Anti-thyroid drug-induced ANCA-associated vasculitis: a case report and review of the literature.

We report a case of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis induced by propylthiouracil (PTU), and review the literature concerning to anti-thyroid drug-induced ANCA-associated vasculitis. A 45-year-old man treated with PTU developed fever and arthralgia without pulmonary, skin or eye involvement. These symptoms persisted for a long period without specific symptom, sign or laboratory data of other arthritis. Laboratory findings of urine and blood were normal, except for positive MPO-ANCA (191EU) and PR3-ANCA (37EU) findings. After PTU was discontinued without steroids or immune modulating drugs, both symptoms disappeared. Our patient had a high titer of MPO-ANCA. Moreover, titers of ANCA fell in correlation with the course of symptoms after the cessation of PTU, and we diagnosed PTU-induced ANCA-associated vasculitis. Most patients with pulmonary renal syndrome receive anti-thyroid drugs over a prolonged period, but the duration of our case was shorter than those of these patients. It is suggested that our patient was diagnosed at an early stage of ANCA-associated vasculitis before the start of pulmonary or renal involvement.