Objective: To characterize the clinical and histologic features of chronic hepatitis C virus (HCV) infection after blood transfusion in Japanese children.
Study design: We studied 231 children with a history of blood product transfusion. Patients were divided into two groups: 116 patients with a history of malignant disease (group 1), 115 patients who had undergone open heart surgery (group 2). We examined changes in serum alanine aminotransferase (ALT) activity and HCV markers, and patients' clinical course. Moreover, in 38 patients in whom the time of HCV infection could be defined, we examined liver histology.
Results: The proportions of patients in each group who were anti-HCV-positive were 35 out of 116 (30%) and 20 out of 115 (17%), respectively. Of the anti-HCV-positive patients, the proportions of HCV RNA-positive patients in each group were 30 out of 35 (86%) and 12 out of 20 (60%), respectively. Levels of ALT activity in patients with HCV infection varied widely for several years after blood transfusion; thereafter ALT activity fell to <100 IU/L in 2 groups. Serum ALT activity in patients who were HCV RNA-negative became normal. With regard to liver histology, there were no differences in the grade of necroinflammation or stage of fibrosis in patients with different durations of infection or when patients were analyzed according to the presence or absence of malignant disease. Patients mostly had grade 2-4 inflammation and stage 1-2 fibrosis. Thus, chronic hepatitis C was a morphologically mild disease in most children in this study.
Conclusions: Sixty percent to 80% of children with HCV infection in this study developed chronic hepatitis C. However, examination of liver histology findings in children with chronic hepatitis C showed only mild changes.