Concomitant drug- and infection-induced antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis with multispecific ANCA.

OBJECTIVE To report the first case of concomitant drug- and infection-induced antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) in a patient treated with propylthiouracil (PTU) and suffering from tuberculosis. PRESENTATION AND INTERVENTION A 28-year-old woman with PTU-treated hyperthyroidism presented with fever, purpura, pulmonary cavitations and ANCA to myeloperoxidase, bactericidal/permeability-increasing protein (BPI), proteinase-3 and elastase. Skin histopathology confirmed vasculitis. However, sputum examination revealed Mycobacterium tuberculosis. Remission was achieved after PTU withdrawal and treatment with antituberculosis drugs. CONCLUSION Our case confirmed that BPI-ANCA are elevated in active tuberculosis. Multispecific ANCA were helpful for the diagnosis of concomitant PTU- and M. tuberculosis-induced AAV.