Secreted Frizzled Related Protein 5 in Nonsegmental Vitiligo: A Clinical and Immunohistochemical Study

Vitiligo is a depigmentation skin disorder affecting 0.5%-1% of the inhabitants worldwide. Wtn signaling cascade is crucial in differentiation and development of melanocytes. Secreted frizzled-related protein 5 (SFRP5), member of the secreted frizzled-related proteins group, is well known as a suppressor of the Wnt signaling and represents a potential target of vitiligo. This study aimed to investigate immunohistochemical expression of SFRP5 in patients with nonsegmental vitiligo in comparison with healthy controls and to associate the results with the clinicopathologic information and included 48 participants: 24 patients with vitiligo and 24 healthy controls. All included participants were exposed to full history taking, full general and skin examination, scoring of vitiligo was done using vitiligo disease activity and vitiligo area scoring index scores. Immunohistochemical staining of SFRP5 was performed on punch biopsies from lesional, perilesional skin, and control skin. Comparison between lesional, perilesional, and control biopsies concerning epidermal SFRP5 expression revealed that SFRP5 staining, H score, and immunoreactivity scoring (IRS) were significantly elevated in all lesional and perilesional samples on comparison with controls ( P < 0.001). There were significant correlations regarding epidermal and dermal SFRP5 expression regarding percentage of positive cells, H-Score, and IRS ( P < 0.001). Also, dermal SFRP5 was significantly associated with vitiligo disease activity score ( P = 0.051). SFRP5 being expressed in lesional and perilesional areas could have a potential role in pathogenesis of nonsegmental vitiligo and it can be a promising therapeutic target in the future. Also, SFRP5 has a prognostic role in these patients.