Utility of Metabolomic Biomarkers to Identify Nonalcoholic Fatty Liver Disease in Liver Transplant Recipients

Background. Nonalcoholic fatty liver disease (NAFLD) is a rising indication for liver transplantation (LT). Identification of NAFLD recurrence and those at risk for more progressive disease after LT remains elusive as the diagnosis requires biopsy, which is invasive and impractical for serial monitoring. We therefore aimed to identify metabolites in the blood associated with recurrent NAFLD that could potentially be used for detection and monitoring. Methods. This cross-sectional pilot study included 37 LT recipients who underwent simultaneous liver biopsy and plasma collection for metabolomic analysis. Metabolic profiles were compared between patients with recurrent NAFLD, normal liver (negative control), and acute rejection (rejection control). Results. Univariate analysis revealed 14 metabolites that were significantly altered in patients with recurrence of NAFLD compared with negative controls and 19 compared with rejection controls (P<0.05). In addition, metabolomic profiling identified 16 metabolites that distinguished nonalcoholic fatty liver versus nonalcoholic steatohepatitis. Metabolite class trends among patients with recurrent NAFLD following LT were consistent with prior metabolomics data in patients with NAFLD in the non-LT setting. Conclusions. In conclusion, we identified candidate metabolites that could be used in the clinical setting to noninvasively identify recurrent NAFLD and differentiate NAFL from the more progressive nonalcoholic steatohepatitis. Further investigation with a larger sample size is warranted to validate these results.