Smoking and two human leukocyte antigen genes interact to increase the risk for MS

Hedström et al. Brain. 2011 Mar;134(Pt 3):653-64. Epub 2011 Feb 8.

As you know from previous postings both genetic and environmental factors are associated with MS. Gene-environment interactions may exert stronger effects. 
In this study, the investigators studied potential interactions between genetic risk factors and smoking in relation to risk of developing MS. Results: a significant interaction between two genetic risk factors was found; smokers who had inherited a particular human leukocyte antigen DRB1*15 were less likely to inherit another leukocyte antigen A*02; the interaction between these two genetic factors was absent among non-smokers. Importantly, compared with non-smokers with neither of the genetic risk factors, smokers with both genetic risk factor were 13.5x more likely to get MS. For smokers without the genetic risk there chances were only 1.4x. For non-smokers with both genetic risk factors there risk was 4.9x greater than the background risk. Conclusion: The risk of developing MS associated with specific human leukocyte antigens is strongly influenced by smoking status. 
Please see previous smoking posts on this blog: “smoking and MS risk” and “young girls and smoking”.
“How these interactions lead to an increased risk of MS is unknown. Clearly we need to explain this if we want to understand the cause of MS.” 

4 thoughts on “Smoking and two human leukocyte antigen genes interact to increase the risk for MS”

  1. Who could have predicted that the 'evil weed' might one day help in the understanding of the causes of MS?

  2. Prof G, you Tweeted a lot about EBV being significant in the development of MS, so much so that I get the sense you may think that it is the cause of MS. I hope that when your survey findings come through you write up on this matter an tell us why you think EBV is the cause and why your peers don't think so. Also, please tell us why EBV is able to, in your view, case MS.

  3. Please see the other posts on the site in relation to EBV and causation. Things are getting very interesting in relation to EBV and MS. All we need now is for the world to try and disprove the hypothesis.

  4. I'm not a scientist, but surely the aim is to prove a hypothesis.If this was a crime, EBV would innocent until proven guilty. As the prosecutor in this trial you'll need to put together a case which proves EBV is guilty.

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