Serum keratin‐18 detects hepatic inflammation and predicts progression in compensated alcohol‐associated liver disease

Abstract

Abstract Alcohol‐associated liver fibrosis accumulates over decades, driven by hepatic inflammation and cell death. We investigated the diagnostic accuracy of keratin‐18 degradation, measured using serum M30 and M65 levels, and the ActiTest for hepatic inflammatory activity in patients with compensated alcohol‐associated liver disease (ALD). Furthermore, we evaluated the prognostic accuracy of markers for liver‐related events and all‐cause mortality. All findings were compared with routine liver function tests: Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma‐glutamyltransferase. Our prospective, biopsy‐controlled, single‐center study included 265 patients with ongoing or prior excessive alcohol intake, representing the full spectrum of compensated ALD. We defined hepatic inflammatory activity as a combined score of lobular inflammation and ballooning. For severe hepatic inflammatory activity (n = 40), we found excellent diagnostic accuracy for M30 (area under the receiver operating characteristics curve [AUROC] = 0.90), M65 (AUROC = 0.86), and AST (AUROC = 0.86). Elevated M30 (M30 > 240 U/L) had the highest positive predictive value (PPV) and specificity, significantly higher than M65, ActiTest and ALT, but not AST (M30: sensitivity = 83%, specificity = 82%, positive predictive value = 45%, negative predictive value = 95%). Patients were followed up for 1445 patient‐years. All markers, except for ALT, significantly predicted liver‐related events and all‐cause mortality. After adjusting for advanced fibrosis, drinking behavior and body mass index, M30 and M65 remained significant predictors of liver‐related events, whereas M30 and AST were significant predictors of all‐cause mortality. Conclusion: M30 and AST accurately detect severe hepatic inflammatory activity in patients with compensated ALD. M30 was the only significant predictor of both liver‐related events and all‐cause mortality after adjusting for advanced fibrosis, body mass index, and drinking behavior at inclusion.