The Influence of Elevated Concentrations of Secretory IgA on the Level of Immunocompetent Cells, Cytokines, Reagins, Circulating Immune Complexes, and C-Reactive Protein in the Blood of Practically Healthy Residents of Murmansk Oblast

A total of 104 (77 women and 27 men) practically healthy residents of the city of Apatity, Murmansk oblast, aged 21–55 years were examined. The following indicators were studied in venous blood: the ratio and count of leukocytes, eosinophils, neutrophils, lymphocytes, and monocytes; the lymphocyte count with the phenotypes CD3+, CD4+, CD8+, CD71+, and CD95+ determined by the indirect immunoperoxidase reaction using monoclonal antibodies; the content of cytokines IL-6, IL-10, and TNF-α and immunoglobulin E; the level of secretory immunoglobulin IgA; and the content of C-reactive protein determined by the enzyme immunoassay. It was found that 31.73% of permanent residents of the city of Apatity, Murmansk oblast, had elevated levels of sIgA in their blood. People with increased sIgA concentrations in venous blood had higher counts of leukocytes, predominantly segmented neutrophilic granulocytes, increased concentrations of proinflammatory cytokines (IL-6, TNF-α) and anti-inflammatory (IL-10), reagins, small circulating immune complexes (IgG), and acute phase protein (CRP).