Biliary stricture is the only concern in ABO-incompatible adult living donor liver transplantation in the rituximab era

Abstract

Background & aims: With the introduction of rituximab prophylaxis, the survival of ABO-incompatible (ABOi) adult living donor liver transplant (ALDLT) has been strikingly improved due to the decreased incidence of antibody-mediated rejection. However, biliary stricture (BS) related to ABO incompatibility remains an unresolved concern.

Methods: Excluding 105 dual graft ALDLTs, 1102 ALDLT cases including 142 ABOi recipients were included in this study. The desensitization protocol for overcoming the ABO blood group barrier comprised pretransplant plasma exchange, and rituximab (300-375 mg/m(2) BSA).

Results: The mean follow-up period was 34.2 ± 15.4 months. The cumulative graft and patient survival rates were comparable in the two groups. The 1- and 3-year BS-free survival rates of ABOi ALDLT were 81.5 and 79.0%, respectively, lower than those of ABOc ALDLT (87.6 and 85.7%, respectively, p=0.022). In the risk factor analysis, diameter of graft bile duct opening <5mm, antecedent acute cellular rejection, and ABO incompatibility were independent risk factors for BS. Diffuse intrahepatic biliary stricture (DIHBS) exclusively occurred in 12 patients (8.5%) receiving ABOi ALDLT. The deaths of 3 patients and 4 cases of re-transplantation were related to DIHBS. Graft and patient survival rates were significantly reduced in ABOi ALDLT recipients with DIHBS. However, we failed to identify any significant risk factors for DIHBS.

Conclusions: The incidence of BS in ABOi ALDLT is higher than in ABOc, mainly due to the fact of DIHBS which significantly affected survival outcomes. To predict and prevent DIHBS, we need further studies to identify significant risk factors.

Keywords: ABO incompatibility; Biliary stricture; Diffuse intrahepatic biliary stricture; Isoagglutinin; Living donor liver transplantation; Non-anastomotic stricture.