Adult Living Donor Liver Transplantation Across ABO-Incompatibility.

Abstract

Background: ABO-incompatible (ABO-i) living donor liver transplantation (LDLT) is an aggressive treatment to across ABO blood-typing barrier for saving life from liver failure. Although antibody-mediated rejection might occur, the graft and patient survival has been improved recently by various treatments. However, these treatments are complicated. Methods: An easy-to-perform regimen was designed based on time course of immunological reaction. First, if isoagglutinin IgG and IgM titers were <1:64, liver transplantation was undergone directly and rituximab (375mg/m2) was administrated on post-operative day (POD) 1. Second, if preoperative isoagglutinin titers were >1:64, rituximab (375mg/m2) was administrated 2-3 weeks before operations. Plasmophoresis or plasma exchange was performed if isoagglutinin titers persisted >1:64 after rituximab administration. After transplantation, additional rituximab was administrated on POD 1. Splenectomy was not performed in all the operations. Postoperatively, immunosuppression was conducted by mycophenolate mofetil, tacrolimus, and steroids. Results: 46 adult ABO-i LDLTs including 36 males and 10 females were performed under this regimen. B-cells were effectively depleted and kept <1% for 3 months at least. Among these patients, 25 patients needed plasmophoresis/plasma exchange to reduce isoagglutinin titers. Acute humoral rejection occurred in two patients (4.3%). Biliary complications happened in 20 patients (43.5%), including 18 anastomotic stenosis and 2 bile leak, which was higher than ABO-compatible patients in this institute. Among the different matching of blood type, B to O had the highest incidence of biliary complications. One-, 3-year and 5-year survival rates were 80.3%, 73.0% and 66.9%, respectively. Conclusion: ABO-incompatible living donor liver transplantation could be successfully performed with an adequate preparation to reduce isoagglutinin titer <1:64. Biliary complication rate was higher than ABO-compatible patients. The survival rates were similar to ABO-compatible patients. However, acute humoral rejection still happened. Cautions are needed to perform ABO-incompatible living donor liver transplantation.