Bronchial challenge test

A 50-year-old spray painter developed severe asthma soon after the introduction of a new paint containing IPDI. A bronchial challenge test with the paint gave a positive response. 

This double-blind, placebo-controlled study included 58 children aged between 5 and 12 years 30 received sublingual desensitization and 28 a placebo for 18 months. The criteria for inclusion were rhinitis and asthma having progressed for at least 3 years. The criteria used to assess efficacy were based on the results of skin tests, symptom and medication scores, nasal inspiratory peak flow, nasal challenge test, nonspecific methacholine bronchial challenge test, assay of IgG (G1 and G4) specific to mites and the levels of T cells CD4 and CD8. 

All patients were monosensitized with a persistence of symptoms despite action to eliminate mites and treatment with inhaled corticosteroids. Patients were included after an 8-week observation period which made it possible to determine the lowest effective dose of budesonide, with the performance of skin tests, lung function tests and a methacholine bronchial challenge test. The efficacy criteria were the medication and symptom scores, global assessment of the patient by the physician, skin tests and total IgE, lung function tests and the methacholine bronchial challenge test. 

The results of positive bronchial challenge tests are considered to provide sufficient evidence for classification on their own. It is however recognized that in practice many of the examinations listed above will already have been carried out. 

Administration devices for medicines used to treat asthma and COPD are prescriptirm products, with an exception for some nebulised (medicine) formulations. Medicines such as amphotericin B or antibiotics (coUstimethate sodium, tobramycin sulphate or gentamicin) for nebulisation in CF therapy are sometimes stUl partly prepared by hospital pharmacists, and so are nebulised solutions for bronchial challenge testing. Although product formulation and the method of preparation of formulations for inhalation are not the main subjects of this chapter, recommendations are given in the subparagraphs about nebulisation. 

Pepys J, Hutchkroft BJ. Bronchial challenge tests in etiologic diagnosis and analysis of asthma. Am Rev Respir Dis 1975 112 829-859. 

In the methacholine challenge test, subjects inhale a drug that can cause the muscles in the small airways to contract. People with asthma will have a reduction in their FEVi after inhaling a low dose of this drug, reflecting increased "irritability" or bronchial h)q5erreactivity. 

An additional consideration is the safety assessment of agents that will be used for challenge stimuli in the evaluation of pharmacodynamics. In some cases, there is a long history of uneventful clinical use of tests, for example, bronchial challenge with histamine and methacholine. If used in a similar manner, there may be no need to consider performing safety studies in... 

From the first study in patients with local IgE against SEs [10] it appeared that the highest IgE concentrations were obtained from samples of aspirin-sensitive subjects. We therefore extended our observations in a nonallergic, but severely inflamed subgroup of patients, who also suffered from asthma. Subjects with nasal polyposis from Poland were classified as aspirin-sensitive (ASNP) or aspirin-tolerant (ATNP) asthmatics, based on a bronchial aspirin challenge test [47], Homogenates prepared from NP tissue were analyzed for concentrations of eosinophilic markers, total IgE and IgE antibodies to enterotoxins (SEA, SEC, TSST-1) [22], and compared to inferior nasal turbinates from healthy subjects. 

In addition to tracheobronchial secretions, bronchial smooth muscle is stimulated by the muscarinic agonists. Asthmatic patients respond with intense bronchoconstriction, secretions, and a reduction in vital capacity. These actions form the basis of the methacholine challenge test used to diagnose airway hyperreactivity. 

Occupational asthma was reported in a worker routinely exposed to suma dust. Sensitivity to the dust was confirmed by immediate skin test reactivity, a positive bronchial challenge (immediate response), and the presence of... 

Munn A (1965) Hazards of isocyanates. Ann Occup Hyg 8 163-169 Newman-Taylor AJ, Davies RJ, Hendrick DJ, Pepys J (1979) Recurrent nocturnal asthmatic reactions to bronchial provocation tests. Clin Allergy 9 213-220 O Brien IM, Harries MG, Burge PS, Pepys J (1979 a) Toluene di-isocyanate-induced asthma. 1 Reactions to TDI, MDI, HDI, and histamine. Chn Allergy 9 1-6 O Brien IM, Newman-Taylor AJ, Burge PS, Harries MG, Fawcett IW, Pepys J (1979b) Toluene di-isocyanate-induced asthma. 2 Inhalation challenge tests and bronchial reactivity studies. Clin Allergy 9 7-15... 

The first three patients with allergic contact dermatitis were exposed for 2-8 months to PU chemicals containing different diisocyanates - in paint laboratory work (IPDI), in PU foam spraying (MDI) and car spray painting (HDI) - before they developed dermatitis. On patch testing, they reacted to IPDI, TMDI, TDI, HDI and MDA. Two of the patients also had diisocyanate-induced asthma confirmed by bronchial challenge, in one case with MDI and in the other with HDI (Kanerva et al. 1989). 

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