Metabolite Profiling Analysis of HBV-induced Liver Cirrhosis Patients Who Have Minimal Hepatic Encephalopathy Using GC-TOFMS and UPLC-QTOFMS.

OBJECTIVE: To analyze the serum metabolite profiling of HBV-induced liver cirrhosis patients who have MHE, to seek out the specific biomarkers of MHE, to reveal the pathogenesis of MHE and to explore a promising approach for early diagnosis of MHE by using GC-TOFMS and UPLC-QTOFMS metabonomic analytical techniques in combination with bioinformatics and pattern recognition analysis methods.

METHOD: Sera samples of 100 normal controls (NC group), 29 cases of HBV-induced liver cirrhosis patients who have MHE (MHE group) and 24 cases of HBV-induced liver cirrhosis patients without MHE (including 12 cases of compensated cirrhosis (CS group) and 12 cases of decompensated cirrhosis (DS group)) were collected and employed into GC-TOFMS and UPLC-QTOFMS platforms for sera metabolites detection, the outcome data were then analyzed by principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA).

RESULTS: There were no significant differential metabolites between the NC group and the CS group. A series of key differential metabolites were detected. According to the VIP values and P-values, 60 small-molecule metabolites were considered to be dysregulated in the MHE group (compared to the NC group); 27 of these 60 dysregulated differential metabolites were considered to be the potential biomarkers (see Table 4, marked in bold). 66 small-molecule metabolites were considered to be dysregulated in the DS group (compared to the NC group); 34 of these 66 dysregulated differential metabolites were considered to be the potential biomarkers (see Table 5, marked in bold). According to the fold change values, 9 of these 27 metabolites were down-regulated in MHE group (compared to the NC group), including Valine, Oxalic Acid, Erythro-sphingosine, 4,7,10,13,16,19-docosahexaenoic Acid, Isoleucine, Allo-isoleucine, Thyroxine, Rac-Octanoyl Carnitine, Tocopherol (vitamin E); the other 18 were up-regulated, including Adenine, Glycochenodeoxycholic Acid, Fucose, Allothreonine, Glycohyocholic Acid, Glycoursodeoxycholic Acid, Tyrosine, Taurocheno-deoxycholate, Phenylalanine, 2-hydroxy-3-methyl-butanoic Acid, Hydroxyacetic Acid, Taurocholate, Sorbitol, Rhamnose, Tauroursodeoxycholate, Tolbutamide, Pyroglutamic acid and Malic Acid. 6 of these 34 metabolites were down-regulated in DS group (compared to the NC group), the other 28 were up-regulated, as shown on table 5.

CONCLUSION: (1) GC-TOFMS and UPLC-QTOFMS metabonomic analytical platforms can detect a range of metabolites in the serum; this might be of great help to explore the pathogenesis of MHE and may provide a new approach for the early diagnosis of MHE. (2) Metabonomics analysis in combination with pattern recognition analysis might have great potential to distinguish the HBV-induced liver cirrhosis patients who have MHE from the normal healthy population and HBV-induced liver cirrhosis patients without MHE.