While allergens (like pollen and specific foods) are innocuous for non-allergic individuals, for allergic individuals allergens are a cause of disease. This is because their immune system has a special propensity to produce IgE antibodies in the presence of allergens. Non-allergic individuals also produce these antibodies but they do not target allergens and act instead as a defense mechanism against certain parasites.
The main reasons why allergic subjects produce IgE antibodies in the presence of allergens are:
1. Genetic predisposition
This determines the propensity to produce IgE antibodies. In general, allergic diseases are hereditary and are more frequent between fathers and sons of allergic individuals.
2. The nature of the allergen
This determines the capacity of these substances to induce the produce of IgE antibodies. Through various mechanisms, allergens are able to regulate the type of immune response produced by the body, enhancing the pro-allergen response in patients.
3. Environmental factors
These factors determine the degree of exposure to allergens and influence the allergenic capacity of the allergens. The environmental factors account for the increase of allergic diseases in recent decades.
Air contamination in cities, food or hygienic drinks with a lower bacterial charge impact the immune response and enhance pro-allergic responses in an increasing number of individuals.