Antibody Responses to Minor Allergen Bet v 2 During Allergen-Specific Immunotherapy in Birch Pollen-Allergic Patients

摘要

Antibodies to the major birch pollen allergen Bet v 1 and the minor allergen Bet v 2 were investigated in sera of SIT treated patients. All sera were positive for IgG and IgE against Bet v 1 before and after SIT. In contrast, 22% of non-treated patients were positive for IgE anti-Bet v 2 and 48% for IgG anti-Bet v 2. Prevalences were unchanged after 1.5 years of SIT, however, after 5 years of treatment the prevalence of IgG anti-Bet v 2 was 91 % while the prevalence of IgE anti-Bet v 2 was unchanged. The relative binding activities of IgG compared to IgE were up to 30 times higher after SIT. Thus, whereas existing responses, i.e., to the major allergen, are increased early in SIT, increase in IgG responses to the minor allergen require prolonged treatment. No new IgE sensitivities were observed when analyzed by quantitative immunoassay; however, 3 sera became IgE anti Bet v 2 positive after 5 years of treatment when measured by immunoblotting. This result may possibly indicate differences in assay sensitivity with respect to denaluration insensitive epitopes.