The association of FOXO3A gene polymorphisms with serum FOXO3A levels and oxidative stress markers in vitiligo patients.

Vitiligo is an acquired epidermal pigment loss of the skin. Oxidative stress is one of the major theories in the pathophysiology of vitiligo. FOXO3A is the forkhead members of the class O (FOXO) transcription factors, and plays an important role in cell cycle regulation, apoptosis, oxidative stress, and DNA repair. The aim of our study was to investigate FOXO3A gene polymorphisms and FOXO3A protein levels, activities of superoxide dismutase (SOD) and catalase antioxidant enzymes in vitiligo patients and healthy controls. Moreover, the level of plasma advanced oxidation protein products (AOPP) in subjects was evaluated to understand the possible role of protein oxidation in disease etiology. Study groups included 82 vitiligo patients and 81 unrelated healthy controls. FOXO3A polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism method. FOXO3A levels and catalase activity were measured by ELISA whereas AOPP levels and SOD activity was measured by spectrophotometric analysis. We found a significant relationship between rs4946936 polymorphism of FOXO3A gene and vitiligo/active vitiligo patients (p=0.017; p=0.019 respectively), but not for rs2253310 (p>0.05). SOD activity and AOPP levels of vitiligo patient were increased compared with control group, whereas FOXO3A levels and catalase enzyme activity of vitiligo patient were decreased compared with control group (p<0.05). Our study indicates that rs4946936 of FOXO3A gene may associate susceptibility of vitiligo, especially active vitiligo. Moreover, our results confirm that oxidative stress may play a role in the pathophysiology of vitiligo. Further studies with larger samples are required to elucidate the role of FOXO3A in vitiligo.