Tissue expression of the hepatitis C virus NS3 protein does not correlate with histological or clinical features in patients with chronic hepatitis C.

Background: In chronic hepatitis B, the HBcAg viral protein in liver tissue demonstrates a positive correlation with serum aminotransferase levels, serum hepatitis B viral DNA, and histological activities. Little is known if similar relationships exist for chronic hepatitis C. This study attempted to determine if expression of the hepatocyte NS3 protein of the hepatitis C virus (HCV-NS3) was correlated with the serum HCV-RNA load, hepatitis activity, or other clinical parameters.

Methods: Clinical and histological data of 214 patients with chronic hepatitis C were retrospectively reviewed. A mouse monoclonal antibody was used to detect HCV-NS3 in hepatocytes. The staining intensity was scored semiquantitatively as 0~3+, and its correlations with the serum HCV-RNA load, hepatitis activity, and other clinical parameters were analyzed.

Results: In total, 202 (94%) of the 214 liver biopsies were positive for HCV-NS3, and the intensity of HCV-NS3 staining was 0 in 12 (6%), 1+ in 181 (84%), and 2+ in 21 patients (10%). The intensity of HCV-NS3 expression in the samples did not correlate with patient age (p = 0.302, ANOVA), patient gender (p = 0.130, Fisher's exact test), the alanine transaminase level (p = 0.177, ANOVA), serum HCV-RNA level (p = 0.305, ANOVA), HCV antibody titer (p = 0.139, Chi-squared test), hepatitis activity index score (p = 0.861, Chisquared test), or sustained viral response rate (p = 0.861, Chi-squared test).

Conclusions: This HCV-NS3 immunohistochemical staining method was reliable for detecting HCV in liver specimens. Hepatocyte expression of HCV-NS3 was not correlated with the serum viral load, severity of hepatic injury, or treatment response.