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
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
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.  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
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.
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