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.