A RECENT study investigated the risk of systemic lupus erythematosus (SLE) associated with long-term exposure to air pollution and evaluated the interactions between joint effects of genetic risk and air pollutants.
The study included 459,815 participants from the UK Biobank, examining the concentrations of various air pollutants, including fine particulate matter (PM2.5), particulate matter (PM10), nitrogen dioxide (NO2), and nitrogen oxides (NOx). The researchers utilised a land-use regression model to estimate pollutant levels and applied Cox proportional hazard models to explore the associations between these pollutants and incident SLE.
The data indicated that exposure to high levels of air pollutants significantly raised the risk of new onset SLE, especially in people with known genetic risk factors. Furthermore, in the study cohort, 18-25% of participants showed increased likelihood of developing SLE for each step, in quartiles for estimated exposure to particulate matter and nitrogen oxides. Moreover, results indicated that the high increases were largely driven by genetic risk as the high risk group exposed to high levels of four major pollutants PM2.5 and PM10, nitrogen dioxide (NO2), and nitrogen oxide (NOx), showed increased SLE risk ranging from 316% to 461% compared to those with low genetic risk and pollution exposure.
During a median follow-up period of 11.77 years, 399 participants were diagnosed with SLE. The study found positive associations between air pollutant exposure and the development of SLE. In particular, PM2.5 showed an 18% increased risk per interquartile range increase (adjusted hazard ratio [HR] 1.18, 95% CI 1.06-1.32). PM10 showed a 23% increased risk (HR 1.23, 95% CI 1.10-1.39). NO2 showed a 27% increased risk (HR 1.27, 95% CI 1.14-1.41), and NOx showed a 13% increased risk (HR 1.13, 95% CI 1.03-1.23).
These findings suggest that long-term exposure to air pollutants could be a significant factor in the development of SLE, particularly among those with a genetic predisposition. The study’s results point to the need for heightened awareness and potentially stricter regulations on air pollution to mitigate the risk of autoimmune diseases like SLE.
Aleksandra Zurowska, EMJ
Reference:
Xing, M et al. Air Pollution, Genetic Susceptibility, and Risk of Incident Systemic Lupus Erythematosus: A Prospective Cohort Study. Arthritis Rheumatol. 2024. [Epub: ahead of print].
