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PubMed1995

[Behavior of various spirometry parameters during bronchial provocation tests with D. pteronyssinus in patients with asthma, sensitized to housedust mites].

Changes in particular spirometry parameters during specific bronchial provocation test (BPT) with an allergen in asthmatics sensitized to house dust mites were evaluated. Studies were carried out on 130 patients. Specific BPT with D. pteronyssinus was performed according to the Ryan's method using a jet De Villbiss 646 nebuliser powered by compressed air and connected to the French Rosenthal dosimeter. The spirometry was measured using Pneumoscreen II (Jaeger - Germany). The provocation was terminated when a value of FEV1 fell at least 20% from baseline and then the spirometry parameters were measured hourly for a period 8 hours. Early and late asthmatic responses were founded. Results were expressed as a percentage of the maximum decrease from the baseline in particular parameters. To the statistical calculations only positive sBPT results founded in 96 patients were selected. The mean values of the decreases during of the EAR were as follow: FEV1 = 30.6 +/- 9.9%, FVC = 18.9 +/- 9.9%, FEV/FVC = 14.6 +/- 9.2%, FEV25-27 = 41.5 +/- 15.7%, PEF = 30.8 +/- 15.7%. The correlation coefficients were between FEV1 and FVC -0.57, FEV1 and FEV1/FVC -0.56, FEV1 and FEF25.75 -0.65, FEV1 and PEF -0.6. The results were statistically significant. Decreases in FEV1 and PEF were very similar each other. The greatest changes were observed in FEF25.75. The curves of the FEV1 and PEF averages observed during LAR were quite close to each other and almost parallel. The usefulness of the both parameters seems to be equal.

Animals↗
PubMedDate not supplied

[Study of the bronchial provocation test with Alternaria in the diagnosis of childhood asthma: sensitivity, specificity, reproducibility].

The results of the cutaneous tests with fungus, and the repercussion of the fungal allergens in asthma via inhalatory route has been a controversial subject for many years. The lack of characterization, purification and standardization of the allergens make the results of the cutaneous tests highly variable. The diagnostic value of the bronchial provocation test (BPT) in asthma, associated with suspicious fungal hypersensitivity, correctly performed with adequate controls and concentrations of non-irritant fungal allergens has been emphasized by various authors. The motive of the present study to demonstrate, by means of the BPT with Alternaria, if the lung is the target organ of hypersensitivity demonstrated by cutaneous tests and RAST, comparing the obtained results by the Score of FOUCARD (fig. 1), with the result of the inhalatory test. The specificity and reproductibility of the BPT was likewise verified according to the employed allergen and its non-unspecific irritant concentrations to the airway. Twenty patients of both sexes, with ages ranging between 7 and 14 years, distributed in two groups, were studied and diagnosed as having bronchial asthma. Group I: Fourteen patients diagnosed with asthma, for hypersensitivity to Alternaria with Score of FOUCARD equal or greater than 5 (Table I). Group II: Control group composed of 6 patients with negative allergological findinds to Alternaria with bronchial hyperreactivity demonstrated in for cases by BPT positive against Dermatophagoides and in two cases with positive methacholine test (PC20 less than 8 mg./ml.). The inhalation of the allergen was performed following the described method by Cockcroft.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1977

A new simple spirometric index for use with bronchial provocation tests.

Spirometric indices such as the forced expiratory volume in one second (FEV1), the maximal expiratory flow rate (MEFR) and the maximal midexpiratory flow rate (MMFR) can be criticized for use with bronchial provocation tests since they are either partly effort-dependent or dependent on the forced vital capacity (FVC). These criticisms can be avoided by the use of a new index corresponding to the volume of air expired in one second starting at 75% of the control FVC, called the (FEV1)-25. This study was performed to evaluate the relative sensitivity of the (FEV1)-25 and the classical FEV1 in detecting airway obstruction caused by an inhaled carbachol aerosol in 20 asthmatic subjects. The mean fall in (FEV1)-25 of 46% following carbachol inhalation compared with a mean fall in FEV1 of 35% indicates that, in addition to its theoretical advantages, the (FEV1)-25 is a sensitive index for use with bronchial provocation tests.

Adolescent↗
PubMed1987

[Bronchial provocation tests using hyperventilation].

The appearance of an asthmatic crisis in the minutes following physical exercise is common in symptomatic asthma. Exercise induced asthma (EIA) is linked to hyperventilation; voluntary isocapnic hyperventilation is capable of triggering a crisis. It is well established at present that EIA and post-hyperventilation asthma (HIA) are triggered by a rise in heat and water loss by the airways, which is inherent in hyperventilation. The respective role of water loss and cooling the airways are uncertain but one tends to think at the present time that the primary stimulus is the variation in osmolality of the liquid lining the epithelium. However, a relationship between the quantity of energy dissipated in the airways and the severity of EIA or HIA exists, although it is less tight than was once thought. This is perhaps not surprising, as the intermediary mechanisms connecting the stimulus to the response of the airways are poorly understood. All in all physical exercise and isocapnic hyperventilation of dry air and possibly cold air are useful and equivalent non-specific bronchial provocation tests, if only the ventilation and physical properties of the inhaled air are the same. Hyperventilation lends itself better than exercise to establishing dose-effect curves linking bronchial response to minute ventilation. Recommendations concerning the interruption of drugs, the measurement of the response and the assessment of the results are the same as with other non specific bronchial provocation tests with irritant substances or pharmacological agents.

Asthma, Exercise-Induced↗
PubMed1985

Beta-adrenoceptor blockade with propranolol and bronchial responsiveness to a number of bronchial provocation tests in non-asthmatic subjects.

The role of beta-adrenoceptors in the mechanisms of bronchial hyperresponsiveness was studied in 20 normal subjects. Propranolol 120 mg b.d. or placebo was taken for one week. Four bronchial provocation tests: exercise, inhalation of nebulised water, histamine, and methacholine, were carried out before and during the last 2 days of the treatments. FEV1 and flow rate at 50% of vital capacity (V50) were measured. Cardio-vascular beta-blockade with propranolol, measured by reduction in exercise heart rate, was shown in 17 subjects. Propranolol enhanced bronchial responsiveness to some tests in some subjects, but there was no consistent pattern. For the group, the only significant increases in response were 1) the maximum fall in V50 on methacholine challenge (P less than 0.05, paired t-test, n = 17), 2) the dose of methacholine giving a 10% fall (PD10 value) in FEV1 (p less than 0.05 n = 11). These results do not support the concept of decreased beta-adrenoceptor responsiveness as a single lesion leading to abnormal bronchial reactivity.

Adolescent↗
PubMed2003

The effect of montelukast on bronchial provocation tests and exhaled nitric oxide levels in asthmatic patients.

BACKGROUND: Leukotriene antagonist therapy in asthmatic patients alleviates symptoms and improves exercise tolerance, however the effect of these drugs on bronchial provocation tests and exhaled nitric oxide levels are less clearly established. OBJECTIVE: To determine the effect of montelukast treatment on airway hyperresponsiveness to exercise, methacholine and adenosine-5'-monophosphate and on exhaled nitric oxide levels in steroid-naive asthmatics. METHODS: Following a 2 week run-in period, 20 mild to moderate asthmatics were enrolled in an open label 6 week trial of oral montelukast-sodium therapy. Bronchial hyperreactivity (exercise, methacholine and adenosine-5'-monophosphate challenges) and exhaled nitric oxide levels were measured before and after the 6 week period. RESULTS: Montelukast treatment resulted in a significant improvement in exercise tolerance: median delta FEV1 20.0% (range 0-50) prior to treatment vs. 15.0% (range 0-50) post-treatment (P = 0.029). A significant difference was also observed for exhaled NO following therapy: median NO 16.0 ppb (range 7-41) vs. 13.0 (range 4.8-26) (P = 0.016). No change was seen in baseline lung function tests (FEV1, MEF50) or in the bronchial responsiveness (PC20) for methacholine and adenosine-5'-monophosphate. CONCLUSIONS: This study demonstrates that the leukotriene antagonist montelukast-sodium reduces bronchial hyperreactivity in response to exercise and reduces exhaled nitric oxide levels but has little effect on bronchial responsiveness to methacholine and adenosine challenges.

Acetates↗
PubMed1999

Occupational asthma in a grain worker due to Lepidoglyphus destructor, assessed by bronchial provocation test and induced sputum.

BACKGROUND: Occupational asthma (OA) can be a debilitating disease even when removal from the workplace is achieved. Today, the "gold standard" in the assessment of OA is the bronchial provocation test (BPT). Induced sputum is a non-invasive method of exploring airway inflammation which can provide additional information about such challenges and thus could be applied in OA diagnosis and monitoring. METHODS: We report the study carried out in a grain worker sensitized to Lepidoglyphus destructor (Ld), who suffered from mild asthma at the workplace. Skin prick test and specific serum IgE were measured. Ld-BPT was performed, and the changes in eosinophil rates, and ECP and tryptase levels in induced sputum were studied 30 min and 18 h after Ld-BPT. We also determined the changes in nonspecific bronchial hyperresponsiveness (NSBH), given as PD20 values. To assess the specificity of the changes, we also carried out sputum induction and methacholine challenge after barley-BPT. RESULTS: An isolated immediate response was obtained with Ld-BPT, while barley-BPT was negative. Induced sputum showed higher tryptase levels 30 min after Ld-BPT, and higher eosinophil and epithelial cell percentages and ECP levels 18 h after Ld-BPT. There was also a decrease in methacholine PD20 values after Ld-BPT. Those changes were not observed after barley-BPT. CONCLUSIONS: The study of eosinophilic and mast-cell markers in induced sputum provides additional knowledge about the inflammatory process occurring in the airways, suggesting that the study of induced sputum should be considered in the assessment of OA.

Adult↗
PubMedDate not supplied

[Indications and utility of allergen provocation testing].

Specific bronchial provocation tests have been used to confirm diagnosis, as a laboratory model for the study of asthma, and to evaluate the efficacy of immunotherapy with allergen extracts. However, despite the advances achieved in our knowledge of the etiopathogenic mechanisms of asthma, bronchial provocation tests with allergens have certain methodological limitations. These are due to the difficulty of evaluating these tests as regards which markers of inflammation (exhaled nitric oxide, carbon monoxide, etc.) should be investigated and at what points in the chronology of the asthmatic response. The current parameters used to assess respiratory function (FEV1, mainly) do not seem to be the most ideal nor do their percentage reductions, usually established by use, always serve to identify a bronchospastic and inflammatory response. Furthermore, the allergen doses indicated in the various protocols do not mimic natural exposure to these allergens, thus introducing an important bias in the interpretation of the results. In this sense, another and no less important difficulty is the lack of adequate standardization of the characteristics of the allergens used; the development of recombinant allergens may eliminate this obstacle and improve the reproducibility of the tests. In view of the above, the requirement of a positive bronchial provocation test to a specific allergen in the etiological diagnosis of asthma does not seem reasonable nor does it seem reasonable that specific immunotherapy is not indicated if the test is negative or that evaluation of its efficacy lies in a negative result for a previously positive test. This premise does not take into account the fact that bronchial reactivity is subject to variables that are difficult to control (prior natural exposure to the allergen, for example).

Allergens↗
PubMed1988

Cross-reaction between aromatic isocyanates (TDI and MDI): a specific bronchial provocation test study.

A study was performed on twenty-five workers exposed to polyurethane varnishes exclusively catalysed with TDI, who developed asthma to this substance. The aim of the study was to establish, using bronchial provocation tests, whether a cross-response to MDI exists. The results were positive but no definitive evidence has been reached because there was cross-response in only 48% of cases. It is interesting, however, that cross-responders did not predominate among the subjects with a late reaction to TDI (P = 0.0038), whereas cross-responders were in the majority among the subjects with a dual reaction to TDI (P = 0.0334). It is possible that the pattern of the asthmatic reaction to BPT with TDI influences the cross-reaction to other isocyanates.

Adult↗
PubMed1986

Diagnosis and immunotherapy of mould allergy. III. Diagnosis of Cladosporium allergy by means of symptom score, bronchial provocation test, skin prick test, RAST, CRIE and histamine release.

Thirty-three adult asthmatic patients suspected of mould allergy were investigated by in vivo and in vitro tests in order to establish a specific diagnosis of asthma caused by the mould species Cladosporium. The patients were evaluated by daily symptom scores in the peak Cladosporium season, bronchial provocation test (BPT), skin prick test (SPT), RAST, histamine release from basophil granulocytes (HIST), and crossed radioimmunoelectrophoresis (CRIE), and the results were scored as negative (score 0), equivocal (score 1) or positive (score 2). Based on daily symptom scores and the result of BPT the patients were classified as being manifest allergic (asthma) to Cladosporium (positive allergy), inconclusive or negative. Positive allergy was defined as asthma symptoms oscillating with the spore concentration and a BPT score 2 (positive at allergen concentration less than 10,000 BU). Negative allergy was defined as no asthma symptoms and a negative BPT (score 0) and inconclusive in the case of symptoms and BPT sum of score 1-3. According to the classification a final diagnosis (positive or negative) could be established in 85% of the patients. "False positive" tests were found: for BPT in 27%, SPT 18%, RAST 0%, HIST 18%, and CRIE 0%. The corresponding figures for "false negative" were: BPT 0%, SPT 0%, RAST 27%, HIST 18%, and CRIE 23%. The relative risk of being allergic in spite of a negative test result was 0% for BPT and SPT, and 25-30% with RAST, HIST, and CRIE. In the case of positive test the risk was 90-100%. Excluding BPT, SPT was found to be the optimal single test to predict/rule out clinical allergy. A stepwise combination of positive SPT and positive RAST was found exclusively in patients clinically evaluated as positive, and does not call for an additional BPT. Using a potent allergenic extract a negative SPT excluded clinically important allergy. The primary conclusion of the study, however, is that the final diagnosis of Cladosporium asthma could not be based on a positive BPT alone (due to "false positive"), but only on a combination of clinical symptoms during the spore season and a positive BPT.

Adult↗
PubMed1993

Effect of cetirizine, a new H1 antihistamine, on the early and late allergic reactions in a bronchial provocation test with allergen.

BACKGROUND: Cetirizine is a highly sensitive H1 antihistamine with particular antiallergic properties, which has been shown to be effective in the treatment of allergic rhinitis, urticaria, and hay-fever-associated asthma. METHODS: To assess the effect of cetirizine on the late allergic reaction to a specific bronchial provocation test (BPT) with allergen, we selected 25 patients with allergic asthma as determined by history, skin tests, and specific IgE levels. They were challenged with increasing doses of a cat or mite extract until a 20% drop in forced expiratory volume in 1 second (FEV1) was recorded. Sixteen patients (11 men and 5 women with a mean age of 22 years; range, 18 to 48 years) exhibited a dual response (early and late allergic reactions). These 16 patients underwent a second BPT 2 weeks later, and each again showed a dual response. They were then randomized to receive either a placebo (8 patients) or cetirizine, 15 mg twice daily (8 patients) in a double-blind fashion. After 7 days of treatment, they underwent a third BPT with the same allergen dose as given in the second BPT. RESULTS: The intensity and duration of early allergic reaction were not affected by cetirizine, whereas all parameters of late allergic reaction were statistically significantly improved in the cetirizine group when compared with those of the placebo group (maximum FEV1 decrease, p = 0.046; FEV1 [area above the curve], p = 0.027; maximum airway resistance increase, p = 0.021; airway resistance [area under the curve], p = 0.036). CONCLUSIONS: Cetirizine produced a significant protective effect against an allergen-induced late allergic reaction in a BPT. Cetirizine might therefore be effective in the treatment of asthma.

Adolescent↗
PubMed1992

[Allergic asthma to latex, proven by a bronchial provocation test].

The authors report the case of a female cook who develops contact urticaria associated with rhinitis and asthma-type dyspnea when using rubber gloves in the course of her work. Allergy to latex was confirmed by a PRICK-test with latex, the presence of specific IgE in the serum, and the onset of contact urticaria after putting on gloves. A latex glove was rinsed with 10 cc of distilled water and the resulting solution, used as a spray, brought on a bronchospasm in the first two minutes. This bronchial provocation test proves that latex can cause asthma-type dyspnea when work involves contact with the substance. The speed of onset and intensity of the respiratory symptoms observed show that such a provocation test must be carried out with extreme care in patients with a marked sensitivity to latex. The future lies in the possibility of easily standardizing the latex protein concentration in order to be able to administer progressive doses without any systemic risk. This case draws attention to the probably underestimated possibility of latex-induced asthma in all subjects who are brought into repeated contact with latex, whatever their profession.

Adult↗
PubMed1994

Bronchial provocation testing in the diagnosis of occupational asthma due to latex surgical gloves.

In sensitized subjects, provocation tests to latex may induce severe systemic reactions and even anaphylactic shock. It is probable that part of the risk is due to the difficulty in grading the stimulating dose and in starting from very low levels of exposure. To identify the aetiological agent of work-related asthma in four nurses with previous allergic contact urticaria to latex surgical gloves dusted with cornstarch powder, we performed a specific bronchial provocation test study, based on exposure on three different days to nonpowdered latex surgical glove extract, powdered latex surgical glove extract and cornstarch powder extract, respectively. Extracts were nebulized in increasing concentrations in a 7 m3 challenge room, in the absence of the patients. The initial extract concentration was a tenfold dilution of the predetermined skin test end-point in the individual undergoing challenge, and the highest concentration was the undiluted extract. After exposure, the patients' forced expiratory volume in one second (FEV1) was monitored for 2 h. If FEV1 decreased by at least 15%, the next scheduled exposure was not carried out and FEV1 was monitored over a period of 24 h. Whereas nebulization of cornstarch powder extract caused no bronchial reaction in the patients, nebulization of nonpowdered latex surgical glove extract induced immediate bronchoconstriction in two subjects as an undiluted solution, and nebulization of powdered latex surgical glove extract induced immediate bronchoconstriction in all subjects at the 1:10 dilution. No systemic reaction was elicited by the bronchial provocation challenges. Our results demonstrate that airborne powder from latex gloves can be an inhalative occupational hazard.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2002

Bronchial provocation tests: the rationale for using inhaled mannitol as a test for airway hyperresponsiveness.

The use of histamine and methacholine is well established for identifying airway hyperresponsiveness (AHR) but the AHR to these agents is not specific for asthma diagnosis. Further, these agents do not identify or exclude exercise-induced asthma (EIA) so they are inappropriate for some occupational and sporting assessments. Measurement of AHR by pharmacological agents has other limitations in that a positive response does not necessarily identify a person who will respond to inhaled steroids and responses do not differentiate between doses of steroids. As most asthmatics remain hyperresponsive to these agents after treatment they have not been useful for guiding steroid dose reduction. Bronchial provocation tests (BPTs) with physical stimuli such as exercise, eucapnic voluntary hyperpnea and hypertonic saline have provided useful information on presence and severity of asthma and EIA. These tests however, can be time consuming and require more resources compared with the pharmacological tests. To simplify testing, a challenge has been developed that uses a dry powder of mannitol administered from a simple hand-held device. The mannitol is given in increasing doses from capsules containing from 5 mg to 40 mg. Mannitol responsiveness identifies people with EIA and those who will respond to inhaled steroids. Mannitol responsiveness is reduced following treatment with inhaled steroids, and some subjects become unresponsive within 6 to 8 weeks. Responsiveness to mannitol can be used to predict risk of exacerbation during back titration of steroids. Should this BPT become more readily available it would be the first to provide a common operating standard for use in the laboratory, office, or field.

Asthma↗
PubMed1983

Interstitial lung disease and asthma in hard-metal workers: bronchoalveolar lavage, ultrastructural, and analytical findings and results of bronchial provocation tests.

Five patients with respiratory disorders associated with hard metal exposure are described. In four patients electron microprobe analysis of bronchoalveolar lavage cells or lung tissue was used to show tungsten and other hard-metal components. Three patients had interstitial pneumonia and fibrosis with unusual multinucleate giant cells. Electron microscopy showed that the giant cells comprised both type II alveolar epithelial cells and alveolar macrophages. The multinucleate macrophages formed a distinctive feature of the bronchoalveolar lavage material but the multinucleate alveolar epithelial lining cells were evident only in lung tissue. The other two patients both suffered from work-related asthma, one of whom also had pulmonary opacities. Bronchial provocation tests in these patients supported the diagnosis of hard-metal-induced asthma and implicated cobalt as the agent responsible.

Adult↗