With some types of MDS, the immune system may prevent the bone marrow from making normal blood cells. Immunosuppressive therapy uses medicines to keep the immune system from attacking the bone marrow. These medicines include ATG (antithymocyte globulin) and cyclosporine.

This therapy helps some MDS patients, especially those with the RA subtype. As with any drug used to treat MDS, the beneficial effects of ATG are temporary.

Side Effects of ATG

When getting the IV, 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.