Analysis of circulating γδ+ T cells in children affected by IgE-associated and non-IgE-associated allergic atopic eczema/dermatitis syndrome

Abstract

Recent studies have suggested that not only αβ+ T cells, but also the less common γδ+ T cells may play a role as effectors and immunoregolatory cells in the development and perpetuation of allergic inflammation. The objective of this study was to focus on the role of γδ+ T cells in atopic dermatitis (AD), a chronic relapsing inflammatory disease of the skin, often associated with allergic bronchial asthma. The present study employed flow cytometric analysis to compare numbers and phenotypic characteristics of γδ+ T cells in the peripheral blood of children with atopic dermatitis and age-matched healthy controls. The percentage of circulating Vγ9Vδ2+ T lymphocytes was significantly increased in AD patients with respect to the age-matched controls, with a positive correlation with clinical score severity. The prevalent phenotype in both AD patients and controls was CD45RO+, with no differences observed in the percentage of Vδ2+ CD45RO+ between these groups. Conversely, memory CD45RO+ CD62L+ Vδ2+ lymphocytes were significantly lower in AD patients. Furthermore, naive circulating Vδ2+ T lymphocytes were significantly lower in AD children than in aged-matched controls. No correlation was observed between circulating Vγ9Vδ2+ expansion and IgE serum levels. It was concluded that an association exists between the levels of circulating γδ+ T lymphocytes and atopic dermatitis, with a positive correlation with clinical score but no link with IgE serum levels. The pathophysiological role of γδ T lymphocytes in atopic dermatitis awaits further investigation. © 2005 British Society for Immunology.