Antineutrophilic cytoplasmic antibody-positive systemic vasculitis associated with propylthiouracil therapy: report of 2 children with Graves' disease.

Systemic vasculitis is a rare complication of therapy with antithyroid medication. Antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis has been described in patients treated with propylthiouracil (PTU) and methimazole (MMI). The majority of cases have underlying Graves' disease. The authors report 2 children who developed ANCA-associated systemic vasculitis during PTU therapy of Graves' disease. One patient, after PTU treatment for 3 years, developed severe systemic vasculitis. After 3 weeks of arthritis, she abruptly presented with hematuria, proteinuria and edema concomitant with anemia. Her serum creatinine was elevated, to 6 mg/dl. Renal biopsy revealed crescentic glomerulonephritis. After admission, she developed intracerebral hemorrhage and pulmonary hemorrhage. She had positive perinuclear-ANCA (p-ANCA) with a titer of 1:160. Despite intensive therapy with immunosuppressive agents and plasmapheresis, as well as discontinuation of PTU, she died of the complications of severe systemic vasculitis. The other patient developed fever, arthralgia and leukocytoclastic vasculitis of the skin during treatment with PTU for about 2 years. Her symptoms and skin lesions disappeared after discontinuation of PTU. However, she has had a persistently high titer of p-ANCA 1:320 through 17 months follow-up time. Thus, patients who are treated with PTU can develop ANCA-positive vasculitis in a mild or severe form. Therefore, they should be carefully followed and monitored, not only for their thyroid status but also the serious complications of PTU.