In vitro IgE production by peripheral blood lymphocytes and rectal mucosal biopsies and antigen-induced basophil degranulation in patients with inflammatory bowel disease.

IgE production by peripheral blood lymphocytes (PBL) and rectal mucosal biopsies in vitro has been examined in patients with ulcerative colitis (UC) and Crohn's disease (CD). The degranulation of peripheral blood basophils to food antigens has also been investigated in these patients. Mitogen-induced IgE production was reduced in patients with UC, but enhanced in PBL cultures from patients with CD. Increased numbers of basophils degranulated in the presence of cows' milk in UC patients, but normal responses occurred in patients with CD. This evidence supports the suggested role of IgE-mediated mechanisms involving mast cell/basophil interactions in the pathogenesis of inflammatory bowel disease.