Recent years of research have shed a new light on the role of IgE in immune reactions. It seems to be more than just a contribution to immediate type of allergic response. It appears that monomeric IgE may enhance mast cell activity without cross-linking of FcεRI by IgE specific allergen or autoreactive IgG anti-IgE antibodies. Monomeric IgE molecules are heterogeneous concerning their ability to induce survival and activation of mast cells only by binding the IgE to FcεRI, but not affecting degranulation of cells. It also turned out that IgE may react to autoantigens occurring in the blood not only in chronic spontaneous urticaria (CSU) but also in other autoimmune diseases. The aforementioned phenomena may promote the activity of mast cells/basophils in CSU that easily degranulate when influenced by various inner (autoreactive IgG against IgE and FcεRI, autoreactive IgE for self-antigens) and outer factors (cold, heat, pressure) or allergens. These findings forced the new approach to the role of autoimmunity, self-antigens and IgE autoantibodies in the pathology of CSU. CSU put in the scheme of autoreactive IgG and autoreactive IgE seems to be either a kind of an autoimmune disease or a clinical manifestation of some other defined autoimmune diseases or both.
Keywords: Autoimmune reactivity; Autoreactive IgE; Chronic urticaria; Mastocyte priming; Self-antigens.