Association of Human Leukocyte Antigen Donor–Recipient Matching and Pediatric Heart Transplant Graft Survival

Abstract

Background— The effect of donor–recipient human leukocyte antigen (HLA) matching on outcomes remains relatively unexplored in pediatric patients. The objective of this study was to investigate the effects of donor–recipient HLA matching on graft survival in pediatric heart transplantation. Methods and Results— The UNOS (United Network for Organ Sharing) database was queried for heart transplants occurring between October 31, 1987, and December 31, 2012, in a recipient aged ≤17 years with ≥1 postoperative follow-up visit. Retransplants were excluded. Transplants were divided into 3 donor–recipient matching groups: no HLA matches (HLA-no), 1 or 2 HLA matches (HLA-low), and 3 to 6 HLA matches (HLA-high). Primary outcome was graft loss. Four thousand four hundred seventy-one heart transplants met the study inclusion criteria. High degree of donor–recipient HLA matching occurred infrequently: HLA-high (n=269; 6%) versus HLA-low (n=2683; 60%) versus HLA-no (n=1495; 34%). There were no differences between HLA matching groups in the frequency of coronary vasculopathy ( P =0.19) or rejection in the first post-transplant year ( P =0.76). Improved graft survival was associated with a greater degree of HLA donor–recipient matching: HLA-high median survival, 17.1 (95% confidence interval, 14.0–20.2) years; HLA-low median survival, 14.2 (13.1–15.4) years; and HLA-no median survival, 12.1 (10.9–13.3 years) years; P <0.01, log-rank test. In Cox-regression analysis, HLA matching was independently associated with decreased graft loss: HLA-low versus HLA-no hazard ratio, 0.86 (95% confidence interval, 0.74–0.99), P =0.04; HLA-high versus HLA-no, 0.62 (95% confidence interval, 0.43–0.90), P <0.01. Conclusions— Decreased graft loss in pediatric heart transplantation was associated with a higher degree of donor–recipient HLA matching, although a difference in the frequency of early rejection or development of coronary artery vasculopathy was not seen.