Sera from two subjects with bakers' asthma and six patients with coeliac condition were examined for the presence of IgE antibodies with specificities for wheat flour components. Sera were studied using the radioallergosorbent test (RAST) together with whole flour and thirteen purified and partially purified flour fractions.

IgE antibodies to a number of flour components were demonstrated in the allergic bakers' sera, but the strongest reactivities were observed with wheat albumins and globulins. A more detailed examination of the flour water-soluble proteins using RAST inhibition methods demonstrated that albumins were more reactive with the allergic sera than the globulins. Apart from the results with the water-soluble proteins, the two sera showed a different pattern of reactivity with the other flour preparations.

No IgE antibodies to whole flour or any of the flour components, including A gliadin, were found in the coeliac sera. Failure to detect wheat gluten- or gliadin-specific IgE antibodies indicates that IgE-mediated reactions are not important in the pathogenesis of coefiac condition. Levels of total IgE in the sera from the coeliac subjects were elevated and, with two of the sera, some success was achieved in identifying the allergens responsible for the elevation. We propose that elevation of serum IgE may frequently occur in coeliac condition and may arise due to an increased uptake of antigens via the damaged intestinal mucosa.