Plasma and stool metabolomic biomarkers of non-alcoholic fatty liver disease (nafld) in Argentina

Abstract

Non-invasive biomarkers are urgently needed to identify NAFLD patients at risk of progression to non-alcoholic steatohepatitis (NASH), particularly in high prevalence areas such as Latin America. Thus, we aimed to identify potential metabolomic biomarkers related to NAFLD stage in Argentina, and to assess their relationship with clinical and host genetic factors.Healthy volunteers (n=19) and biopsy-proven simple steatosis (n=12) or non-alcoholic steatohepatitis (n=22) patients with similar food intake data were recruited. Plasma and stool samples, as well as demographic and clinical data were collected. SNP rs738409 (PNPLA3 gene) was determined in all volunteers. HPLC and flow injection analysis with MS/MS in tandem was applied for metabolomic studies using the MxP Quant 500 Kit (Biocrates Life Sciences AG, Austria) and MetaboAnalyst v4.0. Bivariate and multivariate analyses identified variables independently related to NAFLD stage. Forward stepwise logistic regression models were constructed to diagnose NAFLD and NASH. ROC curves were used to evaluate models? accuracy.The concentration of 33 out of the 424 detected metabolites (25 in plasma and 8 in stool) significantly differed among groups. Levels of triglycerides (TG) were higher among NAFLD patients, whereas levels of phosphatidylcholines (PC) and lysoPC were lower among them. The PNPLA3 risk genotype was related to higher plasma levels of eicosenoic acid FA(20:1) (p<0.001). Plasma metabolites showed a higher accuracy for diagnosis of NAFLD and NASH (AUROC=1) than stool metabolites (AUROC=0.79 and 0.90, respectively). Body mass index and plasma levels of PC aa C24:0, FA(20:1) and TG(16:1_34:1) showed high accuracy for diagnosis of NAFLD (AUROC=1); whereas plasma levels of PC aa C24:0 and PC ae C40:1 showed AUROC=1 for discriminating NAFLD stages.In conclusion, potential metabolomic biomarkers for diagnosis and progression of NAFLD were identified in Argentina. Further validation studies are needed.