Oilseed rape flour: another allergen causing occupational asthma among farmers.
BACKGROUND
Farmers are exposed to a wide variety of sensitizers. Since occupational asthma (OA) can lead to permanent disability, exposure discontinuation is the preferred treatment. When this is not possible, the identification of the causative allergen may allow an alternative therapy.


METHODS
We present three farmers diagnosed with OA as a consequence of handling fodder. We carried out skin tests with common and occupational allergens and with oilseed rape (OSR) extract. Total and specific serum IgE levels were measured. The patients underwent the OSR-bronchial provocation test (OSR-BPT). The day before and 24 h after the OSR-BPT, the methacholine (M)-BPT and induced sputum were performed. Eosinophil percentages and ECP levels were measured in the sputum samples.


RESULTS
OSR sensitization (skin tests and specific serum IgE) was detected in all the patients. The OSR-BPT elicited early responses in two subjects. Methacholine sensitivity, sputum eosinophils, and sputum ECP levels increased 24 h after the OSR-BPT in all the patients.


CONCLUSIONS
We have demonstrated that inhalation of OSR flour causes bronchoconstriction, induces an eosinophilic inflammatory bronchial response, and increases bronchial hyperresponsiveness in sensitized asthmatics. OSR flour contained in animal fodder should be considered another potential cause of OA among farmers.
Alvarez
M J
MJ
Sección de Alergología, Hospital de León, Spain.
Estrada
J L
JL
Gozalo
F
F
Fernandez-Rojo
F
F
Barber
D
D
D000328:Adult; D000383:Agriculture; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000175:diagnosis / Q000276:immunology*; D001798:Blood Proteins / Q000032:analysis; D001937:Brassica / Q000276:immunology*; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000473:pathology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis / Q000276:immunology*; D012260:Ribonucleases; D012882:Skin Tests; D013183:Sputum / Q000737:chemistry / Q000166:cytology; D013997:Time Factors
D000485:Allergens; D001798:Blood Proteins; D016085:Bronchoconstrictor Agents; D047091:Eosinophil Granule Proteins; D016210:Methacholine Chloride; D007073:Immunoglobulin E; D012260:Ribonucleases