Use of monoclonal antibodies OKT3 in immunosuppressive therapy in renal transplantation

In this study we present our experience with the use of monoclonal antibodies (Orthoclone OKT3) in the immunosuppressive therapy of kidney transplantation. Thirty-five patients with renal transplant (27 from cadaver donor, 8 from living-related donor) under cyclosporin and steroid immunosuppression, received OKT3. The drug was given to 18 patients for treatment of steroid-resistant rejection (group A) and, as prophylactic treatment, to 17 high risk patients (group B) because of retransplant or pediatric age. In group A, all the rejection episodes were reversed by OKT3 treatment, however, 10 patients experienced new rejection episodes following OKT3 therapy within one month from the end of the treatment; 6 of these episodes were reversed after a new treatment. In group B, 10 patients had a rejection episode, 5 during OKT3 therapy. There were 2 graft losses because of rejection and one graft failed because of infection. In the whole group (A + B) 14 patients experienced an infection complication and 3 patients died. In conclusion, monoclonal antibodies appear to be a very effective agent in the treatment of steroid resistant rejection, however they are less effective when used as prophylactic treatment. Furthermore the high risk of infection is the major problem in the use of this immunosuppressive drug.