Apoptosis in chronic viral hepatitis parallels histological activity: An immunohistochemical investigation using anti‐activated caspase‐3 and M30 Cytodeath antibody

Abstract

Apoptosis is implicated as a major pathogenic mechanism in chronic hepatitis B and C. Previous studies of the relationship between apoptotic rates and histological necroinflammatory activity have produced conflicting results. Hepatocyte apoptosis was assessed in liver tissue from 32 cases of chronic viral hepatitis, seven cases of hepatocellular carcinoma (HCC) and six cases of steatohepatitis as non-viral disease controls and eight cases of control liver. Apoptotic rates were measured using H&E morphological assessment and immunohistochemical staining with antibodies to activated caspase-3 and M30. Histological necroinflammatory activity of viral hepatitis cases was scored using the Knodell scoring system, and the cases were divided according to their score into group 1 (mean 2.43 +/- 0.48) and group 2 (mean 7.80 +/- 0.49). Apoptotic indices were significantly higher in group 2 than group 1 using H&E (11.53 +/- 2.70 vs. 0 +/- 0, P=0.015) and activated caspase-3 (22.01 +/- 5.27 vs. 1.79 +/- 1.79, P=0.03) methods but were not significantly higher with M30 (3.80 +/- 1.74 vs. 0 +/- 0, P=0.207). Apoptotic scores using an antibody to activated caspase-3 are significantly higher in cases of chronic viral hepatitis with greater histological necroinflammatory scores, supporting a central role for apoptosis in disease pathogenesis. This method offers an alternative to routine histological assessment for measuring disease activity.