title: Immunosuppressive effects of red blood cells on monocytes are related to both storage time and storage solution.
abstract: BACKGROUND
  Reduced monocyte function is associated with adverse outcomes from critical illness. Red blood cells (RBCs) are thought to impair monocyte function but relationships between RBC storage solution and monocyte suppression are unknown. This study was designed to test the hypothesis that immunosuppressive effects of RBCs on monocytes are related to both storage time and preservative solution.
  
  
  METHODS
  Monocytes from healthy adult donors were co-cultured with RBCs that had been stored in AS-1, AS-3, or CPD only for 7, 14, or 21 days. Cells were then stimulated with lipopolysaccharide (LPS) and their supernatants assayed for tumor necrosis factor (TNF)-α and interleukin (IL)-10. Transwell experiments were performed to evaluate the role of cell-to-cell contact. Monocyte mRNA expression was quantified by real-time-polymerase chain reaction.
  
  
  RESULTS
  LPS-induced TNF-α production capacity was reduced compared to controls for all groups, but CPD-only RBCs suppressed monocyte function more than RBCs stored in AS-1 (p = 0.007) and AS-3 (p = 0.006). IL-10 production was preserved or augmented in all groups. A longer storage time was associated with reduced TNF-α production capacity for AS-1 and AS-3 groups but not CPD. Preventing cell-to-cell contact did not eliminate the inhibitory effect of RBCs on monocyte responsiveness. RBC exposure was associated with decreased LPS-induced TNFA mRNA expression (p < 0.05 for all groups).
  
  
  CONCLUSIONS
  CPD-only RBCs suppressed monocyte function more than RBCs stored with additive solutions. TNF-α production was reduced even in the absence of cell-to-cell contact and was impaired at the mRNA level. Further work is needed to understand the role of preservative solutions in this process.
authors: Division of Critical Care Medicine, The Research Institute, Department of Pathology, Nationwide Children's Hospital, Columbus, Ohio 43205, USA.
authors: Jennifer
authors: J
authors: Muszynski
authors: Jyotsna
authors: J
authors: Nateri
authors: Kathleen
authors: K
authors: Nicol
authors: Kristin
authors: K
authors: Greathouse
authors: Lisa
authors: L
authors: Hanson
authors: Mark
authors: M
authors: Hall
mesh_terms: D000328:Adult; D001793:Blood Preservation; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D016753:Interleukin-10 / Q000235:genetics; D009000:Monocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10