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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.
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.
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.
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.
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.
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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.
UNLABELLED: Several methods of bronchial challenging have been described in literature. The comparison of the results obtained in different departments is, of course, very difficult. The Authors have been interested in the standardization of inhalation challenge techniques and they present in this work their method and the results obtained. The standardized method has a good specificity, because of the agreement between B.P.T. and other diagnostic tests. The bronchial reaction generally developes after the exposition to low doses of allergen extract, and this confirms the specificity of the method. Its precision, depending on the standardization of allergen extract activity by RAST and of inhalation procedures, is good. The reproducibility is of 100 per cent. The safety is high (rare untword reactions). IN CONCLUSION: this standardized method of bronchial challenging is useful in etiologic diagnosis of asthma.
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A procedure of bronchial inhalation challenge with acetylcholine accepted by the working group "Aerosols in Medicine" of the GDR on its session in autumn 1976 in Leipzig is reported. The decisions on substance, dose, kinds of application and interpretation are discussed and confirmed.
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198 asthmatics and twenty healthy persons were studied by RAST and in vivo tests with four common inhalant allergens. (a) Higher RAST classes were elicited with mite (Dermatophagoides farinae) extract and lower classes with other allergens. The agreement between positive RAST and skin or P-K tests was highest with the mite extract. RAST sensitivity was dependent on the kinds of allergens and was most sensitive to mite extract. Positive RAST was most closely related to the prick test reactions. (b) RASTs to house dust and mite extract were examined in terms of the threshold dosage of house dust and also the types of bronchial response (early, dual and late) induced by a certain amount of house dust; higher RAST classes were found in subjects with bronchial response to the dual or early type, elicited by a threshold dosage of diluted extract, while lower RAST classes were found in cases of the late-type response elicited by the threshold dosage of concentrated extract. (c) Changes in IgE antibodies to house dust and mite extract were estimated in patients with positive house dust provocation. A greater increase occurred in cases of dual or early response, a smaller increase in those with a late response. Despite discordances in skin tests and RAST between house dust and mite extracts, the increases in IgE antibodies to mite extracts as well as house dust were observed in all cases, presumably caused by an allergenic identity between the allergens.
A study was made of the protective action of the anti-allergic drug ICI 74,917, a phenanthroline derivative, in specific allergen provocation tests and in combating clinical symptoms in thirteen asthmatic out-patients. It was found that ICI 74,917 was able to diminish allergen-induced bronchoconstriction significantly (P less than 0.01) during both the placebo period and during chronic treatment with ICI 74,917 for 4 weeks. The results obtained during these two periods did not differ significantly. There was not, however, any statistically significant difference in the symptom scores or PEF rates during the treatment with ICI 74,917 or placebo for 1 month. This may indicate that although ICI 74,197 is able to prevent bronchoconstriction in an allergen provocation test, it failed to improve asthma clinically. No signs of the phenomenon of tachyphylaxis were observed in the present study. The Student's t-test was used in the statistical analysis.
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