Allergic sensitisation and the environment: latest update

The prevalence of asthma and other allergic diseases is still increasing both in developed and developing countries. Allergic sensitisation against common inhalant allergens is common and, although not sufficient, a necessary step in the development of allergic diseases. Despite a small number of proteins from certain plants and animals being common allergens in humans, we still do not fully understand who will develop sensitisation and to which allergens. Environmental exposure to these allergens is essential for the development of sensitisation, but what has emerged clearly in the literature in the recent years is that the adjuvants to which an individual is exposed at the same time as the allergen are probably an equally important determinant of the immune response to the allergen. These adjuvants act on all steps in the development of sensitisation from modifying epithelial barriers, to facilitating antigen presentation, to driving T-cell responses, to altering mast cell and basophil hyperreactivity. The adjuvants come from biogenic sources, including microbes and the plants and animals that produce the allergens, and from man-made sources (anthropogenic), including unintended by-products of combustion and chemicals now ubiquitous in modern life. As we better understand how individuals are exposed to these adjuvants and how the exposure influences the likelihood of an allergic response, we may be able to design individual and community-level interventions that will reverse the increase in allergic disease prevalence, but we are not there yet.

Authors: Yoo Y, Perzanowski MS. ;Full Source: Current Allergy Asthma Reports. 2014 Oct;14(10):465. doi: 10.1007/s11882-014-0465-1. ;