In some cases of chronic hepatitis C (CHC), it is possible to observe the characteristic histopathological features in liver biopsy specimens stained with conventional methods. However, characteristic histopathological findings are not always present and there is a need to establish the diagnosis with immunohistochemical methods. This study aims to investigate the specificity of immunohistochemical HCV antigen expression and its correlation with the histological activity of hepatitis.
Immunohistochemical expression of HCV antigen was investigated by using the monoclonal TORDJI-22 antigen (Biogenex), in conventionally processed liver biopsy specimens of 121 cases with serologically proved CHC. Histological activity of chronic hepatitis was assessed by grading of portal inflammation, bile duct injury, interface hepatitis, activation of sinusoidal inflammatory cells, focal necrosis, steatosis and accumulation of iron, and scoring of fibrosis. Cytoplasmic granular HCV antigen expression was detected in 45 out of 121 cases (37.19 %), and specificity and sensitivity values were 92% and 54%, respectively. Although the correlation between the immunohistochemical expression of HCV antigen and histological activity of chronic hepatitis was not statistically significant (p:0.059), cases with immunohistochemical HCV antigen positivity were found to be at a more advanced stage.
In conclusion our results suggest that positivity of monoclonal TORDJI-22 antibody in liver tissue alone is not sufficient to establish the diagnosis of CHC, and HCV antigen expression is not related with the histological activity of hepatitis.