Trees within the order Fagales possess particularly potent allergens, e.g. the prototypical Bet v 1, the major white birch (Betula 5️⃣ verrucosa - now called B. pendula) pollen antigen. Bet v 1 is the main cause of type I allergies observed 5️⃣ in early spring. Type I, or immunoglobulin E-mediated (IgE-mediated) allergies affect 1 in 5 people in Europe and North America. 5️⃣ Commonly observed symptoms are hay fever, dermatitis, asthma and, in severe cases, anaphylactic shock. First contact with these allergens results 5️⃣ in sensitisation; subsequent contact produces a cross-linking reaction of IgE on mast cells and concomitant release of histamine. The inevitable 5️⃣ symptoms of an allergic reaction ensue.
Categorization [ edit ]
A nomenclature system has been established for antigens (allergens) that cause IgE-mediated 5️⃣ atopic allergies in humans.[2] This nomenclature system is defined by a designation that is composed of the first three letters 5️⃣ of the genus; a space; the first letter of the species name; a space and an Arabic number. In the 5️⃣ event that two species names have identical designations, they are discriminated from one another by adding one or more letters 5️⃣ (as necessary) to each species designation.
The allergens in this family include allergens with the following designations: Bet v 1, Dau 5️⃣ c 1, and Pru a 1. Other proteins belonging to this family include the major pollen allergens:
Structure [ edit ]
qual a melhor casa de aposta online