Prevalence and Clinical Characteristics of Vasculitis in the Alaska Native and American Indian Peoples of Alaska.

Abstract

Our objective was to determine the prevalence and clinical characteristics of vasculitis in Alaska Native and American Indian (AN/AI) peoples of Alaska. We queried the electronic health records of participating tribal health organizations within the Alaska Tribal Health System (ATHS) to identify adults with diagnostic codes related to vasculitis. Medical record abstraction was performed for all adults with potential vasculitis to confirm fulfillment of inclusion criteria, subtype, and clinical characteristics. The denominator for prevalence was the 2019 ATHS user population ≥ 18 (except giant cell arteritis [GCA], defined for persons ≥ 50). The age-adjusted prevalence per 1,000,000 AN/AI adults was 752 (95% confidence interval [CI] 581-959) for all vasculitis, with systemic vasculitis being the most common at 518 (95% CI 379-695). The most prevalent types of systemic vasculitis were antineutrophil cytoplasmic antibody-associated vasculitis (AAV) at 340 per million adults (95% CI 230-488) and GCA at 28 per 100,000 ≥ 50 (95% CI 12-56). The most prevalent subtype of AAV was granulomatosis with polyangiitis (GPA) at 244 per million adults (95% CI 148-380). AAV was diagnosed at a mean age of 54.2 years (SD 17), often with high markers of inflammation and renal involvement. GCA was diagnosed at a mean age of 69.6 years (SD 9.2). The prevalence of AAV (especially GPA) in AN/AI peoples is high. GCA prevalence is lower than White populations, but higher than many other populations. AN/AI peoples with AAV and GCA may present at younger ages with more severe disease than other populations.