title: Transfusion-induced leukocyte IL-8 gene expression is avoided by the use of human polymerized hemoglobin.
abstract: BACKGROUND
  Red blood cell (pRBC) transfusion is an independent risk factor for multiple organ failure (MOF); a maladaptive immuno-inflammatory response is implicated. Interleukin-8 (IL-8) is one putative mediator of this response. We previously observed that injured patients resuscitated with pRBCs have increased plasma IL-8 compared with those given human polymerized hemoglobin (PolyHb). To further elucidate the mechanisms responsible for this difference in IL-8, we devised an ex-vivo transfusion model. We hypothesize that pRBC transfusion induces increased IL-8 gene expression that is avoided by the use of PolyHb.
  
  
  METHODS
  Human volunteer blood was incubated alone (RB) or with a major transfusion (50% exchange) of either post-storage leukoreduced O-pRBCs (RB + pRBC) or PolyHb (RB + PolyHb) for 30 minutes at 37 degrees C. Total leukocyte (TL) or polymorphonuclear leukocyte (PMN) total RNA was isolated and IL-8 mRNA quantified. Results are reported as amol IL-8 mRNA/microg total RNA +/- SEM. Stats: ANOVA with Bonferroni/Dunn post hoc analysis.
  
  
  RESULTS
  Simulated transfusion of pRBCs increased TL IL-8 mRNA (RB=0.28 +/- 0.10 amol/microg total RNA, RB + pRBC=2.24 +/- 0.25 amol/microg total RNA, p <0.01), whereas PolyHb did not (B + PolyHb=0.82 +/- 0.30 amol/microg total RNA). PolyHb IL-8 mRNA was less than pRBC transfused (p <0.01). In PMNs, simulated transfusion of pRBCs increase IL-8 mRNA (RB=3.17 +/- 1.05 amol/microg total RNA, RB + pRBC=7.60 +/- 1.79 amol/microg total RNA, p <0.01), whereas PolyHb did not (RB + PolyHb=4.53 +/- 1.64 amol/microg total RNA).
  
  
  CONCLUSIONS
  Stored pRBCs induces increased TL and PMN IL-8 gene expression, whereas human polymerized hemoglobin, in lieu or pRBCs, avoids this increase. These experimental results corroborate our previous clinical studies and further encourage the study of PolyHb as a resuscitation strategy to decrease postinjury MOF.
authors.affiliation: Department of Surgery, University of Colorado Health Sciences Center, Denver, Colorado 80204, USA.
authors.forename: Forest R
authors.initials: FR
authors.lastname: Sheppard
authors.forename: Ernest E
authors.initials: EE
authors.lastname: Moore
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Johnson
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Cheng
authors.forename: Nathan
authors.initials: N
authors.lastname: McLaughlin
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Silliman
mesh_terms: D000704:Analysis of Variance; D001802:Blood Substitutes / Q000494:pharmacology*; D002478:Cells, Cultured; D017707:Erythrocyte Transfusion / Q000009:adverse effects* / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects*; D006084:Graft Rejection / Q000517:prevention & control; D006454:Hemoglobins; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics*; D007962:Leukocytes / Q000187:drug effects / Q000502:physiology; D009102:Multiple Organ Failure / Q000517:prevention & control; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology; D011336:Probability; D012313:RNA / Q000032:analysis; D012307:Risk Factors; D012494:Sampling Studies; D012680:Sensitivity and Specificity
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D016209:Interleukin-8; C079129:hemoglobin polymer; D012313:RNA