Researchers are also reporting that people with inflammatory bowel disease
are at increased risk for asthma, arthritis, chronic kidney disease, psoriasis, bronchitis, and other conditions believed to be linked
to the immune system.
"These studies remind us that the effects of inflammatory bowel disorders
extend to every corner of the body, including the lungs and central nervous
system," says Edward Loftus Jr. of the Mayo Clinic, who wrote an editorial
accompanying two studies.
"The findings lend credence to the concept that patients with one chronic
inflammatory condition are more likely than the general population to develop
It is estimated that more than 3 million Americans suffer from either
Crohn's disease or ulcerative colitis, the two conditions that make up
inflammatory bowel disease (IBD).
Ulcerative colitis commonly affects young adults; symptoms can include
chronic diarrhea, abdominal cramping, weight loss, and fever. The condition is
limited to the lining of the large intestine, and because of this it is curable
by surgery that removes the colon. Crohn's disease involves any part of the
intestinal tract from the mouth to the anus.
Unlike the poorly understood but more common condition known as irritable
bowel syndrome (IBS), IBD is frequently associated with symptoms occurring
outside the bowel. These can include inflammation of the eyes, mouth ulcers,
joint pain or swelling, and other inflammatory-related conditions.
Link With MS Long Suspected
A link between IBD and multiple sclerosis has been suspected for some time,
but earlier studies have been conflicting. Powerful new drugs used to treat
IBD, which block inflammation-causing tumor necrosis factor (TNF -- a part of
the immune system), are also suspected of causing multiple sclerosis.
Medications that block TNF like Remicade and Humira are now required to
contain labels warning of a possible link to multiple sclerosis and similar
conditions. But all agree that their role in the disease is far from clear.
In one of the two new studies, University of Pennsylvania School of Medicine
researchers compared 20,000 IBD sufferers in the U.K. to 80,000 people with
similar characteristics who did not have IBD.
The risk of developing multiple sclerosis or a related disease was 1.7 times
higher for the people who had IBD compared with those without IBD.
The researchers characterize the association as "small but significant."
Medications that block TNF had not been introduced at the time the database
was compiled, suggesting an independent link between IBD and multiple sclerosis
and other MS-like disorders, study co-researcher James D. Lewis, MD, tells
"This study does not answer the questions about the safety of this new
collection of anti-TNF-alpha therapies and whether IBD patients should or
should not use them," he says.