Monoclonal antibody for reversal of acute renal allograft rejection in pediatric patients

OKT3 induction in pediatric renal transplantation

Twenty cadaveric renal transplant patients (mean age 12.5 +/- 4.8 years) received 14 days (mean 13.0 +/- 2.8 days) of OKT3 (mean dose 0.16 +/- 0.09 mg/kg) along with prednisone 0.5 mg/kg per day, azathioprine 2 mg/kg per day and cyclosporine 5 mg/kg per day which was increased to obtain therapeutic levels before the discontinuation of OKT3. Actuarial patient and graft survival were 100% and 50%, respectively, at both 1 and 5 years. Four children lost their grafts within the first 48 h. One loss was technical in origin, the remaining 3 had pathological evidence of vascular thrombosis. Of the remaining 16 children, 12 (75%) experienced rejection episodes within the first 2 months post transplant (mean 27 +/- 15 days). Successful reversal of early rejection episodes was achieved in 11 of 12 patients. Clinically significant cytomegalovirus infection occurred in 4 patients and resulted in graft loss in 2 patients. Circulating OKT3 levels ranging from 1,000 to 32,000 ng/ml were seen in all patients within the first 48 h. There was a rapid and total depletion of circulating CD3-positive lymphocytes in all patients. Anti-isotypic and anti-idiotypic OKT3 antibodies were assessed by enzyme-linked immunosorbent assay (ELISA), and blocking anti-idiotypic antibodies were detected by immunofluorescence inhibition assay. Positive OKT3 antibody titers were detected in 11 children by ELISA and 10 children by immunofluorescence inhibition assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibody OKT3 therapy in pediatric kidney transplant recipients

Thirty-one pediatric patients with acute renal allograft rejection were treated with the monoclonal antibody OKT3. In 24 cases, increased doses of steroids followed by a polyclonal antithymocyte globulin were ineffective in reversing the rejection episode. Twenty-eight patients completed the prescribed minimum 10-day treatment course, with effective rejection reversal in 22. Three patients failed to complete the course of therapy: one because of leukopenia that developed after the first dose, one because of a clotted graft, and another because of symptomatic cytomegalovirus infection. The overall success rate of OKT3 for rejection reversal was 74%; however, 55% of recipients had rebound rejection, and 85% of patients had detectable anti-OKT3 antibodies after completion of the course of therapy. Ten patients were treated with a second course of OKT3, and in eight of these patients, rejection was at least temporarily reversed. The starting dose of OKT3 for second-course therapy was the same as that used during first-course therapy, but in five cases the dose was increased during the course because of inadequate therapeutic response. Seven of these patients lost their grafts a mean of 6.5 months after completion of second-course therapy. We looked for anti-OKT3 antibody in nine recipients after completion of a second treatment course and found it in all nine. Our observations regarding a second treatment course with this monoclonal antibody preparation suggest that although rejection reversal may be observed, ultimate graft survival is poor and anti-OKT3 antibody formation is enhanced.

Early use of OKT3 monoclonal antibody in renal transplantation to prevent rejection

OKT3 monoclonal anti-T cell antibody was used during the first 2 weeks following cadaveric renal transplantation to prevent rejection. When compared with a control group receiving triple immunosuppression with cyclosporine, azathioprine, and prednisone, the OKT3, azathioprine, and prednisone group had significantly fewer acute rejections during the first month (6% v 50%; P less than 0.01), and the mean time of onset of the first rejection was significantly delayed (day 47 v day 8; P less than 0.01) in the OKT3 prophylaxis group. OKT3 was administered intraoperatively safely and without complications on the day of transplantation. The well-reported first dose reaction to OKT3 was similar in these patients when compared with patients receiving OKT3 for treatment of rejection. Anti-OKT3 antibody development occurred in half of the patients receiving OKT3, and did not prevent the subsequent use of OKT3 in these patients, whose rejections following OKT3 prophylaxis were steroid reversible. There were no deaths among the patients receiving prophylactic OKT3, and during a 15-month follow-up, only three of 34 kidneys were lost for any reason. In addition to its use for primary and steroid-resistant rejection, OKT3 may be useful early after transplantation to prevent rejection.

Monoclonal antilymphocyte antibody (OKT3) treatment of acute renal allograft rejection

Recent advances in immunosuppressive therapy have dramatically improved the survival rates for recipients of organ allografts by reducing the frequency of rejection. Cyclosporine, azathioprine, and prednisone for immunoprophylaxis are especially effective. When rejection occurs, the treatment usually includes high doses of oral or intravenous corticosteroids, antilymphocyte globulin, or antithymocyte globulin. A new monoclonal antilymphocyte antibody, OKT3, promises to improve allograft survival rates further.

OKT3 monoclonal antibody in pediatric kidney transplant recipients with recurrent and resistant allograft rejection

Twelve pediatric patients, aged 28 months to 17 years, received OKT3 to reverse renal allograft rejection. In 11 patients, the rejection crisis was resistant to conventional antirejection therapy with high doses of prednisone or polyclonal antithymocyte globulin. Reversal of rejection was successful in 10 patients who completed a treatment course. Because of recurring resistant rejection, five patients received a second course of OKT3, which was successful in reversing the rejection crisis in two. Among these patients, the persistence or the appearance of high levels of circulating T3 lymphocytes after initiating the second treatment course correlated with treatment failure. The immediate side effects associated with OKT3 therapy were transient and medically manageable. We conclude that this monoclonal antibody preparation is a safe and effective treatment for pediatric renal allograft in recipients experiencing rejection crisis resistant to conventional therapy. However, the potential impact of this immunosuppressive medication on long-term renal allograft survival in this patient population remains to be determined.