Expression of naive/memory (CD45RA/CD45RO) markers by peripheral blood CD4(+) and CD8(+) T cells in children with asthma

INTRODUCTION: The role of CD4(+) T cells in the immunopathogenesis of asthma is well documented. Little is known about the role of CD8(+) T cells. The aim of this study was to assess peripheral blood subsets of CD4(+) and CD8(+) T cells expressing naive/memory markers (CD45RA(+)/RO(+)) and the activation marker (CD25(+)) in children with allergic asthma. MATERIALS AND METHODS: Peripheral blood mononuclear cells were isolated from children with allergic asthma and healthy children. T cell subsets were analyzed by flow cytometry for the expressions of CD45RA, CD45RO, and CD25. In this study, some differences in the memory compartment of peripheral blood T cells between asthmatic children and healthy controls were detected. RESULTS: The absolute number of CD8(+) T cells expressing CD45RO was significantly elevated and the percentages of CD3(+) T cells expressing activation marker CD25 and of CD4(+) T cells expressing memory marker CD45RO were significantly lower in children with asthma compared with controls. No correlation was found between severity of asthma and peripheral blood lymphocyte subsets. CONCLUSIONS: There were some differences in the memory compartment of peripheral blood T cells between asthmatic children and healthy controls. The increase in the number of CD8(+) T cells expressing the memory marker (CD45RO) in children with allergic asthma may indicate that CD8(+) T cells play a role in the pathogenesis of asthma.