title: Erythropoietin reduces storage lesions and decreases apoptosis indices in blood bank red blood cells.
abstract: BACKGROUND
  Recent evidence shows a selective destruction of the youngest circulating red blood cells (neocytolysis) trigged by a drop in erythropoietin levels.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the effect of recombinant human erythropoietin beta on the red blood cell storage lesion and apoptosis indices under blood bank conditions.
  
  
  METHODS
  Each one of ten red blood cell units preserved in additive solution 5 was divided in two volumes of 100mL and assigned to one of two groups: erythropoietin (addition of 665IU of recombinant human erythropoietin) and control (isotonic buffer solution was added). The pharmacokinetic parameters of erythropoietin were estimated and the following parameters were measured weekly, for six weeks: Immunoreactive erythropoietin, hemolysis, percentage of non-discocytes, adenosine triphosphate, glucose, lactate, lactate dehydrogenase, and annexin-V/esterase activity. The t-test or Wilcoxon's test was used for statistical analysis with significance being set for a p-value <0.05.
  
  
  RESULTS
  Erythropoietin, when added to red blood cell units, has a half-life >6 weeks under blood bank conditions, with persistent supernatant concentrations of erythropoietin during the entire storage period. Adenosine triphosphate was higher in the Erythropoietin Group in Week 6 (4.19±0.05μmol/L vs. 3.53±0.02μmol/L; p-value=0.009). The number of viable cells in the Erythropoietin Group was higher than in the Control Group (77%±3.8% vs. 71%±2.3%; p-value <0.05), while the number of apoptotic cells was lower (9.4%±0.3% vs. 22%±0.8%; p-value <0.05).
  
  
  CONCLUSIONS
  Under standard blood bank conditions, an important proportion of red blood cells satisfy the criteria of apoptosis. Recombinant human erythropoietin beta seems to improve storage lesion parameters and mitigate apoptosis.
authors.affiliation: Banco Nacional de Sangre Hemolife, Bogotá, Colombia. Electronic address: oscar_penuela@hotmail.com.
authors.forename: Oscar Andrés
authors.initials: OA
authors.lastname: Penuela
authors.affiliation: Universidad Nacional de Colombia, Bogotá, Colombia.
authors.forename: Fernando
authors.initials: F
authors.lastname: Palomino
authors.affiliation: Universidad Antonio Nariño, Bogotá, Colombia.
authors.forename: Lina Andrea
authors.initials: LA
authors.lastname: Gómez
keywords: Apoptosis; Blood bank; Erythropoietin; Storage lesion