Long-term follow-up of heart transplant recipients treated with murine antihuman mature T cell monoclonal antibody (OKT3): the Loyola experience.

We describe the long-term follow-up of 25 patients treated with murine antihuman mature T cell (OKT3) monoclonal antibody at Loyola University Medical Center. After OKT3 rescue therapy, 12 patients were monitored for 16.5 +/- 6.5 months. Twenty-two moderate and three severe rejection episodes occurred 11 to 469 days (166.8 +/- 126.0) after OKT3 therapy in nine of 12 patients. During the follow-up period three patients died, and one required retransplantation because of recurrent rejection. The coronary arteries of three failed allografts had severe intimal thickening and infiltration with lymphocytes. Thirteen patients received OKT3 for prophylactic immunosuppression, and their course was compared to that of 13 patients who underwent transplantation during the same period but were given prophylactic horse antihuman thymocyte globulins (HATG). There were no differences between the two drugs with respect to long-term incidence and severity of rejection and infection, cardiac allograft function, and survival. Our results indicate that, despite successful reversal with OKT3, heart transplant recipients with refractory rejection remain plagued by recurrent rejection. Cardiac allografts in recipients who die as a result of recurrent rejection show evidence of immune-mediated vasculitis, which results in severe and diffuse coronary luminal narrowing. OKT3 and HATG appear to be equally effective for rejection prophylaxis.