OxNASH score correlates with histologic features and severity of nonalcoholic fatty liver disease

Oxidative stress is a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). By employing a highly sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) approach we recently were able to define the circulating profile of bioactive lipid peroxidation products characteristic of patients with nonalcoholic steatohepatitis (NASH) and developed the OxNASH score for NASH diagnosis. The aims of this study were to assess the utility of OxNASH as a predictor of NASH and study the association between OxNASH and specific histologic features of NAFLD.

Our cohort consisted of 122 patients undergoing liver biopsy for clinical suspicion of NAFLD. The NAFLD activity score (NAS) was calculated for each patient. Levels of fatty acid oxidation products were quantified using stable isotope dilution LC/MS/MS, and OxNASH was calculated.

The mean age of our patients was 49.3 (±11.6) years, and the mean body mass index was 31.5 (±4.8) kg/m(2). The majority of patients were Caucasian (82 %) and 48 % were female. OxNASH correlated with NAS and with the individual histologic features of NAFLD, namely, steatosis, inflammation, and ballooning (P < 0.05), with the strongest association being with inflammation [rho (ρ) 0.40, 95 % confidence interval 0.23, 0.57, P < 0.001]. There was also a correlation between the stage of fibrosis and OxNASH (P = 0.001). These associations remained statistically significant after adjustment for multiple confounders.

Based on our results, in adult patients with NAFLD, OxNASH correlates with histologic features of NASH and appears to be a promising noninvasive marker.