Long-term impact of human leukocyte antigen mismatches combined with expanded criteria donor on allograft outcomes in deceased donor kidney transplantation.

The long-term impact of human leukocyte antigen (HLA) mismatches combined with expanded criteria donors (ECD) on clinical outcomes has not been fully evaluated in recipients of deceased donor (DD) kidney transplantations. Of 595 DD renal transplant recipients in our center between 1991 and 2011, 210 recipients (36%) had 0-3 HLA mismatches/standard criteria donor (SCD), 353 (59%) had 4-6 HLA mismatches/SCD or 0-3 HLA mismatches/ECD, and 32 (5%) had 4-6 HLA mismatches/ECD. The mortality rate was significantly highest in the patients with 4-6 HLA mismatches/ECD (p = 0.040). The most common cause of death in this group was infection (50%). There were no significant differences in overall graft survival and death-censored graft survival. The biopsy-proven acute rejection rate was significantly higher in the 4-6 HLA mismatches/ECD group (p = 0.011). Cox-regression multivariate analyses showed that 4-6 HLA mismatches plus ECD (adjusted hazard ratio [AHR], 3.2; 95% confidence interval [CI], 1.17-10.56) and diabetes (AHR, 4.3; 95% CI, 1.50-12.28) were significant predictors of recipient mortality. In conclusion, ≥4 HLA mismatches plus ECD were associated with significantly higher rates of biopsy-proven acute rejection and mortality compared with other groups undergoing DD kidney transplantation.