Metabolic profile of chronic liver disease by NMR spectroscopy of human biopsies

Among the different processes occurring during the evolution of liver disease, fibrosis has a predominant role. Liver fibrosis mechanisms are fairly constant irrespective of the underlying etiology. Cirrhosis is the end-stage of this reaction. Metabolic profiles, which are affected by many physiological and pathological processes, may provide further insight into the metabolic consequences of this severe liver disease. The aim of this study was to demonstrate the applicability of 1H high resolution magic angle spinning (HR-MAS) NMR spectroscopy in the biochemical profile determination of human liver needle biopsy samples for the characterization of metabolic alterations related to the severity of liver disease. We recorded and analyzed HR-MAS spectra of 68 liver tissue samples obtained by needle biopsy from patients with chronic liver disease. Multivariate analysis was applied to these data to obtain discrimination patterns and to reveal relevant metabolites. The metabolic characterization of liver tissue from needle biopsies by HR-MAS NMR spectroscopy provided differential patterns for cirrhotic and non-cirrhotic chronic liver disease tissue. Metabolites closely related to the liver metabolism such as some fatty acids, glucose and amino acids show differences between the two groups. Phospholipid precursors, which have been previously correlated with hepatic lesions also show differences. Furthermore, the correlation between histologically assessed liver disease stages and the levels of the most discriminative metabolites show that liver dysfunction is present at the initial stages of chronic hepatic lesions. Overall, this work suggests that the additional information obtained by NMR metabolomics applied to needle biopsies of human liver may be useful for assessing metabolic alterations and liver dysfunction in chronic liver disease.