Analysis of house dust mite-specific IgE, IgG4, and IgG antibodies during immunotherapy in asthmatic children.

House dust mite (Dermatophagoides pteronyssinus, DP) specific IgE, IgG4, and IgG antibodies were analyzed by Western blotting in 18 asthmatic children during the course of 2-years' allergen-specific immunotherapy. Although more than 50 protein bands could be identified in the crude mite extracts by SDS-PAGE, only eight of them elicited both IgE and IgG4 antibodies in most patients. The molecular weights were 110, 60, 55, 43, 33, 27, 16, and 14 kD, respectively. No antibodies against new antigens were induced after immunotherapy. There was a significant correlation between the intensity of reactive bands of Western blotting and RAST. IgG4 antibody was increased in 72% (13/18) of patients, but the simultaneous change in IgE varied. Analysis of allergen-specific IgE and IgG4 antibodies by Western blotting may provide a useful tool for evaluation of clinical response to immunotherapy.