Alternative Etiologies of Liver Disease in Children With Suspected NAFLD.

Objectives: To determine the prevalence of alternative causes of liver disease in a cohort of youth with overweight and obesity undergoing evaluation for suspected nonalcoholic fatty liver disease (NAFLD).

Methods: Multicenter, retrospective cohort study of patients aged ≤18 years with overweight and obesity and evidence of elevated serum aminotransferases and/or hepatic steatosis on imaging, referred for suspected NAFLD to Cincinnati Children's Hospital Medical Center (2009-2017) or Yale New Haven Children's Hospital (2012-2017). Testing was performed to exclude the following: autoimmune hepatitis (AIH), Wilson disease, viral hepatitis (B and C), thyroid dysfunction, celiac disease, α-1 antitrypsin deficiency, and hemochromatosis.

Results: A total of 900 children with overweight and obesity (63% boys, 26% Hispanic ethnicity) were referred, with a median age of 13 years (range: 2-18). Most had severe obesity ( = 666; 76%) with a median BMI score of 2.45 (interquartile range [IQR]: 2.2-2.7). Median alanine aminotransferase level at presentation was 64 U/L (IQR: 42-95). A clinically indicated liver biopsy was performed in 358 children (40%) at a median of 6 months (IQR: 1-14) post initial visit; of those, 46% had confirmed nonalcoholic steatohepatitis. Positive autoantibodies were observed in 13% of the cohort, but none met criteria for AIH. Only 19 (2%) were found to have other causes of liver disease, with no cases of viral hepatitis or Wilson disease detected.

Conclusions: In a large, multicenter cohort, the vast majority of children with overweight and obesity with presumed or confirmed NAFLD tested negative for other causes of liver disease. In contrast to a previous pediatric report, no patient was diagnosed with AIH.