Abstract: Objective To study the role of chemokines and their receptors in the pathogenesis of nickel elicited contact dermatitis.Methods The expressions of chemokine receptors, including CXCR3 and CCR4, were detected by immunohistochemistry in primary and secondary lesions of nickel elicited contact dermatitis.RT-PCR was used to measure the mRNA expression of different types of chemokines, including interferon-y-induced protein 10(IP-10),interferon-inducible T cell α-chemoattractant(I-TAC),thymus and activation regulated chemokine(TARC)and macrophage derived chemokine(MDC),in cultured human keratinocyte cell line HaCaT after treated with nickel sulfate.Results In the lesions of nickel dermantis, CD45RO⁺CD4⁺ T cells were the predominant infiltrating cells, whereas CD8⁺ cells were less than 25%, and more than 50% infiltrating cells were positive for CXCR3, while less than 20% for CCR4.RT-PCR results showed that afrer being treated with nickel sulfate HaCaT cells mainly expressed IP-10 and I-TAC, which are Thl associated chemokines, and the peak expression was observed at 48 h for IP-10 and 72 h for I-TAC.Conclusion The inflammation type at the effector phase of T cell immune response in primary lesions may be identical to that in secondary lesions of nickel elicited contact dermatitis.

Key words: Dermatitis, contact, Nickel, Chemokines, Receptors, chemokine