Are serum quantitative hepatitis b surface antigen levels, liver histopathology and viral loads related in chronic hepatitis b-infected patients?

Background/Aims: Fluctuations in hepatitis B virus (HBV) DNA and alanine transaminase (ALT) levels complicate assessment of the phases of chronic hepatitis B (CHB) infection and correct identification of the inactive HBV carrier state. In this study, we aimed to examine the role of HBsAg quantification (qHBsAg) in the identification of the phases of HBV and to evaluate its association with liver histopathology. Patients and Methods: Inactive HBV carriers (IC) (n = 104) and CHB patients (n = 100) were enrolled in the study. Demographic characteristics of patients were evaluated; biochemical parameters and serum qHBsAg levels were studied, and liver biopsy and histopathology were assessed. Results: Serum qHBsAg levels were found to be significantly low in IC (5150.78 ± 8473.16 IU/mL) compared with the HBeAg-negative CHB (7503.21 ± 8101.41 IU/mL) (P = 0.001) patients. The diagnostic accuracy of qHBsAg to differentiate HBeAg-negative CHB from IC was found to be moderate (c-statistic: 0.695) and the cutoff level for qHBsAg in diagnosis was found as 1625 IU/mL (specificity: 80%; sensitivity: 49%). No correlation was noted between serum qHBsAg level and ALT, histologic activity index (HAI), and fibrosis in IC and CHB. A moderate and positive correlation was observed between the serum qHBsAg level and HBV-DNA in HBeAg-positive CHB patients. Conclusions: Serum qHBsAg levels may prove to be useful in the differentiation between IC and HBeAg-negative CHB when used in conjunction with HBV DNA. Furthermore, patients diagnosed solely on the basis of HBV DNA and ALT may present with higher grade and stage of liver histopathology than expected.