Guidelines for the Optimal Use of Muromonab CD3 in Transplantation

Muromonab CD3 (OKT3), the murine anti-CD3 monoclonal antibody (mAb) of the IgG-2a class, directed against the CD3 molecule on the surface of human T cells, has proven to be a powerful immunosuppressive agent in solid organ transplantation and has been shown to be superior to high-dose steroids as first-line treatment of acute allograft rejection. It is comparable to antithymocyte globulin (ATG) in treating steroid-resistant rejection and it is also effective as rescue treatment in ATG-resistant rejection. However, OKT3 treatment is followed by a substantial percentage of re-rejections, most of which respond well to steroids. In the early post-transplant period, a prophylactic course of OKT3 can delay the onset of acute rejection, in particular in immunologically high-risk patients.