Specific immunosuppressive therapy by monoclonal anti-IL 2 receptor antibody and its synergistic action with cyclosporin.

The effects of anti-IL 2R mab treatment on local GVHR and on heterotopic cardiac allograft survival in rats were investigated. Anti IL 2 mab inhibited specifically both GVHR as well as allograft rejection. IL 2R-targeted therapy was superior to that of anti-T helper/inducer cell treatment, as it did not affect T subset distribution and did not reduce the number of circulating T lymphocytes. This therapy when combined with a low subtherapeutic dose of CsA exerted a strongly synergistic effect. The results support the concept of IL 2R-targeted therapy in suppressing undesired immune reactions with limited side effects.