Does Drug Induced ANCA Associated Vasculitis occur?
• Yes, drug-induced AAV has been reported with medications for hyperthyroidism ( propylthiouracil, methimazole, carbimazole), hydralazine, minocycline, and levamisole-cut cocaine (in addition to other less common offending medications).
• Frequently high-titer MPO-ANCA, much less commonly PR3-ANCA.
• Patients with drug-induced AAV present with constitutional symptoms, arthralgias with occasional synovitis, and cutaneous vasculitis.
• Serious end-organ manifestations, including necrotizing GN and alveolar hemorrhage, occur less frequently.
• Hydralazine is the most common medication-induced AAV. Patients can develop a pauci-immune GN and DAH. Wide-ranging immunologic abnormalities can be seen: high-titer ANA and p-ANCA antibody, anti-MPO antibody, anti-histone and double-stranded DNA antibody, and hypocomplementemia. Thus, features of drug-induced lupus may be present, but renal pathology demonstrates a pauci-immune GN.
• AAV secondary to levamisole-adulterated cocaine may be associated with antibodies against PR3, MPO, and human neutrophil elastase that are simultaneously positive. Additional laboratory findings have been described including antiphospholipid antibodies and cold agglutinins that may contribute to skin necrosis. In addition, levamisole can frequently be associated with leukopenia (28%) due to bone marrow suppression. Common clinical features include retiform purpura (occasionally progressing to necrosis), arthralgias, and constitutional symptoms such as fever, night sweats, and weight loss. Necrotizing GN and alveolar hemorrhage have also been described.
• Minocycline-induced AAV frequently has elevated liver enzymes.
• Treatment involves withholding the offending drug. More serious cases require systemic GC and cytotoxic agents.
