Does ANA positivity affect treatment outcomes in vitiligo? A clinical evaluation of 308-nm excimer light therapy

Vitiligo is an autoimmune skin disorder characterized by melanocyte destruction and frequently associated with autoantibodies such as antinuclear antibodies (ANA). However, the clinical relevance of ANA positivity in relation to phototherapy response remains unclear. This study aimed to evaluate whether ANA positivity influences the efficacy and safety of 308-nm excimer light therapy in patients with vitiligo. In this cohort study, 86 patients with vitiligo received 308-nm excimer light therapy combined with topical agents, with oral mini-pulse prednisone added for active disease when necessary. Patients were stratified by ANA status, and therapeutic response was evaluated using the Vitiligo Area Scoring Index and standardized photographs over 6 months. Of the 23 ANA-positive patients (26.7%), 19 (82.6%) had a titer of 1:100 and 4 (17.4%) had a titer of 1:320, with women comprising 73.9% of this group. ANA-positive lesions on the face and neck more frequently achieved moderate repigmentation (50–74%) but were less likely to reach excellent repigmentation (≥75%) compared with ANA-negative lesions. No significant differences were observed in cumulative treatment doses, adverse events, or the occurrence of new autoimmune conditions. In conclusion, this single-center cohort study suggests that ANA positivity does not significantly affect the efficacy or safety of 308-nm excimer light therapy in vitiligo, indicating that the impact of low-titer ANA may be limited.