Experience with OKT3 in vascularized pancreas transplantation.

With refinements in technical aspects of whole organ pancreas transplantation, allograft rejection is currently the major cause of graft failure. The monoclonal antibody OKT3 has emerged as a highly effective antirejection therapy in renal and hepatic allograft recipients, but its efficacy in pancreas transplantation remains to be determined. During a 12-month period, 28 vascularized whole organ pancreas transplants were performed with pancreatico-cystostomy. Sixteen episodes of allograft rejection were treated with monoclonal antibody OKT3. Indications for OKT3 use included steroid- or antilymphocyte globulin (ALG)-resistant allograft rejection in isolated pancreas (n = 8) or simultaneous kidney-pancreas (n = 8) transplants. A total of 34 rejection episodes occurred in the 16 patients (mean, 2.1; range, one to five). The diagnosis of rejection was based on clinical criteria, a reduction in urinary amylase clearance, radionuclide scanning, hyperglycemia, or associated renal allograft dysfunction in combined engraftments. Postoperative immunosuppression consisted of cyclosporine, prednisone, azathioprine, and prophylactic ALG. OKT3 was administered for a full 14-day course concomitant with low-dose steroids, azathioprine, and cyclosporine. The mean age of the patient population was 32.1 years (range 24 to 39) with a mean duration of insulin-dependent diabetes mellitus (IDDM) of 20.9 years. Monoclonal antibody therapy was instituted in two clinical settings: early rejection (within 3 months of transplant, n = 10); and late rejection (after 3 months, n = 6). OKT3 successfully reversed allograft rejection in ten (62.5%) cases, including six early (60%) and four late (66.7%) episodes. In isolated pancreas transplants, OKT3 therapy reversed pancreas allograft rejection in only two patients (25%).(ABSTRACT TRUNCATED AT 250 WORDS)