Suction blistering of vitiligo lesional skin provides insights into the pathophysiology of organ specific autoimmunity

Abstract

Abstract Vitiligo is an autoimmune disease of the skin in which CD8+ T cells destroy the pigment producing cells of the skin: melanocytes. To study the immune infiltrate that propagates vitiligo directly in human skin, we employed a novel suction blistering technique to study skin interstitial fluid by ELISA and flow cytometry. Consistent with previous publications demonstrating IFNγ signatures in vitiligo, CD8+ T cell number and CXCL9 protein concentration were elevated in vitiligo lesional skin compared to normal control skin. Receiver operator characteristic analysis revealed that these measurements may be used to distinguish active from stable disease. Phenotypic analysis of T cells in the skin interstitial fluid showed that the majority of CD4+ T cells in vitiligo skin express CXCR3, the receptor for CXCL9, whereas only 47% of CD4+ T cells expressing CXCR3 in the skin of healthy subjects. The frequency of CD8+ T cells expressing CXCR3 was high in both vitiligo patients and healthy donors. Higher CXCR3+ T cell recruitment via elevated CXCL9 expression may contribute to an observed increase in CD8+ T cell to Treg ratio observed active vitiligo skin (4.1 to 2.5 non-lesional). Additionally, all T cells in the skin microenvironment highly express PD-1. These results support the hypothesis that vitiligo is driven by IFNγ dependent signaling, and targeting components downstream of IFNγ may be useful in treating vitiligo. Moreover, suction blistering human skin is a powerful tool that can be used to aid the study of other inflammatory skin diseases.