Investigating the Effect of Phototherapy on Expression of CXCR3-B Gene in Vitiligo

Abstract Background Vitiligo is acquired depigmentary disorder characterized by destruction of the epidermal melanocytes leading to the loss of the skin color. Oxidative stress, genetic susceptibility together with autoimmunity are the main players of melanocytic destruction aetiopathogenesis. Aim of the Work The primary aim of the work was to investigate the effect of phototherapy (NBUVB and excimer laser) on CXCR3B expression in vitiligo. The secondary aim was to confirm the claim of causal relationship between CXCR3B levels and vitiligo in an attempt to evaluate CXCR3B role in the pathogenesis of vitiligo. Patients and Methods A prospective cohort study in department of Dermatology, Venereology and Andrology Ain Shams University, (El Demerdash and Al-Haud Al-Marsoud) vitiligo clinics and Biochemistry Department Ain Shams University between 2020 - 2022. In our study we measured CXCR3B mRNA expression in skin of vitiligo patients before and after generalized ‘NBUVB’ and targeted ‘Excimer laser’ phototherapy. Our study was conducted on 25 patients suffering from non-segmental vitiligo. All biopsies were stored in -80C till RNA extraction that was performed using QIAGEN RNeasy Mini Kit, QuantiTect Reverse Transcription Kit and QuantiNova SYBR Green PCR Kit. Results We found that CXCR3B mRNA expression was significantly increased after phototherapy that is well known for immune modulatory properties. Moreover this was higher in excimer group therapy than NBUVB. Such findings highlight CXCR3B as an inherit defect in skin of patients with vitiligo and raise questions about its possible roles in maintaining vitiligo or causing relapses. Conclusion CXCR3B mRNA levels were significantly increased after treatment with either NBUVB or Excimer laser compared to mRNA levels before therapy. From our results we can conclude that elevated CXCR3B mRNA levels are obviously characteristic to patients with vitiligo and suggestive of persistent inherit defect of their melanocytes. It may also be responsible for the relapse and chronicity of vitiligo.