Current progress in ABO-incompatible liver transplantation

ABO-incompatible (ABOi) living donor liver transplantation (LDLT) in adult patients has been controversial because of the high risk of antibody-mediated rejection (AMR) mediated by preformed anti-ABO antibodies. However, outcomes have recently improved owing to various treatment advances.

This review article describes the history and current progress in ABOi liver transplantation, mainly from the viewpoint of the Japanese experience.

The typical clinical manifestations of AMR are hepatic necrosis and intrahepatic biliary complication. The outcomes of early ABOi LDLT were poor, especially in older children and adult cases. Since we first introduced portal vein infusion therapy into adult ABOi LDLT in 1998, local graft infusion therapy has emerged in Japan as a crucial breakthrough to overcome the ABO blood group barrier. From 2003, rituximab prophylaxis has been widely used with local graft infusion, and has resulted in markedly improved patient survival. The novel approach of intravenous immunoglobulin induction may become another option to suppress AMR. Continued patient enrollment and controlled trials will allow further validation of these treatments.

The outcome of ABOi LDLT is now similar to that of blood-type-matched transplantation in Japan. However, infection is the major cause of morbidity and mortality after ABOi LDLT. Thus, evaluation of the patients' immune status and adjustment of immunosuppression will be the way forward in the future.