WHAT ARE THE CAUSES AND TRIGGERS OF ALLERGIC RHINITIS?
The Allergic Response The allergic process, called atopy, and its connection to asthma is not completely understood. It involves various airborne allergens or other triggers that set off a cascade of events in the immune system leading to inflammation and hyperreactivity in the airways. One description is as follows: • The conductor in an orchestra of immune factors that contribute to allergies and asthma appears to be a category of white blood cells known as helper T-cells, in particular a subgroup called TH2-cells. • TH2-cells overproduce interleukins (ILs), immune factors that are molecular members of a family called cytokines, powerful agents of the inflammatory process. • Interleukins 4, 9, and 13, for example, may be responsible for a first-phase asthma attack. These interleukins stimulate the production and release of antibody groups known as immunoglobulin E (IgE). (People with both asthma and allergies appear to have a genetic predisposition for overproducing IgE.) • During an
