The Changes of Mite-Specific Immunoglobulin A and Transforming Growth Factor-β1 During Immunotherapy of Children with Dust Mite Allergy

Abstract

Immunoglobulin A (IgA) is the most important immunoglobulin of the mucosa. It can protect the mucosal surface from invasion by foreign pathogens. However, only a few studies have mentioned the changes of allergen-specific IgA after immunotherapy in patients with bronchial asthma. In this study, we sought to investigate the levels of mite-specific IgA, IgE, and IgG4 as well as total IgE, IgG, IgA, and IgM, before and after immunotherapy. Serum levels of transforming growth factor β1 (TGF-β1), the major cytokine secreted by type 3 T helper (T_H3) cell and a contributing factor for IgA isotype switch, was also assayed. A total of 19 patients were enrolled in this study. The serum levels of total IgG, IgA, and IgM were measured by rate nephelometry. Total IgE, Dermatophagoides pteronyssinus (Der-p), and Dermatophagoides farinae (Der-f)-specific IgE, and mite-specific IgG4 were determined with commercial radioallergosorbent test (RAST) system. Mite-specific IgA and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA). The results showed a significant increase of mite-specific IgA and IgG4 mean of 7 months after immunotherapy (p < 0.05). TGF-β1 decreases significantly (p < 0.05). There were no significant differences in total IgG, IgE, IgA, and IgM or mite-specific IgE after immunotherapy (p > 0.05). We hypothesized that the increased allergen-specific IgA and IgG4 might work as blocking antibodies at the mucosa and in serum, respectively, after immunotherapy. It might prevent the allergen from penetrating the mucosa or from competing with allergen specific IgE. However, further studies are needed to clarify the role of allergen-specific IgA and TGF-β in the working mechanisms of immunotherapy.