# Allergy in the Gut



## eric (Jul 8, 1999)

I have posted this before but it is worth posting again. Interesting 1 to 2 percent.Allergy and the gut. Bischoff SC, Mayer JH, Manns MP Department of Gastroenterology and Hepatology, Medical School of Hannover, Hannover, Germany. bischoff.stephan###mh-hannover.de There have frequently been doubts as to the relevance of food allergy, in particular as far as the involvement of the intestinal tract is concerned. Several studies, however, have confirmed the existence of allergic reactions in the gut, with an estimated prevalence of about 1-2% in adults. Clinical symptoms are unspecific and include nausea, vomiting, abdominal pain, cramping and diarrhea. Intestinal mast cells, as well as intestinal eosinophils, have been shown to be involved in the pathogenesis of food-allergy-related enteropathy. In addition to classical IgE-dependent degranulation, further agonists have been demonstrated for mast cell activation, for example IL-4. The methods used to confirm the diagnosis of intestinal allergy are still insufficient. Until now, blinded oral challenge procedures with food antigens have been accepted as the 'gold standard' in diagnosing food allergy, although these tests have practical problems. Therefore, new test systems have been developed, such as endoscopic provocation tests, that may improve diagnostic procedures. Elimination diet still presents the main basis of therapy. Aspects to be focused on in the future are the role fo IgE-independent allergic mechanisms in intestinal allergy, the impact of cross-reactivity with other allergens and the relationship to other inflammatory bowel diseases such as Crohn's disease, ulcerative colitis, celiac disease and irritable bowel syndrome. Copyright 2000 S. Karger AG, Basel------------------ http://www.ibshealth.com/


----------



## JeanG (Oct 20, 1999)

Thanks for reposting this, Eric!







That 1-2% figure is interesting.JeanG


----------



## eric (Jul 8, 1999)

bump------------------ http://www.ibshealth.com/


----------



## Mike NoLomotil (Jun 6, 2000)

HI ERIC>I aree this is a good post as it is instructive of the minimal involvement of Type I Gel & Coombs reactions in the disease. The problem lies elsewher in the immune system.It reinforces the fact that most of the reaction-types which precipitate the associated food-intolerance symptoms in the gut (and other systemic symptomologic sets)ARE NOT IgE mediated allergic reactions. This 1-2% of the general population which suffers classic food allergy (Type I according to the Gel & Coombs classsification) represents 5% or less of ALL food or additive triggered immune responses. And existing lab methods for in vitro screening for these allergies remain notoriously non-predictive (JAMA says less than 50%). Fortunaely, these tests are not required to identify substances responsible for Type I reactions. Due to the speed of onset and characteristic presentation, oral challenge properly adiminstered has a very high rate of reliablity at identifying "food allergies".Depending upon the immunologist you want to talk to about "relative contribution" of other types of immune reactions to the overall picture, the other 95% of reactions to foods or additives are distributed among reaction-types mediated by IgG, IgA, IgM, Complement (C3, C4), T-Cell types, and then the pharmacotoxic reactions, direct cytotoxic reactions and then the last 5% est. can (at present) be attributed to enzymatic deficiencies of various types (though some immunologists feel that as work continues to progress, the percentage of observed reactions which are enzyme-related will probably increase,as the direct 'cell-toxic' reactions are better understood).The recruitment of mast cell reactions in the gut has also been conventionally attributed to Type I mechanisms only, but as it has been posted before there may be other mechanisms which elicit mast cell degranulation (example: direct-CNS effects). This is only the tissue reaction-effect on the myenteric plexus though. The circulating cell reactions can be seen in recruitment of all granulocyte type reactions, lymphocytic reactions and even platelet reactions (now that the platelet reactions can actually be detected).This article is of particular instructive value as it points out the minimal role of Type I Gel & Coombs reactions in food sensitivity thus IBS. If one only looks at the planets, the majority of astronomical phenomena go unobserved. So if one only looks to IgE one misses 95% of the reactions.--------ugh. Gtta go to Miami. Have a day!MNL


----------



## JeanG (Oct 20, 1999)

Hi Eric:Reading this reminds me of how important it is for us to educate ourselves on IBS. I've bumped up the "Advances in Irritable Bowel Syndrome" Lecture Series so I can start listening to them again. I would urge all of us to listen to at least some of the lectures, to see what a highly complicated condition IBS is, and how much the mind-gut connection plays into it.The url, in case any of you missed it, is at: http://www.conference-cast.com/ibs/Lecture...dRegLecture.cfm . There are 15 lectures that cover all aspects of IBS. I've listened to 5 and plan to do the rest of them also.







JeanG[This message has been edited by JeanG (edited 08-16-2000).]


----------

