Immunofluorescence Detection of Hepatitis B Core Antigen in Formalin Fixed or Frozen Sections of Liver Biopsies from Chronic Hepatitis B Patients

Hepatitis B virus (HBV) infection and its liver related complications are a substantial health concern in the Asia-Pacific region. Health interventions and implementation of vaccine programs have substantially reduced the incidence of HBV infections, however, large proportion of individual remains chronically infected and the disease status of the patients has to be evaluated before initiation of antiviral therapy and during follow-up. The immunostaining of HBcAg have proven useful in the characterization of CHB patients from Bangladesh, specifically in HBeAg-negative CHB patients, usually difficult to differentiate from inactive carriers. The present study was undertaken to detect hepatitis B core antigen (HBcAg) in chronic hepatitis B patients (CHB) and to compare indirect immunofluorescence (IIF) from formalin fixed paraffin block with frozen section of normal saline preparation. Study patients were grouped into HBeAg positive and negative category and HBcAg was detected by using polyclonal rabbit anti HBcAg. Out of 70 study patients 8 (11.4%) had HBeAg positive serology and 62 (88.57%) were HBeAg negative. Among 8 HBeAg positive group all were positive (100%) for core antigen by IIF. Among 62 HBeAg negative patients 55 (88.7%) were positive for core antigen and 7 (11.29%) were negative by IIF. Comparison between frozen section and formalin fixed paraffin block preparation for IIF test for the detection of HBV core antigen from 30 subjects showed, out of 26 HBeAg negative cases 22 (84.62%) were positive for HBcAg by both procedures. Among the 4 HBeAg positive cases all 4 (100%) patients were positive for core antigen by both the procedures. In conclusion, our results suggest that formalin fixed tissues can be effectively used to detect HBcAg expression in hepatocytes of CHB patients, as compared to the frozen section of liver tissues, providing additional benefits in the case of studying previously analyzed biopsies and considering the limitations to obtain such biological samples.