Management of RBC-transfusion dependence.

Strategies for the management of anemia in patients with myelodysplastic syndrome (MDS) have evolved following the U.S. Food and Drug Administration (FDA) approval of three new therapeutics from one of symptom amelioration with red blood cell (RBC) transfusions to one of active treatment. Most patients develop transfusion-dependent anemia over the course of their disease, however, and its adverse consequence on the natural history of disease has only recently been appreciated. Although severe anemia contributes to symptoms of fatigue and reduced quality of life, transfusion dependence increases the risk of organ complications from iron overload coupled with an increased risk of leukemia transformation. Among World Health Organization categories without elevation in bone marrow myeloblasts, an incremental rise in RBC transfusion burden is associated with a proportionate reduction in both overall survival and leukemia-free survival, implying that anemia severity is an important variable limiting the otherwise favorable natural history of patients with lower risk disease. Moreover, therapeutic strategies that successfully restore effective erythropoiesis, such as erythropoetic stimulating agents, immunomodulatory agents, immunosuppressive therapies, or hypomethylating agents, may favorably affect the natural history of this disease, creating perhaps a new urgency for the initiation of erythropoietic promoters that have durable clinical benefit. Selection of primary therapy for the management of anemia should consider four response determinants: age, RBC transfusion burden and duration, endogenous erythropoietin production, and karyotype.