TY - CHAP M1 - Book, Section TI - Chapter 33. Microscopic Polyangiitis A1 - Duvuru, Geetha A1 - Stone, John H. A2 - Imboden, John B. A2 - Hellmann, David B. A2 - Stone, John H. Y1 - 2013 N1 - T2 - CURRENT Diagnosis & Treatment: Rheumatology, 3e AB - Microscopic polyangiitis (MPA) is the most common cause of the pulmonary-renal syndrome of alveolar hemorrhage and glomerulonephritis.Usually includes combinations of two or more of the following:Nonspecific constitutional symptoms, including fatigue, myalgias, weight loss, and fevers.Migratory arthralgias or arthritis, either pauciarticular or polyarticular.Palpable purpura, sometimes with skin ulcerations.Sensorimotor mononeuritis multiplex.Alveolar hemorrhage associated with hemoptysis and respiratory compromise.Glomerulonephritis.Antineutrophil cytoplasmic antibodies (ANCAs) are often critical in making the diagnosis, but a significant minority of patients are ANCA-negative.The majority of patients with MPA who are ANCA positive have antibodies directed against myeloperoxidase (MPO-ANCA).ANCA titers are often elevated during disease flares but do not have a consistent temporal relationship with disease activity. Thus, ANCA titers are not reliable predictors of disease flares. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=57273266 ER -