Childhood GPA, EGPA, and MPA.

Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) is a term used to describe rare primary systemic vasculitides affecting small and medium-sized blood vessels. AAV diseases which include Granulomatosis with Polyangiitis (GPA), Eosinophilic Granulomatosis with Polyangiitis (EGPA), Microscopic Polyangiitis (MPA) and renal limited ANCA vasculitis. These multisystemic disorders involve upper and lower respiratory tract and kidneys associated with organ damage and long term sequelae. Newer understanding of pathogenesis in AAV have paved the way for clinical research with different biologic therapies. In spite of the paucity of clinical trials in pediatric AAV, the long-term survival of patients with AAV has improved dramatically. International collaborations will help to conduct clinical trials in pediatric AAV and help in better understanding of remission rates, relapse rates, and other outcomes. This article aims to provide a comprehensive review of pediatric AAV with a focus on epidemiology, disease pathogenesis, treatment trials, and prognosis.