Tissue expression of glutathione S transferase isoenzymes in vitiligo.

The association of glutathione S-transferase (GST) enzymes with vitiligo is inconclusive. To evaluate tissue expressions of GST isoenzymes in vitiligo patients and to compare these expressions with healthy controls, we used 26 active depigmented patches on the trunk of vitiligo patients and 20 healthy sex and age matched controls. Punch biopsies were taken from the lesioned or normal skin. Tissue expression of GST isoenzymes were analyzed immunohistochemically. Tissue expression of GSTT1, GSTA1 and GSTP1 was significantly higher in the patient group than controls. Tissue expression of GSTM1 was not significantly different between the two groups. The increased tissue expression of GSTT1, GSTA1 and GSTP1 may represent a response to excess free radical formation in vitiligo and may support the role of oxidative stress in the pathogenesis of vitiligo.