In summary, we believe that our experience with concomitant use of OKT3 and either reduced-dose CyA for treatment of renal allograft rejections or full-dose CyA therapy for treatment of liver allograft rejection is both safe and possibly more effective in reversing allograft rejection than use of the antibody alone. This strategy has also allowed us to use this MAb therapy without incurring the untoward consequence of the development of hightiter anti-OKT3 antibodies that could preclude its subsequent reuse.