Acral lesions of vitiligo: why are they resistant to photochemotherapy?

Autor: Esmat SM; Department of Dermatology, Faculty of Medicine, Cairo University, Cairo, Egypt., El-Tawdy AM, Hafez GA, Zeid OA, Abdel Halim DM, Saleh MA, Leheta TM, Elmofty M
Jazyk: angličtina
Zdroj: Journal of the European Academy of Dermatology and Venereology : JEADV [J Eur Acad Dermatol Venereol] 2012 Sep; Vol. 26 (9), pp. 1097-104. Date of Electronic Publication: 2011 Aug 18.
DOI: 10.1111/j.1468-3083.2011.04215.x
Abstrakt: Background: Acral lesions of vitiligo are usually resistant to conventional lines of treatment as well as surgical interventions.
Objective: To clarify causes underlying resistance of acral lesions to pigmentation in vitiligo by studying some of the factors associated with mechanisms of repigmentation following photochemotherapy.
Methods: The study included twenty patients with active vitiligo. Skin biopsies were taken from lesional and perilesional skin of areas expected to respond (trunk and proximal limb) and skin of acral areas, before and after PUVA therapy. Sections were stained with H and E, Melan-A, MHCII, CD1a, SCF and c-kit protein.
Results: Before treatment acral areas showed significantly lower hair follicle density, melanocyte density, Langerhans cell (LC) density, epidermal MHCII expression, lesional SCF expression and perilesional c-kit expression. Following treatment with PUVA in both non-responsive acral and repigmenting non-acral lesions identical immunohistochemical changes in the form of significant decrease in LC density, epidermal MHC-II and SCF expression were observed.
Conclusion: The surprisingly similar histochemical changes in response to PUVA in acral and non-acral lesions did not manifest with clinical repigmentation except in non-acral ones. Factors such as inherent lower melanocyte density, lower melanocyte stem cell reservoirs and/or lower baseline epidermal stem cell factor may be considered as possible play makers in this respect.
(© 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.)
Databáze: MEDLINE
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