Cyclosporin A: pharmacologic activity on the immune system and effects in clinical organ transplantation.

The recently discovered fungal metabolite cyclosporin A (CsA) is a potent immunosuppressant that is effective in preventing transplantation rejection due to allografts and even xenografts. Due to its influence on the biological activity of T-helper lymphocytes CsA's mechanism of action includes inhibition of cell-mediated cytolysis and delayed-type hypersensitivity (DTH) reaction. In addition to studies of the molecular mechanism of action, data on the pharmacokinetics of CsA are given. CsA does not cause anti-mitotic and/or cytotoxic effects. The side effects of the agent are relatively mild and appear to be reversible. CsA has been successfully used clinically in renal, bone-marrow, heart, heart-lung, liver, and pancreas transplantation. The application of the compound in organ transplantation appears to be superior to conventional immunosuppressive therapy.