Splenectomy does not offer immunological benefits in ABO-incompatible liver transplantation with a preoperative rituximab.

Background. Preformed anti-ABO antibodies are primarily responsible for antibody-mediated rejection (AMR) after ABO-incompatible (ABO-I) liver transplantation (LT) resulting in lethal hepatic necrosis and biliary complications. Splenectomy, an integral part of protocol for ABO-I LT, decreases anti-ABO antibodies. With the preoperative rituximab prophylaxis, role of the splenectomy for ABO-I LT is now under debate. We investigated the necessity of splenectomy by retrospective analyses of the short-term anti-ABO antibody response and long-term outcomes of ABO-I LT. Methods. Thirty-seven ABO-I LTs performed from May 2006 through July 2009, at Kyoto University Hospital, Kyoto, Japan, were retrospectively analyzed. Twenty-seven patients who underwent splenectomy (splenectomy group) received 329.6 +/- 35.8 mg rituximab 17.7 +/- 11.9 days before living donor LT. Ten patients without splenectomy (nonsplenectomy group) received 320.0 +/- 10.3 mg rituximab 26.6 +/- 21.3 days before transplantation. All patients received a posttransplant hepatic artery infusion with prostaglandin E1 and methylprednisolone. Perioperative anti-ABO immunoglobulin M and immunoglobulin G antibody titers, rejections, biliary complications, infections, and survival results were compared. Results. Preoperative rituximab with plasma exchange effectively reduced anti-ABO antibodies in both patient groups at the time of LT. There was no statistically significant difference observed in anti-ABO immunoglobulin M and immunoglobulin Gantibody titers between the "splenectomy" and" nonsplenectomy" groups during the initial 8 weeks. The clinical outcomes, including AMR, biliary complications, infections, and survival, were similar in both the groups. Conclusions. Preoperative rituximab effectively decreased the anti-ABO antibodies sufficiently to prevent the AMR irrespective of splenectomy. Splenectomy does not offer any immunological benefit in ABO-I LT with preoperative rituximab.