AUTHOR=Januel Edouard , Dessimond Boris , Colette Augustin , Annesi-Maesano Isabella , Stankoff Bruno 

TITLE=Fine Particulate Matter Related to Multiple Sclerosis Relapse in Young Patients

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.651084

DOI=10.3389/fneur.2021.651084

ISSN=1664-2295

ABSTRACT=<p><bold>Objective:</bold> Particulate matter (PM) of aerodynamic diameter smaller than 10 μm (PM<sub>10</sub>) has been associated with multiple sclerosis (MS) relapse. However, the impact of smaller PM with a greater ability to penetrate human organism has never been assessed. We evaluated the impact of PM smaller than 2.5 μm (PM<sub>2.5</sub>) on the risk of MS relapse.</p><p><bold>Material and Methods:</bold> In a case-crossover study, we included 2,109 consecutive hospitalizations likely due to MS relapse in day hospital in 5 MS centers in the Paris area from January 2009 to December 2013. For each hospitalization, the natural logarithm of the average weekly PM<sub>2.5</sub> concentrations (μg/m<sup>3</sup>) at the patient's residence address during each of the 6 weeks (week[0] to week[−5]) preceding admission was compared with the concentration during the previous week, using a conditional logistic regression adjusted on temperature, flu-like syndrome rate, pollen count, and holiday period.</p><p><bold>Results:</bold> PM<sub>2.5</sub> average concentration during week[−3] was significantly associated with the risk of hospitalization for MS relapse [OR = 1.21 (CI 1.01;1.46)]. The association was stronger in patients younger than 30 years [OR=1.77 (CI 1.10; 2.83)].</p><p><bold>Conclusion:</bold> Our study demonstrates an association between exposure to PM<sub>2.5</sub> and MS relapse, particularly in young people.</p>