Role of chemokines and the corresponding receptors in vitiligo: A pilot study

To determine the levels and sources of chemokines in the serum and epidermis of vitiligo patients, we examined 80 active patients, 80 stable patients and 40 healthy controls. First, the serum levels of candidate chemokines were measured by Luminex assay, and levels of CCR5, CXCR1 and CXCR3 were measured in peripheral mononuclear cells (PMBC) by flow cytometry. Then, the local epidermis levels of elevated chemokines in vitiligo were tested by Luminex. Finally, the mRNA and protein expression levels of elevated chemokines in HaCaT cells stimulated with interferon (IFN)-γ or tumor necrosis factor (TNF)-α were tested by quantitative real-time polymerase chain reaction and Luminex. The serum levels of CCL5, CXCL8 and CXCL10 in active vitiligo were significantly elevated compared with those in stable vitiligo patients. Furthermore, the levels of CCL3 and CCL4 had weak and positive correlations with the Vitiligo Area Scoring Index. In the peripheral blood of active vitiligo patients, the percentages of CD3⁺ CD8⁺ CCR5⁺ and CD3⁺ CD8⁺ CXCR3⁺ T cells were significantly increased compared with those in stable vitiligo and healthy controls. In the epidermis of lesions, the expression levels of CCL5 and CXCL10 in active vitiligo were significantly increased. In addition, the mRNA and protein levels of CCL5, CXCL8 and CXCL10 were significantly elevated in HaCaT cells after stimulation with TNF-α or IFN-γ. The CCR5/CCL5 and CXCR3/CXCL10 axes may play an important role in the progression and maintenance of vitiligo. Moreover, keratinocytes stimulated with TNF-α and IFN-γ may be a primary source of CCL5 and CXCL10.