IgG4: non-IgE mediated atopic disease.

This review article attempts to define the role of IgG4 in allergic disease. Evidence from the literature suggests that IgG4 antibodies may act as sensitizing as well as blocking antibodies. The mechanism(s) of the dual properties of this immunoglobulin sub-class in this disease is discussed in relation to the various immunopharmacologic (target cell) and immunological (lymphocyte) pathways. It is clear that availability of IgG4 myelomas and the development of monoclonal antibodies to IgG4 is essential for further research in this area. Preliminary findings suggest that IgG4 antibodies may be important in certain types of food allergic reactions. More work should be done to analyze pediatric populations for IgG4-RAST to a variety of food allergens.