Oxidized low-density lipoprotein antibodies/high-density lipoprotein cholesterol ratio is linked to advanced non-alcoholic fatty liver disease lean patients

Abstract

Background and aim: A small but significant proportion of patients with normal body mass index show non-alcoholic fatty liver disease (NAFLD). Oxidized low-density lipoprotein (LDL) is a powerful immunogenic molecule, which causes oxidative stress and produces antibodies (oxLDL-ab). We aimed to analyze the role of oxLDL-ab on histological features in lean-NAFLD patients.

Methods: Seventy-two biopsy-proven NAFLD patients were included. Lean patients showed body index mass of <30 kg/m(2) . Liver biopsies were assessed by one pathologist blinded to clinical data. Histological features were non-alcoholic steatohepatitis (NASH), steatosis, hepatocellular ballooning, and liver fibrosis. Metabolic and hepatic profiles were analyzed, and lipid-lowering medication was recorded. OxLDL-ab levels were measured by ELISA. OxLDL-ab-based lipid indexes analyzed: oxLDL-ab/total cholesterol ratio; oxLDL-ab/LDL-c ratio; oxLDL-ab/high-density lipoprotein cholesterol (HDL-c) ratio; and oxLDL-ab/oxLDL ratio.

Results: Lean-NAFLD patients presented 26.5% (9/34) of NASH. OxLDL-ab/HDL-c ratio (r = 0.570; n = 34; P = 0.001) correlated with NAS score and was the only variable associated with NASH in the multivariate analysis [odds ratio, OR, 1.10 (95% confidence interval, CI: 1.01-1.21); P = 0.039]. Severe steatosis was present in 41.2% (14/34) of lean-NAFLD patients. OxLDL-ab/HDL-c ratio was higher in patients with grade-III steatosis (54.9 (37.3-124.6)) than those with grade II (37.1 (20.2-71.1)) and grade I (17.7 (13.1-22.8)) (P = 0.018). Hepatocellular ballooning was present in 20.6% (7/34) of lean-NAFLD patients, and OxLDL-ab/HDL-c ratio (OR 1.03 [95% CI: 1.01-1.05]; P = 0.050) was independently associated with histological features. OxLDL-ab/HDL-c ratio was higher in patients with advanced fibrosis (39.8 (22.9-121.6) vs 17.7 (13.9-30.9); P = 0.025), increasing gradually with the fibrosis stage (P = 0.042) and remained in the final multivariate model [OR 1.05 (95% CI: 1.00-1.11); P = 0.05]. However, in obese-NAFLD patients, oxLDL/HDL-c ratio was not associated with histological features.

Conclusions: Oxidized low-density lipoprotein antibodies/high-density lipoprotein cholesterol ratio could represent an interesting biomarker associated with NASH, hepatocellular ballooning, and liver fibrosis, in lean patients. OxLDL-ab/HDL-c could play an important role for distinguishing patients with and without NAFLD complications.

Keywords: HDL; NASH; fibrosis; inflammation; oxLDL-ab; steatosis.