Methods to improve the noninvasive diagnosis and assessment of disease severity in children with suspected nonalcoholic fatty liver disease (NAFLD): Study design.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity and is the most common liver disease in the developed world. In children with suspected NAFLD, present guidelines suggest consideration of alternative diagnoses via extensive blood testing, though the yield of this work up is unknown. Furthermore, the gold standard diagnostic test for NAFLD remains liver biopsy, making the development of non-invasive tests critically important. OBJECTIVES: Our objectives are: 1) to determine the accuracy of elastography and multiple serum biomarkers - each assessed individually and as algorithms (including those previously tested in adults) - for the diagnosis of nonalcoholic steatohepatitis (NASH) and early fibrosis in children and (2) to examine the utility of extensive testing for rare alternative diagnoses in overweight or obese children with elevated alanine aminotransferase (ALT) suspected to have NAFLD. DESIGN: This is an ongoing, cross-sectional study in children 2-18 years of age with up to 2 years of prospective follow up. Eligible patients are asymptomatic, overweight or obese, and have an ALT ≥35 U/L upon enrollment. Two forms of elastography are obtained serially along with anthropometric data and routine laboratory tests. Elastography and serum biomarkers are also performed immediately prior to any clinically-indicated biopsy. METHODS: Between April 2015 and April 2018, 193 children have been enrolled in this ongoing study and 71 have undergone liver biopsy. Here we carefully report the rationale, methodology, and preliminary data for this study.