A Novel Approach to Successful ABO-Incompatible High-Titer Renal Transplantation

BackgroundCurrently the long-term outcome among recipients of ABO-incompatible renal transplantations is excellent in Japan. However, previous reports have documented poor outcomes in patients with high (> 1:256) anti–A/B antibody titers pretreatment. The immunosuppressive protocol for ABO-incompatible high-titer renal transplantation has remained a medical challenge.MethodsWe treated 3 patients with high (> 1:512) anti–A/B antibody titers prior to ABO-incompatible renal transplantation. Our immunosuppressive protocol was initiated 1 month prior to surgery and included mycophenolate mofetil (1 g/d) and low-dose steroid (methylprednisolone [8 mg/d]). Two doses of the anti–CD20 antibody rituximab, (150 mg/m2) were administered 2 weeks before and on the day of transplantation. We performed antibody removal with 6 to 8 sessions of plasmapheresis (plasma exchange or double-filtration plasmapheresis) before transplantation. Splenectomy was also performed on the day of transplantation. Postoperative immunosuppression followed the same regimen as ABO-compatible cases, in which calcineurin inhibitors were initiated 3 days before transplantation combined with 2 doses of basiliximab.ResultWith this protocol, the anti–A/B antibody was reduced to below 1:16 in all cases. All 3 patients underwent successful transplantation with a mean current serum creatinine of 1.32 mg/dL (range, 1.22–1.50 mg/dL). There were no episodes of antibody-mediated rejection. No serious complications or side effects were encountered.ConclusionsA preconditioning protocol consisting of rituximab infusions, splenectomy, plasmapheresis, and pharmacologic immunosuppression enabled ABO-incompatible renal transplantation in patients with high (> 1:512) anti–A/B antibody titer.