Molecular mechanisms of formation of blood eosinophilia under pulmonary tuberculosis

Abstract

Molecular factors of pathogenesis of the eosinophilic blood reaction under pulmonary tuberculosis are analyzed in the article. It has been established that the key cytokine providing the development of hemic eosinophilia in patients with pulmonary tuberculosis is IL-5. IL-5 plasma concentration turned out to be increased only in patients with eosinophilia. Increase of eotaxin was determined in patients with tuberculosis despite of the pressense of eosinophilia. One-directional nature of the defined changes in eotaxin concentration might be explained by dual properties of this chemokine: on the one hand, eotaxin mediates long-term presence of eosinophils in blood; on the other hand, it initiates the process of adhesion of eosinophilic leucocytes to vascular endothelium with their further migration to the focus of granulomatous inflammation. The established increase in number of IL-5R-positive eosinophils presents one more mechanism which explains the basis of long-term presence of eosinophils in peripheral blood in patients with pulmonary tuberculosis.