Air pollution influence on serum inflammatory interleukins: A prospective study in childhood-onset systemic lupus erythematous patients

Abstract

Objective

To assess the effect of individual exposure, in real-time, to traffic-related pollutants on serum interleukin levels of childhood-onset lupus erythematous systemic (c-SLE) patients.

Methods

A longitudinal and observational design was conducted in 12 repeated measures of serum samples and clinical evaluations (totaling 108 measurements) of c-SLE patients over 30 consecutive months. Real-time, individual exposure to fine particles (PM_2.5) and nitrogen dioxide (NO₂) was measured with portable monitors. Generalized estimating equation was used to evaluate the association between exposure to PM_2.5 and NO₂ and the following serum cytokine levels on the 7 days preceding clinical assessment and serum collection: MCP1, IL-6, IL-8, IL-10, IL-17, IFN-alpha, and TNF-alpha. Disease activity and other risk factors were also controlled.

Results

An interquartile range (IQR) increase in PM_2.5 daily concentration was significantly associated with increased levels of TNF-alpha on the third, fourth, and seventh day after exposure; IL-10 on the third and fourth day after exposure; IL-17 on the third and seventh day after exposure; and INF-alpha on the third day after exposure (p < 0.05). An IQR increase in 7-day moving average of PM_2.5 was associated with a 6.2 pg/mL (95% CI: 0.5; 11.8; p = 0.04) increase in serum IFN-alpha level. An unexpected significant association was observed between an IQR increase in NO₂7-day cumulative concentration and a decrease of 1.6 pg/mL (95% CI: −2.6; −0.7; p < 0.001) in serum IL-17.

Conclusion

Real-time exposure to PM_2.5 prospectively associated with increased serum TNF-alpha, INF-alpha, IL-10, and IL-17 levels in c-SLE patients.