The triggers for Multiple Sclerosis

[Music] and multiple sclerosis is a complex multifactorial disease what we mean by that is many factors come into play to trigger off MS in a certain individual we know some of those factors relate to a person's genotype their genetic Constitution and other factors appear to be more related to the environment that they are in or infections or other factors that might have impinged on them as they grew up now when we use the word multifactorial one example I often like to use is that of a car crash if you think of a car crash sometimes it's because the car's not very Road worthy but often it's because the not very Road worthy car is being driven on a rainy night around a hairpin Bend too fast and you could take the analogy that a car accident can be avoided if we understand at least some of those components and fix them up so if you'd said that the poor car was that an analogy to a person who's genetically very at risk of MS so we need to understand their environment and try and not expose them to hairpin bends that may in fact be the environmental trigger that then develops their disease now when do these environmental factors operate and that's not well understood but certainly there are some studies including season of birth studies one recently published in the British Medical Journal that indicate that even the time of the year the babies born may be related to later MS so there is certainly some interest in the in utero development of the central nervous system and the immune system but we do know that during early life the immune system develops enormous ly from a newborn baby to somebody at the age of say 15 and what we don't understand enough at the moment is what sort of perfect environment will allow somebody's immune system to develop absolutely optimally so it will never be triggered into autoimmune disease is all into allergic disease that's one of the missions that this type of works trying to head towards and then in adulthood when most people develop MS there's a lot of interest in immediate triggers to him SP they certain life events or infections and so on so when we're looking at environment we really want to cover quite a lot of different periods in the person's life course now some of the past work I've been involved in and has been the Tasmanian MS environmental case control study and we reported from that that children who tend to have lower sun exposure at between the ages of 6 to 15 had an increased risk of MS now that's an association we haven't necessarily proven cause but it's now there's now been several other studies indicating that most sunlight or low vitamin D may be associated with MS and other immune studies showing that it's quite important how much vitamin D a person has as as their immune system develops and that work was published in British Medical Journal in 2003 from the same tasmanian case-control study we then looked at the influence of family structure and infection on ms as most people know and there's been a big increase not only in in aspirin allergy but there's actually also been increase in various immune disorders including Crohn's and multiple sclerosis and one of the theories behind this increase in not one but several disorders is the so called hygiene hypothesis that modern individuals are exposed to a different pattern of infections particularly in their early life and it means their immune system doesn't quite get the type of training that it used to and in terms of setting up the immune system optimally not to react to either self or to external environmental allergens such as pollen so and we it is now more than 60 studies showing that children at larger from larger families with more siblings are less likely to have asthma we examined that issue in multiple sclerosis in the Tasmanian MS case control study and we found that individuals who were exposed to more contact with infants that is children under the age of two by the time they were six they were less likely to subsequently develop an MS and this pattern of increase in contact with infants had some evidence of dose response that is the more contact with infants they had the the further reduce the risk was and one of the factors we do know is associated with EMS is epstein-barr virus infection and the body's host response to that infection and that's been now shown is in prospective studies so that people will have high titers of antibodies against epstein-barr virus are more likely to go on and develop ms it's certainly not the whole picture but it does seem to be an important component and in this Tasmanian study we found amongst healthy controls that people who are exposed to more infants and early life were less likely to have these high antibody levels against epstein-barr virus which in our study as in many others was associated with MS and that that were looking at ms onset is now ongoing in National Health and Medical Research Council have contributed some funding for us now to look at genetic factors to see which people have a genetic vulnerability to these type of environmental factors such as infection or possibly although not conclusively proven low vitamin D and and furthermore we with this Tasmanian work and the world recognized work done by large body of neurologists in Australia over time we know that Australia is a country with a very marked latitudinal gradient of N yes in the 1981 prevalence study there was a more than six-fold increase from 11 per 100,000 cases in North Queensland down to 76 400,000 in Tasmania and we were then interested to see whether this latitudinal gradient could be explained in any way by difference in environmental factors across Australia because Australia is ideal and that has a large latitude range yet a very good health care system and very similar ascertain menteur MS or for MS diagnosis across Australia also although there is some ethnic diversity it's certainly not the same extent as in Europe or North America and we were then funded with a large group including 8 universities and research institutes so I'm really speaking on behalf of a large team here and we were funded by the US MS Society to investigate and the environmental determinants of MS across Australia we took some of the components of that Tasmanian work some of the components from other international studies and some new components as well and worked out a study protocol where we compared the lifestyle and environment of people who develop their first mullen ating event for MS that is before oral diagnosis of MS just at first presentation to neurologists and we compared their history to people who were chosen from the electoral roll in the same region and who were a similar age in sex to the cases this study was conducted in Brisbane the Hunter Valley region and Geelong and in Tasmania and it was completed with regard to the first stage of case control fieldwork recently we're currently undergoing analysis of that [Music]

Channel: MS Research Australia

Views: 115,762

Rating: 4.7064219 out of 5

Keywords: ms, multiple sclerosis, msra, ms research australia, ms triggers, Anne-LouisePonsonby, ms researcher, professor ponsonby, anne-louise ponsonby, MS research

Id: BZB0-nYOZo8

Length: 9min 2sec (542 seconds)

Published: Thu Jul 23 2009