title: Effects of erythropoietin on erythrocyte deformability in non-transfused preterm infants.
abstract: OBJECTIVE
  Suppression of erythropoiesis due to low plasma erythropoietin levels is an important factor in the development of anaemia of prematurity. Premature infants may therefore be treated with recombinant human erythropoietin (rhEPO). This prospective, randomised and controlled study was designed to find out whether rhEPO treatment improves erythrocyte deformability in preterm infants.
  
  
  METHODS
  Sixteen infants were treated with rhEPO (250 IU/kg three times weekly) a total of 15 times beginning on day of life 5 whereas fifteen infants served as controls. Haemoglobin concentration, haematocrit, reticulocyte count, ferritin level and erythrocyte deformability were measured on days 5, 14, 28, 42 and 63. Erythrocyte elongation was determined as an indicator of erythrocyte deformability using a shear stress diffractometer (Rheodyn SSD) at shear forces of 0.3 to 60 Pa.
  
  
  RESULTS
  Haemoglobin concentration was significantly higher on days 28 and 42 and reticulocyte percentage on day 28 in the rhEPO group compared to the controls. Serum ferritin was lower in the rhEPO group on day 28. Erythrocyte deformability was significantly increased on days 28 and 42 in the infants receiving rhEPO. We found a strong relationship between erythrocyte elongation and reticulocyte count.
  
  
  CONCLUSIONS
  RhEPO markedly increases the erythropoiesis in preterm infants in the critical first weeks of life and the anaemia of prematurity is obviously reduced. The erythrocyte deformability improved under rhEPO treatment. Erythrocyte deformability was significantly related to the reticulocyte count indicating that the improvement of erythrocyte deformability was due to the formation of well-deformable young erythrocytes.
authors: Division of Neonatology, Department of Paediatrics, University of Heidelberg, Germany. KlippMartina@med.uni-heidelberg.de
authors: Martina
authors: M
authors: Klipp
authors: Anne-Ulrike
authors: AU
authors: Holzwarth
authors: Johannes M
authors: JM
authors: Poeschl
authors: Mathias
authors: M
authors: Nelle
authors: Otwin
authors: O
authors: Linderkamp
mesh_terms: D000751:Anemia, Neonatal / Q000097:blood / Q000517:prevention & control*; D004907:Erythrocyte Deformability / Q000187:drug effects*; D004921:Erythropoietin / Q000494:pharmacology* / Q000627:therapeutic use; D006397:Hematinics / Q000494:pharmacology* / Q000627:therapeutic use; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000517:prevention & control*; D011446:Prospective Studies; D011994:Recombinant Proteins; D017701:Reticulocyte Count
chemical_list: D006397:Hematinics; D006454:Hemoglobins; D011994:Recombinant Proteins; C103998:epoetin beta; D004921:Erythropoietin