How does fibrosis occur in Crohn's disease?

New research has shown that a protein, known as IL-13, could be the key to the development of fibrosis in Crohn's disease. This breakthrough could help to advance new medicines to treat people suffering with the disease.

Crohn's disease is a chronic, debilitating condition characterised by inflammation and occurring at any point in the . Currently there is no cure. One of the major complications of Crohn's disease is the development of fibrosis – hardening and thickening – in the bowel wall. This causes the intestine to lose its mobility and it eventually becomes so narrow that food and are unable to pass.

Fibrosis occurs when there is an overproduction of the proteins which are normally involved in the tissue healing process, including collagens.

The research team, led by the School of at the University of Bristol, found an increase in collagen synthesis and a lack of control of collagen deposition in fibrotic intestine taken from Crohn's disease patients when compared to normal intestine. The researchers believe that this is related to an increase in a soluble mediator, 13 (IL-13), previously identified as promoting fibrosis in the lung, liver and kidney.

Increased levels of IL-13 were found in fibrotic Crohn's gut when compared to normal gut, and tissue culture experiments showed that IL-13 reduced factors necessary to prevent inappropriate collagen deposition.

Dr Jenny Bailey, a researcher in the School of Veterinary Sciences at the University of Bristol, said: "We have identified a novel population of IL-13-producing cells which, in intestinal samples, were found at very high levels in fibrotic muscle. We believe these cells are key to the development of fibrosis.

"Understanding how fibrosis occurs will help us to develop to treat patients."

Since many patients developing fibrosis will require surgery, early intervention strategies may prevent severe morbidity, to which end IL-13 and IL-13-producing cells provide a promising therapeutic target.

Although there is some success in treating the inflammation in Crohn's disease, there are no current effective drugs to treat fibrosis. In cases of severe fibrosis, the only remedy is surgical excision of the strictured gut and around 30 per cent of Crohn's disease sufferers will undergo surgery at least once. Unfortunately, removal of the fibrotic tissue does not prevent recurring in another part of the intestine and Crohn's patients frequently have to endure repeated surgery, eventually resulting in a short bowel which is no longer able to sustain adequate function.

More information: IL-13 Promotes Collagen Accumulation in Crohn's Disease Fibrosis by Down-Regulation of Fibroblast MMP Synthesis: A Role for Innate Lymphoid Cells?, Bailey JR, Bland PW, Tarlton JF, Peters I, Moorghen M, et al., PLoS ONE, 31 December 2012.

Related Stories

Scarred lungs leave trail of beta arrestins

Mar 28, 2011

Targeting a family of signaling proteins called beta arrestins may stop the life-threatening scarring and thickening of lungs associated with pulmonary fibrosis, reports a new Science study in mice.

Recommended for you

Two expats die of MERS in Saudi commercial hub

21 hours ago

Two foreigners died of MERS in the Saudi city of Jeddah, the health ministry said Saturday, as fears rise over the spreading respiratory virus in the kingdom's commercial hub.

UAE reports 12 new cases of MERS

21 hours ago

Health authorities in the United Arab Emirates have announced 12 new cases of infection by the MERS coronavirus, but insisted the patients would be cured within two weeks.

Filipino tests negative for Middle East virus

Apr 19, 2014

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

User comments