Abstract
Eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome) is a rare form of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis characterized by eosinophil-rich granulomatous inflammation and small to medium-size vessel vasculitis associated with bronchial asthma and eosinophilia. Its rarity and unique features such as eosinophilic inflammation have delayed progress of research regarding EGPA for several years, compared to other forms of ANCA-associated vasculitis. However, recently, attention to EGPA as a research subject has been gradually increasing. To resolve problems in existing criteria for EGPA, new classification criteria for EGPA generated by a large international cohort will be launched and is being expected to accelerate future studies. Pathogenesis and roles of ANCA in EGPA are still largely unknown; however, it has been reported that glomerulonephritis is more frequent in ANCA-positive patients than in ANCA-negative patients, while heart failure is more frequent in ANCA-negative patients than in ANCA-positive patients. In addition, a recent genome-wide association study has suggested the presence of two genetically distinct subgroups of EGPA, which correspond to ANCA-positi...Continue Reading