Hydralazine-induced autoimmune disease: comparison to idiopathic lupus and ANCA-positive vasculitis.

We report two cases of hydralazine-induced vasculitis with rare complications: pulmonary renal syndrome and digital gangrene. We also review 68 published cases of hydralazine-induced vasculitis. Hydralazine-induced vasculitis mimics idiopathic antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. However, it also produces other autoantibodies, such as antinuclear antibodies, antihistone antibodies, anti-dsDNA antibodies, and antiphospholipid antibodies. Patients with hydralazine-induced vasculitis typically have a more severe course than those with hydralazine-induced lupus, predominantly due to renal vasculitis, and require a more aggressive treatment.