Effect of Narrow Band Ultraviolet B Therapy on Tissue Levels of Interleukin-33 in Egyptian Vitiligo Patients

Abstract Background Vitiligo is an acquired pigmentary disorder of unknown etiology, affecting approximately 1 % of the world population, without predilection for race or sex. It is characterized by white macules and patches, whose size increases over time, due to the loss of melanocytes. Vitiligo can appear at any time, and it significantly impairs the patients’ quality-of-life. Objectives The aim of the work was to study the influence of the NB-UVB radiation therapy on tissue level of IL-33 in patients with vitiligo. Patients and Methods This prospective study was carried out on 10 patients diagnosed as having non -segmental vitiligo stable for 6 months duration. All patients were selected from the dermatology outpatient clinic of vitiligo, Ain-Shams University Hospitals. All patients were subjected to full history taking, general examination and dermatological examination. The disease characteristics of vitiligo were recorded as regards stability, duration and extent of vitiliginous lesions. The activity of the disease was evaluated according to VIDA score, and the disease severity was evaluated according to VASI score. Digital photographic documentation was done. Results Hydropic degeneration of lower epidermis was also detected in (40%) of them and apoptotic keratinocytes were found in (10%) of them. After therapy, these inflammatory changes were significantly reduced this can be partially explained by immunosuppressive properties of NB-UVB as it is believed to cause a reduction of T cells by inducing apoptosis and impairs in-vitro antigen presentation by both murine DCs and human Langerhans cells. The main limitation of our study was the small cohort of the studied patients. Further large-scale studies are needed. Investigatory techniques other than immunohistochemical analysis may be also used to evaluate abnormalities of keratinocytes in vitiligo skin. Conclusion We concluded that NB-UVB has no effect on tissue expression of IL-33 and and that NB-UVB was effective in treating vitiligo as manifested by VASI score change after treatment with NB-UVB. Based on our results we recommend further studies with larger sample size and studying the effect of treatment on IL-33 expression in active vitiligo cases is also recommended.