Antinuclear antibodies prevalence in Filipinos migrated to Italy

Antinuclear antibodies (ANA) represent the main diagnostic markers for systemic autoimmune disease (AD), although their presence can be detected in blood donors. The aim of this study was to study ANA prevalence in healthy subjects of different racial groups, exposed to the same environmental factors, in order to understand the relevance of genetics or environment in determining autoimmunity. We enrolled in this study 80 healthy Filipinos (Polynesian), migrated to Italy from an average of 15 years, and 60 healthy native Italians (Caucasian) and ANA were detected in their sera (at 1:80 screening dilution) through indirect immunofluorescence assay. We found a higher prevalence of ANA positivity in Filipinos compared to Italians (23.7% vs 8.3%--P = 0.02; OR 3.43; 95% CI 1.2-9.8), above all in females and elderly, although demographic characteristics, clinical history and habits were not significantly different between the two groups. These data confirm that ANA positivity is not a rare condition and healthy non-Caucasians present a higher prevalence of autoantibodies. This could be determined by their autoimmunity-prone immune system or by the exposition to infective agents, pollution, drugs or nutrition of a western country. Future studies to evaluate the ANA prevalence in Filipinos in their own country and the follow-up of positive patients could clarify the real predisposition to AD of this population.