The relationship of melasma with antioxidant markers serum bilirubin and GGT levels

Melasma is a common, chronic and recurrent hyperpigmentation disorder caused by hyperfunctional melanocytes that accumulate excessive amounts of melanin in the epidermis and dermis. Although the formation mechanism of melasma is not clear, factors such as genetic predisposition, UV exposure, pregnancy, OCS use, HRT use, thyroid diseases, cosmetics and drugs are blamed in the etiology. In addition to these, there are many studies showing that oxidative stress is an important factor in the pathogenesis of melasma. There are antioxidant system mechanisms that prevent or partially reduce oxidative damage in cells. bilirubin; It is a potent nonenzymatic endogenous antioxidant molecule formed by physiological means. GGT is a cell surface protein that contributes to the extracellular catabolism of glutathione (GSH); In recent studies, it has been shown that the extracellular metabolism of GSH, which is associated with antioxidant properties, catalyzed by GGT, leads to the production of free radicals in the presence of iron. In many diseases in which oxidative stress is blamed in the etiology, serum bilirubin and GGT levels were compared in the patient and control groups, and serum bilirubin levels were found to be statistically significantly lower in the patient group, while serum GGT levels were found to be statistically significantly higher in the patient group. In this study, it was aimed to measure serum bilirubin and GGT levels in melasma patients and to evaluate the roles of these molecules in the pathogenesis of the disease and their relationship with disease activity and severity. The study was conducted with 82 volunteers, 41 melasma patients and 41 control group. Disease severity and activity in the melasma group were evaluated with the MASI method. The demographic characteristics of the patient and control groups and the data on the disease of the patient group were questioned and recorded. In addition, serum bilirubin and GGT levels of both groups were measured by Elisa method. In both groups, those with concomitant autoimmune, allergic and/or chronic inflammatory systemic and/or skin diseases were excluded from the study as they may affect bilirubin and GGT levels. Both groups included in the study consisted of 41 individuals. The mean age of the patient group (36.95±5.37) and gender distribution (F/M=40/1) and the mean age of the control group (36.95±9.48) and gender distribution (F/M=40/1) were similar. When melasma is classified according to clinical subtypes; There were epidermal in 29 patients (70.7%), dermal in 1 patient (2.4%), and mixed melasma in 11 patients (26.8%). When melasma is classified according to facial location; centrofacial melasma was present in 27 patients (65.9%), malar in 12 patients (29.3%), and mandibular melasma in 2 patients (4.8%). The mean disease duration was 4.37±3.25 years and the age of onset was 32.59±5.77 years. The mean MASI score was 5.59±2.63; The mean score of MYCS was found to be 26.39±6.81. There was a family history of melasma in 10 of 41 patients (24.4%), and the presence of melasma in the family was statistically significantly higher in the patient group compared to the control group (p=0.034). Mean serum direct bilirubin level (0.15±0.07 ng/ml), indirect bilirubin level (0.22±0.13 ng/ml), and total bilirubin level (0.37±0.19 ng/ml) in melasma patients ) was statistically significantly lower than the control group (DBI=0.18±0.08 ng/ml, IBIL=0.31±0.19 ng/ml and TBI=0.49±0.27 ng/ml, respectively) (p=0.05, p=0.021 and 0.025, respectively). There was no statistically significant correlation between serum bilirubin level and MASI scores in the patient group. The mean serum GGT level was 12.71±6.05 U/L in melasma patients and 15.37±6.83 U/L in the control group; There was no statistically significant difference between the serum GGT levels of the patient group and the control group (p=0.066). Although bilirubin and GGT are molecules that can play a role in the etiopathogenesis of melasma, the insignificance of GGT levels and the inability to show the relationship and correlation of both molecules with disease activity and severity suggest the existence of possible molecules that play a more dominant role in the etiopathogenesis of the disease. We think that this issue can be clarified with more comprehensive prospective studies on the etiopathogenesis of melasma.