IgG Subclass Antibodies to Allergens During Immunotherapy

Abstract We studied the IgG subclass antibody response in allergic patients immunized with complex allergen mixtures (grass pollen (GP), birch pollen (BP), house dust mite (HDM), the mould Cladosporium (CS), and yellow jacket venom (YJV)). IgG subclass antibodies were quantitated by means of different types of immunoradiometric assays. We found the IgG antibody response to be restricted to the IgG1 and IgG4 subclasses during immunotherapy with GP, BP, and YJV. Whereas these subclasses also were predominant in the response to HDM and CS, some patients produced large amounts of IgG2 and IgG3 antibodies to CS. In patients immunized with GP or CS, a statistically significant association between low initial IgG4 antibody response and good clinical outcome was observed. Possible immunobiological mechanisms underlying this finding are discussed