Immunologic reactivity to work-related airborne allergens in people occupationally exposed to dust from herbs.

A group of 150 people occupationally exposed to dust from herbs were examined. The examined group consisted of 47 thyme farmers, 32 chamomile farmers, 31 sage farmers and 40 workers of herbs processing industry. As a reference group, 50 urban dwellers, not exposed to any kind of organic dust, were examined. Skin prick tests and precipitin tests were conducted with, respectively, 4 and 11 microbial antigens associated with organic dust. Both skin and precipitin tests were also conducted with herbal extracts of chamomile and sage. Precipitin tests were carried out with sera not concentrated and sera 3-fold concentrated. Tests for inhibition of leukocyte migration (MIF) were also conducted with 4 microbial antigens. People occupationally exposed to dust from herbs showed a higher frequency of positive skin reactions to microbial antigens compared to the reference group. The results of precipitin test also revealed greater reactivity to the environmental microbial antigens in the examined group, compared to the reference group. The highest frequency of positive results was noted with the antigen of Pantoea agglomerans (30.6 % with sera not concentrated and 48.3 % with sera 3-fold concentrated) - the difference compared to the reference group (12.0 %) was highly significant (p < 0.01). The frequencies of positive results of MIF test in the examined group were high with all antigens tested: Arthrobacter globiformis (12.6 %), Pantoea agglomerans (11.1 %), Saccharopolyspora rectivirgula (17.0 %), Aspergillus fumigatus (13.3 %), and, compared to the reference group with no positive result for any antigen, all the differences were significant (p < 0.05). In conclusion, the frequency of positive allergological reactions to airborne microorganisms was high in people occupationally exposed to dust from herbs and suggests a potential role of microbial allergens in the pathogenesis of work-related health disorders among herb workers. The risk of sensitization seems to be greatest among thyme farmers, who showed the highest positive response. The results confirmed the particular allergenic importance of Gram-negative bacterium Pantoea agglomerans.