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PubMed1978

[Allergy diagnosis in patients with bronchial asthma (bronchial provocation test, skin test and RAST) (author's transl)].

87 patients with bronchial asthma underwent skin test, RAST and measurment of airway resistance before and after inhalation of control solution as well as at least 10 times after each of one to four bronchial provocations (making up a total of 171 tests) with extracts of house dust, house dust mite, animal dander, mould spores and pollen in increasing concentrations. An actual clinical significance of the skin test reactions was found in 60% of all cases and of the RAST results in 66% of all cases. The overall agreement between skin test results and RAST results was 61%. The correlations between the different tests depended on the degree of hypersensitivity, on the tested allergen and on whether the results of skin test and RAST, respectively, were positive or negative. There existed a good correlation between the results of all three test methods and case history only for pollen allergens and animal dander. Noticeably often negative RAST results with house dust and mould spores, as well as positive skin tests with house dust mite and mould spores could not be confirmed by the provocation test. Important indications for a bronchial provocation test in asthmatics are doubtful case history, doubtful skin test or RAST results with the problem-allergens house dust, house dust mite and mould spores; the bronchial provocation test is especially commendable when drastic or cumbersome therapeutic measures (immunotherapy, change of home, change of job) are to follow or if late asthmatic reactions are expected.

Allergens↗
PubMedDate not supplied

[Specific bronchial provocation tests with flour in the diagnosis of occupational bronchial asthma].

The gold standard in the diagnosis of occupational asthma is the specific bronchial provocation test (sBPT), but other diagnostic criteria have been proven to have a similar sensitivity, mainly in asthma due to high molecular weight compounds. In order to assess wether some clinical findings can predict the positive response to sBPT, we studied 37 subjects (14 millers and 23 bakers) with suspected occupational asthma who underwent sBPT with wheat flour dust (dust exposure in a small cabin: geometric mean 12.1 mg/m3 for up to 30 min). A positive response to sBPT (FEV1 > 20%) was elicited in 20 subjects (11 early, 4 late, and 5 dual responses). There was no significant difference between subjects with positive or negative sBPT as regards mean age, smoking, length of employment, duration of symptoms, atopy (skin positivity to one or more common allergens) and PD20FEV1 methacholine. The percentage of subjects with work-related symptoms was significantly higher in subjects with positive sBPT with respect to subjects with negative sBPT (81% versus 41.2%, p < 0.01 by chi 2 test); furthermore, FEV1 was significantly lower in subjects with positive sBPT. The percentage of positive skin response to wheat flour extract (mean wheal diameter > or = 3 mm) was mildly but not significantly higher in subjects with positive sBPT (68.4% versus 41.2%). None of the following clinical factors (age < 35 years, asthma symptoms pre-existing occupational exposure, non smokers, atopy and bronchial hyperresponsiveness to methacholine), alone or in combination, were associated with higher prevalence of positive sBPT. We conclude that the response to sBPT in subjects with suspected occupational asthma due to flour dust can not be adequately predicted by other clinical, allergologic and functional data. Therefore, sBPT with flour dust should always be performed in subjects with suspected occupational asthma.

Adult↗
PubMed1994

[Comparative analysis of PD25-V50 and PD20-FEV1 as a judgement of bronchial provocation test].

PD25-V50 as a judgement of bronchial provocation test was compared with PD20-FEV1. Both PD25-V50 and PD20-FEV1 showed linear correlation, but PD25-V50 was more sensitive than PD20-FEV1 for the diagnosis of bronchial asthma, and had higher specificity and sensitivity, and lower false-negative and false-positiverate. Moreover PD25-V50 provided the advantages of shorter period of histamine provocation and lower dose of inhaled histamine, so that avoided the side effects of higher dose of histamine.

Adult↗
PubMed1992

Bronchial provocation tests in small animals: a quantified and automated procedure.

Bronchial provocation tests using aerosols in laboratory animals are difficult to standardize and quantify, because the amount of drug actually reaching the airways is unknown. To improve the quantification of aerosolized inhaled stimuli, we designed an apparatus that allows, in anesthetized intubated ventilated animals, control of temperature and hygrometry of inspired air, computerized measurement of pulmonary resistance, and fully automated delivery of a known amount of aerosolized drug directly into the trachea. Calibration of the aerosol delivery involved direct measurement of liquid delivered at the tip of the tracheal cannula. Despite all our efforts at standardization and full automation of all steps, reproducibility of aerosol delivery was poor, with stroke-by-stroke differences of 26 or 42%, according to whether an air-jet or an ultrasonic nebulizer was used. Histamine dose-response curves performed in 15 guinea pigs with this device confirmed marked differences among animals and also disclosed large intraindividual changes in bronchial responsiveness.

Aerosols↗
PubMedDate not supplied

[Inhalation bronchial provocation tests in children: comparative measurements of oscillation, occlusion pressure and plethysmographic resistance].

Examination of the lung function and bronchial provocation tests are useful for confirmation of an airway obstruction. There is a need for measurements independent of child cooperation. The standard method is body plethysmography. Forced oscillation method and interrupted occlusion method were recently introduced. Measurements of airway resistance by body plethysmography (Raw), by forced oscillation (Ros) and by interrupted occlusion method (Rvd) were compared during 78 inhalative bronchial provocation tests. The correlation index between Raw and Ros total was 0,84 and between Raw and Rvd 0,89. There is a good sensitivity and specifity in allergen bronchial provocation testing in all three methods. A bronchial sensitivity is confirmed in body plethysmography by 100% increase of Raw. In the interrupted method a 50% increase of Rvd in children smaller than 165 cm and in forced oscillation method a relative increase of 25% (0,15 kPa/l/s) is sufficient to assess a bronchial sensitivity to tested allergen.

Adolescent↗
PubMed1994

Bronchial provocation test with allergen: comparison between two different techniques.

Allergen bronchial provocation tests (BPTs) are often used for assessment of treatment efficacy. Usually, the allergen dose provoking a 20% fall of forced expiratory volume in one second (FEV1) (PD20) is determined on a prestudy day, and this single dose is administered for comparisons on study days. The inhalation of allergen may cause both an isolated early asthmatic response (EAR) or, more frequently, an EAR followed by a late asthmatic response (LAR). Whether the method used to elicit EAR, i.e. the inhalation of cumulative doses up to PD20 or the inhalation of a single predetermined PD20, give comparable results has not been established. We have, therefore, compared the results obtained using the two methods. Twelve patients underwent a first BPT with the increasing doses method and a second BPT with a single dose method. EAR, LAR, and allergen-induced increase of methacholine (MCh) sensitivity were compared. Both methods gave similar EAR's and LAR's although EAR tended to be more severe with the increasing dose method than with the single dose method. The ratio of postallergen/preallergen MCh sensitivity was poorly reproducible.

Adult↗
PubMed1995

[Value of a specific bronchial provocation test in comparison with other methods in diagnosis of atopic bronchial asthma].

The aim of this study was to determine the relation between specific Bronchial Provocation Test (sBPT), the serum specific IgE level (sIgE) and specific basophil histamine release (Dpt HR) in asthma patients, sensitive to Dermatophagoides pteronyssinus (Dpt). The studies were carried out on 30 mild asthma patients with positive case history and strongly positive skin tests with Dpt. In all the patients were performed following tests: BPT with histamine, serum specific IgE level against Dpt (sIgE Dpt), spontaneous basophil HR (spHR), anti-IgE depended basophil HR (aIgE HR), Dpt depended basophil HR (Dpt HR), sBPT with Dpt (sBPT Dpt). The positive results of sBPT Dpt were observed in 27 patients. Twenty six of them had the early¿ asthmatic response (EAR) at least, 19--dual asthmatic response (EAR and LAR) and isolated late asthmatic response (LAR) demonstrated only one patient. The correlation coefficient (r) between sIgE and Dpt HR was 0.4 p < 0.04, between sIgE and sBPT Dpt r = -0.4, p < 0.03, and between sBPT Dpt and Dpt HR r = -0.37, p < 0.05. The results showed a significant correlation between sIgE and Dpt HR, sIgE and sBPT Dpt, sBPT Dpt and Dpt HR and these tests appear to be of value in casual diagnosis of allergic bronchial asthma, but only sBPT makes possible to observe LAR.

Adult↗
PubMed1997

A new method for bronchial-provocation testing in asthmatic subjects using a dry powder of mannitol.

We developed a bronchial provocation test (BPT) with a dry powder preparation of mannitol. The mannitol was inhaled from gelatin capsules containing 5, 10, 20, or 40 mg to a cumulative dose of 635 mg, and was delivered via an inhalator, Halermatic, or Dinkihaler device. We studied the airway sensitivity to inhaled mannitol, the repeatability of the response, and the recovery after challenge in 43 asthmatic subjects 18 to 39 yr of age who had a 20% decrease in FEV1 in response to inhaling a 4.5% NaCl. We compared this with the airway response to methacholine in 25 subjects. The geometric mean (GM) for the dose of dry mannitol required to reduce the FEV1 by 15% of the baseline value (PD15) was 64 mg, with a 95% confidence interval (CI) of 45 to 91. Subjects responsive to mannitol had a PD20 to metacholine of < 7.8 mumol, with a GM of 0.7 mumol (CI: 0.4 to 1.2). For the first of two challenges to mannitol the PD15 was 59 mg (CI: 36 to 97) and for the second the PD15 was 58 mg (CI: 35 to 94) p = 0.91 (n = 23). Spontaneous recovery to within 5% of baseline occurred within 60 min and within 10 min after 0.5 mg terbutaline sulfate was inhaled. Arterial oxygen saturation (SaO2) remained at 93% or above during mannitol challenge. Subjects tolerated the inhalation of the mannitol well. A dry powder preparation of mannitol may be suitable to develop for bronchial provocation testing.

Administration, Inhalation↗
PubMed1978

[Reproducibility of bronchial provocative testing in bronchitis (author's transl)].

Bronchial reactivity was examined every 3 month in a follow-up study of 40 subjects mostly showing chronic nonspecific lung disease and all having bronchial hyperreactivity at the beginning of the study. Only 7 of them (17.5%) had constant hyperreactivity for the time of observation. There has been parallelism between test results and complaints in 72% of patients with chronic bronchitis and in 65.2% of the second group (mostly subjects with bronchitis). Seasons had no strong influence on bronchial reactivity. Bronchial provocative testing has proved as a valuabel method for verification of obstructive complaints. The test results shouldn't be interpreted without regarding clinical data. Using as a screening test a more detailed diagnostic and follow-up are necessary to avoid false and premature consequences. As to expert opinions and decisions on compensation the test results can correctly be interpreted only if reproducibility in the single case has been proved and if they are in agreement with the clinical signs and symptoms of the case.

Acetylcholine↗
PubMed1997

Prevalence of childhood asthma based on questionnaires and methacholine bronchial provocation test in Korea.

BACKGROUND: In most epidemiological survey studies, only subjective symptoms and past medical history of asthma have been used as diagnostic criteria. Even though a questionnaire survey can be performed in a large population study at low cost, limitations such as lack of objectivity and poor predictability in non-specific bronchial hyperresponsiveness cannot be avoided. OBJECTIVES: The purpose of this study was to elucidate the prevalence of current asthma based on questionnaires and methacholine bronchial provocation test, and the prevalence of atopy in Korea. METHODS: We performed modified ATS respiratory questionnaires and allergen skin-prick test with 10 common inhalant allergens among 3219 subjects aged 7-19 years in Seoul and a rural part of a small city, Chungju in Korea. Methacholine bronchial provocation tests were also performed among those who had asthma symptoms according to the questionnaire. The criteria of asthma was presence of both asthma symptoms and non-specific bronchial hyperresponsiveness. Atopy was defined as when an allergen induced weal size is same or larger than that caused by histamine. RESULTS: The prevalence of asthma based on questionnaires and methacholine bronchial provocation tests was 4.6%, while the prevalence of wheeze was 8.2% and 19.3% of total population complained of one or more respiratory symptoms related to asthma on the questionnaires. There was no significant difference according to age, sex and living area. The mean prevalence of atopy was 35.0% and the most common allergens were Dermatophagoides farinae (30.9%), Dermatophagoides pteronyssinus (27.5%), cat fur (20.4%) and cockroach (11.8%). The atopy prevalence in Chungju area was higher than that in Seoul and males showed a higher prevalence than females. The asthma prevalence was higher among atopics (6.8%) than among non-atopics (2.7%). None of questionnaire items were enough to predict the presence of bronchial hyperresponsiveness in terms of sensitivity, specificity and positive predictive value. CONCLUSION: The prevalence rate of current asthma in Korea was 4.6% and the prevalence rate of atopy in Korea was 35.0%. Questionnaire-based surveys are not enough to predict the actual prevalence of asthma.

Adolescent↗
PubMed1993

Diagnostic value of the bronchial provocation test with methacholine in asthma. A Bayesian analysis approach.

The Bayesian analysis was used in this study to investigate the diagnostic value of the bronchial provocation test with methacholine in patients with asthma. The best cutoff value of accumulated concentration of methacholine administered that caused a 20 percent fall in FEV1 post-saline (PC20) in our sample, determined with a receiver operator characteristic curve, was 15 mg/ml. The interval security of the test was established by a pretest probability between 0.16 and 0.87 and the best test results were obtained when pretest probability was 0.48. The positive final diagnostic gain of the test was maximal at this pretest probability. We conclude that the application of Bayes' theorem, considering the pretest probability of asthma and the sensitivity and specificity of the individual PC20 obtained, increases the accuracy of the bronchial provocation test with methacholine in the diagnosis of asthma.

Adult↗
PubMed2002

Use of aerosols for bronchial provocation testing in the laboratory: where we have been and where we are going.

Bronchial provocation testing with pharmacological agents that act directly on airway smooth muscle has important limitations. These include the inability to identify exercise-induced asthma (EIA), to differentiate the airway hyperresponsiveness (AHR) of airway remodelling from the AHR of active inflammation and to differentiate between doses of steroids. Recent studies show that tests that act indirectly to narrow airways are more sensitive than pharmacological agents for identifying airway inflammation and response to treatment. Adenosine monophosphate (AMP) is an indirect challenge that acts on mast cells to cause release of mediators. Hypertonic saline is another and, since its development in the 1980s, has become widely used in Australia. Hypertonic (4.5%) saline is used to identify those with active asthma, those with EIA and those who wish to enter certain occupations or sports (e.g., diving). The recent development, again in Australia, of a test that uses dry powder mannitol has promise for use in the laboratory, the office, or for testing in the field. AHR to mannitol identifies people with EIA and is an estimate of its severity. The mannitol response is modified by drugs used to prevent EIA, implying that similar mediators are involved. A mannitol test can be used to monitor response to steroids and is more sensitive than histamine for identifying persistent airway hyperresponsiveness in asthmatics well controlled on steroids. These findings suggest that indirect challenges give more useful clinical information about currently active asthma and the response to treatment than direct challenge and they will become more widely used.

Aerosols↗