Histamine release from human colonic mucosa in response to anti-IgE

Testing of tissue particles for mediator release may be very useful for the diagnosis of localized immunological abnormalities or allergies. The aim of this study was to set up a general procedure to test the reaction of large bowel mucosa to stimuli via the IgE-mediated pathway. Therefore, tissue particles from normal subjects and from patients suffering from different diseases (Crohn's disease, ulcerative colitis, intestinal polyps) obtained at routine coloscopy were exposed to either Hanks or anti-IgE solution to determine the spontaneous or the anti-IgE-induced histamine release, expressed as the percentage of the total histamine content of the biopsy. Histamine was measured using the single isotope radioenzymatic assay. In general, whereas anti-IgE interestingly reduced the histamine release compared to the spontaneous in most of the patients within the polyps group, there was a stimulating effect of anti-IgE throughout all other groups. Thus, the study confirms the possibility of performing functional tests using biopsy particles from the colon.