Potential for treatment of anemia of prematurity with recombinant human erythropoietin.

Anemia of prematurity (AOP) results from several interacting processes, including phlebotomy losses, a temporary failure to release erythropoietin in response to anemia, a short life span of erythrocytes, and rapid growth of body mass and, hence, blood volume after the first few weeks of life. Infants with AOP have erythroid progenitors that respond to erythropoietin in vitro, suggesting that treatment with recombinant erythropoietin might reduce the need for transfusions for AOP. Many pilot studies were needed to define the dose of recombinant erythropoietin (500 to 750 U/kg/wk) that stimulated the early onset of erythropoiesis in infants with AOP. Three large controlled trials have demonstrated that recombinant erythropoietin therapy reduces transfusions in AOP and is apparently safe. Unresolved issues include the ideal dose, the optimal nutrition needed during therapy, the target population, and timing of the start of treatment.