Chronic hepatitis B surface antigen-negative hepatitis after treatment of malignancy.

We reviewed the records of all patients with a diagnosis of malignancy who were treated at our center and who had not had chemotherapy for at least 18 months, to assess the prevalence of chronic hepatitis B surface antigen (HBsAg)-negative hepatitis, to assess the prevalence of a marker of hepatitis C virus infection, and to determine the severity of chronic liver disease. Of 557 eligible patients, 38 (6.8%) had chronic HBsAg-negative hepatitis. Of these 38 patients, 20 (52.6%) had a marker of hepatitis C virus infection. The prevalence of chronic HBsAg-negative hepatitis was higher in patients previously treated for leukemia than in patients treated for another malignancy (11.8% vs 4.6%; p = 0.004). The liver biopsy revealed chronic active hepatitis or cirrhosis or both in 8 (28%) of 28 patients with clinical chronic HBsAg-negative hepatitis. Four patients without hepatitis C virus infection who underwent liver biopsy had hepatitis B virus antigen in the liver, confirmed by immunohistochemistry studies. One patient uninfected with hepatitis C virus had hemochromatosis. We conclude that infection with hepatitis C virus was the major cause of chronic HBsAg-negative hepatitis in pediatric patients previously treated for malignancy; the cause remained unidentified in 30% of the patients.