Gluten

Insoluble "gluten protein" consisting of gliadin and glutenin from cereals such as wheat, oats, rye, spelt, barley, green spelt or kamut. Gluten mainly determines the baking quality ("gas holding capacity") of the grain. They can bind up to three times their weight in water and, when moist, develop rubber-like elastic and plastic properties. In dough preparations, they form skeleton-like structures and ensure, among other things, that a fine-pored, loose dough is formed that does not separate during baking. Wheat provides the highest quality gluten in terms of quantity and quality.

Gliadins consist of a single polypeptide chain with intermolecular disulphide bridges. A toxic fraction is formed by enzymatic action (pepsin, pancrase enzymes) and consists of acid-soluble polypeptides with molecular weights between 0.5 and 1 kD. Gliadins are particularly poorly tolerated by rye and wheat.

Closely related are the avenin of oats and the hordein of barley. Remarkable is a certain sequence homology of alpha-gliadin with a protein encoded by adenovirus type 12. As this virus occurs in the intestine, this could be the starting point of a cross-reaction (Jäger L et al. 2001).

The triggering of autoimmunological reactions against gluten components (gliadin) has been described and is pathogenetically significant in, among others

• Celiac disease see also Celiac disease Skin changes
• Dermatitis herpetiformis (DhD)
• NCGS(non-celiac gluten sensitivity)

This causes autoantibodies against individual members of the transglutaminase enzyme family (9 members of this family have been described to date). In DhD, the intestinal changes often initially remain clinically asymptomatic, which is why DhD patients do not change their diet. High-affinity anti-TG autoantibodies probably only develop after several years of gluten provocation.

Wheat glutens are important allergens and triggers of IgE-mediated wheat-dependent exercise-induced anaphylaxis (WDEIA)

1. Jäger L et al (2001) Food allergies and intolerances. Urban & Fischer Publishing House Munich, Jena S 61
2. Nilsson N et al (2015) Wheat allergy in children evaluated with challenge and IgE antibodies to wheat components. Pediatric Allergy Immunol 26:119-125.
3. Rodríguez del Río Pet al. (2014) Oral immunotherapy in children with IgE-mediated wheat allergy: outcome and molecular changes. J Investig Allergol Clin Immunol 24: 240-248.
4. Sievers S et al (2016) Wheat protein recognition pattern in tolerant and allergic children. Pediatric Allergy Immunol 27:147-155.