Increased prevalence of multiple sclerosis and clusters of different disease risk in Northern Italy.

BACKGROUND: The increasing multiple sclerosis (MS) prevalence is varying across the macroscopic regional areas. Only few studies have explored the microscopic geographic variation of MS prevalence, which could highlight MS spatial clusters. OBJECTIVE: In this ecological study, we aimed to estimate 2016 MS prevalence in the province of Pavia (Northern Italy) and to describe MS risk geographical variation across small area units, compared to the year 2000. METHODS: Bayesian models were fit to estimate area-specific MS relative risks. The mean of the posterior marginal distribution of relative risks differences for each area were used to describe the risk variation. RESULTS: The 2016 overall prevalence was 169.4 per 100,000 inhabitants (95% CI 158.8-180.6). The Bayesian mapping of MS showed some clusters of higher and lower disease prevalence. Furthermore, several municipalities located in the north part of the province were more at risk with respect to the year 2000. CONCLUSIONS: The current MS prevalence sets the province of Pavia among high-risk areas and, compared with the previous prevalence estimate (86 per 100,000 in year 2000), indicates an increased MS risk. The Bayesian mapping highlighted area with a significantly higher/lower MS risk where to investigate etiologic hypotheses based on environmental and genetic exposures.

PM2.5 exposure as a risk factor for multiple sclerosis. An ecological study with a Bayesian mapping approach.

Some environmental factors are associated with an increased risk of multiple sclerosis (MS). Air pollution could be a main one. This study was conducted to investigate the association of particulate matter 2.5 (PM2.5) concentrations with MS prevalence in the province of Pavia, Italy. The overall MS prevalence in the province of Pavia is 169.4 per 100,000 inhabitants. Spatial ground-level PM2.5 gridded data were analysed, by municipality, for the period 2010-2016. Municipalities were grouped by tertiles according to PM2.5 concentration. Ecological regression and Bayesian statistics were used to analyse the association between PM2.5 concentrations, degree of urbanization, deprivation index and MS risk. MS risk was higher among persons living in areas with an average winter PM2.5 concentration above the European annual limit value (25 µg/m3). The Bayesian map revealed sizeable MS high-risk clusters. The study found a relationship between low MS risk and lower PM2.5 levels, strengthening the suggestion that air pollution may be one of the environmental risk factors for MS.

Etiological research in pediatric multiple sclerosis: A tool to assess environmental exposures (PEDiatric Italian Genetic and enviRonment ExposurE Questionnaire).

BACKGROUND: The etiology of pediatric-onset multiple sclerosis is unknown although putative genetic and environmental factors appear to be involved. Among children multiple sclerosis onset occurs closer to the susceptibility window thank in adults and the exposure to etiological environmental factors is more informative. An Italian multicentre case-control study (the PEDiatric Italian Genetic and enviRonment ExposurE, PEDIGREE study) was designed to investigate environmental exposures in pediatric-onset multiple sclerosis and their interaction with genetics. OBJECTIVES: To collect evidence on exposures to environmental risk factors in pediatric-onset multiple sclerosis, a questionnaire was developed for the Italian population (PEDIGREE Questionnaire) and is presented. METHODS: PEDIGREE Questionnaire develops from an existing tool used in case-control studies on pediatric-onset multiple sclerosis in US Americans, and was translated, adapted and tested for the contents perceived relevance, acceptability, feasibility and reliability in a population of Italian pediatric subjects and their parents recruited from clinics and general population. RESULTS: PEDIGREE Questionnaire contents were overall deemed relevant by the study population, acceptable for 100% participants and feasible for at least 98%. PEDIGREE Questionnaire degree of reliability ranged 56% to 72%. CONCLUSION: PEDIGREE Questionnaire proves to be an efficient tool to assess environmental exposures in the Italian pediatric population. We encourage the dissemination of population-specific questionnaires and shared methodology to optimize efforts in MS etiological research.