Pantoprazole and perinuclear antineutrophil cytoplasmic antibody-associated vasculitis

Systemic vasculitis may, at times, be drug-induced and associated with antineutrophil cytoplasmic antibodies (ANCA). However, pantoprazole, a commonly used and well-tolerated proton pump inhibitor, has not previously been reported to cause ANCA-associated syndromes. We describe a patient who developed interstitial nephritis, cutaneous vasculitis, a perinuclear ANCA staining pattern (pANCA) on immunofluorescence, and anti-myeloperoxidase antibodies (MPO-ANCA) in association with pantoprazole. We review various immune-mediated syndromes reported in association with proton pump inhibitors, including one report of omeprazole associated with interstitial nephritis and the development of ANCA.