Childhood-Onset ANCA- Associated Vasculitis: Single center experience from Central California

Abstract

Abstract Background Childhood-onset ANCA-associated vasculitides (AAV) are rare and characterized by necrotizing inflammation and include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Pediatric data is scare and there have been no prior studies examining the characteristics of pediatric AAV in Central California, which has a Hispanic majority population.Methods We conducted a retrospective study of patients ≤18 years of age diagnosed with AAV between 2010 and 2021, in Central California. We analyzed demographic, clinical and laboratory characteristics, treatment, and initial outcomes.Results Of the 21 patients with AAV, 12 were categorized as MPA. Median age at diagnosis was 13.7 years in MPA cohort and 14 years in GPA. MPA cohort had significantly high proportion of females (92% versus 44%). Fifty seven percent of the cohort were racial/ethnic minority including Hispanics (n = 9), Asians (n = 2), and multiracial (n = 1) and 43% were white (n = 9). Hispanic patients were more frequently diagnosed with MPA (89%) and positive for myeloperoxidase antibody (100%). White patients more often were diagnosed with GPA (78%) and expressed PR-3 positivity (89%). Median duration of symptoms prior to diagnosis was 14 days in MPA cohort and 21 days in GPA cohort. Renal involvement was frequent (100% in MPA and 78% in GPA). GPA cohort had more frequent ENT involvement (89%). MPA cohort tended towards more severe disease with 67% requiring ICU admission and 50% requiring dialysis. Two deaths were reported in MPA cohort, related to Aspergillus pneumonia and pulmonary hemorrhage. In MPA cohort, 42% received cyclophosphamide in combination with steroids and 42% received Rituximab in combination with steroids. GPA patients received cyclophosphamide, either with steroids alone (78%) or in combination with steroids and Rituximab (22%).Conclusions Microscopic polyangiitis was the most frequent AAV subtype with female preponderance, shorter duration of symptoms at onset and higher proportion of racial/ ethnic minority patients. We observed more frequent MPO positivity in Hispanic children. Trends towards higher rates of ICU admission and dialysis was noted in MPA. Patients with MPA received Rituximab more frequently. Future prospective studies are needed to understand differences in childhood onset AAV between diverse racial-ethnic groups.