Airway Response to Allergen

The nonallergic airway responsiveness is generally measured with inhalation provocation tests with either histamine or methacholine. This relationship is strong enough that the dose of allergen required to produce a target EAR can be predicted, albeit crudely, by measurement of skin test endpoint (related to the level of allergen-specific IgE) and the provocation concentration of hista- 

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The mechanism of allergen-induced increase in airway responsiveness is uncertain. Animal studies suggest the need for polymorphonuclear leukocytes (43). The relationship of this to the LAR, the relationship of the LAR to allergen-induced airway inflammation (see below), and the correlation between airway responsiveness and airway eosinophilia (44) have led to the hypothesis that allergen-induced increase in airway responsiveness is somehow caused by airway inflammation. In fact, until recently, measurement of allergen-induced increases 

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Bhagat R, Swystun VA, Cockcroft DW. Salbutamol-induced increased airway responsiveness to allergen and reduced protection versus methacholine dose response. J Allergy Clin Immunol 1996 97(1 Pt l) 47-52. 

Cockcroft DW, McParland CP, Britto SA, Swystun VA, Rutherford BC. Regular inhaled salbutamol and airway responsiveness to allergen. Lancet 1993 342(8875) 833-7. 

Cockcroft DW. Inhaled beta2-agonists and airway responses to allergen. J Allergy Clin Immunol 1998 102(5) S96-9. 

InCTeasing airway responsiveness to allergens, viruses, and air pollutants in later cbildhood or adult life. 

Nathan RA, Kinsman RA, Spector SL, Horton DJ. Relationship between airway response to allergens and nonspecific bronchial reactivity. J Allergy Clin Immunol 1979 64 491-499. 

Cockcroft DW, Murdock KY, Kirby J, Hargreave FE. Prediction of airway responsiveness to allergen from skin sensitivity to allergen and airway responsiveness to histamine. Am Rev Respir Dis 1987 135 264-267. 

Cockcroft DW, Killian DN, Mellon JJA, Hargreave FE. Bronchial reactivity to inhaled histamine a method and clinical survey. Clin Allergy 1977 7 235-243. Cockcroft DW, Swystun VA, Bhagat R. Interaction of inhaled P2 agonist and inhaled corticosteroid on airway responsiveness to allergen and methacholine. Am J Respir Crit Care Med 1995 152 1485-1489. 

Boulet LP, Cockcroft DW, Toogood J, Lacasse Y, BaskerviUe J, Hargreave FE. Comparative assessment of safety and efficacy of inhaled eorticosteroids report of a committee of the Canadian Thoracic Society. Eur Respir J 1998 11 1194-1210. Marshik PL, Thomas D, Ahrens R, Braver H, Hendeles L. Dose-response of inhaled beclomethasone (B) for attenuating the airway responses to allergen. J Allergy Chn Immunol 1996 97 316. 

Bronchial asthma is defined as a chronic inflammatory disease of the lungs it affects an estimated 9 to 12 million individuals in the U.S. Furthermore, its prevalence has been increasing in recent years. Asthma is characterized by reversible airway obstruction (in particular, bronchospasm), airway inflammation, and increased airway responsiveness to a variety of bronchoactive stimuli. Many factors may induce an asthmatic attack, including allergens respiratory infections hyperventilation cold air exercise various drugs and chemicals emotional upset and airborne pollutants (smog, cigarette smoke). 

Oxidant gases such as nitrogen dioxide and ozone have also been studied with regards to their role in the development of asthma. Both of these gases have been associated with asthma exacerbations (Pamia et al., 2002), have increased airway responsiveness to inhaled allergens in asthmatic subjects (Jenkins et al., 1999), and can produce inflammatory changes in the airways (Davies Devalia, 1993 Devalia et al., 1999). Asthmatic children exposed to exhaust emissions experience more symptoms and reduction in peak flow measurements and increased hospital admissions for asthma exacerbations (Wyler et al., 2000). 

Tunnicliffe, W.S., P.S.Burge, and J.G.Ayres. 1994. Effect of domestic concentrations of nitrogen dioxide on airway responses to inhaled allergen in asthmatic patients. Lancet 344(8939-... 

Fig. 9.3 Aerosolized STAT-1 decoy ODN decreases development of airway hyperreactivity in allergen-mediated bronchial asthma in mice. Airway responsiveness to aerosolized methacholine was measured in unrestrained, conscious mice and bronchial hyperresponsiveness (Penh) values were...

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