The Mechanism of Excimer Light Induced Repigmentation in Segmental Vitiligo: Assessment of Cutaneous Blood Flow and Adrenoceptor Response

• Main Authors: Yung-Shun Su, 蘇雍順
• Other Authors: Hsin-Su Yu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/60442363714154430020

碩士 === 高雄醫學大學 === 醫學研究所-臨床醫學組 === 102 === Vitiligo, the most common acquired depigmentation disorder, is characterized by progressive loss of melanocytes. It has been proposed that two types of vitiligo exist from the clinical and pathophysiologic points of view. Non-segmental vitiligo is associated with autoimmune disease while segmental vitiligo results from the dysfunction of sympathetic nerves in the affected area. Comparing to non-segmental vitiligo, segmental vitiligo generally responds less favorably to phototherapy. Excimer light has been shown to be effective and able to induce repigmentation more rapidly. To evaluate the mechanism of excimer light induced repigmentation in segmental vitiligo, we utilized laser Doppler flowmetry and iontophoresis of α1-agonist: phenylephrine, α2-agonist: clonidine and β-blocker: propranolol to assess of cutaneous blood flow and adrenoceptor response. 10 segmental vitiligo patients were invited to participate in this study. The cutaneous blood flow and adrenoceptor response were investigated before and after 3-month regular excimer light treatment. Increased cutaneous blood flow and abnormal α1- and α2-adrenoreceptor function in segmental vitiligo lesions were noted. Upon 3-month excimer light treatment, 60% of patients achieved >25% repigmentation. Partial recovery of the sympathetic dysfunction was also noted. TNF-α, IL-1β, IL-10 and vascular endothelial growth factor (VEGF) have been associated with vitiligo repigmentation and sympathetic nerve repairment. Peripheral blood mononuclear cells were collected from healthy volunteers and irradiated with excimer light and low level laser. Compared to control groups, supernatants from excimer group showed elevated TNF-α, IL-1β and VEGF, while those from low level laser group showed elevated VEGF only. We concluded that excimer light could be an effective treatment for segmental vitiligo, possibly through the TNF-α, IL-1β and VEGF elevation and the partial repair of the sympathetic dysfunction.