title: Epidermal hydrogen peroxide is not increased in lesional and non-lesional skin of vitiligo.
abstract: It is widely believed that the loss of the epidermal melanocytes in vitiligo is basically due to excessive oxidative stress. Previous research work described abnormal elevation of the absolute concentration of the epidermal hydrogen peroxide (H2O2) in lesional and non-lesional skin of vitiligo. Based on this finding, our primary research objective was to use this feature as a screening marker in individuals at a great risk of developing vitiligo. Ninety-six patients of non-segmental vitiligo (NSV) of varying durations, skin phototypes, and treatment modalities (psoralen UVA-, narrow band UVB-treated) were recruited for this study. Raman spectroscopic measurements, using an external probehead, of the lesional and non-lesional skin were obtained, and the resulting spectra were analyzed using the Opus software package of the MultiRam spectrometer and the intensity of the peak at 875 cm-1that represents the absolute concentration of H2O2was calculated. Contrary to previous reports, in patients of skin phototype IV, the absolute concentrations of H2O2in non-lesional and lesional NSV of all groups were non-significantly decreased compared to normal control. In patients of NSV of skin phototype V, the decrease in the absolute concentrations of H2O2was not significant in the untreated group, and a slight non-significant increase in the NBUVB-treated group was noted. However, in the PUVA-treated group, the non-lesional skin demonstrated significant increase in the absolute concentration of H2O2, whereas the lesional skin showed only a slight non-significant increase compared to normal control. In NSV patients of skin phototype VI who were previously treated with PUVA, the non-lesional skin showed a slight non-significant increase in the absolute concentration of H2O2; however, the lesional skin showed a marked significant decrease compared to normal control and the non-lesional skin. Thereof, one can conclude that the epidermal H2O2is not increased in NSV as previously thought and may not be responsible for the oxidative stress that leads to the melanocytes destruction, the hallmark of vitiligo pathogenesis.
authors: The Clinical and Experimental Dermatology Unit, King Fahad Medical Research Center, King Abdulaziz University Medical Center, Jeddah, 21589, Saudi Arabia. mzailaie@kau.edu.sa.
authors: Mohammad Z
authors: MZ
authors: Zailaie
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004817:Epidermis / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008297:Male; D008544:Melanocytes / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress; D011701:PUVA Therapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D013059:Spectrum Analysis, Raman; D016896:Treatment Outcome; D014820:Vitiligo / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; D006861:Hydrogen Peroxide
keywords: Epidermal H2O2; Non-segmental vitiligo; Oxidative stress; Raman spectroscopy