ESTIMATION OF LEVEL OF SUBPOPULATION CD14⁺/CD16⁺ MONOCYTES IN PATIENTS WITH JUVENILE DEPRESSIONS

Abstract

At present, at least two phenotypically different subpopulations of blood monocytes have been identified: "classical" monocytes with the phenotype CD14++/CD16- and "nonclassical" (pro-inflammatory) with the phenotype CD14+/CD16+. It has been established that monocytes CD14+/CD16+ participate in latent or so-called systemic non-infectious inflammation in the human body along with blood neutrophils and microglial cells of the brain, which are the analogue of monocyte/macrophage system in the brain. Monocyte function disorders are considered as one of the links in the neurodegenerative process underlying the neuroinflammatory hypothesis of the development of schizophrenia. In this connection, the aim of this research was to study in patients with juvenile depression the amount of pro-inflammatory monocytes in terms of the expression level of CD14+/CD16+ receptors as well as the activity of leukocyte elastase and a1-proteinase of elastase inhibitor. It was also interesting to determine the mechanisms of their interaction in the pathogenesis of immunosuppression, in particular, to identify a possible connection of pro-inflammatory monocytes with the activity of leukocyte elastase and a1-proteinase of elastase inhibitor in patients with juvenile depression at the early stage of disease. 27 male patients aged 17-23 years were examined. The disease diagnostics was carried out in accordance with the criteria of ICD-10 according to which all patients have depression with the syndrome of attenuated psychotic symptoms (Attenuated Psychotic Syndrome) in the structure of psychopathological disorders. 12 mentally healthy age- and gender-matched persons were examined as controls. Monocytes were obtained by the conventional method of adhesion to the plastic surface from mononuclear cells isolated from peripheral venous blood of patients and healthy controls by centrifugation in a ficoll-urographin density gradient (ρ = 1.077). In the blood of patients and healthy controls, the level of monocytes with the phenotype CD14+/CD16+, the enzymatic activity of leukocyte elastase and the functional activity of α1-proteinase inhibitor were studied. The clinical and laboratory study showed an increase of more than twofold in the level of the pro-inflammatory subpopulation of CD14+/CD16+ monocytes in patients compared with its level in healthy individuals. The increase was accompanied by an elevation of leukocyte elastase and a1-proteinase inhibitor activity. A positive correlation was found between the increase of surface receptors CD14+/CD16+ expression on monocytes and elevation of the leukocyte elastase activity.These results confirm participation of CD14+/CD16+ monocytes in the development of latent or non-infectious immune inflammation, and determine the mechanisms of possible interaction between monocytes and neutrophils in the development of immune inflammation in patients with juvenile depressions with the Attenuated Psychotic Syndrome.

Keywords

• juvenile depression
• “classical” monocytes cd14++/cd16-
• pro-inflammatory monocytes cd14+/cd16+
• leukococytic elastase
• a1-proteinase inhibitor
• immune inflammation