Abstract
An 82-year-old female was referred to our hospital because of low-grade fever, anemia, and rapidly progressive nephritic syndrome. Her laboratory data showed mild proteinuria, mild renal failure, and the presence of myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibody. A skin biopsy specimen taken from the erythematous purpura revealed neutrophilic infiltration around the blood vessels with fibrinoid changes in the vessel walls. A renal biopsy specimen revealed segmental necrotizing glomerulonephritis with fibro-cellular crescent formation without deposits of immunoglobulin or complement components, indicating microscopic polyangiitis. The use of corticosteroid treatment, including intravenous methylprednisolone, improved renal failure. After 4 years with low-dose maintenance corticosteroid therapy, she developed de novo acute hepatitis B, and entecavir was remarkably effective, showing a rapid recovery from liver dysfunction with jaundice. To prevent hepatitis B virus (HBV) reactivation and de novo acute hepatitis B induced by immunosuppressive or cytotoxic therapy, including corticosteroids alone, the measurement of HBV-related serological markers needs to be performed prior to the initiation of such therapy, even in renal diseases.