Association of HLA-mismatch with lung graft survival: A UNOS registry analysis

Results from a retrospective cohort study, evaluating the association between human leukocyte antigen (HLA) mismatch and graft survival, stratified by transplant indication, among 37,091 adult deceased-donor lung transplant recipients from the United Network for Organ Sharing (UNOS) registry, were published in the European Respiratory Journal by Otunla et al. The primary explanatory variable of interest was HLA mismatch at HLA-A, HLA-B, and HLA-DR. The primary outcome was graft survival at 5 years.  

Key data: In multivariate analysis, HLA-DR mismatch was associated with an increased risk of graft failure at 1 year (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.00–1.90; p = 0.048) and 5 years (HR, 1.20; 95% CI, 1.03–1.40; p = 0.02). In indication-specific analyses, overall HLA mismatch was associated with graft loss in chronic obstructive pulmonary disease (COPD) at 1 year (HR, 2.39; 95% CI, 1.05–5.44; p = 0.037), 5 years (HR, 1.49; 95% CI, 1.11–2.01; p = 0.008), and 10 years (HR, 1.36; 95% CI 1.08–1.70; p = 0.008). HLA-DR mismatch was associated with increased graft failure at 1 year in COPD (HR, 2.88; 95% CI, 1.34–6.19; p = 0.007) and at 5 years in interstitial pneumonia (HR, 1.28; 95% CI, 1.03–1.58; p = 0.026).  

Key learning: In this study, HLA-DR mismatch was associated with poorer lung graft survival in an indication-specific manner. These findings support indication-specific strategies for post-transplant surveillance and immunosuppression.