How Does Crohn's Disease Affect the Immune System?
What Is Crohn's Disease?
Crohn's disease is a condition characterized by chronic inflammation of the gastrointestinal (GI) tract. The inflammation can occur anywhere from the mouth to anus, although the end of the small intestines and colon are the areas most commonly affected. Symptoms will differ depending on what part of the GI tract is affected, but they include: diarrhea, abdominal pain, fever, and bleeding from the rectum. In some people, other organs such as the joints and eyes are also affected. Most people are usually between fifteen and thirty-five years when they develop the disease, although children and geriatrics can have Crohn's disease. Men and women are affected equally often.
The Role of Genetics
Genetics seem to play an important part in the etiology of the disease. If you have a sibling with Crohn's disease, you are thirty times more likely to develop it, as well.
Genetic research has identified several of the genes involved in hereditary Crohn's disease. One of these genes is involved in helping the immune system recognize harmful bacteria. Many patients with Crohn's disease have a mutation in this gene, which makes it less effective. People with Crohn's disease also have mutations in several other genes that mediate the inflammatory response. So far, all the genes linked to Crohn's disease are related to the immune response.
How Is the Immune System Involved in Crohn's Disease?
The inflammation of the GI tract is caused by a prolonged immune response. Some scientist believe that a triggering event, such as an infection, causes the immune system to become confused and to identify such things as food or bacteria commonly found in the intestines as invaders. The immune system ramps up, and excess white blood cells in the intestinal walls cause inflammation. Some of the byproducts of white blood cell activity can be quite harmful to the body, and these substances can cause ulcerations.
Crohn's disease has traditionally been treated with immune suppressants and modulators. Since the immune system is causing the damage, weakening it will keep further damage from occurring. Indeed, these treatments have proven useful in many patients. Unfortunately, these drugs have many side effects, and a weakened immune system leaves you open to opportunistic infections.
Exciting new research, however, indicates that there may be another, better way to treat Crohn's disease. One group of scientists realized that people with a certain type of genetic immune deficiency often have symptoms similar to those found in people with Crohn's disease. These people are successfully treated with drugs that boost their immune system. Given the similarity in symptoms, the researchers decided to give people with Crohn's disease immune enhancers in the hope that they would be beneficial to them too. Eighty percent of the patients improved dramatically. Fifty percent were technically in clinical remission. Unfortunately, continued use of the drugs was required to sustain the effect. Nevertheless, these results are truly remarkable and provide hope for the future of effectively treating Crohn's disease.