Gender differences in the risk for chronic renal allograft failure

Background, Despite the known differences in immunological reactivity betwe en males and females, no differences in graft survival have been described among renal transplant recipients with regard to gender. To address this pa radox, we analyzed data from 73,477 primary renal transplants collected in the US Renal Data System database. Methods. Logistic regression and Cox proportional hazard models were used t o investigate the primary study end points, graft loss secondary to acute r ejection (AR) or chronic allograft failure (CAF), CAF was defined as graft loss beyond 6 months, not attributable to death, recurrent disease, acute r ejection, thrombosis, infection, noncompliance, or technical problems. The models adjusted for 15 covariates including immunosuppressive regimen, and donor and recipient characteristics. Results. The overall 8-year graft and patient survivals were significantly better in female renal transplant recipients compared with male recipients. However graft survival censored for death was not significantly different by gender. By multivariate analysis, females had a 10% increased odds of AR (OR=1.10, CI 1.02-1.12), but conversely a 10% lower risk of graft loss sec ondary to CAF (RR=0.9, CI 0.85-0.96). The risk for CAF increased significan tly with increasing age for both males and females, but this effect was gre ater for males than for females (P<0.001). Conclusion. Although female renal transplant recipients have a similar deat h censored graft survival compared with males, there are important differen ces in immunological behavior. Females have a higher risk of AR while havin g a decreased risk of graft loss secondary to CAF.