Human leukocyte antigen mismatching and survival after lung transplantation in adult and pediatric patients with cystic fibrosis

Introduction The influence of human leukocyte antigen (HLA) mismatching on survival in adult and pediatric patients with cystic fibrosis (CF) after lung transplantation (LTx) is unknown. Methods The United Network for Organ Sharing database was queried from 1987 to 2013 to determine the influence of HLA mismatching on survival in adult and pediatric CF LTx recipients by assessing the association of HLA mismatching with survival in first-time adult (aged ≥ 18 years) and pediatric (aged <18 years) recipients. Results Of 3149 adult and 489 pediatric patients with CF, 3145 and 489 were used for univariate Cox analysis, 2687 and 363 for Kaplan-Meier survival analysis, and 2073 and 257 for multivariate Cox analysis, respectively. Univariate analyses in adult and pediatric patients with CF demonstrated conflicting associations between HLA mismatching and survival (adult hazard ratio [HR], 1.0; 95% confidence interval [CI], 0.97-1.1; P =.45 vs pediatric HR, 0.87; 95% CI, 0.77-0.99; P =.032). Multivariate Cox models including both pediatric and adult patients confirmed that HLA mismatching had an initially protective effect at young ages (HR, 0.85; 95% CI, 0.73-0.99; P =.044) and that this protective effect diminished at older ages and was no longer associated with survival at P <.05 beyond age 10 years. Conclusions HLA mismatching has significantly different implications for survival after LTx in adult compared with pediatric patients with CF.