Immunodepressive and pathogenetic mechanisms in infectious allergy

The incidence of infectious allergy has been growing mainly due to infection with Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, with enhancing allergic background by yeast-like fungi of the genus Candida. The frequency of infection has currently become a threat without tending to decline. Undoubtedly, Staphylococcus aureus is a pathogenic species producing highly powerful exotoxins exerting properties of cytolysin capable of disrupting the integrity of any cell wall, destroying epithelial cells, damaging mucous membranes in any organ, including the intestines, wherein it becomes accumulated at any location of staphylococcal inflammation. At the same time, almost 90% of cases of allergic reactions are diagnosed with atopic dermatitis because IgE level in some cases of infectious allergy is increased. The mechanism of the pathogenetic action of reagins is realized by re-binding of antigens to IgE fixed on mast cell and basophil surface resulting in FcR1 cross-linking and release of vasoactive mediators responsible for developing early phase of allergy. IgE concentrations, accounting for only 0.002% of the total blood immunoglobulins in an apparently healthy person, may remain low in atopic bronchial asthma, atopic dermatitis, allergic rhinoconjunctivitis, etc. IgE level is increased not only in atopy, but also in oncopathology, autoimmune diseases, whole body cooling and IgA deficiency. In allergic reactions, an increased level in the extracellular pool of various receptor structures is recorded. Of interest is a comparative analysis of the ratio between frequency of IgE reactions and CD23 shedding in infectious allergies of various etiology. The aim of the study is to establish a role of the CD23 extracellular pool in pathogenetic mechanisms of infectious allergy. There were examined 678 subjects who were at apparently healthy state at the time of the examination, including 545 females and 133 males, as well as 1481 patients with verified infectious allergy who live in the Arkhangelsk Region. It has been established that patients with staphylococcal infection had markedly aggravated symptom complex of pathological reactions linked to anemia, neutropenia and deficiency of phagocytic protection. Pathological reactions in infectious allergies are accompanied by sharply increased level of sCD23 with its abnormally high concentrations (> 200 ng/ml) found in 51.7% of cases paralleled by increased level of serum IL-10 and reagins in 21.43 and 35.7% cases, respectively, along with phagocytic defense deficit observed in 85.7% as well as accumulation of CEC in 92.86%. A parallel increase in level of sCD23 and IgE is associated with increased percentage of T helpers, cytotoxic T lymphocytes, activated T cells expressing IL-2 receptor, along with upregulated of the MHC II molecules.