Use of OKT3 monoclonal antibody in the treatment of acute cardiac allograft rejection.

OKT3 is a murine monoclonal antibody that recognizes the T3 surface antigen present on mature T cells, and it has been used to successfully treat renal allograft rejection. We report our experience with OKT3 in the treatment of cardiac allograft rejection. Eight patients with endomyocardial biopsy evidence of moderate or severe rejection were given fourteen daily intravenous treatments of OKT3. Six of the eight patients had complete recovery following OKT3 therapy; one required additional steroid therapy for recurrence and one patient failed to respond. Five of the six patients with a complete response have experienced no further rejection (mean follow-up 437 days). Adverse reactions to OKT3 were common early in the treatment course, but were well tolerated. We concluded that OKT3 is a safe and effective treatment of cardiac allograft rejection and that a majority of patients experience long-term rejection-free periods.