Background: ABO-incompatible (ABOi) living donor liver transplantation (LDLT) in high Model for End-stage Liver Disease (MELD) patients stays uncertain. Using an intention-to-treat analysis, the survival benefit of ABOi-LDLT in patients with a high MELD score was investigated. We also compared the posttransplant outcomes following ABOi-LDLT, ABO-compatible (ABOc) LDLT and deceased donor LT (DDLT).
Methods: We retrospectively reviewed 649 patients with a MELD score ≥30 placed on the liver transplantation waitlist in our center. Based on living-donor eligibility and their ABO match, they were divided into three groups: intention-to-treat (ITT) ABOi-LDLT (n=45), ITT-ABOc-LDLT (n=162), ITT-DDLT (n=442).
Results: ITT-ABOi-LDLT group showed higher 1-year patient survival over ITT-DDLT (66.7% vs. 28.7%, P<0.001) and it was independently associated with reduced mortality in multivariable Cox regression (hazard ratio [HR], 0.32). Among patients who received liver transplant, 1-year posttransplant survival of ABOi-LDLT group (n=32) was not significantly different from those of DDLT group (n=170) and ABOc-LDLT group (n=88, 75.0% vs. 67.2% vs. 78.4%, respectively, P=0.130). ABOi-LDLT group showed similar complication rates compared to DDLT group and even ABOc-LDLT group, except for their higher rate of biliary stricture compared to DDLT group (25% vs. 10%, P=0.038). Postoperative outcomes of living-donors were similar between ABOi-LDLT and ABOc-LDLT group. Among ABOi-LDLT group, the higher isoagglutinin titer, the more in-hospital mortality and graft loss tended to occur, however, no association was observed between the initial titer and the rejection or rebound of ABO antibodies.
Conclusions: ABOi-LDLT offers considerable survival benefits over awaiting DDLT, for patients with a high MELD score. Patients who received ABOi-LDLT showed comparable posttransplant outcomes compared to DDLT and even ABOc-LDLT. ABOi-LDLT is a feasible treatment option for patients with a high MELD score.