[Iron overload and myelodysplastic syndromes]

Abstract

Transfusion of RBC units, the only current treatment for many myelodysplastic syndromes, and excess intestinal absorption of Fe related to dyserythopoiesis often result in iron overload. This condition is associated with high rates of morbidity and mortality. High-risk patients include those with refractory anemia, sideroblastic anemia, 5q-syndrome, patients with a good prognosis (low or lower intermediate international prognosis score), patients having received over 100 RBC units, and patients under the age of 70. Deferoxamine, while it can prevent iron overload, is a strenuous treatment requiring 8-to-12 hour-overnight subcutaneous injections. When patients comply with the regimen, it efficiently prevents mortality due to iron overload, but must be implemented early in the disorder, usually before transfusing 20 RBC concentrates. A simple way of monitoring iron overload is to measure seric ferritin levels and record the number of RBC concentrates. The chelating treatment should be modulated according to age, MDS type, international prognosis score, number of RBC units received, ferritin levels, and most of all, patient tolerance. The direct subcutaneous approach is currently being evaluated by the French Group for Myelodysplasias for its efficiency to prevent disorders, but seems to be both efficient and well complied with (a national protocol is under way). The recent findings on the proteins implied in iron recycling by macrophages after destruction of RBCs, may in the long term, enable us to manage patients with less burdensome treatments and more effective new oral chelates.