Relationship between liver injury and serum cytokeratin 18 levels in asymptomatic hepatitis B virus carriers and in patients with chronic hepatitis B infection.

BACKGROUND AND STUDY AIMS: Apoptosis represents a well-known mechanism of cell death involved in most chronic liver injuries. Our aim was to investigate the serum fragment level of cytokeratin 18 (CK18), M30, in asymptomatic hepatitis B virus (HBV) carriers and patients with chronic hepatitis B (CHB) and to evaluate the relationship between serum M30 levels and the severity of hepatic injury. PATIENTS AND METHODS: Asymptomatic HBV carriers (n=169), patients with CHB (n=100), and healthy control subjects (n=43) were enrolled in the study. Serum CK18 (M30) levels were analysed in all subjects. Liver biopsy for histopathological assessment was performed in asymptomatic HBV carriers and in patients with CHB infection. RESULTS: Serum CK18 (M30) levels were significantly higher in asymptomatic HBV carriers (198.77±77.62U/L) than in healthy control subjects (146.92±40.18U/L). Patients with CHB (283.02±147.45U/L) had significantly higher CK18 (M30) levels than asymptomatic HBV carriers (p=0.001). The diagnostic efficacy of CK18 (M30) levels in distinguishing patients with HBeAg-negative CHB from asymptomatic HBV carriers was found to be moderate (c-statistics: 0.695), and the diagnostic cut-off value of CK18 (M30) was 262U/L (specificity: 85%, sensitivity: 48%, positive likelihood ratio: 3.35, and negative likelihood ratio: 0.60). There was a positive correlation between serum CK18 (M30) levels and histological activity index scores in asymptomatic HBV carriers and patients with CHB. CONCLUSIONS: Serum CK18 (M30) levels may be a valuable indicator in distinguishing asymptomatic HBV carriers from patients with HBeAg-negative CHB when considered together with ALT and HBV-DNA levels.