Lesional skin in vitiligo exhibits delayed in vivo reepithelialization compared to the nonlesional skin

Abstract

Vitiligo, a common skin disorder, is characterized by the loss of functional melanocytes resulting in the depigmentation of skin. Previous studies have demonstrated molecular and architectural alterations in the epidermal keratinocytes upon loss of melanocytes. The physiological implications of these "altered" keratinocytes are yet not known. We investigated the wound healing efficiency of lesional vs nonlesional skin in 12 subjects with stable nonsegmental vitiligo using histological and ultrastructural evaluation of partial-thickness wounds. The wounds were examined 12 days postinjury, coinciding with the reepithelialization phase of healing marked primarily by keratinocyte migration and proliferation. This study demonstrated a significant difference in the reepithelialization potential between the lesional and nonlesional skin. While all 12 nonlesional wounds demonstrated considerable neoepidermis formation on the 12th day post wound, only four of the corresponding lesional samples showed comparable reepithelialization; the rest remaining in the inflammatory phase. Ultrastructural studies using transmission electron microscopy as well as immunohistochemical staining revealed a reduced number of desmosomes, shorter keratin tonofilaments and an increase in myofibroblast population in the dermis of lesional reepithelialized tissue compared to the nonlesional reepithelialized samples. This study implicates gross functional perturbations in the lesional skin during physiological wound healing in vitiligo, suggesting that the breakdown of keratinocyte-melanocyte network results in delayed wound repair kinetics in the lesional skin when compared to patient-matched nonlesional skin.