Serum Phosphatidylcholine Species 32:0 as a Biomarker for Liver Cirrhosis Pre- and Post-Hepatitis C Virus Clearance

Abstract

Phosphatidylcholine (PC) is an essential lipid for liver health and lipoprotein metabolism, but its circulating levels have rarely been studied in patients with cirrhosis. Chronic hepatitis C virus (HCV) infection causes lipid abnormalities and is a major cause of cirrhosis. Effective HCV elimination with direct-acting antivirals (DAAs) is associated with the normalization of serum low-density lipoprotein cholesterol levels. Since PC is abundant in all lipoprotein particles, this study analyzed the association between serum PC species levels and liver cirrhosis before and after HCV eradication. Therefore, 27 PC species were measured by Fourier Transform Mass Spectrometry in the serum of 178 patients with chronic HCV infection at baseline and in 176 of these patients at the end of therapy. The PC species did not correlate with viral load, and the levels of 13 PC species were reduced in patients infected with genotype 3a compared to those affected with genotype 1. Four PC species were slightly elevated 12 weeks after DAA initiation, and genotype-related changes were largely normalized. Patients with HCV and cirrhosis had higher serum levels of PC 30:0 and 32:0 before and at the end of therapy. PC species containing polyunsaturated fatty acids were mostly decreased in cirrhosis. The levels of polyunsaturated, but not saturated, PC species were inversely correlated with the model of the end-stage liver disease score. A receiver operating characteristic curve analysis showed area under the curve values of 0.814 and 0.826 for PC 32:0 and 0.917 and 0.914 for % PC 32:0 (relative to the total PC levels) for the classification of cirrhosis at baseline and at the end of therapy, respectively. In conclusion, the specific upregulation of PC 32:0 in cirrhosis before and after therapy may be of diagnostic value in HCV-related cirrhosis.