Plasma Levels of K18 Fragments Do Not Correlate with Alcoholic Liver Fibrosis

BACKGROUND/AIMS: Noninvasive markers of liver fibrosis in alcoholic liver disease (ALD) are crucial to establish early intervention. Previous studies have suggested that plasma levels of cleaved keratin-18 (K18; M30) fragments can predict the severity of liver disease. The aim of this study was to correlate plasma M30 levels with stages of liver fibrosis in ALD. METHODS: Patients with ALD (n=139, 79.1% males) and liver histology were included, and plasma samples were collected to quantify plasma M30 levels. Patients were stratified into five groups by fibrosis stage (F0=14; F1=15; F2=35; F3=17; and F4=58) according to the Kleiner score. Differences between groups were evaluated using the chi-square test or analysis of variance. Trends by fibrosis stage were calculated by logistic regression analysis, and sensitivity, specificity and positive and negative predictive values were determined. RESULTS: There were no significant differences in M30 levels among fibrosis stages. The correlation between plasma M30 levels and fibrosis was poor (Pearson’s correlation coefficient=0.13, Spearman rho=0.20 [p=0.02]), and M30 levels did not correlate with alcohol-specific histological features. However, significant correlations of M30 levels with aspartate aminotransferase (Spearman rho=0.653, p<0.001) and alanine aminotransferase (Spearman rho=0.432, p<0.001) were found. M30 levels of >200 U/L reveal a sensitivity for predicting cirrhosis of 84.5% with a negative predictive value of 73.5%. CONCLUSIONS: Plasma M30 levels are often elevated in ALD and correlate with serum transaminases but do not reflect fibrosis. The usefulness as a prognostic marker awaits evaluation in prospective studies.