Inhibition of anti-OKT3 antibody generation by cyclosporine--results of a prospective randomized trial.

To investigate the influence of therapy with cyclosporine on the generation of antibodies to OKT3, 51 renal transplant recipients previously maintained on CsA, azathioprine, and prednisone were allocated randomly either to receive 50% of their maintenance dose of CsA (group 1, n = 27) or to discontinue CsA (group 2, n = 24) during treatment with OKT3 for acute renal allograft rejection. In the month following therapy with OKT3, anti-OKT3 antibodies were detected in 11% of patients in group 1 and in 42% of patients in group 2 (P less than 0.02). No patient in group 1 developed antibody titers greater than 1:100, whereas 4 patients in group 2 developed titer greater than or equal to 1:1000. Rejection was reversed in 96% of patients in group 1 and in only 75% of patients in group 2 (P less than 0.03), suggesting that continued administration of reduced doses of CsA during therapy with OKT3 improves the short-term response to this monoclonal antibody. Results of this study suggest that concurrent administration of CsA during therapy with OKT3 inhibits the generation of anti-OKT3 antibodies and improves the response to this monoclonal antibody.