Ethnic association in primary systemic vasculitis: A systematic review

Background: Literature described wide disparities in incidence and prevalence between different types of vasculitis. There were no comprehensive studies on ethnic or racial associations in all types of primary systemic vasculitis (PSV) in any published article, until this review commenced in 2020. The purpose of the review is to synthesize the evidence regarding the relation of ethnicity and the incidence and/or prevalence of different types of PSV. Methods: A total of 52 selected articles which include Clinical trials, cohorts, cross-sectional studies, case series, and case studies and have been published within the last 10 years in the human population, were reviewed by searching The Medline, PubMed, and Google Scholars databases using predefined keywords. The PRISMA diagrams were followed to identify relevant articles. The methodological qualities of the studies were assessed using the EPHPP tool. Finally, a summary of the evidence on the association between ethnic origin and PSV was painstakingly compiled. Results: The connection between ethnicity and different types of PSV has been found to be significantly diverse in this research such as vasculitis is more common in Asians and Scandinavians, Kawasaki disease and periarteritis nodules are more prevalent in Japanese and Alaska-natives, ANCA-associated vasculitis is more frequent in Caucasians, whereas Henoch-Schonlein purpura and Cogan syndrome more usual in Caucasians and Asians. Furthermore, Behçet's disease more commonly occurs on the "Silk Road", especially in Turkey. Conclusion: Genetic susceptibility and environmental elements could be the contributing factors to the global variation in the incidence and prevalence of primary systemic vasculitis.