Seminars in respiratory and critical care medicine
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Antineutrophil cytoplasmic antibodies (ANCAs) are autoantibodies specific for antigens located in the cytoplasmic granules of neutrophils and lysosomes of monocytes. ANCAs are associated with a spectrum of necrotizing vasculitis that includes granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis. ⋯ In this review, we detail the factors that have been associated with the origin of the ANCA autoimmune response and summarize the most relevant clinical observations, in vitro evidence, and animal studies strongly indicating the pathogenic potential of ANCA. In addition, we describe the putative sequence of pathogenic mechanisms driven by ANCA-induced activation of neutrophils that result in small vessel necrotizing vasculitis and extravascular granulomatous necrotizing inflammation.
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AbstractThieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
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Semin Respir Crit Care Med · Aug 2018
ReviewAlveolar Hemorrhage in Vasculitis (Primary and Secondary).
Defined by the accumulation of red blood cells into the alveolar space, diffuse alveolar hemorrhage (DAH) is a severe and potentially fatal medical condition requiring careful attention. In contrast to simple extravasation of erythrocytes facilitated by impaired hemostasis or hemodynamic causes, DAH in vasculitis is due to capillaritis, that is, inflammation of capillaries. Dyspnea, hemoptysis, chest infiltrates, and abrupt fall of blood hemoglobin level represent the cardinal features of DAH; yet, hemoptysis is lacking in one-third of cases. ⋯ Early identification and removal of the putative drug is crucial in drug-induced vasculitis/DAH and may obviate the need for immunosuppressive therapy. High-dose corticosteroids, intravenous cyclophosphamide, and recently rituximab are the mainstay of treatment in vasculitis. Plasma exchange is recommended in anti-glomerular basement membrane disease and in severe DAH associated with systemic lupus erythematosus and is used in selected cases in ANCA-associated vasculitis.