DR. DAVIS:  Yes.

	DR. SMALLWOOD:  DiMichele.

	DR. DiMICHELE:  Yes.

	DR. SMALLWOOD:  Doppelt.

	DR. DOPPELT:  Yes.

	DR. SMALLWOOD:  Fitzpatrick.

	DR. FITZPATRICK:  Yes.

	DR. SMALLWOOD:  Klein.

	DR. KLEIN:  Yes.

	DR. SMALLWOOD:  Lew.

	DR. LEW:  Yes.

	DR. SMALLWOOD:  Schmidt.

	DR. SCHMIDT:  Yes.

	DR. SMALLWOOD:  Stuver.

	DR. STUVER:  Yes.

	DR. SMALLWOOD:  Fallat.

	DR. FALLAT:  Yes.

	DR. SMALLWOOD:  Harvath.

	DR. HARVATH:  Yes.

	DR. SMALLWOOD:  Nelson.

	DR. NELSON:  Yes.

	DR. SMALLWOOD:  Dr. Simon?

	DR. SIMON:  Yes.

	DR. SMALLWOOD:  We have unanimous yes on the vote for the second
question.

	DR. WILLIAMS:  Does the committee concur with FDA's proposed
statistical approach to providing quality control for platelet
contamination?

	DR. NELSON:  Discussion?  Toby.

	DR. SIMON:  Well,  I have a real problem with this, but in a way I
think Dr. Epstein clarified it as a method for the agency to be certain
that the regulated entities are performing their functions as they
should.  I guess it is something to go along with.

	I just don't think that this kind of approach will ultimately improve
safety, and it is going to cost a lot and small organizations will have
to wind up culturing all their units.  So, I think it probably logically
leads you to what the AABB is proposing, which is a release criteria,
but I don't see anything wrong with what the FDA has proposed other than
I think it is going to be a lot of data collection without a lot of
value from it.

	DR. FITZPATRICK:  A comment and a question.  I think Toby's comment
about the small facilities having to culture every unit is very valid.
In the past, FDA has attempted to find a means of providing those
smaller facilities an alternate method, and I think it is essential that
there be an alternate method for them especially if they demonstrate
they are in control over a period of time.

	The other question I have is when a facility finds itself above the 0.2
percent level, are they then to restrict the release of products until
they sample enough products to come below the 0.2 percent level, and
what is the impact on supply of that.

	DR. WILLIAMS:  That is a good question.  If a process is deemed out of
control, I think under normal circumstances, one would basically curtail
production, reassess, and revalidate all the processes and continue,
revalidate and resume production as soon as possible.

	But I think to continue manufacture of product for a procedure that is
significantly not meeting a current standard, it would probably be
arguable that production should continue.

	There is a supply issue and I think probably in that situation,
approaching FDA for a potential solution is probably the best impact.
Jay may wish to comment, as well.

	DR. EPSTEIN:  Well, typically, industry establishes alert levels and
action levels, and I think the discussion hasn't gone that far.  It may
depend what measure you get.  You know, if the estimated rate is 0.4
percent, that is not the same thing as if it was 0.25.

	I don't think we have all the answers there, but I think that Alan's
answer is the correct one, a system that is clearly out of control
shouldn't continue, and it does throw into question the quality of the
products released.

	But that said, more work is needed, more thought is needed to figure
out what the appropriate actions are at any given level.

	DR. SCHMIDT:  I was struck by Dr. Bianco's comment about what do you do
with the information, and the thing I thought back to is a recent event
where a patient who had multiple transfusions, suffered from I think it
was a Klebsiella, and the result of this, I just read the newspaper
account, was shutting down the blood for the whole state more or less,
and some strange things were said in the press.

	I guess what I am saying is when you get to this type of iffy things
and you are looking at the quality of the entire place based on
something that may or may not relate, this can be a pretty dangerous
situation.

	DR. FALLAT:  I was impressed with the fact that there is such a
variation in the literature and you really can't give a standard right
now, so I am not sure how we can set up an industrywide standard when we
don't know what the standard is.

	I was also impressed with the comments made by the CDC representative
that said that there may be several questions that need to be answered,
and I think it would be much more reasonable that this be done as a
pilot or a study to see what your response is with a certain number of
centers that might be willing to cooperate in such a study rather than
making it an industrywide quality control approach at this time.

	DR. ALLEN:  Thank you for saying that.  I concur.  I like this
approach.  It is certainly one that is analogous to what is used in
industry for quality control.  I think it ought to be pursued.  As Dr.
Epstein said, there is still a lot to be worked out on it, and I guess I
am struggling how do I vote to encourage the further development of this
and perhaps a pilot testing of it without indicating that I think it is
anywhere close to being ready to be put into a regulatory mode.

	DR. KLEIN:  I don't think that this in any way as described is going to
improve public health.  First of all, we don't know what the right
number is, and it is more likely that it is less common, which would put
the facilities at risk of being out of compliance for no reason of their
performance.

	Second, as I stated earlier, a high percentage of the endpoints that we
are looking at are not going to be addressed by what we do when we
prepare platelets.  They are from organisms that are circulating in the
donor.

	Point three, I think, is that what we are really looking for is a
release criterion, and you obviously can't do that because the testings
are not licensed for that, but I think that this is not a good
compromise.

	I think it will be laborious and potentially affect supply, and not
improve public health in terms of bacterial contamination of platelets.

	DR. NELSON:  Is the Red Cross going to uniform culturing of platelet
donors?  If so, that could end up being a pretty good database to decide
what the level should be.

	DR. DODD:  Ken, I take it I can comment on this?

	DR. NELSON:  Yes.

	DR. DODD:  The Red Cross is considering whether or how it could engage
in 100 percent quality control of apheresis platelets.  That doesn't
mean that we are actually going to do it although I think there are
other blood agencies that are moving down that track, and I think it
would give an opportunity for collecting appropriate data.

	Ultimately, if and when we do that, we would like to do it in some way
that prevented the usage of a bacterially contaminated product.

	But I did want to take the opportunity of asking either the agency or
the committee if it considered the fact that as of today, the two
methods that have been approved for quality control, they are approved
only for leukoreduced platelets.  I wonder what impact that might have
on answering this question.

	DR. VOSTAL:  I can actually address the question about leukoreduced
platelets.  The reason those devices are approved for that product is
that is because that is the only type of data we saw when we were
clearing the device.

	DR. FITZPATRICK:  I have Dr. Allen's same dilemma as to how do we
answer this question.  As I understand Dr. Epstein's desire for a way to
measure compliance and encourage compliance, but we need a stepwise
approach to that.

	One of the key elements that I think came out today was the pooling
random donor platelets and being able to maintain them as a pooled
product, and then test them.  I think that would add to what we can do
to ensure and reduce bacterial contamination for the patient, if we have
a way of quarantining and release or testing prior to release.

	As Dr. Epstein said, there are a number of unanswered dilemmas here
with this, and the approach taken for the leukoreduction guidance, I
think applies here, but because of the low incidence of positive units,
the N becomes so large that it is very difficult to apply that
statistical model to this.

	I think future exploration and an alternative method to find a way to
establish compliance and standards, and then monitor on a periodic basis
might help, but I find it really difficult to say I concur with this as
the appropriate approach at this point.

	DR. CHAMBERLAND:  I just find myself in the same dilemma.  I would hope
that the committee really wants to signal their strong endorsement as
has been echoed by industry that the time is now to really take
bacterial contamination seriously and to take steps in that direction to
prevent and then appropriate monitoring.

	I don't feel at this point comfortable enough that this proposed
approach, exactly what it will accomplish, and will it incur any real
risk related to supply, et cetera, so I am concerned that if I vote no,
that that might be viewed as not feeling that this is an important
problem.

	We are being asked to really vote on a really detailed, specific plan,
and I think it takes a bit of time to sort of model that and work that
out, and I just wonder if maybe you have all done that and done some
real live kind of testing of this from a modeling perspective to see
what might happen, but I just a little bit uncomfortable that a yes vote
and develop a guidance and it's out there without thoroughly
understanding the implication.

	So, I feel somewhat caught here a bit.

	DR. SIMON:  I guess a question and a comment.  Alan, could I ask, you
are proposing this or FDA is proposing this for both apheresis and
random donor, that is correct, isn't it?

	DR. WILLIAMS:  That's correct.

	DR. SIMON:  One other possibility, and I don't know how FDA feels about
this, would be to table this question for now and at the next meeting,
discuss this issue of quality control and the release issue together,
and see which is the best direction to go to reduce risk, because I
understand that AABB had some of these same kinds of discussions when
they came up with their proposal.

	Since industry is moving towards a sort of different approach for
release, and since it raises all kinds of implications, and I think
there, really where the supply issues get raised, both in terms of units
being held and also in terms of what happens to random donor platelets
in this setting, and are blood centers going to consider it too
hazardous to provide these because they are not amenable to the same
approach, so it has become a very complicated issue.

	Although I don't see anything wrong with what FDA has proposed, it
appears that it may need a more comprehensive discussion and taking into
account both this approach and the release approach.

	DR. DiMICHELE:  I just wanted to echo the comments of several of the
committee members.  It seems to me, although I certainly defer to those
members of the committee who are blood bankers and have had tremendous
experience with this, but it seems to me that the issue of how we
document sterility of platelets is still unclear.

	So, therefore, it becomes very difficult to embark on this type of a
study if we are really not clear on how we are really to measure
platelet sterility in the first place.

	I would agree with those committee members who suggest that maybe the
next step is really to develop a pilot study to really help us to
understand how to measure platelet sterility before we embark on a
widescale regulatory quality control measure that actually attempts to
do this.

	I don't know again the best design for this, but I know that there are
many units of platelets, for instance, that would get discarded anyway
because of hepatitis B core positivity, et cetera, units that would not
be used, and the question is, is whether a study can actually be
designed using units that cannot be salvaged, to start looking at this
in kind of a pilot way.

	DR. NELSON:  There have been a few pilot studies on cultures, and they
are not large enough.  The issue is that to really get this number and
to figure out what is acceptable would take a substantial size study I
think.

	DR. DiMICHELE:  Well, that is if it were a natural history study, but
one of the things that you can do with platelets that wouldn't be used
anyway would be spiking experiments and manipulative studies that might
be able to give you data in a very different way.

	Again, I certainly can't comment on being an expert on the design of
such a study, but it might be considered.

	DR. NELSON:  Are we ready to vote on this one?

	DR. SMALLWOOD:  Question No. 3.  Does the committee concur with FDA's
proposed statistical approach to providing quality control for platelet
contamination?

	Allen.

	DR. ALLEN:  I abstain with strong support for the FDA's continuing its
work in this area.

	DR. SMALLWOOD:  Chamberland.

	DR. CHAMBERLAND:  I also will abstain.

	DR. SMALLWOOD:  Davis.

	DR. DAVIS:  No.

	DR. SMALLWOOD:  DiMichele.

	DR. DiMICHELE:  No.

	DR. SMALLWOOD:  Doppelt.

	DR. DOPPELT:  No.

	DR. SMALLWOOD:  Fitzpatrick.

	DR. FITZPATRICK:  No.

	DR. SMALLWOOD:  Klein.

	DR. KLEIN:  No.

	DR. SMALLWOOD:  Lew.

	DR. LEW:  No.

	DR. SMALLWOOD:  Schmidt.

	DR. SCHMIDT:  No.

	DR. SMALLWOOD:  Stuver.

	DR. STUVER:  No.

	DR. SMALLWOOD:  Fallat.

	DR. FALLAT:  No.

	DR. SMALLWOOD:  Harvath.

	DR. HARVATH:  No.

	DR. SMALLWOOD:  Nelson.

	DR. NELSON:  No.

	DR. SMALLWOOD:  Dr. Simon?

	DR. SIMON:  I would abstain.

	DR. SMALLWOOD:  Results of voting on Question 3. There were 11 no votes
and 2 abstentions, and the industry representative took an abstention
position.

	DR. VOSTAL:  We will move on to Question 4.

	The question reads:  Does the committee concur that data derived from
FDA's proposed clinical trial design would be appropriate to support
clearance of devices for pre-release screening of platelet products for
transfusion?

	DR. NELSON:  Discussion?

	DR. FITZPATRICK:  Of the many designs that we were offered, which one
would you like us to endorse?

	DR. VOSTAL:  I think the basic concept of whether we should require a
clinical trial to evaluate these devices and whether the clinical trial
should be of design where you have two cultures and you are looking for
agreement between a culture early on in the storage period versus at the
end of the storage period.

	DR. FITZPATRICK:  So, would you rephrase your question then?

	DR. VOSTAL:  I guess we could, if you don't like that one.

	DR. KLEIN:  If we answer yes to this, is it pretty nebulous.  If you
want to know if we think there should be a clinical trial, designed
appropriately, I think that is a legitimate question, but it is hard for
us to pick the appropriate design at this point from what you are
offering.

	DR. VOSTAL:  So, we could change it just to say whether the committee
would endorse that a clinical trial is necessary, and the second part of
that question would be whether it should be of a design with the two
cultures.

	DR. KLEIN:  I think that that would answer the question, and I think if
you are going to do it, you need to do it with two cultures.  Having
said that and as a federal employee who looks at our budgets, I think
this is going to be a very large study.

	I think it is going to take a very long period of time, and I think it
is going to be a very expensive study. I look at the culture technology
really as a transient technology.  We all want something that we can use
at the endpoint of issue, and my guess is that in three to five years we
are going to have something that we will be able to do.  Maybe by the
time the study gets done, and we have the results of the study, we won't
use this technology.

	So, having said that I think you need a study in order to license this
for that use, and that this study would be appropriate, I wouldn't
participate in the study and I wouldn't spend any money on it.

	DR. ALLEN:  Thank you, Harvey, that's a hard one to follow.

	I certainly am strongly supportive of the general concept.  I think
very definitely, clinical trials of in-use situation, using real live
materials to the extent that that is possible is very helpful to support
the evaluation approval of devices for this, as well a variety of other
purposes.

	I think the study designs that were presented were probably the purest
in terms of sampling at the beginning and at the end, and maybe at a
couple of mid-points, and I in general would be supportive.  I am not
quite as negative as Harvey on this.  I agree that they will be
large-scale studies and possibly fairly expensive and difficult to
accomplish.

	I think they could be important even in an area where technology will
be evolving rapidly.  Nonetheless, I think that the FDA, in terms of
putting out trial designs, needs to be flexible, because I don't think
that in every instance that you have got to have exactly the same design
and all of the bells and whistles.

	I am supportive of the general concept.  We did hear that there were
many different clinical trial designs that were proposed, and I would
urge flexibility on this, but I think the concept is one that I
certainly am supportive of.

	DR. FALLAT:  Am I correct in understanding that one of the outcomes of
this would be to get more data on the five- to seven-day platelet
release and capability of release, and if so, I would be very much in
favor of that sort of study design.

	DR. VOSTAL:  I think that it depends on the intent of the study,
whether you want to have your device to be used for extension of the
storage period, so that it will be designed to look at day 7 platelets.

	DR. SIMON:  I would agree and being supportive of clinical trials and
design, but would also agree that this is going to be, the kinds of
numbers we are talking about, it is going to be very costly.

	Unlike Dr. Klein, I would do it if somebody gave me the money, but I
think it would be a major task to do. What I am concerned about, because
I think it would be advantageous to go to seven-day platelets having
done the studies in the '80s to support that before the bacterial
contamination issue became in the foreground.

	I would certainly like to see something done that would support
seven-day platelets.  From what I am gathering from your comments,
somebody would need to do this type of study to get permission to do
that extension or to get clearance from the FDA to sell seven-day
platelet or to label their platelet product as being good for seven
days.

	I would certainly like us to find a less severe way to get to that
point, because what I am afraid is going to happen with AABB instituting
a voluntary standard for release of all products, and if the
manufacturers see that their devices are being used on a national basis,
they may not have an incentive to move to do this type of study.

	So, I have the same concerns the other members of the committee have,
but I certainly am supportive of doing clinical trials.  I would hope
that we could work through a model that wouldn't be quite as expensive
to do.

	DR. DOPPELT:  In regards to the cost, how would this be funded?  Would
the banks be required to sort of absorb the cost?

	DR. VOSTAL:  I think we would be looking to the manufacturers to
sponsor their studies because it will be for their device.

	DR. CHAMBERLAND:  Jim, did you propose a wording change, or it was just
kind of--and I tend to agree with you that the idea of a study is
something that I am in complete agreement with--but I would say that I
am not sure we have the design that has been articulated and that there
might be a need for some flexibility?

	DR. ALLEN:  You could perhaps add one word, the FDA's proposed clinical
trial design concept.

	DR. VOSTAL:  Sure, that would make it plural.

	DR. NELSON:  Are we ready to vote on this?

	DR. SMALLWOOD:  I need to have the correct wording.

	DR. VOSTAL:  Clinical trial design concepts would be appropriate.

	DR. DOPPELT:  Is part of the proposed study that would give data to
extend from five to seven, that is or is not included in the current
proposal, because that was one of the four choices, so I just want to be
sure what we are voting on.

	DR. VOSTAL:  There are several issues there.  One would be having a
device for release of platelets up to five days.  Another one would be
to have a device for release of platelets up to seven days.  Or you
could have a study that covers both, pushing storage out of seven days.

	So, I think it depends on what the manufacturers want to have on their
label and what kind of study they are willing to sponsor.

	DR. SIMON:  I take it we can take it for granted that somebody who came
to you and asked to have extension of platelets to seven days, which I
think people like Dr. Aubuchon are doing based on the bacterial
detection device, you would not permit that with a culture at 24 days,
and you would have to have follow-up studies at seven days.

	DR. VOSTAL:  Right.  I mean if you wanted to be able to say that your
device is capable of detecting or making sure that you have a
culture-negative product at seven days, and you are going to be sampling
at 24 hours, we would like to see data that supports that.

	DR. FITZPATRICK:  So, the key to the design of the study and the
concept would be that you want a study designed to correlate the time of
sampling and the result of that sampling to the bacterial condition of
the product at the time of its out-date.

	DR. VOSTAL:  Right.

	DR. FITZPATRICK:  I think I could support that pretty well.

	DR. SMALLWOOD:  Question No. 4 as amended.  Does the committee concur
that data derived from FDA's proposed clinical trial design concepts
would be appropriate to support clearance of devices for pre-release
screening of platelet products for transfusion?

	Roll call.  Allen.

	DR. ALLEN:  Yes.

	DR. SMALLWOOD:  Chamberland.

	DR. CHAMBERLAND:  Yes.

	DR. SMALLWOOD:  Davis.

	DR. DAVIS:  Yes.

	DR. SMALLWOOD:  DiMichele.

	DR. DiMICHELE:  Yes.

	DR. SMALLWOOD:  Doppelt.

	DR. DOPPELT:  Yes.

	DR. SMALLWOOD:  Fitzpatrick.

	DR. FITZPATRICK:  Yes.

	DR. SMALLWOOD:  Klein.

	DR. KLEIN:  My answer to the question is yes.  My caveats are in the
record.

	DR. SMALLWOOD:  Lew.

	DR. LEW:  Yes.

	DR. SMALLWOOD:  Schmidt.

	DR. SCHMIDT:  Yes.

	DR. SMALLWOOD:  Stuver.

	DR. STUVER:  Yes.

	DR. SMALLWOOD:  Fallat.

	DR. FALLAT:  Yes.

	DR. SMALLWOOD:  Harvath.

	DR. HARVATH:  Yes.

	DR. SMALLWOOD:  Nelson.

	DR. NELSON:  Yes.

	DR. SMALLWOOD:  Dr. Simon.

	DR. SIMON:  Yes.

	DR. SMALLWOOD:  The results of voting for Question No. 4, as amended,
is a unanimous yes.

	DR. NELSON:  The next subject is Human Parvovirus B19 NAT Testing for
Whole Blood and Source Plasma.

	Dr. Yu will give an introduction and background.

	DR. SMALLWOOD:  We are now approximately an hour and 23 minutes behind.
 So, maybe if we move quickly, we may be able to meet our goal of 6:30
in completing this.  If not, we will have a continued session regarding
this discussion at a later meeting that we will announce.

II.  Human Parvovirus B19 NAT Testing for

Whole Blood and Source Plasma

A.  Introduction and Background

Mei-ying W. Yu, Ph.D.

	DR. YU:  Hi.  So, now the topics of the discussion is Parvovirus B19
NAT for Whole Blood and Source Plasma.

	My name is Mei-ying Yu.

	[Slide.]

	I will provide the introduction and background and then Dr. Kevin
Brown, who is a B19 expert from NIH, will present the overview of
parvovirus B19 infection.  Then, there will be industry data
presentations.

	They will update data presented at the December 2001 FDA NAT Workshop,
and they will provide data for NAT sensitivity, testing algorithm, time
to resolve to single donations or donors, prevalence and levels of both
B19 DNA and anti-B19 antibodies and profile in serial bleeds, if any.

	The presentations will be made by, first, Dr. Susan Stramer of American
Red Cross, and then will be NGI, Dr. Andrew Conrad.  However, Dr. Andrew
Conrad is sick and he cannot make it here, so I think the committee has
all his slides, so there will be no one to present his.

	Then, there will be consolidated data presentations organized by the
PPTA.  There are three speakers:  Dr. Barbee Whitaker, Dr. Steve
Petteway, and Dr. Ed Gomperts.

	Then, I will come back to address the FDA Perspective and Questions for
the Committee.

	[Slide.]

	Now, I have a lot of background information I need to cover.  We have
talked about B19 NAT issues in quite a few meetings.  They include the
BPAC held in September 1999, FDA NAT Workshops, and NHLBI Parvovirus B19
Workshop both held in December 1999, FDA NAT Workshops held in December
2001 and then the BPAC in this year, March, and another one is the ad
hoc PHS Panel Committee Meeting held in July 2002.

	Parvovirus B19 has been extensively discussed in September of 1999
BPAC.  BPAC agreed then that pending a policy on screening whole blood
donations, FDA need not require studies to validate the clinical
effectiveness of NAT for B19 DNA under IND for plasma for further
manufacturing.

	So, parvovirus B19 NAT was considered as an in-process test, so it is
unlike HIV, HCV, and HBV NAT, as a donor screen test, however, BPAC did
not recommend resolving to the single donation or donor.

	For S/D treated pooled plasma, the reactive 20 unit subpools were
discarded when tests completed, labile components had expired.

	[Slide.]

	At that time, BPAC did recommend to quarantine and destroy in-date
units when possible.  So, FDA requires that the tests be reviewed under
biologic license application--that is called BLA mechanism--for the
manufactured product and that the tests be validated as analytical
procedures with respect to sensitivity, specificity, and
reproducibility.

	[Slide.]

	At both the FDA NAT workshops and NHLBI Parvovirus B19 workshop held in
December of 1999, a strategy for standardizing B19 NAT was outlined.
FDA also proposed a B19 DNA limit that is less than 104 geq/per ml for
manufacturing pools.

	This limit was mainly derived from the B19 transmission associated S/D
treated pool plasma in a Phase 4 study in healthy donors.  In those
product lots that have less than 104 genome equivalents, no B19
transmission in recipients.  These are in zero-negative recipients.

	The residual virus will be complex or neutralizing by anti-B19, always
present in large pooled products, and also the manufacturer procedure,
that is our viral clearance procedure to remove the residual B19
infectivity.

	I want to mention one more point.

	[Slide.]

	We subsequently revised the limit.  The limit was then set as 104 IU/ml
because in year 2000, the WHO standard for B19 NAT and CBER working
standards for B19 DNA are all available, so we have since then revised
the limit to less than 104 IU/ml.

	That limit seems to be technically achievable by most manufacturers.

	[Slide.]

	Fractionators are performing high titer B19 minipool NAT screening by
in-house methods to lower the viral load in manufacturing pools.  In the
December 2001 FDA NAT Workshop,  we learned that the sensitivity of NAT
assay used to exclude donations ranged from 105 to 107 geq/ml.  That is
per original donation.

	The reactive minipools are resolved to single donations.  Testing
results are used to reject reactive donations.  Now, today, you will
hear more the update by the industry speakers.

	[Slide.]

	Establishments collecting whole blood units that are used to prepare
the recovered plasma and transfusible blood components would like to
implement high titer B19 NAT screening similar to that used by source
plasma fractionators.

	So, Dr. Susan Stramer did present some retrospective data and some
study data, and she described the Phase 1 approach that is not resolved
to single donations, labile components would have expired, and in Phase
2 approach, that would resolve to the single donations by a
free-standing test kit.

	Now, Dr. Sue Stramer is going to update the data later.

	[Slide.]

	In March 2002, BPAC, FDA's current thinking on B19 NAT was presented.
The recommendations that FDA is considering are the following.  For
plasma, when identified, high-titer B19 reactive units should not be
used for further manufacturing into injectable products.  This is to
ensure that the FDA proposed limits less than 104 IU of B19 DNA/ml for
manufacturing pools can be met.

	Now, for whole blood, we say when feasible, B19 reactive minipools
should be resolved to identify the individual reactive donors prior to
release of the component for transfusion, and units from reactive donors
should not be used for transfusion.

	For whole blood, when testing is done subsequent to product release,
in-date components from potentially reactive donors should be retrieved
and discarded.  Even when performing an in-process test, testing and
identification of the individual reactive donors constitute medical
diagnostic testing, therefore, such testing would require the use of an
FDA-approved investigational mechanism.

	[Slide.]

	Informed consent should be obtained from blood and plasma donors
subject to such high titer NAT testing.  Reactive donors should be
identified and be informed of their reactive status and be provided with
medical counseling.

	Lastly, because of the transient nature of the infection and rapid
involvement of the immune response, such donors would be suitable to
donate when they test nonreactive.

	[Slide.]

	So, in March 2002, BPAC, the discussion largely focused on the apparent
lack of the medical benefits that might justify donor notification, so
consequently, FDA convened an ad hoc PHS panel in July of this year.

	The panel members include Drs. Harvey Klein and Kevin Brown of NIH,
Larry Anderson, Mary Chamberland, and Bruce Evatt from the CDC, and CBER
representatives.

	[Slide.]

	The conclusion by the PHS panels are regarding the donors, there is no
medical benefit in identifying high titer B19 NAT-positive donors
informing them of their reactive status and providing them medical
counseling.

	Regarding close contacts of the high titer B19 NAT-positive donors,
there are potential medical benefits to donors contact especially those
at risk, for example, persons with certain anemias, pregnant women, and
immune-suppressed or compromised individuals.

	Now, Dr. Brown will elaborate on these medical benefits later in his
talk.

	[Slide.]

	So, FDA is taking a stepwise approach in resolving B19 NAT issues
concerning whole blood and source plasma.  At this meeting, FDA is
seeking advice on the issues that are listed here.

	The need to reduce the risk to transfusion recipients by withholding
high titer positive units of whole blood and its components from use.
The need to temporarily defer the high titer donors and whether
potential benefits to close contacts of B19 infected donors warrant
notifying high titer donors, and if so, what would be the time frame for
notification.

	Accordingly, we ask four questions.  Before you listen to Dr. Brown and
industry presentations, I would like you to bear in mind these questions
that we are going to ask.

	[Slide.]

	First, if donations of whole blood are tested for the presence of human
parvovirus B19, are risks to transfusion recipients sufficient to
warrant withholding high titer positive units.  These are equal or
greater than 106 geq/ml from use for transfusion.

	[Slide.]

	The second question is, is temporary deferral of positive donors
warranted in the setting of:  (a) whole blood donation?  (b) Apheresis
donation?

	[Slide.]

	The third question.  Do potential medical benefits to contacts of
parvovirus B19 infected donors warrant identification and notification
of positive donors?

	[Slide.]

	Finally, if yes to Question 3, should donor notification be limited to
settings where testing and notification can be completed within several
weeks of donation?

	Thank you.

	DR. NELSON:  We will come back to these questions.

	Dr. Brown.

B.  Overview of Parvovirus B19 Infection

Kevin Brown, M.D.

	DR. BROWN:  I am going to give an overview of parvovirus B19 infection,
mainly concentrating on the areas that I think you need to be able to
sort of answer the questions that Mei-ying posed to you.

	[Slide.]

	So, what is parvovirus B19?  It is a small, 22 to 24 nanometer diameter
icosahedral virus.  These are viruses by immune EM.  They are
non-enveloped, so solvent detergents don't work too well.

	They are relatively heat resistant because of the small genome, which
is only 5,500 nucleotides of single-stranded linear DNA.

	It has a high conserved genome and up until a few years ago, it was
said the variation was less than 2 percent of the DNA level.  There have
variants that have been described in the last two years, but I am not
going to say very much more--I am not going to say anything more about
it because they have not been isolated from blood except at extremely
rarely, when we found them in liver samples and other people have found
them in skin.

	[Slide.]

	So, the parvoviruses are divided into three genera.  They are the true
parvoviruses of which canine parvovirus or porcine parvovirus are
members.  There are the dependoviruses, also known as the
adenoassociated viruses, but B19 comes into the third genera, which are
erythroviruses, so-called because they are highly erythrotrophic and
they are only known to replicate in erythroid progenitor cells.

	So, the cells that the virus replicates in are these cells here.  The
precursors are the red cells, that is, the BFU-E and CFU-E.

	[Slide.]

	This is the virus itself.  The virus encodes for one non-structural
protein and two structural proteins.  The two structural proteins are
encode VP1 and VP2.  VP2 is the major structural protein.  It is 58
kilodaltons.  There is about 60 copies in the virus.

	Ninety-five percent of the variant, as I say, is VP2, and you can
express this in baculovirus and it self-assembles to form capsids.
These VP2 capsids hemagglutinate and it was using this property that was
able to go on and show that the receptor for parvovirus B19 is
globosidal, known as Blood Group P antigen.

	The VP1, which is a minor component, has an additional 223 amino acids
at the 5-prime end of the VP2.  If this is expressed, it does not
self-assemble, but it is thought to be the main site of neutralizing
epitopes.

	This is again to show you what the virus looks like, but also to make
the point that it is even quite different, not at the DNA level, but
even at the structural level, looks quite different from the true
parvoviruses.

	[Slide.]

	As I said, I was able to show that parvovirus B19 uses globoside, that
is a glucose single lipid, demonstrated here as its receptor for viral
entry into cells.  I was also able to show that individuals that do not
have P antigen on their red cells or on their cell surface cannot be
infected by B19 either in vivo or in vitro.

	[Slide.]

	The discovery at the receptor for B19 does go on to explain a few of
the things that we didn't know about B19, a lot of the pathogenesis of
which I am not going to say more about it, but globoside is found on
erythroblasts, as you would expect.  It is found on megakaryocytes,
megakaryoblasts, vascular cells, on the cells in the placenta, does
cause transplacental infection, which we will come to, and it is found
in the thecal hematopoietic cells and myocardial cells.

	[Slide.]

	Turning to the epidemiology of the virus, the virus is a very common
infection.  Everywhere that people have looked, they have been able to
find it apart from some isolated communities in South America and
Africa.

	Virtually, all countries where people have looked, 50 percent of adults
have B19 antibody with seroconversion happening in childhood and also as
young adults.  The calculations are that there is an annual
seroconversion rate in women in the USA of about 1 percent.  That is 1.5
percent per year.

	[Slide.]

	It shows classical epidemic behavior, with temperate countries,
increased peaks in the spring.  It also shows variability between the
years, so some years there is a much higher peak of virus than others.

	Looking at natural infection, the incubation period has been calculated
to be between 4 and 14 days depending on the presentation of the
infection, with a maximum up to 20 days.

	[Slide.]

	The major route of the natural infection is by the respiratory route
and it is actually fairly infectious.  In studies that have been done in
susceptible individuals, there is a 50 percent attack rate in household
contacts and 25 percent attack rate in schools or nurseries.

	There also is a high level of viremia and blood products can have virus
in them, and you have already heard about how pooled products can be a
source of B19 infection, but there are cases of single component, which
I am going to come to in a few minutes.

	[Slide.]

	The kinetics of B19 infection were really well established by some
volunteer studies which were done in the UK in the 1980s.  These were
all adult volunteers who had different concentrations of virus dripped
into their nose. They were then followed to see what would actually
happen to them.

	There were a couple of individuals who had pre-existing antibody to
B19.  They remained well, there was no viremia, and as I say, they have
no symptoms.  There were a couple individuals who had low levels, which
were called equivocal IgG levels.  They had a fever and chills, headache
and myalgia, only they didn't develop the second stage infection.  They
also boosted their antibody response.

	However, in those that were antibody-negative, and received more than
108 genome copies into their nose, they had this typical biphasic
illness, so that there was this level which was associated with viremia,
with fever, chills, headache, myalgia.  At that time, there was a drop
in their reticulocyte count, and then a second phase infection which
resembled fifth disease as the antibody came up and the virus cleared.

	However, it is important to note from this that these assays were done
really before PCR was well established and the viremia was measured by a
dot blot, and the dot blot has a sensitivity of between 105 and 106
genome copies/ml.  So, although the viremia could only be measured for
about four or five days, the fact that it goes back to normal or back to
the zero line doesn't mean to say there is no virus actually present,
and that will become relevant in a few minutes.

	Also, there were no infectious assays performed. It is actually very
difficult to grow this virus, and there were no neutralization assays
performed, so we don't know whether these antibodies actually are
neutralizing or not.

	[Slide.]

	The virus can cause a wide range of different disease depending on the
host characteristics, and I am just going to go through and illustrate
each of these.

	[Slide.]

	The majority of infections caused by B19 are asymptomatic and it has
been estimated between 25 percent and 50 percent of infections are
asymptomatic even in an outbreak situation.

	The commonest presentation of B19 infection is erythema infectiousum
also known as fifth disease, slapped cheek disease because of this
characteristic slapped cheek appearance that children get, and also
academy rash, because of the outbreaks that are often seen in schools.

	The prodrome, which is at the time of the viremia, is usually missed or
there may be just mild symptoms, and the diagnosis is usually made at
the appearance of the rash. In children, it is particularly the slapped
cheek on the cheeks.  In adults, this stage is usually missed, but then
there is a second stage where you get this reticular pattern on the
limbs.  It comes and goes and pruritis is very common.  There is no
specific treatment.  It is usually a fairly innocuous infection and
often the parents are more worried about the rash than the children are
about the symptoms.

	[Slide.]

	However, in adults, and especially in women for reasons that we don't
understand, it is often associated with arthropathy or even a frank
arthritis.  This is a peripheral distribution especially in the small
joints.

	Again, it can persist for months.  It often lasts between two weeks to
two months, but can, in fact, last for six months or even up to several
years.  The problem is that it may resemble acute rheumatoid arthritis,
especially as the rheumatoid factor can be positive and also
autoantibodies are often present.

	So, diagnosis, this is B19 as opposed to acute rheumatoid, does have
implications especially for the management of these patients.  These
patients respond to nonsteroidals.

	[Slide.]

	The first disease that was associated with parvovirus B19 was transient
aplastic crisis, and this was seen in patients with increased red
turnover.  Basically, there is a transient arrest of erythroid
production and in those who have a high erythroid turnover or dependent
on that regular erythroid turnover, they develop this aplastic crisis,
which was originally described in sickle cell disease, but it can be
described, it has been seen in many cases of hemolytic anemia, in fact,
any cases where there is increased erythropoiesis including even in
acute hemorrhage.

	Often pronormoblasts, such as are illustrated here, can be seen in the
bone marrow, sometimes in the peripheral circulation.  It is a
self-limiting infection.  As soon as the virus clears, which is about
four to five days, the antibodies come up.

	The reticulocytopenia results.  There is a single episode in a
lifetime, and treatment is supportive to get them through the aplastic
crisis.

	[Slide.]

	However, in some individuals who can't mount an immune response or
can't neutralize the virus, they will go on to develop a persistent B19
infection.  This is being described in a variety of different cases of
congenital immunodeficiency.  I am going to illustrate a case of
Nezelof's in a minute.

	In cases with iatrogenic immunodeficiency, such as chemotherapy or
immunosuppressed patients, it is also quite commonly seen in patients
with AIDS.

	[Slide.]

	So, this is a chart with Nezelof's syndrome who had dot blot positive
instead of the usual three to four days, actually lasted for many
months.  This was associated with an anemia and a reticulocytopenia.

	This was despite the presence of low levels of antibody.  There was IgM
and IgG present, but the virus was there at high titers.

	[Slide.]

	These cases are often very well treated and respond well to commercial
immunoglobulin which has high titers of neutralizing antibody.  This is
a case of a patient with HIV infection who again had high levels of B19
DNA present for many months and was treated here with IVIG. There was a
brisk reticulocyte response peaking and then coming down to normal and a
response of the hemoglobin, and the virus actually disappears.

	It is interesting to note at the time that the antibody responds, many
of these patients have the symptoms of fifth disease.  They have the
arthropathy and they also have the rash.

	[Slide.]

	The next case I want to talk about is where you have a combined, where
you have an immunocompromised or immunosuppressed individual with high
erythropoiesis, by which I mean the fetus.

	In fetal hydrops, there are many, many case reports now in the
literature that are very similar.  B19 can be found in all the tissues.
In some of these cases, this is associated with myocarditis, globoside
is actually found in the fetal heart.  Some of these spontaneously
resolve.

	[Slide.]

	This is a combined study again in the UK where they looked to see what
the risk of B19 was or the outcome was of confirmed B19 infection in
pregnant women.  So, this is a stage that the mothers have their B19
infection. You can see there is an increased fetal risk due to B19
infection, particularly in weeks 9 to 20, so the first half of
pregnancy.  There is an excess of fetal hydrops at this stage.

	[Slide.]

	The conclusion of this double study was that both asymptomatic and
symptomatic infection is associated with hydrops or fetal loss.  There
is a mean interval of about six weeks between the maternal infection and
the fetal symptoms, but 1 in 10 infections, confirmed B19 infections
before week 20 will result in fetal loss due to B19.

	The treatment for hydrops, if it is early, and many of these cases have
been treated with intrauterine blood transfusion with positive results.

	There have been no studies that have confirmed congenital abnormalities
due to B19.  There is a few case reports.  We have described three cases
of congenital anemia following a maternal B19 infection.  Different from
what happens with the persistent infection, these congenital anemias did
not respond to immunoglobulin treatment.

	[Slide.]

	Despite those well attested associations with B19, there are a number
of different disease associations that have been described in the
literature, often based on PCR results, and some of these are
controversial as to whether this is a chance association.

	Certainly, it is being proposed that B19 causes PCH.  It definitely
causes some cases of hemophagocytic syndrome, ITP, vasculitis, Kawasaki
is more questionable, some cases of hepatitis have been ascribed to B19.
 Recently, particularly in Japan, there is a group that is claiming that
B19 may cause rheumatoid arthritis.

	[Slide.]

	This is returning to the picture that I showed earlier based on the
data from the volunteers, which has held up to be fairly good, but as I
say, the first studies were done in the absence of PCR, but when PCR is
now actually added, instead of actually just being positive for three to
four days, the PCR actually remains positive for months, if not years.

	Again, these studies were done without quantitation, so the question is
how high is that virus, is it infectious, and what is it doing.  I just
want to make the point that the viremia that people talk about in the
old literature is associated with this dot blot sensitivity of about 106
genome copies/ml.

	[Slide.]

	The fact that that virus persists at low level detectable by PCR, it is
not really surprising then that when people have gone back and looked in
blood donors, you can actually find virus.

	So, this is not supposed to be exhaustive, but just to show some of the
studies where people have looked at healthy blood donors by a variety of
different methods, that do have different sensitivities, so it is not
surprising that you get different prevalence rates with the highest
sensitivity those based on PCR have given you the higher prevalence of
the virus.

	I am going to go and say more about this study by Yoto, but I want to
make the point that these samples, 1,000 samples were taken at the time
of an outbreak in the community, which is why they are probably higher
than some of the other numbers that people have.  I could allude to the
study by Jordan.

	[Slide.]

	The fact that the virus is present, can go up to 1012, 1014 genome
copies/ml, it can be a problem in pooled products, and all these
products, there have been cases in the literature where B19 has been
said to be transmitted from them.

	But single components, it is much rarer.  There are some case reports,
but there are not an awful lot of them.

	[Slide.]

	I want to go through some of them, and again this is not exhaustive,
but it is supposed to be I think for the solitary.  This was actually a
study by Yoto, which is the group that did the prevalence of B19 by PCR
at the time of an outbreak.

	That was actually triggered by this case that they found.  This was
14-year-old boy who had ALL, who was being well maintained on
chemotherapy.  He received two units of red cells.  They have no
additional information on the red cells, so they went back and looked at
1,000 blood units to see what the prevalence of B19 was, but they didn't
test these two units.

	The child actually developed a profound anemia.  He actually went on
and had a peripheral blood stem cell transplant, was treated with IVIG
just as CMV prophylaxis, not actually because they had recognized that
he had the B19 infection at that stage, but he had a viremia that lasted
for a month.

	Certainly, I can't imagine that they would have done a stem cell
transplant if they had known that he had an acute B19 infection going on
at the time, so this was an infection that was missed.

	[Slide.]

	This is a second case.  This is a 22-year-old woman who had thalassemia
major diagnosed at the age of 15 months, so had been receiving two units
of red cells monthly, so estimated actually received probably about 500
units of blood at this point.

	She again developed a transient aplastic crisis and severe heart
failure.  It turned out she had received two units of red cells nine
days previously, and one of the donors that they were able to show was
IgM positive, DNA positive.  Unfortunately, there is no information
given as to what they mean by "positive."

	This individual had an invasive esophageal echocardiography, was
misdiagnosed as having subacute bacterial endocarditis, treated for a
month with antibiotics before they actually realized what the diagnosis
was.

	So, again, a patient that was mistreated because the diagnosis wasn't
thought about.

	[Slide.]

	This is a third case which was again picked up retrospectively.  This
was one of the cases that was found by Jordan in that study of looking
at the prevalence of B19 in their blood donors.

	What they did was they identified positive blood donors and then went
back to see what happened to the recipients of that blood.  One of the
individuals had a severe anemia, and this was the individual.

	This was 49-year-old man who had a liver transplant for chronic HCV.
He received one unit of red cells two days post transplant.  The donor
was IgM negative, IgG negative, but DNA positive.  Again, unfortunately,
they don't give a titer, but it was strongly positive on their
ELISA-based assay.

	Four months later, he was thought to have recurrent hepatitis, he was
found to be anemic, found to have reticulocytopenia, was treated with
red cells.  B19 wasn't even considered.

	Eight months later when Jordan contacts them to find out what happened
to the recipient of this blood, they find out that he had a B19
infection at this stage.  He has, in fact, seroconverted.  He is IgM
positive, IgG positive, B19 and DNA negative.

	[Slide.]

	These were the 10 recipients that they were able to follow up on.  It
is interesting to note that this was the only patient that received B19
DNA positive.  Now, as I say, we don't know what they mean by that
titer, because they don't actually give a titer.  Had B19-like symptoms,
so was followed up.

	Interestingly, this patient was IgM, the donor was IgM negative and IgG
negative, so presumably this was an acute B19 infection that the donor
had, but was asymptomatic at the time.

	[Slide.]

	The last case I want to talk about is a case where there was
transmission by platelets.  This was a 36-year-old who had CML treated
with chemotherapy, received a bone marrow transplant, had been tested
before and was shown to be B19 IgG prior to the transplant.

	Over the next six months, he had increasing anemia and eight months
later, B19 was diagnosed.  The patient was treated with IVIG.  They were
able to go back, and he had had blood from 90 donors, and they were able
to actually test all of those.

	Two of them had B19 DNA.  One of them, Donor A, it was greater than 106
genome copies/ml.  I can say that because it was dot blot positive, and
I used to work in this lab and I know the sensitivity of the test that
they use.

	They also sequenced the donor's virus, and he had the same B19 sequence
as they found in the patient.  There was a second donor that was
positive.  This had been given prior to the transplant.  This had less
than 106 genome copies/ml.  It was only positive by PCR, not by dot
blot.

	But again this diagnosis was only made eight months after the event.

	[Slide.]

	So, what about levels of B19 DNA?  As I say, there are not that many
studies where people have published where they have looked at actual
levels, but this is a group from Italy where they have taken blood.

	I think it sort of makes the point they divided them into those that
were DNA positive, IgM positive, and IgG negative at the early stage,
and you can see they have relatively high viremia levels, those who were
IgM positive and IgG positive, so within the first couple of months,
following an acute B19 infection, lowered, but there are still some that
are above this cutoff of 106, and then some that were IgG negative and
IgG positive, which suggests they had a B19 infection more than two
months earlier, and yet one of these individuals had greater than a 106
genome copies/ml.

	So, the question that I think that we really don't know the answer is
although we know that B19 can persist for months even at relatively high
titers, if this level of B19 is infectious if it is given as a unit of
blood.

	[Slide.]

	The problem is that we really don't have the answers to some of these
questions.  The virus is very difficult to grow in the culture.  It can
only grow in human bone marrow explants or thecal livers as a source of
hematopoietic cells.

	There are a few cell lines that have been described, but they really
aren't that highly permissive. You can detect virus either by looking
for inhibition of colonies, but it is very insensitive looking by
immunofluorescence for capsid proteins or NS proteins.

	Some people have described in real-time PCR looking for DNA increase.
We prefer to use RT-PCR looking for viral transcripts to distinguish
replication RNA from viral DNA.

	[Slide.]

	I put this slide on really just to illustrate that even if you have an
infection assay, this is using different concentrations of virus at
three different cell lines that are said to be explicit for B19.

	In the most highly sensitive, you can detect down to 104, 103 genome
copies per ml,  but in another cell line, you can't really detect
anything even at 106, so even the cell lines themselves have problems in
their sensitivity as to what you call infectious, and there is obviously
limits to how much virus you can actually put in there.

	[Slide.]

	So, coming back to the FDA questions, who is at risk of parvovirus B19?
 Well, you could argue anybody who is seronegative is at risk of B19
infection, but fifth disease is a relatively innocuous disease and apart
from the problems with arthritis or arthropathy, the main problems in
these patient that have increased erythropoiesis, patients who are
immunosuppressed or immunocompromised, and the pregnant woman and the
fetus.

	By definition, these aren't going to be your blood donors, but they may
well be your contacts of your blood donors.

	[Slide.]

	Is there any way that we can prevent B19?  Well, there is a vaccine
that is in Phase 1 trials, but it is going to be several years at the
least before we actually have a vaccine.

	What about passive immunotherapy?  The only thing that we have is IVIG,
we don't have any antivirals that we know work for B19.  Again, you have
got the problem with the time interval.  If you are trying to actually
stop the viremia, you have got four days to actually do anything about
it.  So, time is limited.

	[Slide.]

	This is my last slide.  This again shows the time course of B19.  What
I tried to do here was to put when you expect to see the symptoms at the
different risk presentations.

	So, the transient aplastic crisis is really at day sort of 4 to 7
following your infectious exposure.  You have not got a lot of time to
do anything there.  The persistent anemia starts probably just about the
same time, but lasts actually months, so even with the late
notification, you might actually be able to go in and make a difference.

	The fifth disease is usually at about sort of 21 days, but the
arthropathy can last for several months.

	So, what are the benefits of notification?  Well, you might be able to
intervene.  I did mention pregnancy, but certainly in the pregnant
woman, you might be able to monitor and see what is happening.

	I think it is important for accurate diagnosis and may be important for
treatment especially chronic infection and also for the monitoring of
pregnant women who might be at risk of hydrops.

	Thank you.

	DR. NELSON:  Thank you, Dr. Brown.

	Questions?  Mary.

	DR. CHAMBERLAND:  Thank you for that nice presentation.  I had a
question.  It seemed, and I am sure this will come up in the discussion
again, that the benefits of notification are going to be not so much
with respect to the donor, but the close contact.

	That is clearly going to probably be linked to the period of time over
which notification can take place after the unit has been tested.

	In your review article, which was distributed to the committee, under
Transmission, it is stated that the case-to-case interval is 6 to 11
days irrespective of the type of B19 related disease.

	Now, if I understand that correctly, it would suggest that let's say in
a typical household setting, a contact setting, that there is really a
fairly limited period of time in which you would have to, if you will,
inform a donor and potentially interdict subsequent transmission.

	Sort of tying that in with the other comment in your slide, you say the
slide that looked at the titers of B19 DNA relative to IgM and IgG, you
ask the question is this level of B19 infectious if given as a unit of
blood.

	Actually, I think the sort of complementary question is, is this level
of B19 infectious through the traditional respiratory route.

	I am just wondering if you could comment on that because I was quite
struck by this statement in your article about this fairly tight time
period.

	DR. BROWN:  It seems to have held us in sort of fairly good stead, this
sort of illustration, because this time of the viremia does seem to
correlate well to the time of infectiousness in close contacts.  So,
this seems to be, as I say, a very good estimate.

	So, as soon as the IgM and especially the IgG starts to come up, then,
you don't actually see exposures continuing to happen.

	Maybe that sentence is a bit ambiguous.  There is a slight difference
in the time between exposure and the disease itself, because the
transient aplastic crisis will appear earlier, which is the first phase.
 If you are looking for fifth disease, it's the second stage, and you
see the viremic stage is missed, so that usually sort of comes up a
little bit later.  So, that is why you have quite a wide range, but the
infectious time is actually very tight exactly.

	DR. SIMON:  If I put that in practical terms, so if we detected
someone, and I gather that fairly insensitive techniques are being used
because we are looking for high titer, so we would be likely to detect
someone at about day 7 time frame.  So, the infectious period, you are
going back to day zero when you say 6 to 11 days?

	DR. BROWN:  Yes, these numbers are based on having high titer virus
dripped into your nose, which is not really an every-day occurrence and
probably doesn't mimic what is happening either if you get a unit of
infected blood or if you are living with somebody who is actually
copping the virus out.

	DR. SIMON:  So, unless we could get to that donor within four or five
days, it probably would not have much utility.

	DR. BROWN:  Exactly.  That is what I was sort of trying to get to here.
 If you actually want to actually go in and actually intervene before
this viremic stage, you have got a very, vary narrow time cap, and I am
not sure, quite frankly, that it is realistic.

	However, if you are trying to actually go in and do something about
patients who have persistent anemia, now, you have got a much longer
time because they are being viremic, but they will continue to be having
symptoms, and they would actually do well with actually being treated
even if it quite a bit later on in their disease.

	DR. SIMON:  Treated with what?

	DR. BROWN:  The only treatment that we have is IVIG, and it actually
works very well, as in the HIV case.

	DR. SIMON:  I am told by our expert that it is considered experimental
therapy.  I know it's off label and that not everyone accepts that it is
beneficial particularly if you don't know the titer of parvovirus
antibody in the preparation.

	DR. BROWN:  It is the only treatment that is available, there is
nothing else.  So, I think when people have actually looked for
neutralizing antibodies in most commercial sources of IVIG, they are
actually at high titers.  I don't know if anybody else wants to comment
on that.

	DR. WU:  I think we ought to let other industry presenters to present
and maybe they have some data, and if not, we do have some data that we
can present later on to shed that light.

	DR. DiMICHELE:  I was really surprised to see the number of people who
get infected in middle age and beyond. Is there any difference in the
morbidity from this infection in the middle age and older age population
compared to the younger population?

	DR. BROWN:  None that I am aware of other than the fact that women, and
it doesn't seem to be particularly old or young, but certainly from 20
up would seem to be more likely to have the arthropathy and the
arthritis, but otherwise, there doesn't appear to be any difference if
you get your B19 when you are 80 as opposed to when you are 20.

	If you get it when you are 8, you will probably have less symptoms and
you will have the slapped cheek.  That is all I can say.

	DR. NELSON:  Thank you, Dr. Brown.

	Dr. Stramer.

C.  Industry Data Presentations

American Red Cross

Susan Stramer, Ph.D.

	DR. STRAMER:  Thank you very much.

	This is a compilation of several presentations. Firstly, most of the
data that I will present were presented at the AABB last year, then
presented as Dr. Yu referenced, at the December 2001 FDA NAT Workshop,
and I have added some new data and comments at the request of FDA.

	I also want to mention that I am not only discussing B19, but I will be
making some remarks about hepatitis A virus, because we really can't
separate the two as we are trying to screen our plasma derivatives for
nonenveloped viruses.  Parvo is one, but so is HAV.

	So, my presentation is contaminated with some HAV material, and I will
try to limit those remarks.

	[Slide.]

	As we have heard, manufacturers of plasma derivatives have implemented
NAT for nonenveloped viruses and such testing will likely be implemented
for recovered plasma.

	Most parvovirus B19 NAT programs target the elimination of equal to or
greater than 1 million copies/ml as already referenced by Dr. Yu.

	Studies of HAV and B19 frequencies in recovered plasma are limited.
Dodd and coworkers at the 1997 AABB reported some results from screening
pools of 512 at NGI, and those results, we had zero positives for HAV
out of 20,000 donations screened, but a frequency of 1 in 1,400 for B19.
 This was using a very sensitive test and as Dr. Brown referenced, the
prevalence is very dependent on the sensitivity of the test that is
used.

	[Slide.]

	Dr. Yu also mentioned solvent detergent treated plasma and through the
three-year experience that has been reported at Vitex for NAT screening
of S/D plasma and final product, which is 2,500 donations, and that is
at NGI for HAV, or by their in-house testing for B19.

	Now, they may screen pools of 100 that are comprised of five subpools
of 20, and if a pool of 100 is found positive, they resolve to the
subpool of 20, and if that subpool of 20 was found positive, they
discarded all 20 individual units.

	But from their testing, their frequency for HAV was about 1.5 million,
and about 1 in 800 for B19 DNA.  When we started to think about
developing programs for B19, we tried to recover some of these positive
units prior to discard, such that we could research the frequency of
B19, the titers of B19, and try to get in-house some positive materials.

	So, what we were provided was greater than 1,000 units, and we have
tested these representing 20 positive subpools of 20, but to our
surprise, of those subpools that we tested, the individual units
comprising those subpools, only 23 of greater than 1,000 units tested
were B19 positive at NGI using a standard test.  Those were from 16
subpools.

	So, of the 72 subpools tested, only 16 were positive.  That indicated
that we had a 77 percent false positive minipool test result using the
sensitivity of the Vitex procedure.

	[Slide.]

	When I presented these data at AABB and at the FDA NAT Workshop, we
only had a couple of positives identified to that point, and this again
supports the data presented by the earlier speakers.

	Here, you can see, even though these are separate units, if you align
these by titer, and then you look at the IgM and the IgG concentrations
or presence of those two antibodies, you can see that only in this very
high titer positive unit there is no IgM or an IgG.  Those that had
lower titers had the presence of IgM.  As titers decreased, IgM
disappeared and then all were positive for IgG.

	[Slide.]

	For the 23 that we have identified at the conclusion of the study, we
haven't completed the IgM and IgG testing, but I just present to you the
titers of the positives of these 23 that we found.

	You can see only five here of three years of Vitex screening, only five
represented very high titer units.  The rest were lower titers and they
do what you would expect here, maybe had a mix of IgM, IgG, and perhaps
some of these represented further contamination as 5 of 16 of these
pools that contained these positives, contained multiple low level
positives suggestive of contamination.

	[Slide.]

	So, from the Vitex studies, we know that HAV was infrequent, B19 NAT
false positivity may be an occurrence that we have to deal with,
especially when you are dealing with very high titer units.

	Low level B19 DNA positive, IgG positive samples do occur, and
individuals with early acute B19 infection have high viral titers and
are likely to be IgG negative.

	[Slide.]

	So, in order to prepare for some type of screening program, which I
should have said at the onset we are not yet doing anything for parvo.
We have done a couple of pilot studies, and I am going to present
results from two of those.

	We did the first study with NGI, and it was an unlinked study to
determine the frequency of HAV and B19 in recovered plasma.  The testing
was done from our surplus NAT negative tubes for HIV and HCV our NAT
negative PPTs that were sent to NGI.  Once at NGI, they were pooled and
tested.

	The testing used at NGI, and NGI won't be here to present, they use a
four-test reaction for both HAV and B19. That is two different primer
pairs that they run each in duplicate.  So, each of the four tests, all
four tests have to be negative for them to report out a negative result.
 If any of the primers or replicates to primers is reactive, it is
considered a reactive.

	So, we took a half million donations that we sent to NGI.  They were
pooled into 100 pools of 512, which is the standard matrix that NGI uses
for pooling.  We tested HAV without dilution and if there was a positive
result, we would resolve to the individual donation and quantify.

	For B19, NGI's standard algorithm is to take the pools of 512, perform
a 1 to 1,000 dilution, and then test. So if we had a positive pool, we
then would resolve to the individual donation, quantify, and look for
antibody.

	One point that we added to the study is if a pool was negative at 1 to
1,000 dilution, we wanted to see what would be in those pools that they
were tested undiluted.  So, 1 to 1,000 dilution negative was further
tested NEET.

	NEET, that is the 512 pool was tested without dilution,  and if that
was positive, the same thing.  Resolve to individual donation,
quantified, and IgM and IgG testing performed.

	I do want to comment because this is in your materials from NGI, that
the sensitivity of the testing that we used at NGI was 20 copies/ml,
actually 22.4 to be exact, and that is what is in NGI's presentation.

	If you then multiply that by a pool of 512, multiply that by 1 to 1,000
dilution, you get a sensitivity for the donation of 1.2 times 107, so
this is where we get the greater than or approximately equal to 106, but
this is the sensitivity of the NGI test.

	[Slide.]

	So, the results.  For HAV, these were easy.  They were all negative.
For B19 in performance of the 1 to 1,000 dilution, we had 3 positive
pools including 4 positive donations.  Two of the positive donations
occurred in the same pool.  So, the 4 positives gives you a frequency in
the study of 1 in 12,800.

	These are the 4 positives, the IgM present, results of IgM testing.
All were IgG negative as you would expect from relatively high titers
especially in these two. No quantifiable IgG.

	One of the high titer ones was IgM positive, and one of the lower
titers was also IgM positive.  Interestingly enough, these two were
detected even though they were below the limit of sensitivity of the
tests we were using, perhaps being in the same pool, there was some
additive effect.

	[Slide.]

	Now, when we took the remaining 97 pools that were negative at 1 to
1,000 dilution and ran them without the 1 to 1,000 dilution, we had an
additional 34 positive pools including 95 positive donations, which gave
us really an unacceptable yield of 1 in 528.

	Again, if you look at the titer of the samples found, IgM, IgG
presence, and then this is the number of samples within these various
titers, you see there are some high titer samples, actually 1, that
probably should have been detected at the 1 to 1,000 dilution but
wasn't, and that one was IgM positive, and plus/minus for IgG.

	The lower titers had IgM as you expect, but also had IgG.  The lower
titer samples had a mix of IgM and again most of them have IgG.

	[Slide.]

	We did a similar study with GenProbe because since we are talking about
a Phase 1 and Phase 2 approach, the NGI would represent the Phase 1
approach where samples would be sent out for testing, but we recognize
in the future that in-house testing may occur, so we wanted to look at
the GenProbe test.

	So, what we did is we took NAT negative pools, pools of 16, about 2,500
of them, and representing April collections, and I should have said in
the NGI study that I showed previously, those also represented
springtime collections, and that is important because it is the highest
time of reported parvovirus prevalence.

	This represented about 40,000 donations.  They were tested at GenProbe
using a combination test for B19 and HAV, that had about 600 copies/ml
test sensitivity.  This was about 100 percent detection level, which in
our pools of 16, was about 9,600.

	Of those 2,547 pools tested, 24, just under 1 percent of these pools of
16 were reactive for B19.  There were no reactives for HAV once again.
If we assume that there was one B19 positive donation per reactive pool
of 16, that would give us a prevalence of the sensitivity that we were
using this test at 1 in 1,700 versus what I showed you for the NGI
study, which used a less sensitive procedure, of 1 in 12,800.  So, in
this case, it was 7-fold higher.

	If you look at product loss, because again at a pool of 16, if we have
a positive, we have to discard all products, due to discard of all
members of a reactive pool when dealing with 16, would be about 1 in
100, which is unacceptable.

	Based on the distribution of quantitative results for those 24 positive
pools, the addition of the ones with 1,000 pre-dilution, which is what
NGI does, would result in a prevalence that was comparable to NGI, of 1
in 13,000.

	[Slide.]

	If you look at the titers of the 24 positives that we got in the study,
the vast majority would be expected to be below the limit of detection
of the GenProbe test in the pool setting, so those are unexplainable
findings or due to contamination, which is likely the outcome.

	Here are some moderate level positives that were detected.  We don't
have antibody signal results on these. Again, we have 3, these are the 3
high titer positive samples.

	[Slide.]

	Currently, we are also doing--this is moving on to something else--we
are doing manufacturing pool testing.  That is where many recovered
plasma units are pooled, approximately 3,250 liters, and these
manufacturing pools are tested for virus prior to final manufacturing.

	I don't want to dwell on this because this is HAV, but again it shows
you the type of result output that you get from NGI.  This is audio
radiogram, and I said that NGI performs two primer pairs, they do them
in duplicate, so here you see a set of four results.

	Lanes, all one are their positive controls, 17 through 19 are all
positives, so this one they didn't have a positive.  I mean there are
certain criteria, and these all met the validity criteria.

	But here you have an unknown and you can see here that it may not be
positive on all of the four rafts, but in this case, it certainly was
positive on three, constituting a positive result.  So, that shows you
the type of data output one would get.

	[Slide.]

	So, the conclusions from the presented studies is that blood collectors
considering implementation of B19 screening will have to evaluate NAT
methods that are relatively insensitive to prevent issues from
contamination and detection of low level NAT positives.

	The frequencies that I showed were 1 in 12,800 using the insensitive
method at NGI.  If you consider only the two very high titer positives
we had, the frequency is 1 in 25,600, and those were IgG negative.

	The frequency, if we increase the sensitivity, was 1 in 528 with
moderate titer samples that were plus/minus for IgG, but positive for
IgM.  Now, if you compare the GenProbe methods, we could get comparable
results depending on whether we do a dilution, which would yield a 1 to
13,500 result, or 1 in 1,700 frequency if we used their sensitive
method.

	[Slide.]

	High-titer screening methods may not capture all infections B19
positive units, however, the infectivity of antibody reactive, low-titer
positives is unknown, as has already been referenced.

	This study defines expected yields of B19 if sensitive and insensitive
NAT methods are used.

	This study also demonstrates the infrequent occurrence of HAV in
recovered plasma, which is about 1.5 million to a million.

	[Slide.]

	So, where does that leave us?  It leaves us with a discussion of Phase
1 and Phase 2, and I will try to answer some of the FDA's questions
here.

	One mechanism to do Phase 1 testing that the Red Cross will likely
implement is the method with NGI where we would outsource the testing to
NGI, and the process time for the testing would exceed the dating of
labile components.

	So, by the time we got test results, the only thing we would have are
frozen components.

	[Slide.]

	Now, how do we limit this, so we are only dealing with recovered
plasma, and not the issues surrounding FFP?

	Following the completion of our current HIV and HCV NAT testing, we
would take our NAT tubes and identify those that correspond to recovered
plasma.  Those recovered plasma tubes would be pooled into pools of 16.
They would be sent to NGI for further pooling, into pools of 512.

	NGI would test for HAV and parvovirus, following a 1 to 1,000 dilution
for the parvovirus.  If negative, the product with the plasma would be
fractionated.  If positive, we would resolve to the pool of 16, and all
in-date frozen products would be discarded, and the good news here is
that we wouldn't have any FFP because they were never tested to begin
with.

	So, the question is then how do we address Phase 2, which would be
testing in-house using a commercial kit. This would represent real-time
testing in pools.  Most likely in our scenario at the Red Cross, we
would maintain our current pools of 16, and as I mentioned with the
GenProbe procedure, we could do a pre-dilution step as part of the
assay, whether that is a 1 to 1,000 dilution to reach about a 107
copy/ml per donation level or 1 to 100 dilution, so we get to 106.  That
remains to be determined.

	Reactives would be resolved to the individual donation within real
time.  So, what does that mean?  For product release, in reactive pool
resolution, for the latter involving usually 3 rounds of testing, we
have anywhere from about a 10 to a 48 hour per donation turnaround time,
and that is really based on our current NAT testing now.

	If pools are negative, our turnaround time is about 10 hours.  If a
pool is reactive, requiring resolution testing, and then if it is a
multiplexed test, discriminatory testing, final results may not be
available for 24 to 48 hours.  So, this really represents the range of
when results are available.  In this model, no product release would
occur unless the units not only test HIV/HCV negative, and in the future
West Nile, but also HAV and B19 negative.

	[Slide.]

	The B19 sensitivity level would initially be set for the removal of
high-titer units that is greater than 106 copies/ml.  We really couldn't
make claims for labile products because we are not removing all parvo,
we are just removing high-titer units.

	Really, again, as reference, we would really need to determine the
needs for recipients of labile products, what the level of sensitivity
should be, who should receive these products, et cetera.

	Donor notification, management of products from NAT-reactive donors'
previous donations and recipient tracing, which we hope won't have to
occur, would have to be determined.  But regarding donor notification,
as has been addressed in the questions from Dr. Brown's presentation, is
our time required for donor notification, varies by the marker, but it
is generally two to three weeks and for some markers where we outsource
supplemental testing, it may take the full 56 days or up to 8 weeks.

	Our timeline for any type of Phase 2 implementation is dependent on the
regulatory policies that FDA mandates, availability of test kits, and I
didn't even list here all of the implementation issues, such as those
outlined for West Nile virus.

	Thank you.

	DR. NELSON:  Thank you, Dr. Stramer.

	DR. SCHMIDT:  What is NGI?

	DR. STRAMER:  Oh, I am sorry, National Genetics Institute.  They are a
clinical reference lab.

	DR. SCHMIDT:  Thank you.

	DR. STRAMER:  I was hoping to get a more challenging question than
that.

	DR. SCHMIDT:  I thought maybe it was a new disease.

	[Laughter.]

	DR. STRAMER:  It could be.

	DR. NELSON:  Actually, ironically, they were supposed to present next,
but I understand Dr. Conrad isn't here.

	DR. STRAMER:  I tried to address two points in his talk because he
presented differing sensitivity, but it is actually the same test at 20
copies/ml, pools of 512, and a 1 to 1,000 dilution.  According to my
$1.99 calculator, that comes out to 1.2 times 107, and I did it twice to
verify my initial results, so it is about 107 sensitivity for their
method.

	DR. FALLAT:  You have presented a lot of data and threw out an awful
lot of numbers.  Can you simplify it for me?  What do you think is the
best estimate from your large sample size of the general incidence of
this virus in donor pools?  I see numbers from 1 to 500 to 1 in 25,000,
and what is the best number?

	DR. STRAMER:  Using sensitivity that I think is reasonable to eliminate
the high titer units, I think we will wind up with a prevalence between
1 in 10,000 and 1 in 15,000.

	Now, if a cutoff of 106 or 107 is adequate, that is what the prevalence
would be.  If we dropped the cutoff, then, we are dealing with
considerably different numbers.

	DR. NELSON:  Next, from the plasma industry, Barbee Whitaker.

Fractionators/PPTA

Barbee Whitaker, Ph.D.

	DR. WHITAKER:  Good afternoon.  Thank you for the opportunity to
present the PPTA approach to reducing parvovirus B19 load in
fractionation pools.

	I would like to mention that there have been a few changes to the
slides that were distributed to the committee last week, and that you
should have the current version, the version I am presenting now in
front of you.

	I would also like to mention that we have three presentations as a part
of our industry presentation and I would like to respectfully request
that you hold questions until the end because it's a comprehensive
presentation.  Thank you.

	[Slide.]

	PPTA is the international trade association and standard-setting
organization for the world's major producers of plasma derived in
recombinant analogue therapies.  Our members provide 60 percent of the
world's needs for source plasma and protein therapies.  These include
clotting therapies, immune globulins, and alpha-1 antitrypsin among
other products.

	PPTA members are committed to assuring the safety and availability of
these medically needed life-sustaining therapies.

	[Slide.]

	Although transmission of parvovirus B19 is uncommon through plasma
therapies, PPTA recognized the particular vulnerability of specific
therapy recipients including pregnant women and immunocompromised
individuals. The industry opted to pursue a strategy of identification
and removal of high-titer units as described already.

	About the same time that we were looking at this, based on experiences
observed with the solvent detergent treated plasma for transfusion, FDA
encouraged the fractionation industry to limit viral loads in
manufacturing pools.

	About a year later, in 2000, the European Medicinal Evaluation Agency,
the EMEA, held a workshop to address viral safety of nonenveloped
viruses.  It was concluded that given the current extent of knowledge,
further introduction of regulatory requirements should be carefully
considered, and to date, there have been no further meetings on this
subject.

	Also, in 2000, the WHO released an International Laboratory standard
for parvovirus B19, allowing the standardization of various laboratory
tests particularly NAT.

	PPTA released its voluntary industry standard for the management of
parvovirus B19 in mid-2001.  This standard is one of five critical
standards in PPTA's Quality Standards of Leadership Excellence and
Assurance Program.

	The goal of our Standards Program is to enhance the margin of safety
and quality of each and every product that reaches our consumers.

	[Slide.]

	PPTA's parvovirus B19 standard requires in-process control testing of
incoming source plasma by NAT for parvovirus B19 DNA.  Plasma that would
result in a manufacturing pool exceeding 105 International Units/ml is
removed.

	Effective July 1st, 2002, manufacturing pools may not exceed 105 IU
parvovirus B19 DNA/ml.

	PPTA's standard is designed to enhance the safety of the finished
product and is based upon the recommendations of the September 1999
Blood Products Advisory Committee specifically and described by Mei-ying
a little bit earlier.

	The recommendation to treat parvovirus B19 is an in-process control
that no studies were required to validate clinical efficacy of B19 NAT
under IND for plasma for further manufacture.  The validation should
proceed as an analytical test only and that no clinical correlates were
necessary if no decisions regarding donor or recipient management were
taken.

	[Slide.]

	As Dr. Yu has described, FDA has requested additional data regarding
specific industry practices, and I would like to introduce Dr. Steve
Petteway of Bayer Biological Products, who will walk you through the
requested data.

	[Slide.]

	As agreed with FDA, industry data will be presented in an anonymized
fashion.  Companies represented are as follows:  Alpha Therapeutic
Corporation, Aventis Behring, Baxter BioScience, and Bayer Biological
Products.

	Following Dr. Petteway's presentation, Dr. Edward Gomperts of Baxter
BioScience will present the potential impact of donor notification.

	Thank you.

Stephen R. Petteway, Jr.

	 DR. PETTEWAY:  Thanks.

	The FDA has requested that we provide an update for our in-process
control testing of source plasma for parvovirus B19, but before I do
that, I want to address the FDA issues that are specific here from
testing algorithm through to profiles for B19 serial bleeds.  I will
address those.  I think that you have them in front of you.

	[Slide.]

	However, before I do that, I want to remind everyone that pathogen
safety is a comprehensive approach with effective redundant measures
that provide a high margin of safety.

	Beginning with the donor, with donor screening, management of
donations, and management through testing donations and inventory hold
and lookback, followed by manufacturing and specifically the management
of plasma or manufacturing pools, coupled with virus inactivation and
removal, and this coupling is very important in the whole safety
profile.

	Then, moving through the process ending with postmarketing surveillance
in support of our patients.

	[Slide.]

	Specifically for parvovirus B19 management, we focus on two of these
manufacturing safeguards, the plasma or manufacturing pool, and
in-process control of the plasma manufacturing pool again coupled with
virus inactivation and virus removal through the purification and
manufacturing processes.

	I think to understand the value of this in-process test method that we
have implemented, understanding the link between these two is critical.

	[Slide.]

	Prior to implementation of our testing paradigm, no plasm units were
tested for B19.  This resulted in manufacturing or production pools that
ranged from 101 to 109 International Units/ml, followed by process viral
reduction gave us a defined margin of safety, however, after
implementation, high-titer units are identified through minipool testing
and removed, now providing production or manufacturing pools with a
titer of 105 International Units/ml when coupled with the same process
viral reduction lead to an increased margin of safety.

	That is really the target of this testing is increasing the margin of
safety.

	[Slide.]

	To address the first issue that we were asked to address, the NAT
sensitivities for minipool testing and original units, what we are
presenting is targeted testing threshold for minipool testing as opposed
to analytical sensitivity.

	[Slide.]

	The reason for that is that the sensitivities required to achieve
reduced manufacturing pool loads are a function of minipool size and the
manufacturing pool size. They are a volume factor.  So, the differences
in the size of the minipools i.e., the volume or the manufacturing pool
greatly influence what this targeted cutoff is.

	Minipool and manufacturing pool sizes vary across the industry.
Therefore, each manufacturer has set the testing threshold based on the
size of minipools and manufacturing pools to achieve the PPTA standard.
That is why you see different threshold levels from company to company.

	[Slide.]

	The targeted threshold levels for original units we have calculated for
you here because we don't actually test the original units.  We
back-extrapolated from the minipools.  We remind you again that each
manufacturer has set the testing threshold based on the size of the
minipool and the manufacturing pool, and the goal is to achieve the PPTA
voluntary standard.

	You can see the differences, 5 times 105 to up to 107, and it's a
volume related issue.

	[Slide.]

	So, minipools that are reactive and based on the targeted threshold are
assessed and units are released or discarded based on individual company
processes for carrying out that activity.

	[Slide.]

	Looking at the prevalence and levels of B19 DNA in minipools, as you
can see, they range from 1 in 3 minipools down to 1 in 40 minipools.  Of
course, this is because the frequency in minipools is influenced by the
size of the minipool and it varies across the industry.

	[Slide.]

	The B19 DNA levels can range up to 1011 International Units/ml
depending, of course, on the titer and the donation.

	[Slide.]

	The next issue is the prevalence of reactive minipools, original units,
manufacturing pools, and the levels of B19 DNA in each, and we will
attempt to provide that for you.

	[Slide.]

	The frequency and levels of B19 DNA in original donations.  What we are
showing here is the frequency of discarded units, that is, in the
testing paradigm, because of the logistics of testing, all the units
that we discard are not necessarily greater than the threshold, so what
you are seeing is the units that we actually discard.

	It ranges from 1 in 2,000 to 1 in 5,000, and you can see that it
correlates with the threshold, and some companies have a lower threshold
than other companies have for identifying and dealing with units.

	[Slide.]

	For B19 DNA in manufacturing pools, I think this is a very important
slide and pretty graphically illustrates the whole point of this testing
and what we gain from it and the value of it.

	Prior to B19 in-process testing, this represents,  each line, each data
point represents the titer in a manufacturing pool and you can see that
many manufacturing pools have titers as high as 108 to 109 International
Units.

	Following the implementation of the B19 in-process testing, however,
there is a consistent reduction of the titer of B19 in the manufacturing
pools across the same time frame.  This data clearly demonstrates the
value of the in-process control testing for manufacturing pools of B19
NAT, and this again is our whole goal, is to reduce the load in the
manufacturing pools.

	[Slide.]

	Resolution Times.  Now, you can interpret resolution times in many
ways.  Resolution time may be from the time a sample is received in a
laboratory to the time the result is available.  So, we interpreted
resolution time as from the time collection occurs, the collection of he
unit, until a result is available.

	You need to understand that this doesn't include time for confirmation
testing and/or notification of donor, and the resolution times range
from a mean of about 25 to 60 days.

	As far as resolution times as it relates to the single donor, that is
not done in our process.

	[Slide.]

	Now, there are factors influencing resolution time, and I think this is
pretty critical in trying to understand how this works and what the
issues are.  These factors, of course, are shipping logistics, when
samples are moved, when units are moved, and how they are managed.

	Laboratory capacity and through-put and even seasonality of infection,
and I will show you in the next slide exactly what I mean by that.

	[Slide.]

	This is from one member company.  This is about two years, and this is
the trends in the incidence of parvo-positive units over time.  You can
see that it is cyclic, as you would expect, and at certain points in
time there is a very low incidence, i.e.,  the through-put through a lab
would be very rapid, at other points in time there can be 5 to 6 times
as many positives to deal with, so that is certainly going to affect the
through-put of a lab.

	So, I think we have to be very cautious in describing or relating
turnaround times, that they can be a little inconsistent and they can
vary on us depending on the conditions.

	[Slide.]

	The next issue was the prevalence and levels of anti-parvovirus B19
antibodies, if any.

	[Slide.]

	To summarize, anti-B19 antibody level is not affected by the
implemented in-process control measures, that is, removing the high
titer donations.  About 98 percent of manufacturing pools, whether
before testing or after testing, are above 10 International Units/ml,
and there are no manufacturing pools below 5.

	This demonstrates appropriate strategy for effective management of
parvovirus B19 loads in manufacturing pools while, importantly,
retaining necessary antibody levels.

	[Slide.]

	I will just make a couple more comments about that.  We were also asked
if it was possible to look at serial donations and look at the temporal
relationship of positives, negatives relative to serial donations, and
this happens to be a very high frequency donor, a profile from the high
frequency donor.

	There are about 12 of those, and this is one example, and this is meant
to be a prototype.  Each box represents a donation and the status of
that donation relative to our threshold, whether it is above or below
the threshold.

	What you can see is that at this particular point, we were very lucky
and we identified a donation actually at the point of initial infection,
and the increase in titer was very rapid up to a very high titer, and
then the next donations decreased very rapidly until it decreased below
the threshold, and then went back to nondetection or non-elevated based
on our tests.

	This does not mean there is no titer.  This means that it is
non-elevated relative to our testing paradigm.

	There is one important point to make here relative to antibody levels,
and that is that what we have superimposed is the expected IgG profile
based on publications based on the literature.

	We also have data that actually confirms this, so we have got data
where we actually looked at titer relative to donations, and we looked
at IgG.  What you can see, I think the first speaker already pretty much
said this, is that most of the high-titer donations that we remove are
not likely to have an impact on B19 antibody titers in either
manufacturing pools or immunoglobulin products.

	However, if we remove a great deal of the low-titer donations, then,
the possibility exists for a significant impact on the antibody titers
in both manufacturing pools and final product, and that is clearly one
of the main reasons why we have adopted this particular paradigm.

	[Slide.]

	So, in conclusion, then, PPTA member companies have implemented
appropriate processes which have been shown to be effective in managing
parvovirus B19 in manufacturing pools, thus achieving an increased
margin of safety for life-saving plasma protein therapies.

	Ed Gomperts is going to discuss public health impact of donor
notification and counseling.

Edward Gomperts, M.D.