Prof. Jorge Correale Reviews Environmental Factors Associated with Multiple Sclerosis at ECTRIMS 2015

Three parallel sessions concerning multiple sclerosis (MS) prevention, clinical phenotypes and magnetic resonance imaging (MRI) were featured at the 31st Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), recently held in Barcelona, Spain (October 7 – 10, 2015). The first parallel session was entitled “Will MS be prevented?” and included six presentations on the subject.

Prof. Jorge Correale from the Institute for Neurological Research Dr. Raul Carrea in Buenos Aires, Argentina gave the first presentation of the session, entitled “Environmental factors,” where he argued that environmental factors that influence the propensity to develop MS may lead to novel effective strategies to prevent and treat the disease in the future.

According to Prof. Correale, although the pathogenic mechanisms associated with MS development still need to be clearly identified, autoimmunity seems to play an important role in MS development. In addition, evidence also suggests that genetic susceptibility and environmental factors influence disease development and pathogenesis.

Regarding environmental factors, Prof. Correale stated during his presentation that, “vitamin D plays an important role in MS inflammation (…) vitamin D has an immunomodulatory effect: it inhibits CD4 proliferation, enhances interleukin (IL)-10 secretion, and induces Tregs [regulatory T cells].” In fact, several studies have suggested that vitamin D is involved in the control of T cell response, inducing T cells with immunosuppressive properties.

Prof. Correale also reported on other factors that can influence MS development, including Epstein-Barr virus (EBV) infection, where EBV infection is thought to trigger the activation and expansion of self-reactive B and T cells. A high sodium intake can also “exacerbate the disease” noted the Professor, as salt has been shown to modulate the differentiation of Th17 cells (immune cells involved in MS pathogenesis). In addition, “melatonin could be a key player of seasonal relapses, (…) melatonin levels negatively correlated with MS relapses in humans”, he added. The levels of the hormone melatonin have been reported to influence the frequency of flare-ups in MS patients, where higher melatonin levels were found to be linked to fewer disease flare-ups.

Finally, Prof. Correale also mentioned that “cigarette smoking is associated with an increased risk of MS, [as] smoking modifies the immunological profiles in MS patients”. Interestingly, “when you stop smoking, you can decrease the risk of disease progression” noted Prof. Correale. Smoking is thought to alter pathways controlling regulatory T cells, leading to a pro-inflammatory state.

Data on some of these environmental factors have been previously discussed in other Multiple Sclerosis News Today articles. To learn more about it, visit the following links:

– Vitamin D
– Epstein-Barr virus
– Salt intake
– Melatonin
– Smoking