Longitudinal changes of sensitization to farming-related antigens among young farmers.
BACKGROUND
We have shown previously that the prevalence of allergic sensitization in Tyrolean farming students is high, with a clear relationship to occupational exposure.


OBJECTIVE
It was the aim of this investigation to assess longitudinal changes in sensitization and a possible impact on lung function.


METHODS
Of the 147 farming students in the original cohort, we could re-examine 42 after a mean interval of 4.0 years. All individuals completed a questionnaire and had spirometry, skin prick tests, total and specific IgE analysis, and testing for precipitating antibodies.


RESULTS
As compared to the first study, there was a decrease in the frequency of IgE-mediated allergy (30.1 vs. 54.8%; p < 0.05) and in total serum IgE levels (107.4 +/- 254 vs. 157.8 +/- 304 U/ml; p < 0.001). Conversely, 3 individuals had developed precipitating antibodies de novo, and those who had initially had a positive precipitin test (n = 6) were still positive. A larger-sized estate, the lack of a hay dryer, and the presence of moldy hay were confirmed as risk factors for allergic sensitization. Although there was a slight overall decrease in forced vital capacity, no new cases of occupational lung disease were found.


CONCLUSIONS
In young Tyrolean dairy farmers, the prevalence of precipitins is constantly high and rising while IgE-mediated allergy declines. Within 4 years, no clinically relevant impact of allergy on lung function was noticed.
Department of Medicine, University of Innsbruck, Innsbruck, Austria.
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C
Prior
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Falk
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Frank
D000293:Adolescent; D000328:Adult; D000382:Agricultural Workers' Diseases / Q000276:immunology*; D000485:Allergens / Q000009:adverse effects*; D001317:Austria / Q000453:epidemiology; D015331:Cohort Studies; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology / Q000276:immunology*; D007114:Immunization / Q000379:methods; D007073:Immunoglobulin E / Q000032:analysis*; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D010328:Patch Tests; D012129:Respiratory Function Tests; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000276:immunology*; D012307:Risk Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires
D000485:Allergens; D007073:Immunoglobulin E