Results Of Bronchial Provocation Tests Research Articles

The Value of Fractional Exhaled Nitric Oxide and Forced Mid-Expiratory Flow as Predictive Markers of Bronchial Hyperresponsiveness in Adults with Chronic Cough

Bronchial provocation tests are standard for diagnosing the etiology of chronic cough, but they are time consuming and can induce severe bronchospasm. A safer and faster clinical examination to predict bronchial hyperresponsiveness (BHR) is needed. The objective of this study was to investigate whether small-airway function tests can predict BHR in adult patients with chronic cough. A retrospective, cross-sectional study of diagnoses made using spirometry and bronchial provocation test results was performed in 290 patients with chronic nonproductive cough. BHR-predictive values were analyzed via the area under receiver operating characteristic curves (AUCs). Optimal cutoff values were determined by maximizing the sum of sensitivity and specificity. Patients with chronic cough with BHR showed lower forced expiratory flow between 25% and 75% (FEF25%-75%), higher fractional exhaled nitric oxide (FENO), and a higher percentage of eosinophils in blood than patients without BHR (P < .0001 for all). The AUCs of FENO and FEF25%-75% for a BHR diagnosis were 0.788 (95% CI, 0.725-0.851) and 0.702 (95% CI, 0.641-0.763), respectively. Optimal cutoff values were 43 ppb for FENO and 78.5% for FEF25%-75%, with negative predictive values of 85.38% and 81.34%, respectively. The combined use of FENO and FEF25%-75% increased the AUC to 0.843 (95% CI, 0.794-0.892), significantly higher than either FENO (P= .012) or FEF25%-75% (P < .0001) alone. Small-airway dysfunction is present in patients with chronic cough and BHR. FEF25%-75% has value as a negative predictive parameter for BHR, especially when combined with FENO. FENO > 43 ppb and FEF25%-75% <78.5% strongly predicted a positive bronchial provocation test.

Serum periostin levels correlate with airway hyper-responsiveness to methacholine and mannitol in children with asthma.

Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of TH 2-induced airway inflammation, and (importantly) as a measure of the response to TH 2-targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children. The study included 83 children aged 6-15 years in an asthmatic group (n = 54) and healthy controls (n = 29). We measured the periostin levels in serum and performed methacholine and mannitol provocation challenges. The responses to mannitol were expressed as the provocative dose causing a 15% fall in the FEV1 (the PD15 dose). Of the 54 subjects with asthma, all had positive methacholine bronchial provocation test (BPT) results and 38 had positive mannitol BPT results. Children with asthma had significantly higher periostin levels than controls [76.0 (65.0-91.8) vs 71.0 (57.5-80.0) ng/mL; P = 0.017]. Periostin levels were significantly correlated with both the methacholine PC20 and mannitol PD15 values. Serum levels of periostin, a new biomarker induced by IL-13, were higher in asthmatic children, and were associated with AHR to methacholine and mannitol.

Asthma tests in the assessment of military conscripts

Respiratory diseases such as asthma may affect individuals' fitness for military service. In order to assess fitness for military service in subjects with asthma symptoms at conscription, objective and reliable tests are needed. To prospectively determine the diagnostic value of the mannitol and methacholine bronchial provocation test (BPT) as well as exhaled nitric oxide in assessing physician-diagnosed asthma in a group of Swiss Armed Forces conscripts. Questionnaire, spirometry, BPT with methacholine and mannitol, exhaled nitric oxide (FeNO) and skin prick testing were conducted in 18-20-year-old male conscripts. Asthma was diagnosed by a military physician not involved in this study according to the medical record, results of BPT, current respiratory symptoms and use of asthma medication. Two hundred and eighty four subjects participated in the study. Complete data for the BPT with methacholine, mannitol and measurement of FeNO were available on 235 subjects. Forty-two conscripts (17.9%) had physician-diagnosed asthma. The sensitivity/specificity of mannitol to identify physician-diagnosed asthma was 41%/93% and for methacholine it was 43%/92%. Using a cut-off point of 36.5 p.p.b., FeNO had a similar negative predictive value to rule out physician-diagnosed asthma as BPT with mannitol or methacholine. BPT with mannitol has a sensitivity and specificity similar to methacholine for the diagnosis of physician-diagnosed asthma in military conscripts but is less costly to perform without the need to use and maintain a nebulizer.

Usefulness of Inmunoglobulin E Antibody Levels to Recombinant Fel d 1 in Predicting the Cat Specific Bronchial Provocation Test Results

Usefulness of Inmunoglobulin E Antibody Levels to Recombinant Fel d 1 in Predicting the Cat Specific Bronchial Provocation Test Results

Accuracy of Two Cat Allergen Extracts in Predicting the Specific Bronchial Provocation Test Results

Accuracy of Two Cat Allergen Extracts in Predicting the Specific Bronchial Provocation Test Results

COMPARISON OF THE 2 BRONCHIAL PROVOCATION TESTS OF DIFFERENT DOSAGE CONCENTRATION GRADIENTS FOR INFANTS

INTRODUCTION: Bronchial provocation tests (BPTs) assist in diagnosing and evaluating the curative effect of asthma. OBJECTIVE: The objective of this study was to compare the sensitivity, reliability, and safety between 2 tidal breathing methods in BPT. METHODS: Sixty-five infants, including those with asthma and chronic cough, were divided into groups A and B at random. BPT by the improvement of tidal breathing method was performed in group A (35 infants), and the traditional tidal breathing method was performed in group B (30 infants). In 10 normal infants (control subjects), the traditional tidal breathing method was used. In addition, we observed arterial oxygen saturation, respiratory system resistance, %T-PF, percent of tidal volume of peak tidal expiratory flow, and lung symptoms and monitored the vital sign and adverse effects of the test. RESULTS: Results of the BPTs for all children with asthma were positive. The positive rates for children with chronic cough were 69.57% and 60.00% in groups A and B, respectively; the results of BPTs in control subjects were completely negative. There was no significant difference in positive rate, and both methods had a similar degree of airway hyperresponsiveness; however, in group A, the effect was of shorter duration and the test was more efficient. During the BPT, 6 infants in group A and 9 in group B had cough, but none exhibited an acute asthma episode. CONCLUSIONS: The improved tidal breathing method, used as a BPT, outweighs the traditional method in sensitivity, specificity, efficiency of detection, dosage of medicine, and safety.

Diagnostic tests in enzyme allergy

Background: Allergies to enzymes occur frequently in enzyme manufacturing plants. In epidemiologic studies the number of exposed subjects with symptoms is considerably higher than the number of sensitizations as assessed by skin tests or RAST. It was the aim of this study to evaluate the sensitivity and specificity of skin prick tests, enzyme allergosorbent test, and immunoprint with enzymes by using the results of bronchial provocation tests as the “gold standard.” Methods: We performed 82 bronchial provocation tests with nine different enzymes in 42 chemical plant workers, all of whom had reported work-related symptoms. All tests with the exception of bronchial provocation tests were also performed in 10 atopic and 10 healthy control subjects. Results: Thirteen workers showed positive results to bronchial provocation tests (50% or greater fall in specific airway conductance) with an enzyme at a maximal concentration of 10 mg/ml. Equivocal test results, that is, tests with a 30% or greater and less than 50% fall in specific airway conductance were seldom. Skin prick tests with nondialyzed aqueous enzyme extracts at a concentration of 10 mg/ml yielded a sensitivity of 100% and a specificity of 93%. Control subjects had no cutaneous reactions to enzymes. Discrepancies between skin tests and bronchial provocation tests occurred in 5 of 82 tests, all with a positive skin test and a negative bronchial provocation test. False-positive skin tests were considered more likely in four subjects and a false-negative bronchial challenge more likely in one case. Enzyme allergosorbent test was 62% sensitive and 96% specific, and atopic control subjects showed positive results in two cases. Results of immunoprint with amylase showed one main band at pH 3.4; this band was also found in exposed subjects without further signs of sensitization, but was not found in control subjects. All but one person with positive results to bronchial provocation tests with enzymes showed bronchial hyperresponsiveness. We identified 13 subjects with bronchial hyperresponsiveness, but without occupational allergy: five of these had sensitizations to nonoccupational allergens and the remainder showed bronchial hyperresponsiveness without any detectable cause. Conclusions: Occupation-related symptoms were not indicative of occupational allergy. Bronchial provocation tests and skin prick tests with nondialyzed aqueous enzyme extracts were appropriate techniques for the diagnosis of enzyme allergy.

Does non-specific bronchial responsiveness indicate the severity of asthma?

It is difficult to analyse the relationship between bronchial responsiveness and the severity of asthma since each alone is difficult to assess. Asthma is a heterogeneous condition with many patterns of expression, and clinical methods used to assess its severity have their limitations. Problems also arise in interpreting the results of bronchial provocation tests and methodological differences make comparisons between studies difficult. The findings of both cross-sectional and longitudinal studies have shown a general relationship between the degree of responsiveness and the severity of asthma, but within subjects the relationship is weaker. A greater understanding must await increased knowledge of the mechanisms underlying asthma and the contribution which hyperresponsiveness makes to each of these.

Childhood asthma following hospitalization with acute viral bronchiolitis in infancy.

A prospective follow-up of 48 infants hospitalized with respiratory syncytial virus bronchiolitis in the first year of life revealed that 44 of these infants had symptoms suggestive of asthma in the 5 years following their initial illness (cumulative prevalence 92%). Symptoms became less frequent and less troublesome during the follow-up period. Thirty-five of these children visited the laboratory for clinical examination, pulmonary function testing, and histamine challenge. Twenty-five children were believed to have clinical evidence of asthma at the time of the laboratory visit (point prevalence 71%). Five children were unable to perform pulmonary function tests; 25 of the remaining 30 (67%) had a positive histamine challenge test. No relationship could be demonstrated between a clinical diagnosis of asthma, a family history of atopy, and the results of histamine challenge testing. These results question the relationship between the results of bronchial provocation tests and clinical asthma in this age group.

236 Immunotherapy with animal dander extracts. Results of bronchial provocation test and total and individual antigen-specific IgG tests in a double blind cross-over study

236 Immunotherapy with animal dander extracts. Results of bronchial provocation test and total and individual antigen-specific IgG tests in a double blind cross-over study

Some aspects of occupational asthma.

The behaviour of forty-four patients, taken from a group of 133 cases of extrinsic pulmonary granulomatoses (EPG), who before developing the disease had no history of atopy and after being affected presented asthma-like symptoms, is analysed. Some of these patients had simultaneously clinical signs of rhinitis which proved to be due to lesions identical to those found in the bronchial mucosa. From the presented results, the author concludes that the clinical manifestations of these patients are not of the classical allergic type but bronchial and nasal reactions of the EPG in which, at least, a type III hypersensitivity reaction is involved. This is supported by the results of bronchial provocation tests performed on twenty-three patients with suberosis.