Wheat hypersensitivity

Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan. Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan. Wheat allergy may be a misnomer since there are many allergenic components in wheat, for example serine protease inhibitors, glutelins and prolamins and different responses are often attributed to different proteins. Twenty-seven potential wheat allergens have been successfully identified. The most severe response is exercise/aspirin induced anaphylaxis attributed to one omega gliadin that is a relative of the protein that causes celiac disease. Other more common symptoms include nausea, urticaria, and atopy. Gluten sensitivity is not usually classified as a wheat allergy. Management of wheat allergy consists of complete withdrawal of any food containing wheat and other gluten-containing cereals (gluten-free diet). There are four major classes of seed storage proteins: albumins, globulins, prolamins and glutelins. Within wheat, prolamins are called gliadins and glutelins are called glutenins. These two protein groups form the classic glutens. While gluten is also the causative agent of celiac disease (CD), celiac disease can be contrasted to gluten allergy by the involvement of different immune cells and antibody types (See Comparative pathophysiology of gluten sensitivities), and because the list of allergens extend beyond the classic gluten category of proteins. Prolamins and the closely related glutelins, a recent study in Japan found that glutenins are a more frequent allergen, however gliadins are associated with the most severe disease. A proteomics based study found a γ-gliadin isoform gene. Glutenin (wheat glutelin) is a predominant allergen in wheat. Nine subunits of LMW-glutenin have been linked in connection with wheat allergies. At present many of the allergens of wheat have not been characterized; however, the early studies found many to be in the albumin class. A recent study in Europe confirmed the increased presence of allergies to amylase/trypsin inhibitors (serpins) and lipid transfer protein (LPT), but less reactivity to the globulin fraction. The allergies tend to differ between populations (Italian, Japanese, Danish or Swiss), indicating a potential genetic component to these reactivities. Respiratory allergies are an occupational disease that develop in food service workers. Previous studies detected 40 allergens from wheat; some cross-reacted with rye proteins and a few cross-reacted with grass pollens. A later study showed that baker's allergy extend over a broad range of cereal grasses (wheat, durum wheat, triticale, cereal rye, barley, rye grass, oats, canary grass, rice, maize, sorghum and Johnson grass) though the greatest similarities were seen between wheat and rye, and that these allergies show cross reactivity between seed proteins and pollen proteins, including a prominent crossreactivity between the common environment rye pollen and wheat gluten. Proteins are made of a chain of dehydrated amino acids. When enzymes cut proteins into pieces they add water back to the site at which they cut, called enzymatic hydrolysis, for proteins it is called proteolysis. The initial products of this hydrolysis are polypeptides, and smaller products are called simply peptides; these are called wheat protein hydrolysates. These hydrolysates can create allergens out of wheat proteins that previously did not exist by the exposure of buried antigenic sites in the proteins.