Cytoplasmic-anti-neutrophil cytoplasmic antibodies targeting myeloperoxidase in Wegener's granulomatosis: A rare phenomenon.

Wegener’s granulomatosis (WG) patients can rarely have antineutrophil cytoplasmic antibodies (ANCAs) directed against myeloperoxidase (MPO), producing a cytoplasmic pattern on indirect immunofluorescence (IIF). This has important implications in the diagnosis and pathophysiology of the disease. We present to you a report of three cases of WG, demonstrating a cytoplasmic- ANCA pattern on indirect IIF, but directed against MPO. It is necessary to diagnose a patient taking into account both the autoimmune test results and the clinical features.