Both Th2 and Th1 chemokines (TARC/CCL17, MDC/CCL22, and Mig/CXCL9) are elevated in sera from patients with atopic dermatitis

Abstract

Background : Chemokines and their receptors are important elements for the selective attraction and activation of various subsets of leukocytes. Expression of CXCR3 ligands, such as monokine induced by IFN-γ (Mig) leads to preferential Th1 recruitment, whereas CCR4 ligands, thymus and activation regulated chemokine (TARC) or macrophage derived chemokine (MDC), mediate preferential Th2 recruitment. Although atopic dermatitis (AD) has been shown to be a Th2-type disease, recent studies have revealed that Th1-type cytokines, such as IFN-γ, especially in chronic skin lesions, play important roles in pathogenesis of AD. Objective : The purpose of this study was to investigate serum levels of Th2 chemokines TARC and MDC and a Th1 chemokine Mig in the same samples from patients with AD and their clinical correlation. Methods : Serum chemokine levels in patients with AD ( n=55), contact dermatitis (CD; n=15), and normal controls ( n=30) were examined by ELISA. Results : Serum levels of TARC and MDC in AD patients and CD patients were significantly higher than those found in normal controls. Serum levels of these chemokines were similar for AD patients and CD patients. Furthermore, these levels correlated positively with disease severity, total IgE levels, and peripheral eosinophilia in AD patients. Serum Mig levels in AD patients and CD patients were significantly higher than those in control subjects. However, serum Mig levels were significantly elevated in CD patients relative to AD patients. Furthermore, serum Mig levels correlated positively with levels of both TARC and MDC in AD patients. Conclusion : These results suggest that both Th2 and Th1 chemokines may play roles in the development of AD.