Study of oxidative stress in peripheral blood of Indian vitiligo patients

Vitiligo is an acquired skin disease that involves the interplay of complex genetic, immunological, neural and self-destructive mechanisms in its pathogenesis. According to autocytotoxic hypothesis, oxidative stress has been suggested to be the initial pathogenic event in melanocyte degeneration.

The aim of our investigation was to evaluate the role of oxidative stress by studying the role of catalase (CAT) in the destruction of melanocytes in patients with vitiligo and compare the same in healthy normal controls.

We determined the serum catalase enzyme by ELISA method. The catalase activity was studied in two groups, Group I-localized vitiligo: (i) active stage, (ii) static or inactive stage and Group II-generalized vitiligo: (i) active stage, (ii) static or inactive stage patients, and the levels were compared with healthy controls.

Group I active stage patients showed significant difference in the catalase levels with a P < 0.044 when compared with healthy controls, whereas Group II static stage patients did not show any significant difference (P < 0.095) although the catalase activity was increased.

Our study could not explain the cause of melanocyte damage in patients in the active stage of the disease. The increase in the oxidative stress as detected by catalase activity was more significant in Group I active disease than Group II active disease patients although the levels were higher than the healthy normals. This is the first study conducted on active and static stage of vitilgo in India. It is possible that the number of compounds of hydrogen peroxide produced is not balanced by the production of catalase in the body.