Effect of Different Iron Chelating Modalities on Whole Blood Levels of Iron, Copper and Zinc in Young Patients With β-Thalssemia Major

Abstract

SUMMARY B eta thalassemia major is an inherited disease resulting from reduction or total lack of beta globin chains. Patients with this disease need repeated blood transfusion for survival. This may cause oxidative stress and tissue injury due to iron overload, altered antioxidant enzymes, and other essential trace element levels. In view of these data, this study aimed to determine the levels of essential trace elements; copper and zinc in children and adolescents with β-thalssemia major and assessed the effect of different iron chelating modalities on parameters of iron overload and serum levels of copper and zinc among those patients. The study included 60 patients with β-thalassemia major; 30 patients on monotherapy (one iron chelating agent) and 30 on combined therapy (more than one agent). Patients were compared with 20 age and sex matched healthy subjects served as controls. The control group consisted of 9 males and 11 females (ratio: 1:1.2). The mean age of thalassemia patients was 10.6 ± 4.0 years (range: 1.5-18 years) while that of controls was 9.8 ± 3.7 (range: 2-17 years). All included patients were subjected to detailed medical history and thorough clinical examination with special emphasis on disease duration, anthropometric measures, tanner scoring, blood pressure, evidence of renal, hepatic or cardiac disease, history of splenectomy, transfusion history and chelation therapy. Laboratory investigations included CBC, hemoglobin analysis, liver and kidney function tests, markers of hemolysis (indirect bilirubin), mean serum ferritin, serum level of trace elements (copper and zinc) using atomic absorption. All patients were in steady state and followed-up during the study period. In the current work, it was found that patients had significantly lower BMI SDS than controls. Moreover, serum iron was significantly higher while serum copper and zinc were significantly reduced. Analysis of serum iron, copper or zinc in relation to the clinical characteristics of thalassmeia patients revealed that patients with positive viral hepatitis had significantly lower levels of zinc and patients with pulmonary hypertension showed significantly reduced levels of both serum copper and zinc. By comparison between patients receiving mono- and combined chelation therapy it was found that significantly lower serum iron and ferritin levels among thalssemia patients on combined therapy while Serum copper and zinc were significantly higher in patients receiving combined chelation compared to the mono-therapy group. As regards the effect of different chelating agents on serum iron and trace elements, thalassemia major patients on DFO mono-therapy showed significantly higher levels of serum copper and zinc compared to those on other mono-therapy agents, while no significant difference was found among patients receiving DFP or DFX alone. On the other hand, all compliant patients to chelation had significantly lower serum iron with higher levels of copper and zinc compared to those with poor compliance. Correlation studies revealed significant positive correlation between serum copper and zinc among the studied patients with β-thalassemia major. Moreover, serum copper was negatively correlated to indirect bilirubin while serum zinc was negatively correlated to WBCs count and ferritin levels.