MS, common virus and lack of sunshine linked
Multiple sclerosis is more prevalent in latitudes that get less sunshine. A new study also links a higher risk of developing the disease among individuals with a history of mononucleosis, commonly known as the “kissing virus”. Mono, as it is commonly called, is a herpes virus that causes Epstein-Barr syndrome.
Past studies suggest virus, vitamin D link to multiple sclerosis
Environmental factors, such as higher activity in brain lesions associated with MS during spring and summer months have been identified, but researchers aren’t certain what triggers exacerbation of MS or even what triggers the autoimmune response that causes the disease.
Researchers from Stanford University School of Medicine discovered last years there may even by two types of multiple sclerosis when they discovered some patients respond to treatment with beta-interferon while others do not, depending on whether T-cells in the immune system secrete gamma-interferon or IL-17, both of which are inflammatory cytokines.
Interestingly, Epstein-Barr was found in a May 2008 study, published in the Journal of European Immunology, to cause dysregulation of IL-17. To correlate, it was patients with very low levels of IL-17 that the Stanford researchers found respond well to beta-interferon treatment.
New multiple sclerosis findings link virus and low UV exposure to MS
For the newest study, researchers looked at 56,681 cases of multiple sclerosis and 14,621 cases of infectious mononucleosis from hospital admissions in England over a seven-year period, including NASA data about sunlight (UV) intensity in England.
Individually, sunlight accounted for 61 percent of occurrences of multiples sclerosis, but the effect of mononucleosis and low exposure to UV accounted for 72 percent of occurrences.
George C. Ebers, MD, with the University of Oxford in the United Kingdom and a member of the American Academy of Neurology (AAN) explains, “Since the disease has been linked to environmental factors such as low levels of sun exposure and a history of infectious mononucleosis, we wanted to see whether the two together would help explain the variance in the disease across the United Kingdom.
He says, based on the study findings, it may be possible that lack of vitamin D from sunshine causes an abnormal response to the Epstein-Barr virus. He points out the virus is extremely common among teenagers and usually leads to infectious mononucleosis. Ebers say the risk of MS is even higher for those born during spring when sunshine is not as predominant.
Dr. Ebers says, "More research should be done on whether increasing UVB exposure or using vitamin D supplements and possible treatments or vaccines for the Epstein-Barr virus could lead to fewer cases of MS." The new study uncovers new information that links multiple sclerosis to lack of sunshine and vitamin D and the common “mono” virus that causes Epstein-Barr.