Fine particulate matter air pollution linked to increased ANA positivity

A Canadian data analysis revealed a dose-dependent association between long-term exposure to fine particulate matter (PM2.5) and increased prevalence of anti-nuclear antibodies (ANA) in the general population, suggesting a link between air pollution and systemic autoimmune rheumatic diseases (SARDs).

Ambient air pollution has long been suspected to contribute to autoimmune diseases, however, robust serological evidence remained limited. In the Ontario Health Study, one of Canada’s largest population health databases, Dr Sasha Bernatsky (Research Institute of the McGill University Health Centre, Canada) and colleagues explored the relationship between PM2.5 exposure and ANA positivity, a recognised biomarker of SARDs [1].

The researchers analysed data from 3,548 randomly selected serum samples collected between 2010–2013. ANA titres were determined by indirect immunofluorescence, and 5-year average ambient PM2.5 levels were assigned to participants using residential postal codes. Multivariable logistic regression models were adjusted for age, sex, ethnicity, smoking, and the Rurality Index of Ontario.

While lower ANA titres (≥1:160 or ≥1:320) showed no statistically significant association with PM2.5, higher titres revealed an exposure-response pattern. Individuals in the highest quartile of PM2.5 exposure had an adjusted odds ratio (aOR) of 1.67 (95% CI 0.99–2.82) for titres ≥1:640 and an aOR of 2.33 (95% CI 1.11–4.91) for titres ≥1:1280, indicating more than a two-fold increased likelihood of high-titre ANA positivity.

These findings support the hypothesis that sustained exposure to airborne pollutants can affect immune regulation, potentially triggering or exacerbating autoimmune responses. The effect was particularly notable at the highest ANA titres, reinforcing the need for environmental considerations in autoimmunity research and prevention strategies.

According to the authors, this analysis underscores the immune-disruptive effects of air pollution and its potential link to the development of autoimmune diseases.

1. Zhao N, et al.Fine particulate matter air pollution and anti-nuclear antibody positivity: the Ontario Health Study. POS0101, EULAR 2025, 11–14 June, Barcelona, Spain.

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Posted on 18 June 2025