Bronchoprovocation

Airway hyperresponsiveness is defined as the exaggerated ability of the airways to narrow in response to a variety of stimuli. Although AHR exists in patients without asthma, it is a characteristic feature of asthma and appears to be directly related to airway inflammation and the severity of asthma.1,3 Treatment of airway inflammation with inhaled corticosteroids attenuates AHR in asthma but does not eliminate it.1 Clinically, AHR manifests as increased variability of airway function. Although not commonly used to diagnose asthma, AHR can be evaluated clinically using a methacholine or histamine bronchoprovocation test. 

Assessment of diurnal variation of PEF may be useful in patients who have asthma symptoms and normal spirometry. When spirometry is equivocal, a 20% or greater decrease in FEV after the administration of methacholine is diagnostic for asthma. A negative bronchoprovocation test with methacholine may help rule out asthma. 

Park, H.S., et al., Specific IgG, but not specific IgE, antibodies to toluene diisocyanate-hu-man serum albumin conjugate are associated with toluene diisocyanate bronchoprovocation test results, J. Allergy Clin. Immunol,. 104, 847, 1999. 

Bronchoprovocation tests using an occupational agent are infrequently performed because only a few medical facilities in the United States are equipped to perform this test. 

Lopez M, Voigtlander JR, Lehrer SB, Salvaggio JE Bronchoprovocation studies in basidiospore-sensitive allergic subjects with asthma. J Allergy Clin Immrmol 1989 84 242-246. 

Messina MS, Smaldone GC. Evaluation of quantitative aerosol techniques for use in bronchoprovocation studies. J Allergy Clin Immunol 1985 75(2) 252-257. 

O Riordan TG, Walser L, Smaldone GC. Changing patterns of aerosol deposition during methacholine bronchoprovocation. Chest 1993 103(5) 1385-1389. 

Diagnosis of aspirin-induced asthma requires a detailed medical history. The definitive diagnosis is made by aspirin provocation tests, which may be done via different routes. An oral provocation test is used commonly where threshold doses of aspirin induce a positive reaction measured by a drop in forced expiratory volume in 1 second (FEVi) and/or the presence of symptoms. A nasal provocation test is done by the application of one dose of lysine-aspirin, and aspirin sensitivity is manifested with clinical symptoms of watery discharge and a significant fall in inspiratory nasal flow. When lysine-aspirin bronchoprovocation was compared with oral aspirin provocation, both methods were equally sensitive. ... 

Challenge of sensitized subjects with inhaled allergen has been a vital experimental approach in asthma research since the first bronchoprovocation studies were performed by Max Samter in Berlin in 1933. Allergen inhalation results in an early bronchoconstrictor ( asthmatic ) response (EAR) at 5 to 10 minutes lasting up to an hour and, in about half of subjects, a late bronchoconstrictor response (LAR) starting at 2 to 3 hours and lasting for 12 to 24 hours (Pepys, 1973). 

Cases of occupational sensitization to the compound papain have been reported in a number of persons working with this compound. Sensitization has been confirmed by skin prick testing, detection of specific IgE antibodies, and specific bronchoprovocation tests (Van Kampen et al. 2005). 

Standardized and controlled inhalation challenge with allergen has become a valuable laboratory tool in investigating the pathogenesis and pharmacotherapy of IgE-mediated asthmatic responses (1). This chapter reviews the history and science of standardized bronchoprovocation with allergen and the value of these tests in understanding the pathophysiology and treatment of asthma. 

VI. Predicting the Clinical Efficacy of Asthma Drugs from Their Inhibitory Effect on Allergen Bronchoprovocation... 

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