The impact of preformed donor-specific antibodies in living donor liver transplantation according to graft volume.

Introduction: The roles of preformed anti-HLA donor-specific antibodies (DSAs) in liver transplantation remain controversial. We evaluated the impact of preformed DSAs in living donor liver transplantation.

Methods: Adults who underwent living donor liver transplantation (n = 175) in our institute were included in this study. Lymphocyte cytotoxicity test (LCT), flow cytometric crossmatch (FCXM), and single-antigen bead assays were performed.

Results: Among adult living donor liver transplantation recipients, 27 (16.5%) and 14 (8.5%) had pretransplant FCXM-positive findings and LCT-positive findings, respectively. FCXM-positive patients displayed a significantly worse 5-year graft survival rate (77.3%; vs. DSA-negative, 91.6%). Six of 14 LCT-positive patients exhibited graft loss shortly after transplantation (5-year survival rate: 57.1%). All LCT-positive patients with graft loss underwent left lobe living donor liver transplantation. Significantly lower ratio of graft volume relative to standard liver volume (32.9 ± 5.7%) and smaller graft size (365.3 ± 57.9 g) were observed in patients with graft loss (p < .03, vs. surviving grafts). Significantly higher DSA-mean fluorescence intensity (MFI) values were present in patients with graft loss (p = .0012, vs. surviving grafts).

Conclusions: Patients with preformed DSAs exhibited worse graft outcomes in living donor liver transplantation. Higher DSA-MFI values and smaller graft size were associated with worse outcomes in LCT-positive patients. High-risk patients with preformed DSAs should be considered for appropriate graft selection and application of a desensitization protocol.