UC and atopy connection?

[beelady]

My 4yr old first developed eczema and food allergies as an infant, then at 4 yrs. was diagnosed with ulcerative colitis.  I've learned that both can be caused from a defective intestinal barrier function, or problems with innate immune defenses in the intestine.  Could she have some kind of immune deficiency, such as IgA deficiency, that is the root cause of both conditions?  Is there anything that medical science can do to help an immune deficiency?

[beelady]

Dr. Kini--

Please look a little beyond your textbook definitions...

Think about how one becomes sensitized to an allergen.  Becasue the intestinal barrier function is compromised, perhaps due to a secretory IgA deficiency, or maybe just because of an exogenous irritant, the allergic protein is allowed to penetrate that barrier without being properly broken down, increasing the chances that it will be identified by the immune system as a foreign invader and that protein specific antibodies will be generated (IgE).  Hypersensitivity is most likely initiated by a breakdown of our innate defenses.  In fact, researchers have exposed rats to both cholera toxin and peanut protein at the same time in order to make them peanut allergic.  (The murine model of peanut allergy).  Cholera toxin is thought to be effective because it compromises the intestinal barrier function.

Now, with UC, it's true that it's an inflammatory process, but what initiates the inflammation?  From my research, it's been stated that a breakdown of the innate defenses in the intestine, perhaps by a defeciency of antimicrobial peptides such as defensins, which protect the normal mucosa extremely efficiently against adherent or entering microbes, is a possible cause.  A lack in the innate defense system of antimicrobial peptides may lead to a permanent but slow bacterial invasion triggering the inflammatory process

Also, a defect in regualtory T cell function has been implicated in the pathogenesis of both atopy and in UC.  As you may know, the regulatory cytokine IL-10 plays an important role in maintaining the barrier function.  Secretory IgA production is linked to the integrity of our mucosal barriers, and it's interesting to note that in atopic populations, researchers have often observed a defeciency of sIgA.

-beelady

[Ratnakar Kini]

Hi beelady,
Atopy is due to hypersensitivity and not due to immunodeficiency. Likewise UC is due to inflammatory process and immune activation and not immunodeficiency.

Atopy is due to Type I hypersensitivity and UC does not come under this group.

So atopy and UC are not related.
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The information provided is for patients’ education only and is not a medical advice. Always consult your personal physician for complete evaluation of your health problem.

- Ratnakar Kini M.D.