PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Bronchial Provocation Tests”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

Relationship between the results of bronchial, nasal and conjunctival provocation tests in patients with asthma.

Skin tests and bronchial, nasal and conjunctival provocation tests with pollen and animal dander allergens were performed in thirty patients with atopic asthma. In vivo test results were compared only when the same batch of allergen had been used. A nasal reaction was mostly elicied at a lower concentration of allergen than was needed to elicit a bronchial reaction (P less than 0.01). Positive nasal reactions were often obtained when the corresponding bronchial tests were negative. The conjunctiva reacted to lower concentrations than the bronchi in a third of the instances of testing, with most of these being tests with mugwort allergen (P less than 0.05). A positive skin test in cases with a negative bronchial challenge test was often accompained by a positive nasal test and in some cases by a positive conjunctival test. It is concluded that nasal or conjunctival provocation tests do not replace bronchial challenge tests. In an asthmatic patient who gives no reaction to bronchial challenge with a particular allergen, a positive skin test may reflect a nasal allergy.

Adolescent↗

Swiss chard hypersensitivity: clinical and immunologic study.

Allergy to vegetables and fruits seems to be more prevalent in atopics, especially in birch pollen-sensitized individuals. We report a case of a grass pollen-sensitized woman, in whom the inhalation of vapor from boiling Swiss chard precipitated rhinoconjunctivitis and asthma. Type I hypersensitivity to Swiss chard was demonstrated by means of immediate skin test reactivity, specific IgE determination by RAST, basophil degranulation, histamine release test, and an immediate bronchial provocation test response to Swiss chard extract. The controls did not react to any of these tests. RAST inhibition assays suggest the presence of some cross-reactivity among Swiss chard and grass pollen antigens, as well as cross-reactivity between vegetables and weed pollens of the chenopod family.

Adult↗

Inhalation provocation tests using nonisotonic aerosols.

The measurement of bronchial hyperresponsiveness with inhaled aerosols is now accepted as an objective measurement of the severity of asthma. The most commonly used agents administered as aerosols are methacholine and histamine, which are believed to cause airways to narrow by contracting bronchial smooth muscle via specific receptors. Patients with asthma may also have an attack provoked by inhaling aerosols that increase or decrease the osmolarity of the fluid lining the airways. There is evidence to suggest that a change in the osmolarity of the airways causes the release of mediators from inflammatory cells in the airways. Thus, inhalational challenge with nonisotonic aerosols, such as water and hyperosmolar saline, may be useful to assess bronchial hyperresponsiveness to endogenously released mediators. Described in this article are some of the techniques used to challenge with nonisotonic aerosols, and airway responses are discussed in relation to responses obtained with other bronchial provocation tests. The mechanisms whereby these aerosols cause airways to narrow are considered, and the clinical implications of identifying responsiveness to these aerosols are discussed. Specific recommendations are made with respect to equipment, technique, and choice of aerosol.

Aerosols↗

Immunotherapy with dog and cat extracts in children.

Hypersensitivity to dogs and cats causes asthma in many children. In this open controlled clinical study we wanted to establish whether immunotherapy can be recommended as a supplement to conventional medical therapy in dog- and cat-induced asthma in children. Twenty-seven children with mean age 10 7/12 years and with allergy to dog or cat according to anamnesis, skin prick test (SPT), specific IgE (RAST) and bronchial provocation test (BPT) entered the study. On the basis of age and bronchial sensitivity they were randomly allocated to either immunotherapy with dog or cat extract (active group, n = 14) or conventional medical therapy (control group, n = 13). Immunotherapy comprised subcutaneous injections with an alum-adsorbed depot extract (Alutard-SQ), and a maintenance dose of 100,000 SQ-U or the maximum tolerated dose. Before entering the study and after 9 months' therapy the patients were evaluated by BPT, SPT, RAST - and IgG4 analyses. The active group showed statistically significant change in bronchial tolerance (P less than 0.02), whereas no such change was found in the control group (P greater than 0.05). The change in skin sensitivity was significantly greater in the active group than in the control group (P less than 0.05), whereas no significant differences were found in RAST and IgG4. However, a significant (P = 0.05) increase in IgG4 was seen in the active but not in the control group. Frequency and degree of side effects in this study were acceptable.

Adolescent↗

Bronchial provocation determined by breath sounds compared with lung function.

Bronchial provocation testing with methacholine was undertaken in 15 children aged 5 to 8 years with obstructive lung disease, mostly asthma (13/15). The methacholine was inhaled during two minutes of tidal breathing in increasing concentrations. After each inhalation, lung function was measured and clinical signs recorded independently by two observers unaware of each other's results. The logarithm of the concentration of methacholine which caused wheezing over the trachea correlated closely with the logarithm of the concentration of methacholine causing a 20% fall in the forced expiratory volume in one second (FEV1) but was 52% greater on average. At the end of the test there was a mean (SD) fall in FEV1 of 33.3 (7.4)% and a fall in oxygen saturation of 5.2 (3.1)%. Bronchial provocation testing by listening for wheeze over the trachea is a safe technique, which correlates with objective measures of lung function in young children.

Bronchi↗

Occupational rhinoconjunctivitis and asthma in a wool worker caused by Dermestidae spp.

BACKGROUND: The family Dermestidae belongs to the order Coleoptera. Occupational allergy has been described in museum personnel. A 31-year-old male wool worker presenting rhinoconjunctivitis and asthma episodes probably linked to exposure to Dermestidae-infected wool was investigated. METHODS: Extracts prepared either from insect bodies or from dust from parasitized wool were used for skin prick testing (SPT), conjunctival and bronchial provocation tests and in vitro determinations. RESULTS: SPT and provocation tests were positive to both extracts. PEFR measurement demonstrated the association between the patient's symptoms and occupational exposure to Dermestidae. Specific IgE to both extracts was detected and immunoblotting revealed several protein bands from 5 to 200 kDa that were reactive to IgE from the patient's serum. CONCLUSIONS: Dermestidae exposure in wool workers when handling parasitized wool can be a cause of IgE-mediated rhinoconjunctivitis and asthma.

Adult↗

Increased secretion of tumor necrosis factor alpha and interleukin-6 by alveolar macrophages consecutive to the development of the late asthmatic reaction.

The late asthmatic reaction (LAR), consecutive to bronchial allergen challenge, is characterized both by the influx of various cells in proximal and distal airways and by the enhancement of bronchial hyperresponsiveness. However, the exact conditions for the development of the inflammatory reaction during the LAR remain to be specified. Since monokines play a key role in inflammatory processes, particularly in the lung, the production of tumor necrosis factor-alpha (TNF-alpha), interleukin; 1-beta (IL-1-beta) and interleukin-6 (IL-6) by alveolar macrophages (AM), collected 18 to 20 hours after exposure to allergen, was evaluated in 15 allergic subjects with asthma submitted to a challenge test with Dermatophagoides pteronyssinus (N = 6) or with wheat flour (N = 9) and in three healthy subjects. After bronchial provocation test, four patients presented no bronchial response (group 1), and six patients, a single early reaction (group 2). In contrast, five patients developed successively an immediate plus a late response (group 3). The monokine production was compared to that from nine allergic subjects with asthma studied at baseline (group 0) and from 11 unchallenged healthy subjects (control subjects). Measurements of cytokines were evaluated for TNF-alpha and IL-1-beta by a specific immunoradiometric assay, whereas IL-6 levels were appreciated by the proliferation of 7TD1 cells. No detectable amounts of TNF-alpha, IL-1-beta, and IL-6 were in bronchial alveolar lavage fluid, even after a tenfold concentration. In contrast, a significant increase of TNF-alpha (10,642 +/- 3127 U/ml) and IL-6 (1250 +/- 427 U/ml) concentrations was noted in AM supernatants from patients exhibiting an LAR (group 3) compared to cells recovered from groups 2, 1, and 0 and to challenged or unchallenged control subjects (805 +/- 244, 995 +/- 521, 1269 +/- 524, 688 +/- 85, and 445 +/- 74 pg of TNF-alpha per milliliter, respectively; 190 +/- 64, 114 +/- 91, 242 +/- 95, 80 +/- 9, and 54 +/- 19 U/ml of IL-6 per milliliter, respectively). No modification of IL-1-beta contents could be detected between the different groups. A significant correlation was detected between concentrations of TNF and IL-6 (r = 0.92; p less than 0.001). These results demonstrate TNF-alpha and IL-6 secretion by AM consecutively to the development of LAR in allergic subjects with asthma, confirming that AMs are activated after allergen challenge.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Occupational asthma due to ethylene diamine.

We report a case of bronchial asthma due to ethylene diamine in a chemical worker. The typical relationship with work exposure was elicited from the occupational history and serial peak flow measurements. A late dual asthmatic reaction was seen in bronchial provocation test with ethylene diamine. Bronchial hyper-responsiveness to isopropyly alcohol and histamine was observed and was likely to be the result rather than a predisposing factor for the development of occupational asthma. Amines are a powerful group of small molecular weight asthmatogens that are commonly used in various types of industries locally and should be recognised in the clinical evaluation of workers with asthma.

Adult↗

Comparison of conventional and rush immunotherapy with der PI in childhood respiratory allergy.

BACKGROUND: Rush immunotherapy results obtained in Der PI-sensitive children with asthma and the changes in clinical and immunological parameters were investigated. METHODS: We studied 18 patients with Der PI sensitivity. Two groups were randomized: nine patients received RIT and nine patients received conventional immunotherapy (CIT) for three years. The RIT group reached the optimal maintenance dose at the end of one week. The CIT group reached the optimal maintenance dose in approximately three months. Symptom medication scores, lung function, side effects scores, skin-prick test, diluted skin-prick test with Der PI, bronchial provocation tests with Der PI, and Der PI-specific IgE and IgG4 were investigated in baseline conditions, at six months and at the end of the third year. RESULTS: There were no significant differences between groups in age, sex, and duration of illness. Treatment was tolerated very well. However, mean side-effect scores were higher in the RIT group than in the CIT group (p < 0.005). There were no significant differences between groups in the other parameters. CONCLUSION: CIT is more advantageous than RIT in Der PI-sensitive children, although the maintenance dose was achieved more rapidly with RIT.

Allergens↗

SO2-induced enhancement of inhalative allergic sensitization: inhibition by anti-inflammatory treatment.

Epidemiological studies have shown a relationship between air pollution and allergic airway disease. In a previous study we have found that exposure to SO2 enhances allergic sensitization to inhaled ovalbumin (OA) in the guinea pig. We have now investigated the influence of pre-treatment with anti-inflammatory drugs on SO2-induced enhancement of allergic sensitization in this model. Four groups of 6 guinea pigs each were exposed to 5 ppm SO2 on 5 consecutive days over 8 h per day with intermittent inhalation of OA, while the air-control group was exposed to clean air and OA. During the period of SO2 exposure and sensitization three experimental groups were treated with indomethacin (group I), methylprednisolone (group M) and nebulized nedocromil sodium (group N), while the control group remained untreated. Guinea pigs were investigated for sensitization to OA by specific bronchial provocation tests using body plethysmographic measurement of compressed air (CA) and by measurement of specific antibody response in serum. While in the SO2-exposed control group 5 of 6 animals reacted to specific bronchial provocation testing (CA median 0.15 ml, range 0-0.175 ml), only 1 animal was sensitized in group M (CA 0 ml, 0-0.125, p < 0.05), whereas no bronchial reactions were seen in groups I and N (CA 0 ml, 0-0.05, p < 0.025). Specific IgG antibody titres increased in the control group (median 43 EU-->85 EU), but not in the treatment groups (medians group I 35 EU-->35 EU, group M 30-->35 EU, group N 64-->50 EU).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

Circulating histamine and neutrophil chemotactic activity during allergen-induced asthma: the effect of inhaled antihistamines and anti-allergic compounds.

Plasma histamine and serum neutrophil chemotactic activity (S-NCA) were measured in ten atopic asthmatic patients on four separate occasions after allergen bronchial provocation testing (BPT). Single doses of inhaled sodium cromoglycate (SCG; 20 mg), clemastine (0.5 mg), ketotifen (0.5 mg) and isotonic saline (0.9% NaCl) placebo were administered 30 min before bronchial provocation testing in random order and double-blind. The airflow obstruction after BPT was monitored by measurement of forced expiratory volume in 1 s (FEV1). Plasma histamine was measured by the double-isotope radioenzymatic assay and S-NCA by a modified Boyden chamber technique. A highly significant decrease in FEV1 after BPT occurred on the placebo pre-treatment visit (P less than 0.001). Prior administration of inhaled SCG, clemastine and ketotifen significantly reduced the decrease in airflow obstruction seen after BPT when compared with placebo treatment (P less than 0.01, P less than 0.02, P less than 0.05 respectively). No significant alteration in plasma histamine was detected during allergen-induced airflow obstruction. Levels of S-NCA were significantly higher 5, 10 and 15 min after BPT when compared with the pre-challenge level (P less than 0.01, P less than 0.01, P less than 0.001 respectively). These levels were not significantly decreased when airflow obstruction was inhibited by the prior inhalation of SCG, clemastine or ketotifen.

Adult↗

Bronchial hyperresponsiveness in young students of southern China: relation to respiratory symptoms, diagnosed asthma, and risk factors.

A cross sectional study was carried out to determine the prevalence of bronchial hyperresponsiveness and asthma in 3067 students aged 11-17 years in an urban and a rural area of Guangzhou (Canton), China. The methods used included a self administered questionnaire, a histamine bronchial provocation test, and allergen skinprick tests. Bronchial hyperresponsiveness was defined as a 20% fall in FEV1 and peak expiratory flow at a provoking dose of histamine (PD20) less than 7.8 mumol on two occasions four weeks apart. The response rate was 98.0% and 99.2% in the two areas. The prevalence of bronchial hyperresponsiveness was 4.1% and of diagnosed asthma 2.4% in the total population. There were no significant differences in prevalence between the urban and the rural area or between boys and girls. The 11-12 year group had a higher prevalence of bronchial hyperresponsiveness (7.6%) than the older groups. Of the 125 with bronchial hyperresponsiveness, 12.0% were defined as having severe or moderate (PD20 less than 0.8 mumol), 26% mild (0.9-3.2 mumol), and 62% slight bronchial hyperresponsiveness (3.3-7.8 mumol). The severity of bronchial hyperresponsiveness was closely related to diagnosed asthma, wheezing, and cough, though half the students with bronchial hyperresponsiveness were symptom free. The most common allergens were house dust and house dust mite in the city, and hay dust, pollen, and feathers in the rural area. The odds ratios for having respectively slight, mild or moderate, and severe bronchial hyperresponsiveness were 5.9, 21.0, and 30.4 for atopy; 1.9, 1.9, and 7.3 for early respiratory infection; and 3.1, 2.5, and 5.6 for a history of parental asthma.

Adolescent↗

Predictive markers of asthma exacerbation during stepwise dose reduction of inhaled corticosteroids.

To determine predictors for failed reduction of inhaled corticosteroids (ICS), in 50 subjects with well-controlled asthma (age 43.7 [18-69]; 22 males) taking a median dose of 1,000 microg ICS/d (100-3,600 microg/d), ICS were halved every 8 wk. Airway hyperresponsiveness (AHR) to a bronchial provocation test (BPT) with histamine was measured at baseline. AHR to BPT with mannitol, spirometry, exhaled nitric oxide (eNO), and, in 31 subjects, sputum inflammatory cells were measured at baseline and at monthly intervals. Thirty-nine subjects suffered an asthma exacerbation. Seven subjects were successfully weaned off ICS. Using a Kaplan- Meier survival analysis, the significant predictors of a failure of ICS reduction were being hyperresponsive to both histamine and mannitol at baseline (p = 0.039), and being hyperresponsive to mannitol during the dose-reduction phase of the study (p = 0.02). Subjects older than 40 yr of age tended to be at greater risk of ICS reduction failure (p = 0.059). Response to mannitol and percentage sputum eosinophils were significantly greater before a failed ICS reduction than before the last successful ICS reduction, whereas there were no significant differences in symptoms, spirometry, or eNO. These findings suggest that documentation of patient's AHR or sputum eosinophils may be useful in guiding the reduction of ICS doses.

Adolescent↗

Comparison between intracutaneous and prick tests in detecting sensitizations to common Mediterranean allergens.

The role of the intracutaneous test (IC) in clinical allergy routine was evaluated comparing its results with those from the prick test, the radioallergosorbent test (RAST), and the specific bronchial provocation test (BPT). The study was carried out making an a posteriori survey of 384 patients suffering from symptoms of perennial and seasonal rhinitis and/or bronchial asthma. They were tested with the most common allergens in the Mediterranean countries; 681 prick tests and 489 IC tests were compared with RAST and 69 with BPT. The IC tests showed disagreement with RAST and BPT more frequently than prick tests: this is attributable to a lesser degree of specificity of IC test performed with the usual concentrations, and depends on the nature of the allergens. On the other hand the prick test is no less sensitive than the IC test, being the occurrence of RAST positivity in patients with negative skin tests similar for the prick and IC tests. These results support the concept of the prick test as preferable with respect to the IC test because of its specificity and sensitivity.

Adolescent↗

Effect of antihistamines and antiallergic drugs on responses to allergen and histamine provocation tests in asthma.

The inhibition of immediate allergen or histamine induced airflow obstruction by inhaled ketotifen, clemastine, sodium cromoglycate, and placebo was studied in two groups of asthmatic subjects. Single doses of ketotifen (0.5 mg), clemastine (0.5 mg), sodium cromoglycate (20 mg), or placebo were administered by inhalation 45 minutes before bronchial provocation testing at weekly intervals, double blind and in random order. Inhalation of ketotifen and clemastine, but not sodium cromoglycate, caused an increase in the amount of histamine which had to be administered to cause a 20% fall in FEV1 from control levels (PD20-FEV1) compared with placebo. The PD20-FEV1 for allergen increased significantly after inhalation of clemastine and sodium cromoglycate. Clemastine, primarily an H1 receptor antagonist, inhibited airflow obstruction after inhalation of both histamine and allergen. Its inhibitory effect on allergen induced asthma did not differ significantly from that of sodium cromoglycate. Ketotifen, when inhaled in a single dose of 0.5 mg before bronchial provocation testing, showed potent antihistamine activity, but there was no evidence of any additional "antianaphylactic" activity.

Adult↗

Occupational asthma caused by Ipe (Tabebuia spp) dust.

BACKGROUND: Ipe is a resistant hardwood that contains naphtoquinones. It is easily found and frequently used in South and Central America. Naphtoquinones are skin sensitizers. OBJECTIVE: To describe a case of occupational asthma related to Ipe wood dust. METHODS: The patient was submitted to a clinical evaluation consisting of a respiratory symptom questionnaire, occupational history, serial measurements of lung function by spirometry, skin prick tests, patch tests, specific IgE and specific bronchial provocation tests to Ipe dust. RESULTS: Serial lung function measurements showed sustained regression of obstruction following removal from exposure. Skin prick tests, but not patch tests, were positive to Ipe, and a specific bronchial challenge showed a late asthmatic reaction. Specific IgE search was negative. CONCLUSIONS: Exposure to Ipe wood dust can lead to occupational asthma. The underlying mechanism should be investigated.

Asthma↗

Skin-prick tests for hypersensitivity to alpha-amylase preparations.

Twenty-five asthmatic subjects with suspected alpha-amylase hypersensitivity were studied by skin-prick tests, a capture ELISA, immunoblotting and bronchial provocation tests. At the same time, different amylases were analysed by SDS-PAGE and immunoblotting using a polyclonal rabbit antiserum. Eight patients showed a positive bronchial response to amylase. Seven of them had positive skin-prick tests, with this method being the most sensitive approach for diagnosis. However, in four cases, skin tests were also positive although the patients had a negative provocation test, thus demonstrating that skin tests are not specific. ELISA and blotting showed similar results in terms of sensitivity and specificity. The enzymes used by the workers included several antigens besides alpha-amylase. The rabbit antiserum to alpha-amylase detected a protein in a wheat flour extract. In one case, the IgE antibodies were specific only for a contaminant of lower molecular weight than amylase. These facts suggest that proteins from the culture medium could be responsible for some cases of amylase hypersensitivity, making the diagnosis difficult. The presence of amylase in another enzymatic extract, a protease produced by Aspergillus oryzae, was proved by means of skin tests and immunoblotting, thus demonstrating the allergenic properties of this enzymatic preparation.

Asthma↗