Atopic dermatitis (AD) is a chronic and relapsing inflammatory
skin disease characterized by the predominant infiltration of T cells, eosinophils and macrophages in lesional skin. Recently,
eotaxin-2/CCL24 and
eotaxin-3/CCL26 were identified as
CC chemokines that signal exclusively via the
CCR3 receptor and have eosinophil-selective
chemoattractant activity, as does eotaxin/CCL11. We previously reported that serum levels of
thymus and activation-regulated chemokine (TARC)/CCL17 and
macrophage-derived chemokine (MDC)/CCL22 were correlated with the severity of AD. In this report, we investigated the participation of
eotaxin-2/CCL24 and
eotaxin-3/CCL26 in AD, first measuring the serum levels of
eotaxin-2/CCL24 and
eotaxin-3/CCL26 in 30 patients with
AD, 20 patients with
psoriasis vulgaris and 20 healthy controls. The serum levels of
eotaxin-3/CCL26 (but not
eotaxin-2/CCL24) were significantly higher in patients with AD than in either healthy controls or patients with
psoriasis vulgaris; furthermore, the
eotaxin-3/CCL26 levels in patients with moderate and severe AD were significantly higher than
eotaxin-3/CCL26 levels in patients with mild AD. The serum
eotaxin-3/CCL26 levels tended to decrease
after treatment, but there was no significant difference between groups. Moreover, the serum
eotaxin-3/CCL26 levels were significantly correlated with the serum TARC/CCL17 and MDC/CCL22 levels, eosinophil numbers in peripheral blood and the scoring AD (SCORAD) index. Our study strongly suggests that serum levels of
eotaxin-3/CCL26, but not of
eotaxin-2/CCL24, have a notable correlation with disease activity of AD and that
eotaxin-3/CCL26, as well as TARC/CCL17 and MDC/CCL22, may be involved in the pathogenesis of AD.