Immunosuppressive Drug Therapy

Immunosuppressive drug therapy lowers your body's immune response. This prevents your immune system from attacking your bone marrow, lets stem cells grow back, and raises blood counts. In acquired aplastic anemia, immunosuppressive therapy with anti-thymocyte globulin (ATG) plus cyclosporine is the therapy of choice for older patients. It is also used for patients who do not have a matched stem cell donor. About 8 out of 10 patients have a positive response to this treatment.

How ATG Helps

ATG kills specific cells in your immune system called T-lymphocytes — the cells that are attacking your stem cells. This allows your bone marrow to rebuild its supply of stem cells. The stem cells, in turn, make more blood cells.

How ATG Is Given

Usually, ATG is given by IV for 8-12 hours a day, for 4 days. The schedule depends on your needs, the type of ATG used, and the methods of your doctor or hospital. No one schedule has been shown to be better than another.

How Well Does ATG Work?

  • When used alone, ATG improves blood counts about half of the time.
  • When used with cyclosporine, ATG improves blood counts in about 7 out of 10 cases.
  • If it works, ATG usually stops the need for transfusions within 3 months. Full success can take at least nine months.
  • Some patients may respond well, but may later relapse and need another treatment.

Side Effects of ATG

When receiving the treatment, you may have:

  • Chills
  • Fever
  • Hives

These side effects go away after treatment.  

Less Common Side Effects of ATG

Rarely, patients experience a severe allergic reaction to ATG. This is called anaphylaxis (an-uh-fuh-LAK-suss) which causes a drop in blood pressure and trouble with breathing. It can even cause death.

Before you receive ATG, you should have a skin test to find out if you are likely to develop anaphylaxis to this medicine. If you have a mild allergic reaction to the skin test, you can still take ATG, but you will need to start with a small amount to get your body used to it.

Another side effect of ATG is serum sickness. This happens when your immune system reacts to foreign proteins in the medicine. It causes fever, rash, joint pain, and muscle aches. If you get serum sickness, you will probably notice it 1 to 2 weeks after the first dose of ATG. You can take steroids (prednisone) during ATG treatment and for a few weeks afterward to prevent or treat serum sickness.


How Cyclosporine Works

Cyclosporine prevents T-lymphocytes from becoming active. Once the T-lymphocytes are turned off by the cyclosporine, they stop attacking stem cells in the bone marrow. Then the stem cells may be able to grow back.

How Cyclosporine Is Given

 Cyclosporine comes in liquid and pill forms. The first dose is based on how much you weigh. Later doses depend on the amount of cyclosporine in your blood. Too little cyclosporine will not work; too much will cause side effects. If you are responding well to cyclosporine, your doctor may decrease your dose over time.

How Well Does Cyclosporine Work?

  • When used alone, cyclosporine is less effective than ATG.
  • When used with ATG, cyclosporine improves blood counts in about 7 out of 10 cases.

Side Effects of Cyclosporine

Your doctor should monitor you for side effects. Cyclosporine may cause:

  • High blood pressure
  • Kidney damage
  • Loss of magnesium or potassium
  • Liver inflammation
  • Increased hair growth
  • Gum swelling

These problems can usually be fixed. You can take medicine to lower your blood pressure and to replace magnesium or potassium.