Diagnostic accuracy of fibrosis tests in children with Non-Alcoholic Fatty Liver Disease (NAFLD): a systematic review.

Background and aims Non-Alcoholic Fatty Liver disease (NAFLD) has become the most common chronic liver disease in children. Even at young age it can progress to liver fibrosis. Given the drawbacks of liver biopsy, there is a need for non-invasive methods to accurately stage liver fibrosis in this age group. In this systematic review we evaluate the diagnostic accuracy of non-invasive methods for staging liver fibrosis in children with NAFLD. Methods We searched MEDLINE, Embase, Web of Science and the Cochrane Library, for studies that evaluated the performance of a blood-based biomarker, prediction score, or imaging technique in staging liver fibrosis in children with NAFLD, using liver biopsy as the reference standard. Results Twenty studies with a total of 1787 NAFLD subjects were included, that evaluated three prediction scores, five simple biomarkers, two combined biomarkers and six imaging techniques. Most studies lacked validation. Substantial heterogeneity of studies and limited available study data precluded a meta-analysis of the few fibrosis tests evaluated in more than one study. The most consistent accuracy data were found for transient elastography by FibroScan®, ELF test and ultrasound elastography, with an area under the receiver operating characteristics curve varying between 0.92 and 1.00 for detecting significant fibrosis. Conclusion Due to the lack of validation, the accuracy and clinical utility of non-invasive fibrosis tests in children with NAFLD remains uncertain. As studies have solely been performed in tertiary care settings, accuracy data cannot directly be translated to screening populations.