Influence of HLA Mismatching on Survival in Lung Transplantation

Background: Data on human leukocyte antigen (HLA) mismatching and survival after lung transplantation (LTx) are variable. Methods: The UNOS database was queried from 1987 to 2013 to examine survival associated with total HLA mismatch ≥3 and mismatches of 2 at A, B, and DR loci. Results: Of 23,528 first-time, adult LTx recipients, 23,384 were included in the univariate Cox analysis, 19,944 in the Kaplan–Meier survival function evaluation, and 16,224 in the multivariate Cox models. Adjusted models found that the total HLA mismatch ≥3 increased the mortality hazard [hazard ratio (HR) 1.214; 95 % confidence interval (95 % CI) 1.073, 1.374; p = 0.002]. Both HLA-A (HR 1.070; 95 % CI 1.023, 1.119; p = 0.003) and HLA-DR (HR 1.053; 95 % CI 1.007, 1.101; p = 0.024) were associated with increased mortality risk, but HLA-B (HR 1.006; 95 % CI 0.958, 1.056; p = 0.805) was not. Older age, higher creatinine, and higher body mass index were associated with increased risk for death. More recent lung transplant and longer ischemic time were associated with reduced mortality risk. Induction with basiliximab at time of transplant was beneficial by significantly decreasing the risk of death (HR 0.846; 95 % CI 0.786, 0.909; p < 0.001). Conclusions: HLA mismatching is associated with increased hazard risk for death after LTx, while induction with basiliximab and other factors related to LTx reduce the risk.