Serum metabolomic profiling in acute alcoholic hepatitis identifies multiple dysregulated pathways

Background and Objectives While animal studies have implicated derangements of global energy homeostasis in the pathogenesis of acute alcoholic hepatitis (AAH), the relevance of these findings to the development of human AAH remains unclear. Using global, unbiased serum metabolomics analysis, we sought to characterize alterations in metabolic pathways associated with severe AAH and identify potential biomarkers for disease prognosis. Methods This prospective, case-control study design included 25 patients with severe AAH and 25 ambulatory patients with alcoholic cirrhosis. Serum samples were collected within 24 hours of the index clinical encounter. Global, unbiased metabolomics profiling was performed. Patients were followed for 180 days after enrollment to determine survival. Results Levels of 234 biochemicals were altered in subjects with severe AAH. Random-forest analysis, principal component analysis, and integrated hierarchical clustering methods demonstrated that metabolomics profiles separated the two cohorts with 100% accuracy. Severe AAH was associated with enhanced triglyceride lipolysis, impaired mitochondrial fatty acid beta oxidation, and upregulated omega oxidation. Low levels of multiple lysolipids and related metabolites suggested decreased plasma membrane remodeling in severe AAH. While most measured bile acids were increased in severe AAH, low deoxycholate and glycodeoxycholate levels indicated intestinal dysbiosis. Several changes in substrate utilization for energy homeostasis were identified in severe AAH, including increased glucose consumption by the pentose phosphate pathway, altered tricarboxylic acid (TCA) cycle activity, and enhanced peptide catabolism. Finally, altered levels of small molecules related to glutathione metabolism and antioxidant vitamin depletion were observed in patients with severe AAH. Univariable logistic regression revealed 15 metabolites associated with 180-day survival in severe AAH. Conclusion Severe AAH is characterized by a distinct metabolic phenotype spanning multiple pathways. Metabolomics profiling revealed a panel of biomarkers for disease prognosis, and future studies are planned to validate these findings in larger cohorts of patients with severe AAH.This study was funded by Grant 5K08AA017622 from the National Institutes of Health and a University of Pittsburgh Medical Center Pilot Grant to JB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Multivariate logistic regression for predictors of weight loss (N = 924).

<p>Abbreviations: AOR, Adjusted odds ratio; CI, confidence interval; BMI, body mass index.</p><p>Multivariate logistic regression for predictors of weight loss (N = 924).</p

Univariate logistic regression for predictors of weight loss (N = 924).

<p>Abbreviations: OR, odds ratio; CI, confidence interval; BMI, body mass index.</p><p>Univariate logistic regression for predictors of weight loss (N = 924).</p

Demographics and clinical characteristics of the study population (N = 924).

<p>Values presented as *mean ± SD or ^†N (%) or median(ICR).</p><p>Demographics and clinical characteristics of the study population (N = 924).</p

Percent change in body weight at the end of the study period relative to the initial weight.

<p>Patients with final body weight within 5% of their initial weight were included in the “No change” group. N = 924 for the entire cohort.</p