Pathogenic mechanism Asthma is Characteristic of hyper reactivity of the airway Chronic (allergic) inflammation is the basic lesion of asthma
Pathogenic mechanism • Asthma is Characteristic of hyperreactivity of the airway • Chronic （allergic） inflammation is the basic lesion of asthma
Allergic inflammation is divided into 3 subtypes according to the different cytokines secreted by cd4 Th cell Th0、 Thl and th2。 Investigations have shown that allergic reactions like asthma are mediated by Th2 cells There is an increase or predominance of Th2 or its cytokines. The resulting airway inflammation could be classified into the following two types 1. IgE mediated and t lymphocyte dependent pthway 2. Nonlge mediated and T lymphocyte dependent pathway
Allergic inflammation Is divided into 3 subtypes according to the different cytokines secreted by CD4 Th cell: Th0、Th1 and Th2。Investigations have shown that allergic reactions like asthma are mediated by Th2 cells. There is an increase or predominance of Th2 or its cytokines. The resulting airway inflammation could be classified into the following two types: 1. IgE mediated and T lymphocyte dependent pthway 2.NonIgE mediated and T lymphocyte dependent pathway
Immunologic factors the role of ige mediation The combination of allergen with specific IgE triggers the degranulation of the mast cells and eosinophils, resulting in release of mediators including leukotrienes C, D,E, and the subsequent smooth muscle contraction edema of the mucosa increase of secretion, and finally stenosis of the bronchioles which all contribute to asthma. Total serum Ige or specific serum ige titer increase is allergic reactions might be preser ting type I seen in patients with asthma, indi
Immunologic factors the role of IgE mediation • The combination of allergen with specific IgE triggers the degranulation of the mast cells and eosinophils, resulting in release of mediators including leukotrienes C,D,E, and the subsequent smooth muscle contraction, edema of the mucosa, increase of secretion, and finally stenosis of the bronchioles ,which all contribute to asthma. Total serum IgE or specific serum IgE titer increase is seen in patients with asthma , indicating type I allergic reactions might be present
nonlgE mediated, T lymphocyte dependent pathway In delayed type allergic reaction Th2 cell directly initiates imflammatory response by activation and agglutination of various inflammatory cells via the release of multiple cytokines(L-4、I-13、I3 IL-5)
nonIgE mediated, T lymphocyte dependent pathway • In delayed type allergic reaction, Th2 cell directly initiates imflammatory response by activation and agglutination of various inflammatory cells via the release of multiple cytokines(IL-4、IL-13、IL-3、 IL-5）
Neuromental factors The complicated autonomic innervation of the bronchopulmonary sysytem includes cholinergic, adrenergic nonadrenergic and noncholinergic nerves. B-adrenergic receptor malfunction and the increased tone of the vagus, or with simultaneous increase of a adrenergic reactivity, would promote contraction of the smooth muscle and secretion of the glands resulting in attack of asthma
Neuromental factors The complicated autonomic innervation of the bronchiopulmonary sysytem includes cholinergic, adrenergic ,nonadrenergic and noncholinergic nerves. -adrenergic receptor malfunction and the increased tone of the vagus, or with simultaneous increase of - adrenergic reactivity,would promote contraction of the smooth muscle and secretion of the glands, resulting in attack of asthma