title: The effects of cryopreservation on red blood cell rheologic properties.
abstract: BACKGROUND
  In transfusion medicine, frozen red blood cells (RBCs) are an alternative for liquid-stored RBCs. Little is known about the rheologic properties (i.e., aggregability and deformability) of thawed RBCs. In this study the rheologic properties of high-glycerol frozen RBCs and postthaw stored in saline-adenine-glucose-mannitol medium were compared to those of conventionally liquid-stored and fresh RBCs.
  
  
  METHODS
  Fresh RBCs were obtained from healthy volunteers. Leukoreduced liquid-stored and thawed deglycerolized RBC units were obtained from the Sanquin Blood Bank. RBCs were tested for aggregability (aggregation index [AI]), deformability (elongation index [EI]), and various hematologic variables.
  
  
  RESULTS
  The AI of thawed RBCs was reduced, compared to fresh and liquid-stored RBCs (p<0.05). The EI of stored RBCs was significantly enhanced over a shear stress range of 2.0 to 50Pa compared to fresh RBCs (p<0.05). No significant differences in EI between thawed and 21- or 35-day liquid-stored RBCs were observed. The osmotic fragility, hemolysis, mean cell volume, and mean cell hemoglobin concentration of thawed RBCs were markedly altered, compared to fresh and liquid-stored RBCs (p< 0.05). The adenosine triphosphate (ATP) content of thawed RBCs was similar to 3- or 21-day liquid-stored and fresh RBCs.
  
  
  CONCLUSIONS
  Thawed RBCs are more fragile than conventionally liquid-stored and fresh RBC. The freeze-thaw-wash process, however, did not adversely affect the aggregability and deformability or the ATP content of thawed RBCs. Based on the rheologic properties, cryopreserved RBCs are a valuable alternative to liquid-stored RBCs.
authors.affiliation: Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Henkelman
authors.forename: Johan W M
authors.initials: JW
authors.lastname: Lagerberg
authors.forename: Reindert
authors.initials: R
authors.lastname: Graaff
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rakhorst
authors.forename: Willem
authors.initials: W
authors.lastname: Van Oeveren
mesh_terms: D000225:Adenine / Q000494:pharmacology; D001793:Blood Preservation / Q000379:methods*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004903:Erythrocyte Aggregation / Q000187:drug effects / Q000502:physiology; D004907:Erythrocyte Deformability / Q000187:drug effects / Q000502:physiology; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D006801:Humans; D008353:Mannitol / Q000494:pharmacology; D009996:Osmotic Fragility / Q000187:drug effects / Q000502:physiology; D012212:Rheology / Q000187:drug effects*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D003451:Cryoprotective Agents; D008353:Mannitol; D012965:Sodium Chloride; D005947:Glucose; D000225:Adenine; D005990:Glycerol