CC chemokine receptor 4 expression on peripheral blood CD4(+) T cells reflects disease activity of atopic dermatitis

Recent studies indicate that Th1 and Th2 cells differ in their chemokine re ceptor expression and their responsiveness to various chemokines. Therefore , selective Th2 cell recruitment in Th2-predominant inflammatory diseases s uch as atopic dermatitis may be under the influence of some chemokines. It is reported that CC chemokine receptor (CCR) 4 is selectively expressed on Th2 cells whereas CXC chemokine receptor (CXCR) 3 is selectively expressed on Th1 cells. In this study we examined CCR4 and CXCR3 expression on periph eral blood CD4(+) and CD8(+) T cells obtained from adult atopic dermatitis subjects, and compared the results with those from patients with psoriasis vulgaris and healthy controls. CCR4 was preferentially expressed on CD4(+) T cells from atopic dermatitis subjects and CXCR3 was preferentially expres sed on CD4(+) T cells from psoriasis vulgaris subjects. This CCR4 expressio n was prominent especially in severe atopic dermatitis subjects. CCR4 expre ssion on CD4(+) T cells in severe atopic dermatitis subjects decreased on i mprovement of disease activity. CD25 was preferentially expressed on CCR4()CD4(+) T cells but not on CXCR3(+)CD4(+) T cells in atopic dermatitis subj ects. Cutaneous lymphocyte-associated antigen was also preferentially expre ssed on CCR4(+)CD4(+) T cells but not on CXCR3(+)CD4(+) T cells in atopic d ermatitis subjects. CD4(+) T cells in atopic dermatitis skin lesions were p redominantly CCR4(+) cells. Taken together, this study strongly indicates t hat CCR4(+)CD4(+) T cells reflect disease activity and suggests that CCR4 e xpression is important for T cell infiltration into atopic dermatitis lesio ns. Thus, CCR4 may be a possible target for therapy of atopic dermatitis in the future.