Persistent alanine aminotransferase elevations in children with parenteral nutrition-associated liver disease

Background: Parenteral nutrition-associated liver disease (PNALD) is a serious condition affecting many children with short bowel syndrome. The aim of this study was to longitudinally assess serum alanine aminotransferase (ALT), a marker for hepatocyte injury, in enterally fed children with PNALD. Methods: Retrospective chart review of 31 patients treated from 1999 to 2006 by the Center for Advanced Intestinal Rehabilitation at Children's Hospital Boston (Mass). Inclusion criteria included PN duration of greater than 3 months with subsequent tolerance of full enteral nutrition and evidence of PN-associated liver injury. Time to normalize ALT and direct bilirubin were estimated using Kaplan-Meier and Cox proportional hazards methods. Results: Mean age PN cessation was 6 months (range, 2-14 months). Median PN duration was 18 weeks (interquartile range [IQR], 13-33 weeks), and median follow-up was 24 weeks (IQR, 14-48 weeks). After transition to full enteral nutrition, 74% of children normalized direct bilirubin, whereas only 50% normalized ALT. Kaplan-Meier median time to direct bilirubin and ALT normalization were 13 weeks and 35 weeks, respectively (P = .001). Conclusion: Children with PNALD who have achieved PN independence have persistent ALT elevation despite normal direct bilirubin levels. This implies that hepatic injury may be ongoing beyond the time of bilirubin normalization in this cohort of patients.