Influence of air pollution on renal activity in patients with childhood-onset systemic lupus erythematosus.
BACKGROUND
Childhood-onset systemic lupus erythematosus (cSLE) is an autoimmune and multifactorial disease that can affect the renal system. Exposure to air pollution can trigger systemic inflammation in cSLE patients and increase risk of disease activity. We evaluated effects of individual real-time exposure to air pollutants on renal activity in cSLE patients using the Systemic Lupus Erythematosus Disease Activity Index 2000.


METHODS
Longitudinal panel study of 108 repetitive measures from 9 pediatric lupus patients. Over three consecutive weeks, daily individual levels of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were measured, as well as weekly clinical evaluation and laboratory tests. This was repeated every 10 weeks over a 1-year period. Specific generalized estimating equation models were used to evaluate the impact of these pollutants on risk of nephritis and anti-dsDNA > 20 UI/mL and on 24-h urine protein and serum complement (C3) levels.


RESULTS
An interquartile range (IQR) increase of 18.12 μg/m3 in PM2.5 daily concentration was associated with increased risk of nephritis and positive results for anti-dsDNA. Moreover, increase in 24-h urine protein and decrease in C3 serum levels also associated with exposure to pollutants. An IQR increase in PM2.57-day moving average was associated with increased risks of leukocyturia (3.4; 95% CI 2.6:4.3), positive anti-dsDNA (3.1; 95% CI 2.1:4.0), and 36.3-mg increase (95% IC 20.2:52.3) in 24-h urine protein. An IQR increase (63.1 μg/m3) in 7-day cumulative NO2 levels was associated with decreased serum C3 levels.


CONCLUSIONS
This prospective study suggests exposure to air pollution can trigger renal activity in cSLE patients.
['Goulart|Maria Fernanda Giacomin|MFG|', 'Alves|Andressa Guariento Ferreira|AGF|', 'Farhat|Juliana|J|', 'Braga|Alfésio Luis Ferreira|ALF|', 'Pereira|Luiz Alberto Amador|LAA|', 'de Faria Coimbra Lichtenfels|Ana Julia|AJ|', 'de Arruda Campos|Lúcia Maria|LM|', 'Silva|Clóvis Artur Almeida da|CAAD|', 'Elias|Adriana Maluf|AM|', 'Farhat|Sylvia Costa Lima|SCL|']
D000293:Adolescent D000397:Air Pollution D001938:Brazil D002648:Child D002675:Child, Preschool D004784:Environmental Monitoring D005260:Female D006801:Humans D007668:Kidney D008137:Longitudinal Studies D008180:Lupus Erythematosus, Systemic D008297:Male D052638:Particulate Matter D011446:Prospective Studies D018570:Risk Assessment
Air pollution Renal activity Childhood-onset systemic lupus erythematosus Nephritis Anti-dsDNA Complement C3