Increased Incidence of Thrombotic Microangiopathy After ABO-Incompatible Living Donor Liver Transplantation

BACKGROUND Thrombotic microangiopathy (TMA) is a severe life-threatening complication associated with solid organ transplantation. We retrospectively investigated the incidence, risk factors, and appropriate treatment of TMA following adult living donor liver transplantation (LDLT). MATERIAL AND METHODS The subjects were 129 adult patients who underwent LDLT in our department from 1997 to 2014. Patients with TMA were identified retrospectively based on diagnostic criteria. We calculated the incidence of TMA and performed a risk factor analysis for TMA occurrence. We also assessed our past treatments for TMA and sought to identify the most appropriate form of treatment. RESULTS Thirteen patients were identified as having TMA. The incidence of TMA in the study cohort was 10.1% but was especially high (37.9%) among ABO-incompatible cases. A univariate analysis revealed that ABO incompatibility, usage of tacrolimus, usage of rituximab, and cold ischemic time ≥50 minutes are risk factors for occurrence of TMA (p<0.10). Multivariate analysis demonstrated that ABO incompatibility was the only independent risk factor for TMA (p=0.009). Initiation of treatment on the day of TMA diagnosis was associated with better survival. CONCLUSIONS ABO incompatibility is an independent risk factor for TMA following adult LDLT. Our results suggest that early initiation of treatment is crucial for improving the outcomes.