title: Splenectomy does not offer immunological benefits in ABO-incompatible liver transplantation with a preoperative rituximab.
abstract: 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 G antibody 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.
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery and Transplantation, Graduate School of Medicine, Kyoto University, Shogoin, Sakyo-ku, Kyoto, Japan. drvikramraut@gmail.com
authors.forename: Vikram
authors.initials: V
authors.lastname: Raut
authors.forename: Akira
authors.initials: A
authors.lastname: Mori
authors.forename: Toshimi
authors.initials: T
authors.lastname: Kaido
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ogura
authors.forename: Iida
authors.initials: I
authors.lastname: Taku
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nagai
authors.forename: Naoya
authors.initials: N
authors.lastname: Sasaki
authors.forename: Kosuke
authors.initials: K
authors.lastname: Endo
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hata
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yagi
authors.forename: Hiroto
authors.initials: H
authors.lastname: Egawa
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000328:Adult; D000906:Antibodies / Q000097:blood; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D001787:Blood Group Incompatibility / Q000276:immunology*; D005260:Female; D006084:Graft Rejection / Q000276:immunology* / Q000517:prevention & control*; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D007165:Immunosuppression Therapy; D015994:Incidence; D008107:Liver Diseases / Q000601:surgery; D016031:Liver Transplantation / Q000276:immunology*; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange; D012189:Retrospective Studies; D000069283:Rituximab; D013156:Splenectomy
chemical_list: D000017:ABO Blood-Group System; D000906:Antibodies; D058846:Antibodies, Monoclonal, Murine-Derived; D007155:Immunologic Factors; D000069283:Rituximab