Delta infection and liver disease in hemophilic carriers of hepatitis B surface antigen.

The prevalence of infection with hepatitis B virus (HBV)-associated delta (delta) agent was assessed in 277 treated hemophiliacs (primarily adolescents and adults) and 24 treated hemophilic children. Hemophiliacs who carry hepatitis B surface antigen (HBsAg) are at high risk of delta infection. Antibody to delta (anti-delta) was found in 14 (49%) of 29 HBsAg-positive adult or adolescent hemophiliacs and four (25%) of 16 HBsAg-positive hemophilic children; it was identified in none of the patients without serologic evidence of exposure to HBV and only occasionally and in low titers in hemophiliacs convalescent from HBV infection. Either histologic or biochemical evidence of chronic hepatitis was found in 10 (56%) of 18 HBsAg-positive hemophiliacs with anti-delta. In two patients with anti-delta a potentially pathogenic role for delta was suggested by the intrahepatic expression of delta antigen, detected by immunofluorescence. It appears that delta infection is a major cause of chronic liver disease in hemophiliacs.