COMMON DYSREGULATION AMONG ALLERGIC CONDITIONS
Allergic asthma, allergic rhinitis and atopic dermatitis are prevalent allergic diseases. These diseases can be distinguished by the location of their most important symptoms; lungs, sinuses and skin respectively.
They also share many characteristics, including the same underlying immune system dysregulation as evidenced by inappropriate T-cell mediated responses to innocuous antigens, peripheral eosinophilia, elevated serum IgE levels, chronic immune system activation, and over-production of inflammatory mediators, including leukotrienes, cytokines and chemokines.
LEUKOTRIENES AND INFLAMMATION IN ALLERGIC DISEASES
Leukotrienes are eicosanoid lipid mediators and are derived from the essential fatty acid arachidonic acid (AA), which is concentrated in the membrane phospholipids of cells of the immune system. The role of inflammatory mediators (leukotrienes) in allergic diseases is well characterized. In particular, leukotrienes play a significant role in the pathophysiology of allergic diseases. In all of these allergic diseases, there is an overproduction of leukotrienes. Leukotrienes are important for innate immunity and the physiological response to pathogens. However, excess production of leukotrienes promotes the inappropriate response, such as inflammation, to harmless antigenic substances that characterizes allergy.
LEUKOTRIENES IN ALLERGIC INDIVIDUALS
Blood leukocytes of allergic individuals produce higher levels of leukotrienes upon stimulation than do the same types of cells from nonallergic individuals (14,23). Further, the response of allergic individuals to leukotrienes is exaggerated compared to the response by non-allergic individuals. This exaggerated response causes the problematic and uncomfortable symptoms common in allergies and asthma.