RECONSTRUCTIVE IMMUNOMODULATION, UNDER THE INFLUENCE OF THYMIC HEXAPEPTIDE, OF THE NUMBER AND PHENOTYPE OF SUBSETS CD16+CD62L+CD11B+CD63- AND CD16+CD62L+CD11B+CD63+OF NEUTROPHILIC GRANULOCYTES IN CHILDREN WITH ACUTE DESTRUCTIVE PNEUMONIA, IS ASSOCIATED WITH POSITIVE CLINICAL EFFICACY

Abstract

Dysfunctions of neutrophilic granulocytes (NG) are decisive factors in the development and progression of atypical purulent-inflammatory diseases, including acute destructive pneumonia (ADP) in children. Inclusion of immunocorrective therapy in complex treatment, which promotes the restoration of NG functions, is promising.

Objective: based on clarification of the features of defective functioning of NG associated with changes in the ratio and phenotype of the CD16⁺CD62L⁺CD11b⁺CD63^-NG and CD16⁺CD62L⁺CD11b⁺CD63⁺NG subsets in children with ADP, to evaluate the clinical and immunological effectiveness of the use of immunomodulatory therapy in complex postoperative treatment using a pharmaceutical drug, the active substance of which is a synthetic thymic hexapeptide. Materials and methods: The study involved children aged 2-4 years: with a diagnosis of ADP (n=21) – the study group (SG) before complex treatment and the group after treatment (SG1) with the inclusion of hexapeptide (pdHP), 20 conditionally healthy children – the comparison group (CG), 20 children with ADP – the archival comparison group (aCG). The functions of NG were assessed by the content of CD16⁺CD62L⁺CD11b⁺CD63^- and CD16⁺CD62L⁺CD11b⁺CD63⁺ subsets (FC500, Beckman Coulter), indicators characterizing phagocytosis (%PAN, PN, PI, %D, ID), NADPH oxidase activity (%PPC, MCI) in the NBT test.

Results. It was established that there are a transformation of the phenotype of the physiological subset to CD16^dimCD62L^dimCD11b^brightCD63^- NG with defective immune properties, a 3-fold increase in the content of NG subset with a hyperactivated phenotype CD16^brightCD62L^brightCD11b^brightCD63^bright (p<0.05), a defect in phagocytic function, but increased oxidase activity (p1.2<0.05) in immunocompromised children with ADP. After complex treatment with the inclusion of pdHP, normalization of NG effector functions associated with phenotype remodeling and restoration of the subpopulation ratio was observed. Positive clinical dynamics were revealed, relative to aCG receiving traditional treatment: a large effect size of reducing the duration of fever (|δ|=0.98), respiratory failure (|δ|=0.99), more rapid regression of pleural effusion (|δ|=0.96) and early removal of drains (|δ|=1.00).

Conclusion. The obtained results indicate a pronounced positive clinical and immunological effectiveness of the use of pdHP in the complex treatment of children with ADP.