[Effect of immunotherapy on house dust mite allergen-specific IgG1 and igG4 antibodies in nasal secretion for patients with perennial allergic rhinitis].

Objective: To investigate the effect of immunotherapy on allergen-specific IgG1 and IgG4 in nasal secretion for patients with nasal allergy.

Methods: Nasal secretion was collected with suction from normal subjects, patients with allergic rhinitis untreated and treated with immunotherapy. Indirect, non-competitive streptavidin-biotin ELISA was applied to analyze allergen-specific IgG1 and IgG4 in nasal secretion.

Results: Patients with nasal allergy both treated and untreated showed a higher concentration of IgG1 and IgG4 (Z = -3.623, -3.061, P < 0.01, respectively), treated group showed higher concentration of IgG1 and IgG4 than untreated group (Z = -2.453, -3.408, P < 0.01, respectively). IgG4 antibody specific to purified allergen Der f I in the treated group was higher than normal subjects (Z = -3.518, P < 0.01), both IgG1 and IgG4 antibodies specific to purified allergen Der f II in treated group were higher than normal subjects (Z = -2.366, -2.936, P < 0.01, respectively) and than untreated group (Z = -2.366, -2.937, P < 0.01, respectively). In the IgG subclasses of IgG1 and IgG4, there was positive correlation among crude mite extract, Der f I and Der f II. There was a positive correlation between IgG1 and IgG4 for all 3 kinds of allergens. There was a positive correlation between IgG1 in the nasal secretion and IgE in the serum and between IgG4 in the nasal secretion and IgE in the serum for crude mite extract.

Conclusions: Patients with nasal allergy showed higher responsiveness to natural allergen exposure and produced higher level of IgG1 and IgG4 antibodies to specific allergens. Immunotherapy increased the concentration of IgG1 and IgG4 antibody in the nasal secretion, which might function as a blocking antibody to specific allergen.