Abstract
To investigate seasonal variation in non-specific bronchial reactivity in wheat workers, we carried out histamine inhalation tests in 29 workers (28 of them men) from a small farming community with symptoms of wheat associated asthma before, during and after the 1983-4 Australian wheat harvest season. Four were cigarette smokers, and the age range was 12-54 (mean (SD) 30 (10)) years. Twenty eight subjects were atopic (one positive skinprick test result in tests with 10 common antigens), 60% reacting to house dust mite and all to at least one of eight wheat antigens. Baseline spirometry gave normal results (mean FVC1 90% (SD 8%) predicted; FVC 91% (7%) predicted). Bronchial reactivity was tested by the method of Yan et al. The cumulative doses of histamine acid phosphate (up to 3.91 mumol) that caused a fall of 20% from baseline in FEV1 was determined (PD20) and expressed as the geometric mean. In the low exposure season, May 1983, nine subjects had a PD20 (mean 1.2, range 0.3-3.9 mumol). The number rose to 19 in the summer harvest season, December 1983 (mean 0.8, range 0.07-3.9 mumol) and returned to nine in the subsequent winter, July 1984 (mean 1.8, range 0.4-3.9 mumol). The change in the number of subjects with a PD20 was significant (p less than 0.01). Four additional subjects probably had increased bronchial reactivity in the harvest season: in two the post-saline FEV1 was too unstable to give them histamine challenge and in two the challenge was inadvertently discontinued prematurely. Baseline FEV1 and FVC fell by 8% between the first and second studies (p less than 0.001); values were intermediate in the third study (FEV1 3.74, 3.44, and 3.57; FVC 4.66, 4.28, and 4.41 litres respectively). Linear modelling analysis of log PD20, season, FEV1, FVC, age, seasonality of asthma symptoms and skin test data indicated that the harvest season was the only significant determinant of variation in log PD20. It is concluded that in these wheat workers there is a seasonal variation in bronchial reactivity that may reflect a response to allergens associated with grain.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baldo B. A., Wrigley C. W. IgE antibodies to wheat flour components. Studies with sera from subjects with baker's asthma or coeliac condition. Clin Allergy. 1978 Mar;8(2):109–124. doi: 10.1111/j.1365-2222.1978.tb00456.x. [DOI] [PubMed] [Google Scholar]
- Boulet L. P., Cartier A., Thomson N. C., Roberts R. S., Dolovich J., Hargreave F. E. Asthma and increases in nonallergic bronchial responsiveness from seasonal pollen exposure. J Allergy Clin Immunol. 1983 Apr;71(4):399–406. doi: 10.1016/0091-6749(83)90069-6. [DOI] [PubMed] [Google Scholar]
- Britton J., Mortagy A., Tattersfield A. Histamine challenge testing: comparison of three methods. Thorax. 1986 Feb;41(2):128–132. doi: 10.1136/thx.41.2.128. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chan-Yeung M., Lam S. Occupational asthma. Am Rev Respir Dis. 1986 Apr;133(4):686–703. doi: 10.1164/arrd.1986.133.4.686. [DOI] [PubMed] [Google Scholar]
- Cockcroft D. W., Killian D. N., Mellon J. J., Hargreave F. E. Bronchial reactivity to inhaled histamine: a method and clinical survey. Clin Allergy. 1977 May;7(3):235–243. doi: 10.1111/j.1365-2222.1977.tb01448.x. [DOI] [PubMed] [Google Scholar]
- Cockcroft D. W., Ruffin R. E., Dolovich J., Hargreave F. E. Allergen-induced increase in non-allergic bronchial reactivity. Clin Allergy. 1977 Nov;7(6):503–513. doi: 10.1111/j.1365-2222.1977.tb01481.x. [DOI] [PubMed] [Google Scholar]
- Darke C. S., Knowelden J., Lacey J., Milford Ward A. Respiratory disease of workers harvesting grain. Thorax. 1976 Jun;31(3):294–302. doi: 10.1136/thx.31.3.294. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davies R. J., Green M., Schofield N. M. Recurrent nocturnal asthma after exposure to grain dust. Am Rev Respir Dis. 1976 Nov;114(5):1011–1019. doi: 10.1164/arrd.1976.114.5.1011. [DOI] [PubMed] [Google Scholar]
- Empey D. W., Laitinen L. A., Jacobs L., Gold W. M., Nadel J. A. Mechanisms of bronchial hyperreactivity in normal subjects after upper respiratory tract infection. Am Rev Respir Dis. 1976 Feb;113(2):131–139. doi: 10.1164/arrd.1976.113.2.131. [DOI] [PubMed] [Google Scholar]
- Knudson R. J., Slatin R. C., Lebowitz M. D., Burrows B. The maximal expiratory flow-volume curve. Normal standards, variability, and effects of age. Am Rev Respir Dis. 1976 May;113(5):587–600. doi: 10.1164/arrd.1976.113.5.587. [DOI] [PubMed] [Google Scholar]
- Makino S. Clinical significance of bronchial sensitivity to acetylcholine and histamine in bronchial asthma. J Allergy. 1966 Sep;38(3):127–142. doi: 10.1016/0021-8707(66)90036-0. [DOI] [PubMed] [Google Scholar]
- Mink J. T., Gerrard J. W., Cockcroft D. W., Cotton D. J., Dosman J. A. Increased bronchial reactivity to inhaled histamine in nonsmoking grain workers with normal lung function. Chest. 1980 Jan;77(1):28–31. doi: 10.1378/chest.77.1.28. [DOI] [PubMed] [Google Scholar]
- Perks W. H., Sopwith T., Brown D., Jones C. H., Green M. Effects of temperature on Vitalograph spirometer readings. Thorax. 1983 Aug;38(8):592–594. doi: 10.1136/thx.38.8.592. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sotomayor H., Badier M., Vervloet D., Orehek J. Seasonal increase of carbachol airway responsiveness in patients allergic to grass pollen. Reversal by corticosteroids. Am Rev Respir Dis. 1984 Jul;130(1):56–58. doi: 10.1164/arrd.1984.130.1.56. [DOI] [PubMed] [Google Scholar]
- Warren C. P., Manfreda J. Respiratory symptoms in Manitoba farmers: association with grain and hay handling. Can Med Assoc J. 1980 Jun 7;122(11):1259–1264. [PMC free article] [PubMed] [Google Scholar]
- Yan K., Salome C., Woolcock A. J. Rapid method for measurement of bronchial responsiveness. Thorax. 1983 Oct;38(10):760–765. doi: 10.1136/thx.38.10.760. [DOI] [PMC free article] [PubMed] [Google Scholar]