Cyclosporine

Cyclosporines are drugs used in the field of immunosuppressant medicine to prevent the rejection of transplanted organs. They were discovered by Jean F. Borel in 1972. The cyclosporine used for transplant surgery is called cyclosporine A (CsA) and in 1984 it was added to the group of medicines used to prevent transplant rejection. Cyclosporine A is the most common form of the Norwegian fungus Tolypocladium inflatum.

The discovery of cyclosporine has led to a significant rise in the number of organ transplant operations performed as well as the rate of success. Cyclosporine has increased both the short- and long-term survival rates for transplant patients, especially in heart and liver operations. The rejection of grafted tissues occurs when white blood cells (lymphocytes) called T-helper cells stimulate the activity of cell-destroying (cytotoxic) T-killer cells. It is believed that cyclosporine interferes with the signals sent by the T-helper cells to the T-killer cells. These T cells, along with other white blood cells like monocytes and macrophages, cause the tissue rejection of the implanted organs.

Cyclosporine has proven to be the most effective medicine used to combat the body's own immune system, which is responsible for the rejection of transplanted organs. In addition to curtailing the activity of T-helper cells, cyclosporine is also able to fight the infectious illnesses that often occur after a transplant operation and can lead to death.

Cyclopsporine must be administered very carefully, since it can produce a number of toxic side effects, including kidney damage. Many clinical trials have been conducted using other drugs in combination with cyclosporine in an effort to reduce these side effects.

Aside from potential damage to the kidneys, there are a number of other side effects of cyclosporine. They include elevated blood pressure, a raise in potassium levels in the blood, an increase in hair growth on certain parts of the body, a thickening of the gums, problems with liver functioning, tremors, seizures, and other neurological side effects. There is also a small risk of cancer with cyclosporine as well as with the other immunosuppressant drugs.