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A new glass microfibre-based histamine analysis for allergy testing in children. Results compared with conventional leukocyte histamine release assay, skin prick test, bronchial provocation test and RAST.

A new microfibre method for allergy testing measuring histamine release from human basophil leukocytes is described. Samples of 50 microliter washed blood are challenged with the suspected allergens. Released histamine is bound to microfibres and measured by a spectrofluorometrical method after removal of interfering substances by washing. The microfibre method (HR-MM) was compared to the conventional histamine release assay using the Ficoll-Hypaque gradient method (HR-FH) in 19 allergic children tested with one of three allergens. In addition, a comparison was made between the microfibre method and in vivo provocation tests, i.e. skin prick test (SPT), bronchial provocation test (BPT) and allergen specific serum IgE (RAST). It was found that the same individuals responded with histamine release to the same allergens in both histamine release assays, and the dose-response curves were almost identical. A positive correlation was found between the in vivo and in vitro tests. Thus it is concluded that the new method can provide reproducible, analytically precise (at the nanogram level) histamine release results in pediatric cases where: a positive SPT does not correlate with case history; BPT may be considered too hazardous or inconvenient; confirmation of negative or inconclusive SPT or RAST is needed. In contrast to other histamine release assays it is a convenient diagnostic tool in children since only small amounts of blood are needed and at least 96 tests can be carried out in 2 1/2 h.

Asthma

The correlation between skin tests, bronchial provocation tests and the serum level of IgE specific for common allergens in patients with asthma.

Cutaneous and bronchial immediate allergic reactivity and the serum level of IgE specific for each of four common inhalant allergens were determined for 153 asthmatic patients. Positive bronchial reactivity to an extract was not detected in any of the patients with a negative prick test reaction to that extract but did occur in 9% of the patients in whom the serum tests results for IgE specific to that allergen fell within the range regarded as negative. Highly significant correlation coefficients between the degree of bronchial and cutaneous allergic reactivity to the allergen extracts were found and these were slightly but significantly less than the correlation between the serum level of allergen specific IgE and the degree of bronchial allergic reactivity to the allergen extracts. These findings indicate that the results both of prick testing with appropriate extracts and estimation of the serum level of allergen specific IgE can be used to predict not only the presence of detectable bronchial reactivity to inhalant allergens but also the degree of this reactivity. However, for the routine investigation of asthmatic patients measurement of the serum level of allergen specific. IgE would appear to have little advantage over properly performed prick tests.

Aerosols

Decrease of beta-receptors after the antigen-specific bronchial provocation test in bronchial asthma.

Airway hyperreactivity to different stimuli is a characteristic feature of bronchial asthma. The beta-adrenergic theory, as proposed by Szentivanyi in 1968, tried to explain with beta-adrenergic dysfunction, the cause not only of bronchial hyperreactivity but of all atopic diseases. In a previous work, we found that asymptomatic asthmatic patients presented a number of beta-receptors similar to that of a normal control group, while symptomatic asthmatic patients presented a significantly decreased number when compared to both groups (40% decrease). In view of these results, we proposed to study the possible changes in the number of beta-receptors in asymptomatic asthmatic patients after a bronchial provocation test. Fifteen patients, diagnosed of bronchial asthma and sensitive to the house dust mite, D. pteronyssinus, were studied. All were free of medication and asymptomatic at least 90 days before the study. A test of specific bronchial provocation was performed on 10 patients, determining the number of beta-receptors in basal conditions, after 30 minutes and 24 hours. The other five patients underwent an unspecific provocation test with methacholine, with determination of the beta-receptor number at basal conditions, and 24 hours later. Only a significant decrease (30.4%) was found in the beta-receptor numbers, 24 hours after specific bronchial provocation with p less than 0.025 with the Student test for paired data. With regards the beta-adrenergic theory of atopy, in our opinion our results show that the detected decrease of beta-receptors would be the consequence and not the cause of atopic diseases.

Allergens

Papain-induced asthma: diagnosis by skin test, RAST and bronchial provocation test.

Seven out of eleven workers occupationally exposed to airborne papain developed immediate hypersensitive reactions, predominantly asthma and rhinitis. Skin tests and RAST with papain were positive in all symptomatic workers, but not in the four asymptomatic workers. Furthermore, out of forty non-exposed asthmatics, thirty-eight had negative RAST results and all had negative skin test results. Bronchial provocation tests with 0.15-0.5 mg papain performed in five patients with a positive case history showed in each case an immediate asthmatic reaction; in addition to that, one patient developed signs of a dual asthmatic reaction. Our results suggest that airborne papain is a highly immunogenic agent in humans, which induces type I allergic reactions in a large percentage of the exposed subjects.

Asthma

Quantitative skin prick and bronchial provocation tests with platinum salt.

Occupational asthma due to platinum salts is a frequent disease in platinum refineries. The diagnosis is based upon a history of work related symptoms and a positive skin prick test with platinum salts. Bronchial provocation tests have not been performed in epidemiological studies because the skin test is believed to be highly specific and sensitive. As no reliable data about this issue currently exist, this study assesses the use of skin prick and bronchial provocation tests with methacholine and platinum salt in platinum refinery workers. Twenty seven of 35 workers, who were referred to our clinic with work related symptoms and nine control subjects with bronchial hyperreactivity underwent a skin prick test and bronchial provocation with methacholine and platinum salt. For skin prick and bronchial provocation tests with platinum salt a 10(-2)-10(-8) mol/l hexachloroplatinic acid solution, in 10-fold dilutions was used. Four of the 27 subjects and all controls showed neither a bronchial reaction nor a skin reaction. Twenty three subjects were considered allergic to platinum salt; 22 of these showed a fall of 50% or more in specific airway conductance after inhalation of the platinum salt solution. Four workers experienced a positive bronchial reaction despite a negative skin prick test. No correlation of responsiveness to methacholine with responsiveness to platinum salt was found, but the skin prick test correlated with the bronchial reaction to platinum salt (rs = 0.50, p less than 0.023, n = 22). One dual reaction was seen in bronchial provocation tests. Side effects of both skin tests and bronchial provocation tests with platinum salt were rare and were not encountered in workers without a skin reaction to platinum salt. It is concluded that bronchial provocation tests with platinum salts should be performed on workers with work related symptoms but negative skin tests with platinum salts.

Adult

Clinical value of bronchial provocation testing in childhood asthma.

Previous studies have shown a positive relationship between the results of skin tests, radioallergosorbent tests, and bronchial provocation testing. The purpose of this study was to compare the results of skin and bronchial provocation testing to determine the extent to which the results of provocation testing could be predicted from puncture and intracutaneous skin tests. In the 1,596 provocation tests performed in 276 patients, more than 90% of patients with a wheal greater than or equal to 5 mm in diameter on skin testing by puncture technique using 1:20 w/v allergen extract experienced positive reactions on provocation testing for most antigens. If the wheal produced by puncture testing was less than 5 mm in diameter, a large wheal on intracutaneous testing only slightly increased the likelihood of a positive challenge, but if the wheal on intracutaneous testing was less than 5 mm, a positive challenge did not occur. It is concluded that the results of provocation tests may often be predicted from simple skin testing, and that in clinical use, provocation testing is likely to be useful primarily in patients for whom skin testing indicates moderate sensitization to allergens.

Adolescent

Intradermal skin tests with Dermatophagoides pteronyssinus in asthmatic children: correlation with specific IgE and bronchial provocation tests.

The purpose of the present study was to compare the results of the skin tests, the specific IgE levels and bronchial provocation tests in a group of sensitive asthmatic children with a Dermatophagoides pteronyssinus extract standardized by the RAST inhibition method. Skin tests showed a positive 'end point' in twelve children of 0.5 U/ml antigen; in eleven 5 U/ml; seven of 50 U/ml; six of 500 U/ml. Specific IgE was present in thirty-three children (92%). A close relationship between positive skin tests and serum IgE levels was found. Bronchial provocation tests were positive in twenty-eight children (78%): eight children with both positive RAST and positive skin tests had negative bronchial provocation tests.

Adolescent

Clinical experiences with bronchial provocation test using oscillation technique in Chinese patients.

Bronchial provocation tests using the forced oscillation method were conducted on 115 Chinese. Each subject continuously inhaled stepwise increased concentrations of methacholine and respiratory resistance (Rrs) was measured. The test results were regarded as responsive if Rrs increased by twice the baseline values. It was found that all normal subjects and patients with restrictive lung diseases were nonresponders. One hundred percent of the asthmatic patients and 61% of the patients with chronic obstructive pulmonary disease (COPD) were responders. However, only 29% of the 28 patients with acute bronchitis showed bronchial hyperreactivity. Baseline Rrs values for the various groups are as follows: normal subjects, 3.2 +/- 0.7 cmH2O/L/sec; patients with restrictive lung diseases, 4.2 +/- 0.6 cmH2O/L/sec; asthmatic patients, 5.6 +/- 0.9 cmH2O/L/sec; COPD patients, 7.5 +/- 0.7 cmH2O/L/sec; and those with acute bronchitis, 4.3 +/- 0.8 cmH2O/L/sec. Baseline Rrs was significantly higher in patients with airway obstruction than in normal subjects. The cumulative dose (DA, the bronchial sensitivity) of methacholine to induce a positive reaction in responders was not correlated with either respiratory conductance (Grs) or the bronchial reactivity (SGrs, the slope of Grs during a positive reaction). The dose-response curves can be classified into 6 types according to their appearances: flat form (type I), isolated spike form (type II), terminal spike form (type III), triangular form (type IV), step form (type V) and mixed form (type VI). Normal subjects and patients with restrictive lung diseases usually manifested with type I or II curves. Most asthmatic patients had type IV curves, but occasionally types V and VI were also encountered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Aerosol deposit sample in aspecific bronchial provocation test: a nuclear medicine study for quantification].

A method of standardization of inhalation bronchial provocation tests is induced. The distribution of radioactivity of in- and exhaled 99mTc human albumin (Venticoll) enables an exact calculation of intrabronchial aerosol deposition. The investigations were carried out at twelve normal test persons by using the device of bronchial provocation tests of PARI. Linearity exists between nebulized aerosol quantity in the bag and bronchial aerosol deposition. The intrabronchial aerosol deposition is calculated about 100 mg after emptying the ten liter-bag. Slowly inspiratory maneuvers of vital capacity produce a precision of the inhaled aerosol of about 15 percent.

Aerosols

[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

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

[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

A study of the bronchial provocation test with methacholine in patients with active pulmonary tuberculosis.

Bronchial hyperreactivity is a characteristic feature of bronchial asthma. Recent respiratory infections, allergic rhinitis, atopic family history, pulmonary tuberculosis, pulmonary sarcoidosis, cystic fibrosis, and farmer's lung have also been demonstrated to have bronchial hyperreactivity to inhaled methacholine. It is not known if pulmonary tuberculosis can cause nonspecific bronchial hyperreactivity and what the mechanism would be. We therefore undertook to evaluate nonspecific bronchial hyperreactivity in active pulmonary tuberculosis using the bronchial provocation test with methacholine and we measured the total serum IgE and peripheral eosinophil count to seek some mechanisms. There were 5 patients among 18 subjects with active pulmonary tuberculosis whose response to methacholine was positive. The mean baseline FEV1 of positive responders was 71.40 +/- 17.39%, and that of negative responders was 110.18 +/- 17.65% (p less than 0.05). There were no significant differences in serum IgE and peripheral eosinophil count between positive and negative responders. We found that active pulmonary tuberculosis would increase the nonspecific bronchial response with methacholine, and the mechanism of the bronchial hyperreactivity in patients with active pulmonary tuberculosis may not be related to an immunologic mechanism but may be related to the stimulating receptors.

Acute Disease

[Preventive measures in bronchial provocation tests].

The author's own experiences together with the data from the literature are presented for application the bronchial provocation tests in the hospital and in out-patient's department for pulmonary disease. Contraindications and side effects in testing the nonspecific provocative agents are presented (metacholine, histamine, carbachol), in specific provocative agents as well as in exercise testing. These tests are relatively harmless if the preventive measures are taken into account.

Bronchial Provocation Tests

[Bronchial provocation tests using bacterial suspensions in patients with bronchial asthma treated with autologous vaccines].

In 15 patients with non-atopic bronchial asthma bronchial aspirates were carried out. Bacterial strains were isolated from the aspirates and used to produce material for provocation tests andautologous vaccines. Bronchoprovocation was carried out twice--before and after treatment with autovaccines. A decrease in bronchial reactivity was seen after treatment with autologous vaccines. The improvement in spirometric indices was accompanied by clinical improvement in 11 out of the 15 treated cases (73.3%).

Adult

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