Infection with the delta agent in chronic HBsAg carriers

To establish the mechanism of progression to chronicity of the HB(s)Ag-associated δ infection, serum hepatitis B virus and δ markers were tested in five babies born to HB(s)Ag-positive mothers with anti-δ, in 42 follow-up patients with acute hepatitis B virus and δ hepatitis, and in collections of sera from 8 HB(s)Ag carriers with anti-δ. Evidence of δ infection was found in the baby born to a mother with serum Hb(e)Ag and in none of the four babies born to mothers with anti-HB(e). Hepatitis was self-limited in the 42 patients acutely infected by hepatitis B virus and δ agent; none developed persistent HB(s)-antigenemia and the majority displayed transient anti-δ of IgM class. In seven HB(s)Ag carriers high titers of anti-δ developed during the follow-up; coincident with the rise of the antibody, aminotransferase elevation occurred in five previously asymptomatic carriers and persisted in three of them. No sign of infectious hepatitis B virus replication was detected in five of the carriers throughout the follow-up, and all of them had anti-HB(e) before the rise of anti-δ and of aminotransferase. HB(s)Ag carriers with diminished hepatitis B virus synthesis appear to be at high risk of developing chronic δ infection and disease when exposed to the δ-infectious serum of other carriers.