RESUMO
The mechanism of iron-induced organ failure in iron overload disorders is not known, but it is conjectured that excess iron-catalyzed free radical generation contributes to organ damage. We hypothesized that free radical generation, quantified by the presence of 20 separate cytotoxic aldehydes in plasma, would be significantly increased in non-chelated beta-thalassemia major patients, in comparison to those chelated with either deferiprone (L1) or deferoxamine (desferal). We also report on red cell glutathione peroxidase activity in these patient groups, an enzyme involved in averting the damaging effects of free radicals. Ten patients were chelated with nightly subcutaneous infusions of desferal and 10 received the experimental oral chelator L1. Body iron burden was assessed by serum ferritin and hepatic iron concentrations. In comparison to non-chelated controls, significant decreases of 62% and 64% in total cytotoxic aldehyde concentrations were observed in patients chelated with desferal and L1, respectively (p < 0.001). Significantly lower red cell glutathione peroxidase activity was also observed in non-chelated controls, in comparison to those chelated with either desferal or L1 (p < 0.001). This is the first report on the concentrations of cytotoxic aldehydes in non-chelated beta-thalassemia major patients, and the first to report on the effects of L1 against cytotoxic aldehyde formation in plasma of patients with iron-overload.
