Researchers have long looked for the cause of Crohn's disease, an autoimmune illness in which the immune system attacks parts of the digestive system stretching from the esophagus to the large intestine. Recent research has found mutations in human genes that were correlated with an increased incidence of the disease, one of which is a virus infection response gene. But now there is evidence that a specific type of virus, enterovirus species B, is present in the intestines of children who have Crohn's disease, according to a new study published in Clinical and Translational Gastroenterology.

Researchers found that patients who had mutations in the NOD2 gene, which has previously been implicated in Crohn's Disease, as well as a mutation in the ATG16L1 gene, a viral infection responsive gene that is also seen mutated in many Crohn's sufferers, were likely to have evidence of the presence of a specific type of enterovius. The virus was seen in the mucosal surface of the intestines and also in the highly innervated nerve-dense region of the intestines.

Another interesting point that the researchers made was that the virus' presence in the nerve ganglia in the intestines may be key in its abilities to spread through the digestive tract. The virus may use the nervous system of the digestive system as a highway to move around and affect far away sections of the intestines.

The researchers mentioned that a larger study must be performed to confirm the results. The current study looked at samples taken from nine children with advanced Crohn's disease, and 15 children who were at the initial stages of disease development.

The disease is severe and can cause significant weight loss due to the inability to retain water because the intestines have been damaged and cannot absorb water easily. The cause of Crohn's disease is unknown, but more than 140 genes have been linked with the disorder, with NOD2 and ATG16L1 high on the list of linked genes. Researchers suspect that because these genes are important in a person's defenses against bacterial and viral infections, their mutations may lead to a misguided attack on a person's own tissues by the immune system.

Crohn's disease is different than it's cousin disease, ulcerative colitis (UC). While UC has the ability to enter a remission period, Crohn's disease does not, and patients are always in a phase of "flare up." Additionally, while UC only affects the large intestine, Crohn's disease can attack anywhere along the length of the digestive system from the throat all the way to the rectum. A significant amount of research is currently invested in trying to determine the root causes of the disease.

If the disease is first sparked by the infection with a virus in people who are genetically susceptible, eventual genetic testing and prophylactic immunization may be the route to take to prevent the disease in the future.

Source: Nyström N, Berg T, Lundin E, et al. Human Enterovirus Species B in Ileocecal Crohn's Disease. Clinical and Translational Gastroenterology. 2013.