Link found between Crohn's disease and RNA enterovirus

17 July 2013

A study of a small group of children in Sweden has found a new link between Crohn's disease and an RNA virus that is known to infect the mucosal lining of the intestine.

Following studies that showed a link between Crohn's disease and genes important for the immune defence against RNA viruses, researchers from Uppsala University and Uppsala University Hospital investigated whether the RNA virus was present in children with Crohn's disease.

The study population comprised nine children with advanced Crohn's disease and fifteen children with incipient Crohn's disease symptoms. The results showed significant amounts of enteroviruses in the intestines of all of the children with Crohn's disease, whereas the control group had no or only minimal amounts of enteroviruses in their intestines. Similar results were obtained using two different methods.

Enteroviruses were found not only in intestinal mucous linings but also in so-called nerve cell ganglia in deeper segments of the intestinal wall. Receptors for a group of enteroviruses were also found in both the intestinal mucous linings and nerve cell ganglia, which may explain how the virus can make its way into the nerve system in the intestine.

Another interesting finding is that the enterovirus could be thought to be stored in nerve cells in the intestine and to spread to different parts of the intestine via nerve fibres. This would explain both the fact that the disease is periodic (comes and goes) and the fact that it often affects multiple segments of the intestines, says Alkwin Wanders.

The findings have been published in Clinical and Translational Gastroenterology. [1] The researchers now want to examine larger groups of patients and more control individuals. They also want to pursue experimental research to investigate the link further.

The cause of Crohn’s disease is not known, but mutations in more than 140 genes have been shown to be associated with the disorder. This genetic connection is not a sufficient explanation, however. Many of these genes play key roles in the immune defence, which has prompted theories that the disease might be caused by impaired immune defence against various microorganisms. Recent research has shown that some of the genes that are strongly linked to the disorder are important for the immune defence against RNA viruses (ie their genetic material is RNA not DNA), pointing the researchers to the new study.

In Sweden several thousand adults live with Crohn’s disease, and each year about 100 children and adolescents develop the disorder. The disease affects various parts of the gastrointestinal system and causes symptoms such as stomach aches, diarrhoea, and weight loss – in severe cases fistulas, or strictures in the intestines.

The study was funded by, among others, Uppsala County Council, the Swedish Society for Medical Research, Cancerfonden, Karolinska Institutet, and the Swedish Research Council.


1. Nyström N, et al. Human Enterovirus Species B in Ileocecal Crohn’s Disease, Clinical and Translational Gastroenterology (2013) 4, e38; doi:10.1038/ctg.2013.7 Published online 27 June 2013.

See also

Vitamin A plays protective role in inflammatory bowel disease

Genetics shows Crohn's, colitis and other inflammatory diseases share common biological pathways

Linoleic acid is novel therapy for Crohn's disease

Increase in young people suffering from inflammatory bowel diseases

Article: Ultrasound of inflammatory bowel disease



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