Tuğcan YÜKSEK, Simge ÜNAL IŞIK
Cyprus Journal of Medical Sciences - 2026;11(4):259-265
BACKGROUND/AIMS: Oxidative stress is central to vitiligo, driven by excess reactive oxygen species and weakened antioxidant defenses. Although bilirubin and uric acid (UA) are important endogenous antioxidants routinely measured, current evidence regarding their systemic relevance to vitiligo is limited. MATERIALS AND METHODS: To compare serum bilirubin and UA levels between vitiligo patients and healthy controls and to determine whether these biomarkers correlate with clinical characteristics or reflect disease burden. This cross-sectional study included 44 patients with non-segmental vitiligo and 45 healthy controls. Serum total bilirubin (Tbil), direct bilirubin (Dbil), and UA levels were measured. Disease severity was evaluated using the vitiligo extent score (VES) and vitiligo area scoring index (VASI). Disease stability was defined as the absence of new or enlarging lesions for >=12 months. Correlation and subgroup analyses were performed to assess associations between biomarkers and clinical parameters. Receiver operating characteristic (ROC) analysis was used to evaluate diagnostic performance. RESULTS: No significant differences were found between vitiligo patients and controls in Tbil (p=0.070), Dbil (p=0.978), or UA (p=0.311). Subgroup analyses showed no associations of bilirubin or UA with disease activity, severity (VES, VASI), duration, or anti-thyroid peroxidase status (all p>0.05). Correlation analyses revealed no significant relationships between these markers and clinical features. ROC analyses demonstrated low diagnostic accuracy. CONCLUSION: Serum bilirubin and UA levels appear unaltered in vitiligo and show no correlation with clinical features. These findings suggest that oxidative stress may be predominantly localized, highlighting the need for research on skin-specific oxidative pathways and alternative biomarkers.
