Study identifies infection risks for patients with inflammatory bowel disease

A new Mayo Clinic study finds that patients who are 50 or older and take multiple immunosuppressive medications for inflammatory bowel disease have a higher risk for developing infections. The study is published in this month's issue of Gastroenterology.

More than 1 million Americans are believed to have ulcerative colitis or Crohn's disease, the most common forms of inflammatory bowel disease. These conditions inflame the lining of the digestive tract and cause severe bouts of watery diarrhea and abdominal pain. The cause of these conditions is not known, but the most common theory is that the immune system of patients with inflammatory bowel disease reacts abnormally to bacteria in the gut.

"Patients with inflammatory bowel disease are often treated with a combination of immunosuppressive medications to help relieve symptoms," says Edward Loftus, M.D. a Mayo Clinic gastroenterologist and an author of this study. "Since these medications compromise immune reactions in the body, patients can develop what are called opportunistic infections, or infections from common organisms that would not affect individuals with healthy immune systems."

Dr. Loftus and a team of Mayo Clinic researchers set out to identify and quantify the risk factors that are associated with opportunistic infections in inflammatory bowel disease patients. They studied the medical records of 300 patients with inflammatory bowel disease. One hundred of these patients had contracted opportunistic infections and 200 patients had no history of these infections. The team found that patients who were age 50 or older were three times more likely to have infections than younger patients. Additionally, patients on one immunosuppressive medication were three times more likely to develop opportunistic infections than those on none. Patients on two or three different immunosuppressive medications were 14 times more likely to develop opportunistic infections than those on none.

"This study shows that patients with inflammatory bowel disease who are on immunosuppressive medications should have a low threshold for seeking medical attention at any sign of infection, such as cough or fever," says Dr. Loftus. "For the medical community, this is another example of the need to be cognizant of the potential risks of combination immunosuppressive therapies."

Other members of the Mayo Clinic research team included Murat Toruner, M.D.; W. Scott Harmsen; Alan Zinsmeister, Ph.D.; Robert Orenstein, D.O.; William Sandborn, M.D.; Jean-Frederic Colombel, M.D.; and Laurence Egan, M.D.

Each year, physicians at Mayo Clinic's campuses in Arizona, Florida and Minnesota treat thousands of patients who have digestive diseases.