Allergen-specific IgE in circulating immune complexes in patients with inhalant allergy undergoing specific...

Specific immunotherapy (SIT) has been used worldwide since it was introduced near the beginning of this century. Although this mode of therapy has been known for over 80 years, its mechanism of action is still not definitely clear. The problem of the presence of allergen-specific IgE in IgE-containing circulating immune complexes of patients with inhalant allergy has been mentioned in the literature. However, there are no data concerning specific immunotherapy. The aim of our study was to evaluate the influence of SIT in patients with inhalant allergy on allergen-specific IgE in serum and in IgE circulating immune complexes. A total of 112 subjects with allergic rhinitis (57 with grass pollen allergy and 55 sensitive to house dust mites Dermatophagoides pteronyssinus) were included in the study. SIT was administered to 29 patients suffering from pollinosis and 27 patients sensitive to house dust mites. The remaining patients were treated with an H2-receptor antagonist only. The decrease of allergen-specific IgE concentration in IgE circulating immune complexes was parallel to the analogous changes in the serum only in the patients with pollinosis. Immunotherapy of house dust mite-sensitive patients caused a much slower decrease of allergen-specific IgE in circulating immune complexes than in serum. The binding index of allergen-specific IgE in circulating immune complexes increased during the course of the treatment. No significant associations were found between the immunological indices studied and clinical score of the disease activity.