Presence of neutrophil extracellular traps and antineutrophil cytoplasmic antibodies associated with vasculitides

Anti-neutrophil p-ANCA antibodies are directed against antigens in the peripheral cytoplasm of both neutrophilic granulocytes and monocytes. They are detected in several autoimmune disorders and are particularly associated with systemic vasculitis. We report a case of a 54-year-old female presenting with a pruritic rash, including purpura and diffuse erythema. A biopsy with hematoxylin and eosin (H & E) analysis, direct immunofluorescence (DIF), immunohistochemistry (IHC) and enzyme-linked immunosorbent assays for ANCAs were performed. The H & E staining demonstrated leukocytoclastic vasculitis, with focal vascular fibrinoid necrosis. The DIF revealed evidence of vasculitis, the presence of p-ANCAs and neutrophil extracellular traps (NETs). The IHC displayed autoreactivity to myeloperoxidase within the vessels. The IHC aided in ruling out any intrinsic autofluorescence of the vessels. By observing the deposition of neutrophil extracellular traps and myeloperoxidase in inflamed skin vessels, biopsy analysis may alert physicians for rapid therapeutic intervention in patients presenting with possible vasculitides.