Teachable moment in classrooms:
- cellular basis of life chapter – cell membrane proteins can function as receptors
- digestive system chapter – anatomy of the digestive system, location of large intestine
- digestive system chapter – layers of the gastrointestinal tract, location of mucosa
- immune system chapter – cell-based immunity depends on cytotoxic T-lymphocytes
The news item: Recently the following article appeared online:
New drug for IBD, ulcerative colitis wins FDA approval: ‘Amazing results’
“We’re seeing pretty amazing results” with newer treatments, said one expert. “If you look over the last few years, it’s been game-changing.”
The article states that inflammatory bowel disease and ulcerative colitis are diseases of the lining of the large intestine and rectum where open sores develop, and while the precise cause is unknown, we consider this a consequence of the improper functioning of the immune system. The article describes the symptoms as diarrhea, abdominal pain, fatigue, and rectal bleeding. The article states that the current steroid and other injectable treatments are effective, but patients could be treated easier with oral medication.
So, Why Do I Care?? Each year over 70,000 people in the US are diagnosed with inflammatory bowel disease; currently about 2.1 million people are treated for the disease. Because the symptoms are debilitating, and treatment options have been limited to injectable drugs, the significance of Etrasimod (Velsipity) is that it provides a treatment option using oral medication instead of injections.
Plain English, Please!!! First, let’s talk about what inflammatory bowel disease is. This disorder happens when the immune system overreacts to viruses or bacteria in the gastrointestinal tract (GI-tract), the tube-shaped part of the digestive system going from the mouth to the anus. Most of the time the large intestine and the rectum are the location for inflammation. The overactive immune system sends a large number of cytotoxic T-lymphocytes to the inner lining, the mucosa, of the GI-tract. Once there, those T-lymphocytes release inflammatory mediators that cause vasodilation, and eventually tissue damage. The damaged mucosa prevents absorption of nutrients and causes bleeding and diarrhea.
Second, let’s talk about how the immune system becomes overactive during the disease. Normally most of the T-lymphocytes reside in the lymph nodes limiting the number of T-lymphocytes released into