Published Online: November 13, 2015
Sensitization to allergens is associated with several allergic conditions and it is considered to be an important risk factor for asthma. Epidemiological and clinical studies have shown that the prevalence of allergic sensitization is higher in younger people than in older adults. Does this mean that as people age, the body reacts less to the presence of allergens? Or is it that people born more recently are more likely to be sensitized than those born many years ago?
In an article recently published in The Journal of Allergy & Clinical Immunology (JACI), Amaral et al. assessed the changes in allergic sensitization in a large population sample of adults from 25 centers in Europe and Australia. The subjects were followed over a period of 20 years. Whether these changes were different depending on when the subjects in the study were born was also examined. Allergic sensitization was assessed by measuring the presence of IgE antibodies specific to house dust mite, cat and grass pollen allergens in blood.
The authors have found that the prevalence of sensitization to house dust mite and cat clearly decreased as people got older, but this was not so clear for grass pollen. The findings for house dust mite and cat support the hypothesis that prevalence of allergic sensitization is lower in older than in younger adults due to aging. Regarding grass pollen, the authors speculate that, in our modern society, something makes pollens more allergenic than previously – this could be air pollution. These findings suggest the need for further studies on the environmental determinants and biological mechanisms of allergic sensitization so that the understanding of the causes of allergy and allergic conditions improves.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.