Metabolomic-Based Noninvasive Serum Test to Diagnose Nonalcoholic Steatohepatitis: Results From Discovery and Validation Cohorts

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the most common type of chronic liver disease worldwide and includes a broad spectrum of histologic phenotypes, ranging from simple hepatic steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). While liver biopsy is the reference gold standard for NAFLD diagnosis and staging, it has limitations due to its sampling variability, invasive nature, and high cost. Thus, there is a need for noninvasive biomarkers that are robust, reliable, and cost effective. In this study, we measured 540 lipids and amino acids in serum samples from biopsy-proven subjects with normal liver (NL), NAFL, and NASH. Using logistic regression analysis, we identified two panels of triglycerides that could first discriminate between NAFLD and NL and second between NASH and NAFL. These noninvasive tests were compared to blinded histology as a reference standard. We performed these tests in an original cohort of 467 patients with NAFLD (90 NL, 246 NAFL, and 131 NASH) that was subsequently validated in a separate cohort of 192 patients (7 NL, 109 NAFL, 76 NASH). The diagnostic performances of the validated tests showed an area under the receiver operating characteristic curve, sensitivity, and specificity of 0.88 +/- 0.05, 0.94, and 0.57, respectively, for the discrimination between NAFLD and NL and 0.79 +/- 0.04, 0.70, and 0.81, respectively, for the discrimination between NASH and NAFL. When the analysis was performed excluding patients with glucose levels >136 mg/dL, the area under the receiver operating characteristic curve for the discrimination between NASH and NAFL increased to 0.81 +/- 0.04 with sensitivity and specificity of 0.73 and 0.80, respectively. Conclusion: The assessed noninvasive lipidomic serum tests distinguish between NAFLD and NL and between NASH and NAFL with high accuracy.Supported by the National Institutes of Health Blueprint for Neuroscience Research (R01AT001576 to S.C.L., J.M.M.), Agencia Estatal de Investigacion of the Ministerio de Economia, Industria y Competitividad (SAF2014-52097R to J.M.M.), CIBER Hepatic and Digestive Diseases and Instituto de Salud Carlos III (PIE14/0003 to J.M.M.), Etorgai 2015-Gobierno Vasco (ER-2015/00015 to R.M., I.M.A., C.A., A.C.), Plan de Promocion de la Innovacion 2015-Diputacion Foral de Bizkaia (6/12/IN/2015/00131 to A.C., C.A.), National Institute of Diabetes and Digestive and Kidney Diseases (RO1DK81410 to A.J.S.), and Czech Ministry of Health (RVO VFN64165 to L.V.)