The pathology of hepatitis C as a function of mode of transmission: blood transfusion vs. intravenous drug use.

We reviewed the clinical records of 140 consecutively evaluated patients with chronic hepatitis C infection. One hundred twenty-four patients (89%) contracted infection through blood transfusion or intravenous drug use. The liver biopsy specimens of 83 patients (43 blood transfusion cases and 40 intravenous drug abuse cases) were examined without knowledge of the mode of disease transmission. The mean histological activity index score was significantly higher in the blood transfusion group (10.2 +/- 4.2) than in the intravenous drug use group (6.9 +/- 4.5) (p = 0.001). The transfusion group had more periportal bridging necrosis (p = 0.0015) and fibrosis (p = 0.0016) than did the intravenous drug use group, whereas significant differences between lobular degeneration and portal inflammation were not achieved across the two groups. The distribution of final biopsy interpretations also differed significantly between the two groups (p < 0.001), with chronic active hepatitis more frequent in the transfusion group. Moreover, lymphoid aggregates and bile duct damage were more common in patients with chronic hepatitis due to blood transfusion. Multivariate analysis showed that the mode of viral transmission was the most powerful predictor of histological activity index score when tested against patient gender, duration of disease or age at biopsy. One year after completion of this study, 9 of 70 transfused patients and 1 of 54 intravenous drug users had died of liver disease or are awaiting liver transplantation at this writing (p = 0.03). We conclude that transfusion-acquired hepatitis C is associated with more aggressive histological inflammatory activity than hepatitis resulting from intravenous drug use.(ABSTRACT TRUNCATED AT 250 WORDS)