Therapeutic Use of OKT3 Monoclonal Antibody for Acute Renal Allograft Rejection

OKT3, a murine monoclonal anti-T-cell antibody, was used to treat acute renal allograft rejection crises in 140 patients. When used for primary treatment of initial rejections, it was effective in all 20 recipients of related-donor (RD) grafts and in 70 of 74 recipients of cadaver-donor (CD) grafts. OKT3 was also used for resistant rejection unresponsive to conventional antirejection drugs and was effective in 11 of 13 RD and in 26 of 33 CD recipients. Rerejection occurred in 58% of patients in the OKT3 primary treatment group and in 35% of patients in the OKT3 rescue group. Fifty-nine percent of the patients produced anti-OKT3 antibodies. Nearly all recipients experienced a flu-like syndrome following the first and second daily doses of OKT3. Two-year actuarial patient survivals were 100 and 96% for RD and CD recipients, respectively. In the OKT3 primary treatment group, two-year actuarial RD and CD graft survivals were 91 and 76%, respectively. In the OKT3 rescue group, the two-year actuarial RD and CD graft survivals were 85 and 55%, respectively. A proposed immunosuppressive effect of OKT3 is T-cell inactivation by blocking antigen receptors linked to OKT3-reactive molecules. Reuse of OKT3 for recurrent rejection or subsequent organs may be hampered by anti-OKT3 antibody production. OKT3 is an effective steroid-sparing treatment for renal allograft rejection.