A serum metabolomic analysis of HCV-infected patients successfully treated with IFN-free DAA regimens

HCV infects about 170 million of subjects worldwide. The virus has a high propensity to persist in the host, leading to cirrhosis and liver cancer. Metabolomics is the study of metabolic changes in biological systems and may identify specific profiles associated with subtle alterations induced by diseases. Few studies are available on metabolitic changes in liver injuries, and since none of which was focused on HCV-infected patients before and after reaching a SVR following treatment with direct acting antivirals (DAAs), the aim of this study was to perform a serum metabolomics analysis in this setting Sera were collected from 52 HCV patients (18 men, mean age 65±9,7) successfully undergoing different IFN-free DAA regimens, before therapy (baseline) and at post-treatment week 12 (SVR12). HCV genotype was 1a/1b in 70%, 2a/2c in 23%, 3 in 4.7% and 4 in 2.3%. METAVIR score indicated F3-F4 score in 55% of patients, the remaining 45% had F0-F2 We also analyzed a small group of 12 sera from healthy subjects in order to localize them in the PLS plot respect to baseline and SVR12 as a preliminary negative control for both groups. Samples were analyzed using proton nuclear magnetic resonance spectroscopy (1H-NMR). Partial Least Squares (PLS) and the canonical analysis (CA) were applied, demonstrating a significant pair-wise discrimination (96% of accuracy) for the two time-points of each patient and highlighting a metabolic shift Several metabolites with unequivocal assignment (i e amino acids, organic acids, creatine, creatinine, lactate and choline) differed comparing baseline with SVR12. Baseline featured higher level of formate and acetate (p<0.05) and methionine was higher in SVR12 (p<0.05). Preliminary analysis revealed also a progressive nearing of SVR12 to the healthy fingerprint. The serum metabolomic analysis of pre- and post-treatment samples showed remarkable profile changes from baseline to SVR12. We found variations, with opposite directions, in formate (produced in adults only by hepatocytes) and methionine. These metabolites take part in biochemical ways (i e glucose metabolism) also involving acetate and other amino acids, going through the synthesis of folates These alterations could be implied in the metabolic impairment previously observed in chronically infected HCV-patients. Also, since methionine is the major source of methyl groups, an understanding of its variation, could reveal important dysfunctions in liver essential pathways requiring methylation (i e epigenetic regulation of DNA) in HCV-related chronic infection.