Evaluation of glutathione peroxidase enzyme in patients with melasma: a clinical and immunohistochemical study

Abstract

ObjectiveTo evaluate the role of glutathione peroxidase (GPX1) in melasma.BackgroundMelasma is a common acquired disorder of hyperpigmentation. GPX1 is an intracellular enzymatic antioxidant, and its levels are used as a major parameter representing oxidative damage that occurs in melasma. However, the clear association between GPX1 expression and melasma remains unknown.Patients and methodsThis prospective case–control study was conducted on 20 cases having melasma and 20 normal age-matched and sex-matched healthy volunteers. All sections were immunohistochemically stained for GPX1 antibody.ResultsThere was significant difference between melasma cases and normal skin as regards GPX1 epidermal distribution (P = 0.001) and intensity (P = 0.005). Also there was a statistically significant association between epidermal intensity and distribution of GPX1 and the severity of melasma assessed by the modified Melasma Area and Severity Index (MASI) score. Moreover, there was statistically significant difference between epidermal intensity and distribution of GPX1 and the degree of dermal inflammation. Also, there was a tendency of melasma cases receiving hormonal therapy to show positive dermal expression of GPX1 than cases not receiving therapy (P = 0.07).ConclusionGPX1 was expressed diffusely in the epidermis of all control cases (100%), eight of them were of mild intensity and 12 were of moderate intensity while expressed in most of melasma cases in a focal form with mild intensity expression.