IgG4 Antibodies in Patients with House-Dust-Mite-Sensitive Bronchial Asthma: Relationship with Antigen-Specific Immunotherapy

Abstract
Sera from 40 patients with house-dust-mite (Dermatophagoides farinae)-sensitivebronchial asthma were evaluated by solid-phase radioimmunoassay for their mite-specific IgG4 antibody levels. Asthmatic patients undergoing specific immunotherapy possessed a significantly higher mean value of IgG4 antibodies than normal controls and asthmatics without immunotherapy (p < 0.01 and p < 0.05, respectively). Moreover, evaluation of 11 patients before and after immunotherapy showed that IgG4 antibodies tend to increase during immunotherapy. The clinical significance of the IgG4 subclass as blocking antibodies in immediate allergic reactions is also briefly discussed.