NHS Blood - Give Blood England and Wales

How Plasma is used

How plasma is used

Plasma is a complex mixture of over 700 proteins and other substances which are crucial for the smooth running of our bodies. When extracted, these proteins and substances become key ingredients in medical products designed to replace body fluids, antibodies and clotting factors. Plasma is quite simply a lifesaving resource that benefits thousands of people every day. As the largest single component of blood, plasma makes up about 55 percent of total blood volume. It's a clear, straw coloured liquid, mostly made up of water, in which platelets, red and white cells are carried. It provides a 'storage area' for fluids for the body, helping maintain blood pressure as well as cooling and warming the body.

Once separated from blood cells, plasma for patient use goes in one of two directions. It can be used for blood transfusion as fresh frozen plasma and other transfused plasma products. It can also be directed to a plasma fractionation plant to undergo a more complicated type of processing to separate out its many individual proteins.

In much the same way that crude oil is separated into its component parts to make different oils, a fractionation plant breaks down plasma into a vast array of substances that can be used to make all sorts of medical products. These products can be grouped into three main types: coagulation factors, human albumin solutions and immunoglobulins.

Coagulation is the name for the complex process of blood clotting. For this process to be successful a person needs all the clotting (coagulation) factors – proteins that work together with platelets to clot blood.

Missing one or more of these factors leads to blood clotting disorders. The best known of these is haemophilia, a hereditary disease that affects almost exclusively males, who are missing one of two clotting factors, either Factor VIII or FactorIX. The most common treatment for people with haemophilia is replacement therapy – literally replacing the missing clotting factor.

There are many other deficiencies such as von Willebrand disorder, and rare clotting disorders such as Factor VII, X, XI and XIII, that are also treated using plasma replacement therapies. Albumin is the most abundant protein in blood plasma and is responsible for helping to clean the blood, carry substances and maintain the right amount of fluid circulating around the body.

If circulation is functioning at the correct level, all vital hormones, cells, and enzymes are transported to the right parts of the body to do their job. If it's not at a correct level, the circulatory system starts to break down with serious consequences such as fluids being retained in the cells. The problem can be corrected by using human albumin solution to ensure the right amount of fluid is circulating in the blood stream. People with liver or kidney disease and patients who have lost fluid such as burns patients all benefit from albumin.

Immunoglobulins are part of our immune system. They are antibodies – proteins produced by the body to fight invading viruses or bacteria as they enter the body. Two different types of immunoglobulins are produced from plasma, specific and non-specific. Those containing high levels of a particular antibody (specific) can be given to people who have been exposed to a specific infection to give immediate though temporary protection. The antidotes to tetanus, rabies, chickenpox, hepatitis B, and Anti-D are all examples of such products.

Immunoglobulins containing a wide variety of antibodies (non-specific) are given to people who make faulty, or no antibodies of their own. They are also given to people having treatments (such as for cancer) that harm their ability to make antibodies. People who are born with a faulty immune system depend on these products for life. To make sure most of the everyday antibodies are contained in a single dose of the immunoglobulin product, 10,000 donations of plasma are pooled together.

Plasma is first tested for viruses to be sure that it's safe to use, in just the same way that whole blood is tested. Depending on the product to be made, it undergoes many chemical and physical processes, such as spinning and heat treatments to separate the individual proteins. The fractionation process takes place in huge Cohn vessels, named after the 'grandfather of fractionation' Dr Edwin Cohn. Cohn was the first person to break down blood plasma to isolate a protein called albumin in the 1940s. The fractionation process is a fully automated system and takes up to five days to complete. Solvent/detergent treatment, dry heat treatment, filtration and pasteurisation are also used to kill or remove any viruses that may be present. All of the finished products undergo further testing to make sure that they contain the right biological make-up. Once the processing and testing is complete, the products are labelled, coded and packed ready to be used by hospitals, clinics and GP surgeries. The total number of products that can be made with plasma fractionation runs into hundreds.

Find a venue


Need some help?

There are many ways we can help you:

Read Mike's story