Leukocytosis is Common Following Pediatric Liver Transplant for Biliary Atresia but Should be Interpreted with Caution

Infection is a leading cause of short-term morbidity and mortality in pediatric patients after liver transplant (LT). Diagnosing infection in this population can be challenging, requiring consideration of laboratory results and clinical context. The prevalence and significance of post-operative leukocytosis has not yet been explored in children after LT. Our goals were to characterize post-transplant leukocytosis in pediatric patients after LT for biliary atresia (BA) and evaluate the relationship between post-LT leukocytosis and infection. Retrospective review of patients aged 0-18 years who underwent LT between 2012-2022 for BA. Clinical data were extracted from electronic medical records. Infectious outcomes were characterized as organism-confirmed infection (OCI), presumed infection, and no apparent infection. Differences between groups were assessed using two-sample t-tests and Fisher’s Exact tests. 60 children met criteria for inclusion (mean age at LT 33.7 ± 50.9 months; 65% female). Forty-four (73.3%) had leukocytosis in the 14 days after transplant. There was no association between leukocytosis in general and OCI (p = 0.67) or presumed (p = 0.71) infection. Only leukocytosis >30,000/µL was associated with OCI (p = 0.008). Leukocytosis after LT for BA is common, although only white blood cell (WBC) count >30,000/µL was associated with organism-confirmed infection. This study is the first to describe the prevalence of leukocytosis in children after LT and emphasizes the importance of considering the multifactorial nature of leukocytosis when evaluating for and treating infections in this population.