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=Volume 12 - 2021

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=Objective: 
Particulate matter (PM) of aerodynamic diameter smaller than 10 µm (PM10) 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 (PM2.5) on the risk of MS relapse.
Material and methods: 
In a case-crossover study, we included 2109 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 PM2.5 concentrations (µg/m3) at the patient’s residence address during each of the six 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. 
Results: 
PM2.5 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]).
Conclusion: 
Our study demonstrates  an association between exposure to PM2.5 and MS relapse, particularly in young people.