Non-invasive prediction of NAFLD severity: a comprehensive, independent validation of previously postulate serum microRNA biomarkers

Liver biopsy is currently the only reliable method to establish non‐alcoholic fatty liver disease (NAFLD) severity. However, this technique is invasive and occasionally associated with severe complications. Thus, non‐invasive diagnostic markers for NAFLD are needed. Former studies have postulated 18 different serum biomarker microRNAs with altered levels in NAFLD patients. In this study, we have re‐examined the predictive value of these serum microRNAs and found that only 6 of them (miR‐34a, ‐192, ‐27b, ‐122, ‐197 and ‐30c) are validated in our independent cohort as biomarkers associated with NAFLD severity. Among them, miR‐192, ‐27b and ‐122 are abundantly expressed in liver and confidently detected in serum, and display strong correlations with transaminases. The classification performance of validated miRNAs (and their ratios) for patients with non‐alcoholic steatohepatitis (NASH) is similar to that reached by AST, whereas for advanced fibrosis prediction, the miR‐27b/‐197 ratio demonstrated a good performance and an excellent sensitivity and, along with the FIB‐4 index, may constitute a potent non‐invasive predictive tool. 8 patients classified in SAF1 and SAF2 groups. SAF1 as control and SAF2 as case