Assessment of CXCL10 Before and After Narrow Band UVB Phototherapy in Non-Segmental Vitiligo Patients

BACKGROUND: Vitiligo is a common depigmenting skin disorder characterized by white macules and patches accompanied by local melanocyte loss, caused by autoimmune destruction. Vitiligo is classified into two major forms: segmental vitiligo (SV) and non-segmental vitiligo (NSV). It was also found that the IFN-ȣ/CXCL10 axis is functionally required for both progression and maintenance of the disease. Chemokine 10 (CXCL10) is a pro-inflammatory chemokine which was found to be elevated in the serum of vitiligo patients. UVB has been found to be a useful therapy that results in rapid repigmentation in NSV patients. OBJECTIVES: To evaluate CXCL10 in vitiligo patients before and after narrow band UVB (NB-UVB) phototherapy, which if targeted could provide new insights for therapeutic intervention for vitiligo. PATIENTS AND METHODS: The study included 25 active NSV patients who were able to comply with the study protocol in the Center of Excellence, Dermatology Outpatient Clinic, National Research Center, Egypt (February 2020–2021). All recruited patients were subjected to documentation of complete history. Dermatological assessment of vitiligo lesions, including vitiligo area score index (VASI) score, CXCL10 and extent of the disease were performed. A 3 mm punch biopsy from active vitiligo lesion (site of biopsy) was taken before and after treatment by NB-UVB, and then immunohistochemical staining was performed to evaluate expression of CXCL10. RESULTS: After treatment by NB-UVB there was a significant decrease in VASI score, extent of the disease and CXCL10 expression. CONCLUSION: The decrease in CXCL10 levels could be attributed to the effect of NB-UVB which leads to decrease in IFN-γ level, necessary to release CXCL10 through its pathway resulting in repigmentation and decrease in the extent of the disease and VASI scores.