Reactivation of hepatitis B virus in two chronic GVHD patients after transplant.

We report two cases of hepatitis B virus reactivation following allogeneic bone marrow transplantation (BMT) for severe aplastic anemia and acute myelocytic leukemia. The presence of antibodies to HBsAg, HBeAg and HBcAg prior to transplant indicated previous infection with hepatitis B virus (HBV). These antibodies disappeared 2 and 4 months after the onset of chronic graft versus host disease (GVHD) following immunosuppressive treatment, but HBsAg reappeared in their sera 6 and 10 months later, respectively. This suggests that chronic GVHD and immunosuppressive drugs can reactivate HBV in HBsAb-positive patients, most likely because of the decrease in quality and function of helper T cells and B cells during chronic GVHD to induce clearance of HBV antibodies and reactivation of HBV. Our observation confirms that patients with HBsAb, HBeAb and HBcAb present in their sera should not be considered to have 'immunity' to HBV after BMT.