Influence of sunlight on the treatment of Multiple Sclerosis

Moderate exposure of sun can help in regulating the immune system and also reduce the risk of MS.

In US, more than 200,000 people suffer from the nerve disease and multiple sclerosis. The causes of this chronic inflammatory disease that can lead to sensory loss, paralysis and optic neuritis are largely in the lack of sun. Again and again, but the sunlight being discussed as a component in the pathogenesis of Multiple Sclerosis. Because epidemiological studies show that northern Europeans, North Americans and Canadians much more frequently become ill than people who live near the equator. Genetic causes seem so much a role to play, because who is moving to a sunnier region in early childhood, adjusts its risk of Multiple Sclerosis.

Sun is contributes to the regulation of the immune system.

Therefore scientists wanted to find out if the amount of sunlight can actually affect on the risk or the progression of multiple sclerosis. Over a period of six weeks they sent nine Multiple Sclerosis patients regularly in a specially medical designed sun chamber. Irradiation was carried out every day except on weekends.

The results are amazing. After the first date in blood and in the skin of patients was found more regulatory T cells and dendritic cells than before irradiation. Both cell types protect the immune system against attack to itself – a process which is the central characteristic of multiple sclerosis.

In parallel, the exact molecular pathways can be decrypted, for example on value of UV-B radiation in mice: The induced regulatory cells migrate from the skin to the site of inflammation, ie into the blood, into the bones or – as in the MS – in the central nervous system. Here they trigger a protective immune response and so curb harmful autoimmunity reaction.

Protective effect is only temporarily effect.

The results thus provide evidence that sunlight can actually influence on the development of multiple sclerosis. There is obviously an relate between the skin and nervous system. UV-B radiation has an influence on the immune tolerance in the nervous system. However, the protective effect was faster than by tanning. If the treatment is interrupted even for a few days, blood levels and immune status deteriorated again – both in mice and humans. Nevertheless, the study could help in the long term to enhance the treatment options of MS and improve.