Aim: We aimed to investigate the use of serum quantitative hepatitis B surface antigen (qHBsAg) and cytokeratin 18 (CK18) levels as noninvasive markers to differentiate inactive HBsAg carriers from hepatitis B e-antigen (HBeAg) negative chronic hepatitis B (CHB) patients.

Methods: Sixty randomly selected treatment-naive patients with CHB and 25 healthy volunteers as control group were included in the study. Virological, serological and biochemical test results were assessed. Levels of M30 antigen which is the active form of CK18 were measured by M30-Apoptosense enzyme linked immunosorbent assays (ELISA). Liver biopsy specimens were assessed according to the modified Ishak scoring.

Results: Forty-eight (56.5%) participants were female. There was no significant difference between three groups in terms of age, gender, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin (T.Bil), direct bilirubin (D.Bil), prothrombin time (PT), international normalized ratio (INR), alfa-fetoprotein (AFP) and CK18 values. HBVDNA and qHBsAg levels were found to be significantly lower in inactive carriers compared with HbeAg-negative chronic HBV patients. The diagnostic efficacy of CK18 in differentiating inactive carriers from HbeAg-negative CHB patients was not statistically significant.

Conclusion: In conclusion, when used along with HBVDNA, qHBsAg may be an important parameter to differentiate inactive HBsAg carriers from HbeAg-negative chronic HBV patients. However, as one of the parameters targeted in this study, serum CK18 levels can not be used as a noninvasive marker.

Keywords: Cytokeratin 18, hepatitis B, non-invasive markers