It has been known for some time that two HLA genes (DQ2, DQ8) predispose to celiac disease. What was recently discovered, and reported in The New England Journal of Medicine, is that is seems to take a virus to activate these genes that leads to the disease. The research focused on the interplay between viruses and genes causing celiac disease, with its gluten sensitivity. The genes alone don’t cause celiac disease.
The virus that appears to be the culprit is a Reovirus that infects the intestines, but is otherwise innocuous, in that is doesn’t cause any symptoms or illness. But in people who inherited HLA-DQ2 or DQ8, the genes are “switched on” and the auto-immune gluten sensitivity develops.
This is very compelling research because development of a viral vaccine could prevent millions of cases of celiac disease.