Impact of early immunosuppression on pediatric liver transplant outcomes within 1 year

Objectives The Starzl Network for Excellence in Pediatric Transplantation identified optimizing immunosuppression (IS) as a priority practice improvement area for patients, families, and providers. We aimed to evaluate associations between clinical characteristics, early IS, and outcomes. Methods We analyzed pediatric liver transplant (LT) data from 2013 to 2018 in the United Network for Organ Sharing (UNOS) and the Society of Pediatric Liver Transplantation (SPLIT) registries. Results We included 2542 LT recipients in UNOS and 1590 in SPLIT. IS choice varied between centers with steroid induction and mycophenolate mofetil (MMF) use each ranging from 0% to 100% across centers. Clinical characteristics associated with early IS choice were inconsistent between the two data sets. T‐cell depleting antibody use was associated with improved 1‐year graft (hazard ratio [HR] 0.50, 95% confidence interval [CI] 0.34−0.76) and patient (HR 0.40, 95% CI 0.20−0.79) survival in UNOS but decreased 1‐year patient survival (HR 4.12, 95% CI 1.31−12.93) and increased acute rejection (HR 1.58, 95% CI 1.07−2.34) in SPLIT. Non‐T‐cell depleting antibody use was not associated with differential risk of survival nor rejection. MMF use was associated with improved 1‐year graft survival (HR 0.73, 95% CI 0.54−0.99) in UNOS only. Conclusions Variation exists in center choice of early IS regimen. UNOS and SPLIT data provide conflicting associations between IS and outcomes in multivariable analysis. These results highlight the need for future multicenter collaborative work to identify evidence‐based IS best practices. What is Known Immunosuppression (IS) plays a critical role in the success of pediatric liver transplant (LT). No best‐practice guidelines exist for early IS in pediatric LT. What is New IS choice largely depends on the transplant center as much as individual patient characteristics. Currently available retrospective data provide conflicting associations between early IS choice and outcomes.