Influence of donor-recipient sex mismatch on long-term survival of pancreatic grafts

To assess the role of sex mismatch on graft survival after pancreas transplantation. We evaluated 24,195 pancreas-transplant recipients reported in the Scientific Registry of Transplant Recipients over a 25-year period. Pancreatic graft survival (PGS) was analyzed according to donor-recipient sex pairing using Kaplan-Meier estimations. Hazard ratios were estimated using Cox proportional hazard models. A total of 14,187 male and 10,008 female recipients were included in final analyses. Mean follow-up was 8.3 +/- 5.7 years. In multivariate analyses, neither recipient sex nor donor sex was associated with pancreatic graft failure (PGF), but donor-recipient sex mismatch (regardless of recipient sex) was an independent predictor of PGS (HR, 1.09; 95% CI, 1.04-1.14; p < 0.001). Compared with M -> M sex-matched recipients in univariate analyses, M -> F and F -> M sex mismatches were associated with an increased risk of PGF. Adjustment for significant recipient and donor factors eliminated the association between F -> M sex mismatch and PGF (HR, 1.02; 95% CI, 0.93-1.10; p = 0.752), but not M -> F (1.09; 1.02-1.17; 0.020). Stratified analyses suggested that the negative effect of donor-recipient sex mismatch could be neutralized in older patients. These findings suggest that donor-recipient sex pairing should be taken into consideration in organ-allocation strategies.