Paraoxonase 1 in Vitiligo

Abstract

Vitiligo is the most common pigmentary disorder affecting 0.5%-1% of the world’s population, characterized by acquired, idiopathic, progressive, circumscribed hypomelanosis of the skin and hair and probably affects the pigmentary system of the whole skin of the body (lesional, perilesional and distant apparently normal skin). The etiology of vitiligo remains unclear, but oxidative stress and the accumulation of free radicals have been proposed as important pathogenic mechanisms. Several studies reported its role in the pathogenesis of vitiligo. This study included twenty patients presenting with stable non-segmental vitiligo (NSV),the patients divided into 2 groups, the first with disease duration less than one year and the other with disease duration up to 5 years and the study also included fifteen healthy controls. Examination under Wood’s light for objective identification of true size of the patch of vitiligo and Photographs of the lesion were taken before and after wood's light examination then a 3 (5 mm) punch biopsies were taken from every patient (lesional biopsy from Vitiligo patch, peri lesional away from the Vitiligo patch by 5 centimeters and distant biopsy from distant apparently normal skin) away from vitiligo patch by 20cm and a single 5 mm punch biopsy was taken from every control subject for assessment of paraoxonase 1 enzyme levels in normal healthy controls and compare it with the lesional, perilesional and distant levels of PON1 . Our aim was to evaluate the role of oxidative stress represented in the decreased levels of PON1 in skin tissue of vitiligo patients and compare its levels in lesional, perilesional and distant skin. Paraoxinase1 (PON1) levels were detected in tissue homogenate using ELISA kit .The results of our study showed statistically significant (p<0.01) lower levels of PON1 in lesional, perilesional and distant normal skin compared with controls which means that vitiligo is a systemic disease affecting the perilesional areas of vitiligo patch and the distant apparently normal skin of vitiligo patients. On compairing PON1 levels in lesional skin biopsies versus perilesional skin biopsies of vitiligo patients there was a statistically significant lower levels of PON1 in lesional skin biopsies compared with perilesional skin biopsies where as there was a statistically significant lower levels of PON1 in perilesional skin biopsies compared with distant skin biopsies taken from distant apparently normal skin, support the concept of decrease the degree of oxidative stress in relation to increasing distance from vitiligo spot.