Australasian Science: Australia's authority on science since 1938

Multiple Risks for Multiple Sclerosis

By Stephen Luntz

Genes and Epstein-Barr virus increase MS risk

A combination of certain versions of genes and exposure to Epstein-Barr virus (EBV) raises the risk of precursors for multiple sclerosis (MS) by 20 times, a study in Neurology has found. EBV is best-known as the cause of glandular fever.

According to A/Prof Robyn Lucas of the Australian National University: “These findings are consistent with other studies showing an association between markers of past EBV infection and MS risk, and we have also shown further interaction with other immune system genes”.

Lucas says that previous studies have often relied on people with MS to recall the severity of an attack of glandular fever. However, someone who is sick may recall past events differently from a control group, and their immune system might also be compromised.

Instead Lucas looked at people who had experienced a first demyelinating event. While this is the first indication of MS, Lucas hopes those who have yet to develop the full disease will be a more reliable study group for the research.

No vaccine against EBV exists, and Lucas says that making one would be a challenge as there are a number of different strains. However, exposure to EBV as a child produces a very mild illness, or none at all. “The best thing for MS is no exposure to EBV at all,” Lucas says. “However, it seems that exposure at a young age is only slightly worse, while exposure as an adult is much more dangerous.”

Vitamin D is known to usually provide a protective effect against MS, but Lucas says that her team’s research found this was more complex than previously suspected. “It’s very difficult to unpick all the factors,” she says. Nevertheless her work suggests that a current attack of EBV does not raise the risk of a first demyelinating event. “The danger seems to be at least 5 years afterwards. We’re not sure why.”