title: Storage of red blood cells with improved maintenance of 2,3-bisphosphoglycerate.
abstract: BACKGROUND
  During storage, red blood cells (RBCs) rapidly lose 2,3-bisphosphoglycerate (2,3-DPG) leading to an increase in the affinity for O(2) and a temporary impairment of O(2) transport. Recent clinical evaluations indicate that the quality of transfused RBCs may be more important for patient survival than previously recognized.
  
  
  METHODS
  Glucose-free additive solutions (ASs) were prepared with sodium citrate, sodium gluconate, adenine, mannitol, and phosphates at high pH, a solution that can be heat-sterilized. CP2D was used as an anticoagulant. Additional CP2D was added to the AS to supply glucose. RBCs were stored at 4 degrees C and assayed periodically for intracellular pH (pHi), extracellular pH, glucose, lactate, phosphate, ATP, 2,3-DPG, hemolysis, and morphology.
  
  
  RESULTS
  Storage in 175 mL of the chloride-free, hypotonic medium at a hematocrit (Hct) level of 59 to 60 percent resulted in an elevated pHi and the maintenance of 2,3-DPG at or above the initial value for 2 weeks without loss of ATP. The addition of 400 mL of storage solution followed by centrifugation and removal of 300 mL of excess solution to a Hct level of 60 to 66 percent further reduced the chloride concentration, resulting in the maintenance of 2,3-DPG for 4 weeks. Hemolysis was at 0.1 percent at 6 weeks.
  
  
  CONCLUSIONS
  Improvements in the maintenance of 2,3-DPG were achieved with 175 mL of a chloride-free storage solution with familiar additives at nontoxic concentrations to increase pHi. Adding, instead, 400 mL of storage solution followed by the removal of 300 mL reduced the chloride concentration, increasing the pHi and extending the maintenance of 2,3-DPG to 4 weeks.
authors.affiliation: Department of Clinical Immunology and Transfusion Medicine, Academic Laboratory, University Hospital, Uppsala, Sweden. claes.hogman@telia.com
authors.forename: Claes F
authors.initials: CF
authors.lastname: Högman
authors.forename: Helena
authors.initials: H
authors.lastname: Löf
authors.forename: Harold T
authors.initials: HT
authors.lastname: Meryman
mesh_terms: D019794:2,3-Diphosphoglycerate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000925:Anticoagulants / Q000494:pharmacology; D001793:Blood Preservation / Q000379:methods*; D002951:Citrates / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005240:Feasibility Studies; D005947:Glucose / Q000494:pharmacology; D006400:Hematocrit; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007038:Hypotonic Solutions / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D002951:Citrates; D007038:Hypotonic Solutions; D019794:2,3-Diphosphoglycerate; C007077:citrate phosphate dextrose; D000255:Adenosine Triphosphate; D005947:Glucose