Background: Chronic hepatitis C genotypes 3 and 1 are the two most common genotypes in Thailand.
Objective: Identify the pathologically different features between genotypes 3 and 1and to compare the fibrosis score of Knodell HAI and Ishak modified HAI.
Material and method: The pathological features of 114 liver biopsies were evaluated.
Results: Steatosis was more commonly found in genotype 3 than in genotype 1 (97.1% vs. 77.8%, p = 0.001). Portal lymphoid follicles were commonly found, but bile duct damage was uncommon. The majority of portal tracts showed partial involvement. The majority of patients had Knodell fibrosis 1 and Ishak fibrosis 3.
Conclusion: Steatosis is significantly more common in genotype 3, while other features do not show any differences. The portal tracts show partial involvement because inflammatory cells tend to aggregate and form lymphoid follicles. The most comparable fibrosis scores are Knodell fibrosis 1 and Ishak fibrosis 3.

Keywords: Steatosis, Pathology, HCV