Pulmonary involvement in microscopic polyangiitis

Abstract

The pulmonary manifestations of microscopic polyangiitis are diverse and often difficult to manage; however, as our understanding and experience grows so does our ability to successfully diagnose and treat these patients.

Pulmonary fibrosis presenting as an early manifestation of microscopic polyangiitis

“…MPA is also a prime cause of the pulmonary-renal syndrome resulting in two major consistent pathologic features: focal segmental necrotising glomerulonephritis and pulmonary capillaritis [2,3]. Other manifestations include cutaneous vasculitis, peripheral neuropathy, musculoskeletal involvement, diarrhea and gastrointestinal bleeding and in a few cases sinusitis.…”

“…The second is that ANCA antigens such as MPO undergo translocation to the surface of neutrophils (possibly in response to proinflammatory cytokines), and subsequent binding of circulating ANCA results in neutrophil degranulation and the release of reactive oxygen species, causing injury and consequent fibrosis. In this setting, fibrosis could represent a reparative response to the underlying chronic lung injury [3,7].…”

“…Lung involvement is present in 25-55% of patients. Diffuse alveolar hemorrhage caused by pulmonary capillaritis is the most common manifestation of respiratory involvement presenting clinically with dyspnea, hemoptysis, cough, pleuritic chest pain and anemia [2,3]. Pulmonary fibrosis is a rarely reported clinical feature and can be seen months to years prior to, at the time of, or years after the diagnosis of MPA [1,4].…”

Microscopic Polyangiitis Causing Diffuse Alveolar Hemorrhage and Rapidly Progressive Glomerulonephritis

“…Our patient responded to the initial treatment with steroids, immunosuppressant, and plasmapheresis, which is the standard of care (1)(2)(3)(4)(5)(6)(7)(8). Th e combination of oral cyclophosphamide and methylprednisolone induces remission in about 80% to 90% of patients with ANCA-associated vasculitis, with about 75% experiencing complete remission and most remissions occurring between 2 and 6 months.…”

Microscopic Polyangiitis

“…[6,14,30] The classic pulmonary manifestation of MPA is diffuse alveolar hemorrhage caused by pulmonary capillaritis, which has been reported in 12-55% of patients. [37][38][39] Common presenting symptoms of alveolar hemorrhage include dyspnea, cough, hemoptysis, and pleuritic chest pain. [40] In patients with alveolar hemorrhage, chest radiographs show patchy, bilateral airspace opacities, usually involving both the upper and lower lung fields.…”