Preformed donor-specific class II DQ antibodies are associated with graft loss after liver transplantation: A...

The aim of this study was to assess whether preformed donor-specific human leukocyte antigen antibodies (DSAs) are associated with graft loss after liver transplantation. We conducted a prospective multicenter study at 4 liver transplant centers. Presence of preformed donor-specific antibodies was analyzed using a single-antigen bead assay and a virtual crossmatch unknown to clinicians at a central laboratory. Graft survival was assessed using Kaplan-Meier analysis and Cox regression during a 2-year follow-up. Class I DSAs were observed in 106 of 832 patients (13%) and showed no association with graft loss. Class II DSAs were detected in 131 of 831 patients (16%), and DQ in 79 (10%). Class II DQ subtype was the only independent predictor of graft loss (adjusted hazard ratio 2.0, 95% confidence interval [CI]: 1.1-3.6, P = .02) with a 2-year graft loss rate of 23% (95% CI: 15%-34%) compared to 10% (95% CI: 8%-12%) without class II DSAs and 7% (95% CI: 2%-20%) for DR-specific antibodies (log-rank P = .002). Mean fluorescence intensity was not independently associated with graft loss after adjustment for DQ status. Preformed class II DQ DSAs are independently associated with an increased risk of graft loss even at low mean fluorescence intensity.