| Popis: |
The increased production of IgE forms the hallmark of the atopic type of allergy and has implications for many cell types involved. The importance of IgE was first recognized in immediate type hypersensitivity or Type I hypersensitivity. The major effector mechanism in this type of hypersensitivity is the IgE-dependent stimulation of tissue mast cells and their circulating equivalent, the basophils. Cross-linking of IgE, bound to the high affinity IgE receptor (FceRI) expressed on these cells, by allergens results in the rapid release of a variety of mediators, including histamine, leukotrienes, prostaglandins, and several proteases such as tryptase and chymase, and has been demonstrated more recently, interleukin 4 [1-3]. The presence of these mediators results in tissue-specific symptoms like hay-fever, broncho-constriction, and urticaria as classical manifestation of IgE-dependent type I hypersensitivity reactions. |
