IgE levels in intestinal juice.

This investigation was performed to determine the possible significance of the IgE levels in intestinal secretions for the recognition of type I food allergy (immediate hypersensitivity). Four groups of individuals were studied and compared with each other: (1) healthy controls and patients with gastrointestinal disorders not affecting the small intestine; (2) patients with small intestinal disease; (3) patients with various manifestations of allergy but without food intolerance; and (4) patients with atopic sensitivity to foods. Despite the presence of proteolysis in the intestinal fluid, a statistically highly significant increase of the intestinal IgE level was observed in patients of group 4 with type I food allergy and in patients of group 3 as compared with normals. This was associated with an increase in the serum IgE level. An increased synthesis of the IgE in the lamina propria of the small intestine is most probable, but not yet adequately established.