[Treatment of transfusional iron overload]

Frequent packed red blood cell (pRBC) transfusion can cause transfusional iron overload. Excess iron generates reactive oxygen species and provokes organ dysfunction. In lower-risk myelodysplastic syndrome (MDS), hyperferritinemia is known as one of the negative prognostic factors. Thus far, iron chelation therapy (ICT) is the only effective treatment for chronic iron overload induced by transfusion. Transfusional iron overload is diagnosed when serum ferritin (SF) levels are ≥500 ng/ml and cumulative volume of pRBC transfusion is ≥20 JPN units. ICT should be initiated when SF levels are ≥1,000 ng/ml and will be further continued until SF levels decline to <500 ng/ml. ICT serves to ameliorate organ dysfunction. A prospective study demonstrated that in patients with lower-risk MDS, ICT can reduce the risk of combined events, including cardiac events, hepatic events, AML transformation, and death of any cause. In some patients, hematological improvement will be observed. However, clinical features underling this hematological phenomenon are not fully understood. Therefore, ICT should not be performed solely for the purpose of hematological recovery.