Reactivation of hepatitis B virus infection in two patients: immunofluorescence studies of liver tissue.

Two patients, 1 with chronic active hepatitis, the other with Goodpasture's syndrome, became HBsAg-positive after the start of immunosuppressive drug therapy. At the same time of presentation, sera contained anti-HBc antibodies of IgM and IgG class in the absence of HBsAg or anti-HBs and immunofluorescent studies of liver biopsy specimens showed core antigen in the nuclei of liver cells. It is suggested that these findings reflected an unusual pattern of hepatitis B virus infection with a very low level of viral replication and that the appearance of HBsAg in both serum and liver cells after immunosuppressive drug therapy was due to reactivation of this infection, possibly as a result of changes in levels of antibodies which suppress viral replication. In 1 patients, the change in viral replication was associated with continuing liver cell necrosis and progressive deterioration in liver functio