Impact of Preformed Donor-specific Antibodies in Comparison to ABO Incompatibility in Living Donor Liver Transplantation: A Propensity Score-Matched Analysis.

Background: Immunological factors play a pivotal role in the outcomes of solid organ transplantation. We aimed to elucidate the effects of donor-specific antibodies (DSAs) and ABO compatibility on living donor liver transplantation (LDLT) outcomes.

Methods: A retrospective analysis was conducted on 584 LDLT recipients from 2015 to 2020. The recipients were stratified into 3 groups: ABO-compatible recipients without DSAs (group 1), ABO-compatible recipients with DSAs (group 2), and ABO-incompatible recipients without DSAs (group 3). Propensity score matching was used for balanced comparisons.

Results: In the matched comparisons, group 2 exhibited a higher incidence of T cell-mediated rejection compared with group 1 (22.7% versus 4.5%, P  = 0.030). Despite this, the 5-y survival rates were similar between groups 1 and 2 (81.6% versus 95.5%, P  = 0.085). Group 3, in comparison with group 1, showed elevated rates of cytomegalovirus infection (23.2% versus 7.3%, P  = 0.008), T cell-mediated rejection (28.0% versus 7.3%, P  = 0.001), and antibody-mediated rejection (13.4% versus 0%, P  = 0.001). However, the survival rates were comparable between group 3 and group 1 (82.0% versus 86.5%, P  = 0.220, respectively). Comparisons between group 2 and group 3 did not reveal significant differences in postoperative outcomes or survival rates ( P  > 0.05).

Conclusions: DSA positivity and ABO incompatibility contribute to distinct posttransplant complications in LDLT. The integrated consideration of both factors in pretransplant assessment may enhance risk stratification and inform tailored interventions. Further research is required to corroborate these findings and provide mechanistic insights.