Plasma ALS and LG3BP predict liver fibrosis in NAFLD patients

Non-alcoholic fatty liver disease (NAFLD) is estimated to affect 25% of the world’s population and its prevalence is increasing with the rise in obesity. The evolution of this disease includes different pathological stages: steatosis, inflammation, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Liver biopsy stands as the gold standard for NAFLD assessment despite its invasive nature and limited performance. Liver fibrosis is the most important clinical parameter, as it is closely related to mortality, and biopsies are only considered when advanced fibrosis is suspected. This scenario makes the finding of a non-invasive and reliable biomarker an urgent need for an accurate diagnosis. To this end, we first performed a discovery study on 159 plasma samples from histologically characterised NAFLD patients using mass spectrometry (MS)-based quantitative proteomics. Insulin-like growth factor-binding protein complex acid labile (ALS, P35858) and Galectin-3-binding protein (LG3BP, Q08380) were selected for a verification by enzyme-linked immunosorbent assay (ELISA) in the same cohort and finally validated in an independent NAFLD cohort of 200 plasma samples.ALS and LG3BP were validated as advanced liver fibrosis biomarkers and successfully included in a panel with FibroTest variables. ELISA kits availability would allow to achieve relatively fast clinical translation if further investigations in larger cohorts confirm these results.