Introduction: ANCA-associated vasculitis (AAV) is an infrequent disease in childhood. International literature about pediatric vasculitis is scarce, and it mainly refers to other systemic vasculitides with a higher incidence in childhood, such as IgA vasculitis and Kawasaki disease.
Objective: To describe the clini cal and laboratory characteristics of a series of pediatric cases with AAV.
Patients and method: Re trospective, descriptive study of patients with diagnosis of AAV treated at a tertiary health center from Santiago, Chile, between 2000 and 2020. Electronic medical records were reviewed collecting epidemiological, laboratory, images, and biopsies data.
Results: There were five cases of pediatric pa tients with AAV, with varying degrees of severity, and the age range at the onset was 5.5 to 13.5 years. We observed frequent renal involvement in microscopic polyangiitis (MPA) and eye involvement due to orbital pseudotumor in patients with granulomatosis with polyangiitis (GPA), an infrequent manifestation in the international pediatric literature. Patients were treated according to recommen dations extrapolated from clinical trials in adult populations, showing excellent clinical response to induction therapy with systemic corticosteroids and cyclophosphamide or rituximab. During main tenance therapy, most of the patients were stable on rituximab, azathioprine, or methotrexate. No patient developed organ damage and all cases achieved discontinuation of the corticosteroid therapy.
Conclusion: This report describes the clinical characteristics of AAV in a series of pediatric patients. In this series, renal involvement was common in MPA and eye involvement due to orbital pseudotu mor in GPA. The clinical response with treatment according to recommendations extrapolated from the adult population was favorable.