A non-invasive evaluation of DNA photodamage in epidermal keratinocytes subsequent to UV phototherapy for vitiligo

Summary: Abstract Body: Objective: To evaluate DNA damage in epidermal keratinocytes subsequent to ultraviolet phototherapy for vitiligo, employing the tape stripping method in a non-invasive manner. Methods: Epidermal cells from multiple stratifications were isolated from the lesions of 11 patients diagnosed with vitiligo, all of whom had undergone six months of phototherapy. Furthermore, epidermal tissue sections were procured from the same region using the suction blister epidermal graft technique. Both hematoxylin and eosin (HE) staining and immunofluorescence staining were applied to the cellular and epidermal tissue samples. A subsequent correlation analysis was performed to assess the expression levels of the epidermal DNA damage marker γ-H2AX between the cellular samples and the epidermal tissue sections. Results: HE staining, along with immunofluorescence staining for pan-cytokeratin (pan-CK), demonstrated the successful collection of nucleated keratinocytes from the deeper layers of the epidermis. The acquisition of these cells was effectively achieved using 20 to 40 consecutive tape strips. The quantity of γ-H2AX positive cells in collected cellular samples demonstrated a positive correlation with those in the corresponding epidermal tissue sections, as determined by Spearman correlation analysis (P=0.034, r=0.639). Additionally, a correlation was observed between the epidermis and granular layer cells at the same site (P=0.014, r=0.711). Conclusion: The tape stripping technique constitutes a non-invasive and reliable method for the effective assessment of epidermal DNA damage marker expression in patients with vitiligo undergoing ultraviolet phototherapy. Rong Wei¹, Jun Zhang¹, Dechao Jia¹, Ning Han¹, Ji Gao¹, Yu Peng¹, Yulin Yang¹, Yu Wang¹, Hongguang Lu¹ 1. Department of Dermatology, Guizhou Medical University, Guiyang, Guizhou, China. UV Biology/Injury and Non-melanoma Cancers