Liver Biopsy

Liver biopsy is not necessary for diagnosis but is helpful for grading the severity of disease and staging the degree of fibrosis and permanent architectural damage. Hematoxylin and eosin stains and Masson’s trichrome stain are used to grade the amount of necrosis and inflammation and to stage the degree of fibrosis. Specific immunohistochemical stains for HCV have not been developed for routine use. Liver biopsy is also helpful in ruling out other causes of liver disease, such as alcoholic liver injury, nonalcoholic fatty liver disease, or iron overload.
HCV causes the following changes in liver tissue:

• Necrosis and inflammation at the edge of the portal areas, so-called “piecemeal necrosis” or “interface hepatitis”
• Necrosis of hepatocytes and focal inflammation in the liver parenchyma
• Inflammatory cells in the portal areas (“portal inflammation”)
• Fibrosis may exist in an early stage, being confined to the portal tracts, an intermediate stage consisting of expansion of the portal tracts and bridging between portal areas or to the central area, or a late stage of frank cirrhosis characterized by architectural disruption of the liver with fibrosis and regeneration. Several scales are used to stage fibrosis. One common classification is a scale from 0 to 4 where stage 0 indicates no fibrosis; stage 1 indicates enlargement of the portal areas by fibrosis; stage 2 indicates fibrosis extending out from the portal areas with rare bridges between portal areas; stage 3 indicates many bridges of fibrosis that link up portal and central areas of the liver; and stage 4 indicates cirrhosis.

By assigning scores for severity, grading and staging of hepatitis are helpful in managing patients with chronic hepatitis. The degree of inflammation and necrosis can be assessed as none, minimal, mild, moderate, or severe. The degree of fibrosis can be similarly assessed. Scoring systems are particularly helpful in clinical studies on chronic hepatitis.