Protein Build-Up Could Mean Crohn's

Crohn's disease linked to proteins that come when stomach and colon become inflamed

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Finding out if those stomach pains are from Crohn's disease can be hard to test. But the build up of certain proteins in the body could be a future test for the stomach problem, according to a new study.

If the end of the small intestine and colon is inflamed, certain auto-antibodies which have been tied to Crohn's disease (CD) can grow.

With further study, the build up could "be one of those tests that can be added in the diagnostic workup of patients with CD," researchers said.

"Stomach upset? See a doctor."

Auto-antibodies, which are proteins created by the immune system, are normally found in patients with inflammatory bowel diseases. These proteins, called zymogen glycoprotein-2 or GP-2,  fight other proteins in the person's body.

When these proteins are present in a part of the body, it normally means that particular body part is inflamed, though scientists are not yet sure why.

The aim of the study, led by Polychronis Pavlidis, MD, from the Division of Transplantation Immunology and Mucosal Biology at King's College in London, was to see if this autoantigen could also be found in the patients with two different inflammatory bowel diseases along their colon. Researchers tested for the proteins in 225 patients with Crohn’s and another 225 patients with ulcerative colitis.

Patients were chosen based on where Crohn's was located in their body. More than half the patients were women and all averaged about 40 years of age.

Of the Crohn's patients, 45 had it in their colon, another 45 had it in the last part of their small intestine just below the stomach and the rest had it somewhere along their intestines.

Researchers found the protein in more than a quarter of Crohn's disease patients. At the same time, only about 7 percent of patients with ulcerative colitis had the protein. Only five of the 45 patients with Crohn's in the colon had the antibody, compared to 30 percent of patients with the disease in their small intestine.

"Our study clearly demonstrates that patients with the restricted colonic form of the disease do not show significant antibody reactivity against GP2 compared to those with a disease location that involves the ileum…" researchers wrote in their report.

Family history, the age of the patients and how long they had the disease did not affect whether patients had the protein.

The authors note that the protein is absent from almost three quarters of Crohn's patients and they cannot accurately guess how often patients have the protein.

For now, looking at how much protein is present in a person is not a strong way to diagnose the disease.

The study, which was supported by UK Clinical Research Service, European Association for the Study of Liver and the Higher Education Funding Council for England, was published online October 17 in the journal Clinical and Development Immunology.

One of the authors is a shareholder of GA Generic Assays and Medipan, which may be a competing interest in the study. 

Reviewed by: 
Review Date: 
November 18, 2012
Last Updated:
December 3, 2012