title: Immunologic profiles of red blood cells using in vitro models of transfusion.
abstract: BACKGROUND
  Transfusion of packed red blood cells (RBCs) produces a myriad of immunologic derangements, from suppressive to stimulatory. Proliferation of human T cells is suppressed in vitro after exposure to processed red blood cells (PRBCs). We hypothesized that this effect would be mitigated by using fresh RBCs. We also hypothesized that this suppressive effect was a generalized effect on lymphocyte proliferation and would be observed in both CD4+ and CD8+ T-cell subpopulations as well as B cells.
  
  
  METHODS
  We isolated human T cells from donor peripheral blood mononuclear cells and exposed them to either blood bank PRBCs or fresh RBCs from volunteer donors and stimulated them with anti-CD3/anti-CD28. Human B cells were stimulated with lipopolysaccharide and exposed to PRBCs or fresh RBCs. We measured proliferation of B cells by thymidine incorporation assays. We also treated RBCs with citrate-phosphate-dextrose (CPD) at different time points before culture them with stimulated T cells to determine the role of this common RBC storage solution in lymphocyte proliferation.
  
  
  RESULTS
  In vitro proliferation of CD4+ and CD8+ T cells was suppressed by blood bank RBCs. This suppression is eliminated when fresh RBCs were used. The B cells showed inhibition of proliferation when exposed to similar conditions, which appeared to be consistent over serial dilutions. Fresh RBCs exposed to CPD did not appear suppressive in the first 6 h after exposure.
  
  
  CONCLUSIONS
  T-cell and B-cell proliferation inhibition by blood banked RBCs suggests a generalized effect of RBCs on cellular proliferation. The lack of suppression by fresh RBCs further suggests that something involved in blood banking alters RBC properties such that they attain a suppressive phenotype. One such blood banking component, CPD, does not appear to affect this suppressive phenotype within the first 6 h.
authors.affiliation: Section of Trauma and Critical Care, Division of General Surgery, Department of Surgery, University of Kentucky, Lexington, Kentucky 40536, USA. kristin.long@uky.edu
authors.forename: Kristin
authors.initials: K
authors.lastname: Long
authors.forename: Cindy
authors.initials: C
authors.lastname: Meier
authors.forename: Martin
authors.initials: M
authors.lastname: Ward
authors.forename: Dennis
authors.initials: D
authors.lastname: Williams
authors.forename: Jerold
authors.initials: J
authors.lastname: Woodward
authors.forename: Andrew
authors.initials: A
authors.lastname: Bernard
mesh_terms: D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D000094902:Blood Banking / Q000379:methods; D001793:Blood Preservation / Q000379:methods; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000166:cytology* / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D056747:Immunomodulation / Q000276:immunology; D066298:In Vitro Techniques
keywords: Critical care; Immunomodulation; Red blood cell; Transfusion; Transfusion-related immunomodulation