Limited value of plasma cytokeratin-18 as a biomarker for NASH and fibrosis in patients with non-alcoholic fatty liver disease

Background & Aims Liver biopsy is the only reliable way of diagnosing and staging NASH but its invasive nature limits its use. Plasma caspase-generated cytokeratin-18 fragments (CK-18) have been proposed as a non-invasive alternative. We studied its clinical value in a large multiethnic NAFLD population and examined its relationship to clinical/metabolic/histological parameters. Methods 424 middle-aged subjects in whom we measured adipose tissue, liver and muscle insulin resistance (IR), liver fat by MRS (n = 275) and histology (n = 318). Results Median CK-18 were elevated in patients with vs. without NAFLD by MRS (209 [IQR: 137–329] vs. 122 [IQR: 98–155] U/L) or with vs. without NASH (232 [IQR: 151–387] vs. 170 [IQR: 135–234] U/L, both p