[Exploring potential serum metabolite markers of intrahepatic cholestasis based on liquid chromatography-mass...

Objective: To analyze the blood differential metabolites of patients with intrahepatic cholestasis (IHC) by liquid chromatography-mass spectrometry metabolomics technology so as to find potential metabolic target. Method: Serum samples were collected from thirty patients with intrahepatic cholestasis and thirty healthy individuals after metabolomics analysis. The differential metabolites were initially screened based on the multiple differences and significance. KEGG enrichment analysis was performed on the differential metabolites to determine the candidate targets. The potential clinical application value of these characteristic metabolites was analyzed using the receiver operating characteristic curve. Result: A total of thirty patients with intrahepatic cholestasis and thirty healthy adults were included. The age difference between the two groups was not statistically significant (P>0.05). The clinical condition was consistent with the statistically significant differences in liver biochemical indicators, blood routine, coagulation, and inflammatory indicators between the two groups (P<0.05). Furthermore, a blood metabolomics screening analysis revealed 99 differentially expressed metabolites associated with intrahepatic cholestasis. Of these, 15 showed statistically significant differences. Glucose, lipid, and energy metabolisms were the various primary types of differential metabolites involved. The receiver operating characteristic curve>0.9 included the following twelve kinds of metabolites: 1H-indole-3-carboxaldehyde, 6-hydroxy-1H-indole-3-acetamide, phenylalanyl tryptophan, 1-methylguanosine, 2-ethoxy-5-methylpyrazine, p-hydroxybenzaldehyde, 5-(2-chlorophenyl)-3,4-dihydro-2H-pyrrole, methylthioadenosine, alanylisoleucine, anabsinthin, N-acetyl-DL-histidine monohydrate, N-methylnicotinamide, and others. The fifteen metabolites that were previously identified and calculated according to the differential quantitative value of the metabolite corresponding ratio exhibited fold-changes in the upregulated and downregulated potential biomarkers (phenylalanine tryptophan, phenylalanine, 5'-methylthioadenosine, anabsinthin, and N-methylnicotinamide) in combination with the area under the receiver operating characteristic curve>0.9. Conclusion: Phenylalanyl tryptophan, phenylalanylalanine, 5'-methylthioadenosine, anabsinthin, and N-methylnicotinamide may serve as potential metabolic markers to distinguish patients with cholestasis from healthy controls. N-methylnicotinamide, among them, is of great importance as a potential marker.