LYMPHOCYTE SUBSETS AND CYTOKINES IN BLOOD AND CEREBROSPINAL FLUID IN CHILDREN WITH VIRAL AND BACTERIAL MENINGITIS

Introduction of flow cytometry caused an increase in the investigation of liquor lymphocyte pool phenotype in the case of different brain disorders, including viral and bacterial meningitis, however this type of research in children has been relatively rare. Phenotype and lymphocyte functions are under cytokine control system, therefore detection of interconnections between lymphocyte pool subpopulation composition and cytokine level in blood and liquor of the patients concerns a great interest. The purpose of this research was to study lymphocyte subpopulation composition and the level of cytokines IL-1 beta, IL-6, IL-8, IL-10, IFN alpha, IFN gamma and IL-4, and also IgG in liquor and blood of children with viral and bacterial meningitis. There was performed blood and liquor investigation in 46 children aged from 1 to 16 years old with viral (n = 35) and bacterial (n = 11) meningitis. Immunophenotyping of blood and liquor cells was performed by the method of flow cytometry with the use of monoclonal antibodies to CD3, CD4, CD8, CD19, CD16, CD56, CD25 and CD95. The content of cytokines was detected in ELISA, and that of IgG - by the method of quantitative immunoturbodimetry. During an acute period of viral meningitis there was detected a decrease in NK portion and activated CD25(+) cells in the blood of patients accompanied by the increase in B-lymphocytes number, along with cytokine IFN gamma, IL-8 and IL-10 serum level rise. There was determined T-lymphocytes accumulation in liquor with the prevalence of CD4(+) T-cells and, to a lesser degree, CD25(+) and CD95(+) cells, NK and B-lymphocytes. Intrathecally there was noted the predominance of IL-6 response accompanied by the growth of IL-8 and IL-10 concentration as well. During an acute period of bacterial meningitis there was noted a decrease in percentage of CD3(+), CD4(+), CD8(+) T-lymphocytes, NK, CD25(+) and CD95(+) cells, along with, on the contrary, sharp increase in B-cells pool, simultaneously with an expressed system response of IL-8 and IL-10. Liquor T-lymphocyte content was relatively correlated with blood indicators whereas the fraction of NK exceeded it, and B-lymphocyte content was 3-4 times higher than in patients with viral meningitis. There was IL-6, IL-10, IFN gamma and IL-4 response intrathecally, and 10-multiply-growth of IgG level. Thus, the redistribution of lymphocyte subpopulations, and system and local cytokine response in children with meningitis have both common and special features depending on the aetiology and severity of disease. Phenotyping of lymphocytes and determination of both cytokines and immunoglobulins simultaneously in two biologic fluid allow to clear up the pathogenetic value of immunologic abnormalities in blood and cerebrospinal fluid of the patients in the aspect of interactions between cell and humoral factors of system and local immune response in neuroinfections of various aetiology.