The characteristics of serum circulating immune complexes of patients with atopic asthma with different severity degree

Abstract

Aim. To evaluate the serum level of pathogenic circulating immune complexes in patients with mild and severe atopic bronchial asthma. Methods. Serum samples of patients with atopic asthma of mild persistent (30 patients) and severe persistent (20 patients) forms were analyzed. The control group consisted of 15 healthy volunteers. To detect the giant, large, medium and small-sized serum immune complexes, 3, 3.5, 4 and 7% polyethyleneglycol-6000 solutions were used. For quantitative evaluation of the immune complexes we measured the ultraviolet optical density at 280 nm wave length. To separate the immune complexes from immunoglobulin, Protein-G-Sepharose was used. Determination of the protein composition of circulating immune complexes was performed by electrophoresis in 8% polyacrylamide gel. Results. The concentration of immune complexes was increased in patients with bronchial asthma compared to healthy donors. Small and medium-sized immune complexes were prevailing, their concentrations correlated with the severity of asthma. Large, medium and small-sized immune complexes participated in immunopathological reactions in patients with both mild and severe asthma, with immune complexes pathogenicity coefficient significantly increased depending on the severity of the disease. Electrophoretic analysis of circulating immune complexes has shown the presence of proteins with molecular weight of 60 kDa in the complexes of all sizes. In the severe asthma group, an antigen fraction with a molecular mass of 36 kDa within the small-sized molecular complexes was revealed. Conclusion. The observed increase of small and medium-sized circulating immune complexes serum levels in patients with bronchial asthma may be an indicator of of these patients predisposal to autoimmune reactions development.