[Allergen specific-IgG4 in circulating immune complexes in patients with inhalant allergy undergoing specific...

The mechanism of action of specific immunotherapy (SIT) is still not definitely clear. The problem of the presence of allergen specific-IgG4 in circulating immune complexes (CIC) of patients with inhalant allergy is being discussed. The aim of the study was to determine the allergen specific-IgG4 serum levels and concentration in CIC in patients with inhalant allergy who underwent specific immunotherapy with relevance to its clinical benefits. The trial was carried out on 57 patients with seasonal allergic rhinitis (SAR) and 55 with perennial allergic rhinitis (PAR). Each of them underwent 3-year specific immunotherapy with Allergovit (Nexter-Allergopharma) or Novo Helisen Depot (Nexter-Allergopharma). 56 patients with pharmacologically treated allergic rhinitis served as a control group. Serum levels of allergen specific-IgG4 (as-IgG4), IgE, as-IgE and as-IgG4 concentration in CIC were measured in each patient and correlated with the clinical score of the disease activity. Nonparametric tests (the U Mann-Whitney test, Kruskall-Wallis test and Spearman's correlation rang test) were used. Serum levels of as-IgG4 and bound in CIC were statistically higher in the SIT group than in the control group and differed significantly between SAR and PAR groups. Immunotherapy caused significantly higher concentrations of as-IgG4 in CIC in PAR group than in SAR patients. No significant associations were found between studied immunological indices and clinical effects of SIT. Specific immunotherapy of allergic rhinitis is connected with the increase of as-IgG4 serum level and its concentration in circulating immune complexes.