Air pollution may trigger disease activity in children with lupus
Exposure to air pollution may play a role in triggering disease activity and inflammation of the airways among children with systemic lupus erythematosus (SLE), say Brazilian researchers at the European League Against Rheumatism Annual Congress (EULAR 2016) held in London, UK.
This longitudinal study of childhood-onset SLE (cSLE) was carried out for 108 consecutive visits over four consecutive weeks, to investigate the association between daily real time exposure to air pollutants and disease activity. The cycle was repeated every 2.5 months for 1 year. The participants’ recorded daily personal measures of nitrogen dioxide (NO2), fine particle matter (PM2.5), ambient temperature and humidity. Data on pH of exhaled breath condensate (EBC pH), fractional exhaled nitric oxide (FeNO), and disease activity was collected weekly. [EULAR 2016, OP0220]
The researchers measured the impact of these pollutants on the risk of moderate/severe disease activity using specific generalized estimation equation models (SLEDAI-2K≥8).
Increased short term effect in FeNO at first 3 days after exposure was observed for an increase in of 18.12 µg/m3 in daily PM2.5 concentration. The 3-day FeNO moving average effect increased by 0.75 ppb (95 percent confidence interval [CI], 0.38-1.29). EBC pH levels decreased on day 7 and 10 of exposure (0.09, 95 percent CI, 0.15-0.02; and 0.09, 95 percent CI, 0.17-0.01, respectively). SLEDAI-2K≥8 risk increased at day 4 (relative risk [RR], 1.45, 95 percent CI, 1.24-1.66) and day 11 (RR, 1.34, 95 percent CI, 1.05-1.62) after exposure.
“Our findings have shown that air pollution doesn’t just increase the incidence and prevalence of chronic lung disease and acute respiratory infections, lung cancer, heart disease and strokes, it is also an important contributory factor in childhood rheumatic diseases, such as lupus,” said study author Dr. Maria Fernanda Goulart from the department of Paediatric Rheumatology, University of Sao Paulo, Brazil. “With air pollution increasing in many major cities, paediatric rheumatologists can expect to see a resultant impact on the disease activity of their lupus patients.”
While, previous studies have shown a link between higher risk of disease activity in cSLE patients and increased hospitalization among paediatric rheumatic patients and outdoor pollution, [Lupus 2012;21:526-33; Arthritis Care Res 2015;67:1609-1614], this is the first study to show a direct link between an individual’s personal exposure to fine particles and their lupus activity.
“To our knowledge, this was the first study that showed the effects of daily exposure to PM2.5, assessed by personal real time monitoring, on airway inflammation and increased risk of disease activity in cSLE patients,” said Goulart.