Exposure to a farming environment affects children’s immune responses to certain allergens, according to a study by researchers with the Arizona Respiratory Center (ARC) at The University of Arizona College of Medicine in Tucson.
Led by Donata Vercelli, MD, ARC assistant director and UA professor of cell biology, and Debra Stern, ARC principal research specialist, the study examined the immune responses of 812 European school-age children – about half of whom lived on farms – to three allergens: timothy grass pollen, house-dust mites and cat dander.
(Allergens can cause the immune system to respond by causing certain cells to release powerful chemicals, including histamine, resulting in wheezing, sneezing, and itchy nose and eyes.)
Previous studies have shown that farming protects against the development of allergic disease (which include asthma and seasonal allergic rhinitis), but the exact mechanism for this effect is unknown. “We found that most of the children – whether living on a farm or not – had an immune response to all three allergens, regardless of whether they were allergic or not, but only some of them developed the type of responses associated with disease,” says Dr. Vercelli.
“Unexpectedly, we found that farming had the greatest impact on the immune response to timothy grass but a much weaker, if any, effect on the cat and dust mite responses. These results suggest that interventions to prevent allergic disease may need to be tailored to specific allergens.”
Study results were published in the Journal of Allergy & Clinical Immunology February issue.