Iron Chelation
On this page:
The benefits and risks of chronic transfusion in transfusion-dependent anemias are best documented and understood in thalassaemia major, a disease with a greatly improved survival rate since the development of therapeutic iron chelation approaches. As the body has no active mechanism for iron excretion, excess iron will accumulate unless iron chelation therapy is initiated. Although the benefits of iron chelation therapy with regard to a reduction in morbidity and mortality are usually apparent within a much shorter timeframe, it may take years for body iron levels to reach normal levels. The availability of effective iron chelation has significantly extended the life expectancy of transfusion-dependent patients, and consistent therapy reduces the toxicity and organ damage associated with excess iron [1-4].
Hepatic benefits of iron chelation
As the liver is the major site of stored iron, pathological damage from iron overload is primarily observed in hepatic tissues. Deferoxamine has been shown to reduce LIC and has been reported to ameliorate hepatic dysfunction in patients with previous abnormalities [5;6]. In patients with highly elevated LIC, high-dose intravenous deferoxamine has been employed to reduce LIC to an acceptable range [7]. Similar reductions in LIC have been observed with deferasirox (Exjade®) [8;9]. In addition, a reduction in biochemical and pathological markers of iron overload-induced liver damage has been observed following deferasirox therapy [10].
Cardiac benefits of iron chelation
Myocardial disease is common among patients with transfusional iron overload [11] and, although less common, has been observed in patients with hereditary iron overload [12]. This is largely due to the toxicities associated with iron overload and because cardiac myocytes also accumulate NTBI [13]. The beneficial effects of deferoxamine in preventing early death due to cardiac disease are well documented [14].
Iron Chelation prevents early cardiac death
Used with permission [14]. Among patients with thalassaemia, effective iron chelation therapy correlates with extended cardiac disease-free survival. In one study, patients whose serum ferritin levels did not exceed 2500 ng/mL in more than a third of measurements had a >80% chance of avoiding death due to cardiac disease 15 years after initiation of therapy. Patients whose serum ferritin levels exceeded the 2500 ng/mL threshold on two-thirds of measurements had an approximate 50% chance of cardiac disease-free survival within the same time span.
1 | 2 | next >
|
