Background: Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in children and can progress to liver cirrhosis during childhood. Patients with more advanced fibrosis on biopsy tend to have more liver complications. Noninvasive hepatic fibrosis scores have been developed for adult patients with NAFLD; however, these scores have not been validated in children. The aim of our study was to evaluate some of these scores in assessing the presence of fibrosis in children with biopsy-proven NAFLD.

Methods: Our study consisted of 92 biopsy-proven NAFLD children from five major US centers. Fibrosis was determined by an experienced pathologist (F0-4). Clinically significant fibrosis was defined as fibrosis stage ≥ 2, and advanced fibrosis was defined as F3-4. The following fibrosis scores were calculated for each child: AST/ALT ratio, AST/platelet ratio index (APRI), NAFLD fibrosis score (NFS), and FIB-4 index. ROC was performed to assess the performance of different scores for prediction of presence of any, significant, or advanced fibrosis. A p value < 0.05 was considered statistically significant.

Results: Mean age was 13.3 ± 3 years, and 33 % were females. Eleven (12 %) subjects had no fibrosis, 35 (38 %) had fibrosis score of 1, 26 (28 %) had fibrosis score of 2, and 20 (22 %) had a score of 3. APRI had a fair diagnostic accuracy for the presence of any fibrosis (AUC of 0.80) and poor diagnostic accuracy for significant or advanced fibrosis. AST/ALT, NFS, and FIB-4 index all either had poor diagnostic accuracy or failed to diagnose the presence of any, significant, or advanced fibrosis.

Conclusion: Noninvasive hepatic fibrosis scores developed in adults had poor performance in diagnosing significant fibrosis in children with NAFLD. Our results highlight the urgent need to develop a reliable pediatric fibrosis score.