What is Mucosal Healing and Why Is It Important?
Here we will review and compare what happens to the cells of your intestinal lining (mucosa) in health and in active Crohn’s and ulcerative colitis! This will illustrate the importance of mucosal healing as a primary goal of achieving good health in your IBD care.
Facts about the normal lining of the colon
Did you know that the lining of your colon regenerates itself every 5-7 days? That’s right! The amazing regenerative properties of the colon enable it to withstand the wear and tear of peristalsis, digestion, and even caustic effects of NSAID’s attempting to damage it. If you think back to those days in biology class, you may recall that the process of a cell regenerating and replicating itself is known as mitosis. Every time a cell undergoes mitosis, it must replicate its DNA perfectly in order to produce a perfectly functioning cell. The human body does this extremely well in fact with rare mistake!
Quicker cell turnover with active IBD
In IBD, the lining of the intestine is swollen and bleeding from ulcerations (like cuts) throughout the affected segments of the GI tract. In Crohn’s disease, the ulcers may be quite deep and even result in fistulae, or over time scar down to result in strictures. In ulcerative colitis, the blood vessels weep and ooze blood accounting for the bloody diarrhea.
As you may have surmised, when you have actively inflamed mucosa, your cells die faster and need to be regenerated (mitosis!) more frequently. With each mitotic event, there is an opportunity for a mistake to be made in replicating the DNA. This is known as a mutation. The more frequent the cell mitosis and turnover, then the more opportunities for mutations to occur. Think of an assembly line that is moving faster and faster like one of those ‘I Love Lucy’ episodes where she can hardly package the chocolates fast enough as the assembly belt moved faster. I Love Lucy Episode – Chocolate Assembly Line.
The risks and effects of inflamed mucosa
These mutations can pass onto the next generation of cells and then those cells can make mutations as well. This means mutations can stack up and when you have enough mutations, the cells do not function properly. Their function, growth, and even physical appearance appear abnormal too!
Doctors call these cells dysplastic which means pre-cancerous. Pre-cancer (dysplasia) is NOT cancer. However, there is a spectrum from where a normal cell progresses to neoplasia, aka cancer. Early pre-cancer is known as low grade dysplasia (LGD) and later pre-cancer cells are known as high-grade dysplasia (HGD).
Again, active disease in Crohn’s can result in strictures, fistulae or cancer. In ulcerative colitis, chronic active disease can result in colon scarring and cancer.
In general, the more intestinal segments that are inflamed and the greater the duration of active disease, then there is an increased risk of cancer in one’s lifetime.
What are the benefits of mucosal healing?
Multiple benefits! First off, your active symptoms get better. This means your GI symptoms such as abdominal pain and diarrhea resolve. Also if you have symptoms from outside the intestinal lumen in other organ systems (extraintestinal manifestations) then these may improve too!
The long-term benefit of mucosal healing is that when your therapy heals the ulcers and calms the inflammation, then you return cell mitosis to its normal rate. This means you decrease the risk of developing scar, fistulae and of course – cancer!
So there you go, now you know the benefit of mucosal healing and why we as GI and IBD physicians are focusing on this as one of the primary goals of therapy in healing your IBD. Talk to your physician about the health of your mucosa today!
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