RESUMO
BACKGROUND: Glutathione (GSH) may provide defense against reactive oxygen species (ROS) generated by ultraviolet radiation. Furthermore, some authors have demonstrated a relationship between the GSH of peripheral blood erythrocytes (GSHe) and resistance to chemotherapy. PATIENTS & METHODS: To observe the influence of GSH on the genesis and evolution of Malignant Melanoma (MM), we assessed the concentration of GSH in erythrocytes (GSHe) in MM patients (n = 566) and controls (n = 164) by the method of Beutler (1963). RESULTS: No differences were found between the two groups (5.94 +/- 1.61 cases vs 6.08 +/- 1.49 mmol/gr Hb, controls; p > 0.05). Fifty seven patients with poor evolution (disease-free survival < 2 years) had higher GSH levels than the remaining patients (6.35 +/- 1.83 vs 5.83 +/- 1.62 mmol/g Hb; p < 0.01). GSHe increased significantly after antineoplastic therapy (4.75 +/- 1.26 vs 7.73 +/- 1.39 mmoVg Hb; p < 0.001), thus indicating a possible role in chemoresistance. 2 CONCLUSIONS: GSHe is not related to the risk of developing MM. GSHe may be related to the evolution of MM, being higher in patients who suffer relapse or metastasis. GSHe increases significantly during cytostatic treatment.