Effect of recipient gender and donor-specific antibodies on antibody-mediated rejection after heart transplantation

Gender-difference regarding antibody-mediated rejection (AMR) after heart transplantation has been described. However, no study accounted for the presence of preformed donor-specific antibodies (pfDSA), a known risk factor of AMR, more common among women than men. In a single-institution 6-year cohort (2010-2015), time to AMR was assessed, comparing men with women by survival analysis with a 1-year death-censored follow-up. All AMRs were biopsy proven. Confounding variables that were accounted for included mean intensity fluorescence (MFI) of pfDSA, recipient age, HLA-, size- and sex-mismatch. 463 patients were included. Overall incidence of AMR was 10.3% at 1 year. After adjusting for confounding variables, independent risk factors of AMR were female recipient gender (adjusted hazard-ratio [adj. HR] = 1.78 [1.06-2.99]), P = .03) and the presence of pfDSA (adj. HR = 3.20 [1.80-5.70], P < .001). This association remained significant when considering pfDSA by their MFI; female recipient gender had an adj. HR = 2.2 (P = .026) and MFI of pfDSA (per 1 MFI-increase) adj. HR = 1.0002 (P < .0001). In this cohort, women were at higher risk of AMR than men and this risk increase was additive to that of pfDSA. These findings may suggest a gender-related difference in the severity of pfDSA.