A 42-year-old female who was an asymptomatic carrier of hepatitis B virus (HBV) was diagnosed with antineutrophil cytoplasm antibody- (
ANCA-) associated vasculitis and was induced to remission with 30 mg/day
prednisolone nine years ago. Four years ago, she suffered recurrence of
ANCA-associated vasculitis and with 30 mg/day
prednisolone was induced to remission. This time, laboratory data showed 3-fold increase in
myeloperoxidase antineutrophil cytoplasmic antibody (MPO-
ANCA) levels. Administration of 30 mg/day
prednisolone was started. Three days later, she was admitted to our hospital suffering from
fatigue. After admission, urinalysis showed glomerular
hematuria. Despite administration of 30 mg/day
prednisolone, MPO-
ANCA titer had been of high level, ranging from 42 to 83 EU for 2.5 months. Furthermore, the adverse effects of
steroid were seen. We decided the tapering of
prednisolone (25 mg/day) and the start of
mizoribine (4-carbamoyl-1-β-D-ribofuranosyl imidazolium-5-olate) administration. After
mizoribine treatment, MPO-
ANCA titer was decreased without any
mizoribine-related adverse effects. Six months later, MPO-
ANCA titer was decreased to normal levels and she was induced to clinical remission without reactivation of HBV. We describe the effectiveness of
mizoribine for the
ANCA-associated vasculitis complicated with HBV-carrier.