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Mast celi iSjp	Cross-linking of IgE that binds to high affinity Fcc receptors leads to release of a variety of mediators key to the earty-phase response including histaminę, mast celi proteases and leukotrienes. Stores and secretes a rangę of pro-inflammatory cytokines
Eosinophil	Appearance in sputum predates and predicts asthma exacerbations. Presence in airway suggests corticosteroid responsrveness. Charcot-Leyden crystals found in sputum derived from eosinophil products. Eosinophil granules contain an array of proteases, including major basie protein, with the potential to disrupt airway epithelium
T lymphocyte	Coordinates the reeruitment and behaviourof other inflammatory cells. Th2 cells secrete cytokines that promote the allergic response. Increased numbers of activated T cells present during asthma exacerbations. Patients with corticosterołd-resistant asthma have shown in vitro T-cell corticosteroid resistance
Ncutrophil	Identified in increased numbers in the airways of patients with severe and near-fatal asthma. Also a feature in some forms of occupational asthma. Predominance in sputum may predict poor response to inhaled corticosteroids
Macrophage C ^	Secretes Chemicals likely to be relevant to injury and repair including the secretion of growth factors that may be involved in airway wali remodelling
Epithclium	Epithelial integrity disrupted, facilitating increased antigen translocation. Creola bodies (clumps of shed epithelial cells) and Curschmann's spirals (strips of desquamated epithelium) seen in tnopsies from asthmatic patients. Participates in inflammatory response by secreting pro-inflammatory cytokines and growth factors. Increased mucus secretion and reduced mucociliary clearance. Subepithelial basement membranę thickened
Airway smooth muscle	Undergoes hypertrophy and hyperplasia contributing to airway wali remodelling. Altered function contributes to airway hyper-reactivity. Secretes pro-inflammatory cytokines and growth factors
Endothelium	Increased microvascular permeability contributes to increased mucus secretion. Expression of adhesion molecules promotes reeruitment of inflammatory cells
Neuronal dysfunction	Non-adrenergic non-cholinergic (NANC) nerves promote bronchodilatation; defects proposed as a potential mechanism of increased bronchial tonę. Neuropeptides influence function of inflammatory cells. Remains unclear whether cholinergic mechanisms important in stable asthma but increased cholinergic tonę a feature of acute asthma

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