Immediate hypersensitivity to bakery, brewery and wine products in yeast-sensitive atopic dermatitis patients

Ultrafiltered (> 1000 Da) samples of beer, aged red wine, young white wine, sparkling wine and extracts of fresh wheat bread and dried rye bread were analysed by skin-prick test (SPT), radioallergosorbent test (RAST) inhibition, sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting to find out if they contain Saccharomyces cerevisiae (S. cerevisiae, baker's yeast) allergens. Serum pool consisting of S. cerevisiae positive sera was used in the assays. The results were compared with freeze-dried reference S. cerevisiae and cereal antigens. The beer, bread, red wine and sparkling wine extracts elicited immediate reactions. However, no evident correlation with suspected symptoms was observed. White wine extract caused reactions in four out of six atopic dermatitis (AD) patients with symptoms, and in five out of seven symptom-free AD patients and in two of the 24 controls. In SDS-PAGE, protein bands were found in wheat and rye bread extracts and beer. In IgE immunoblotting, however, no staining was seen with the S. cerevisiae positive sera suggesting that they were of cereal origin. In white wine and champagne extracts a non-specific staining was seen in the region 20 kDa representing, e.g. lectin-like activity. No baker's yeast antigen could be detected in brewery and bakery products with IgE-immunoblotting even in the excessively concentrated extracts. The IgE mediated allergy to baker's yeast alone should thus not lead to denial of bakery, brewery and wine products.