title: P-selectin mRNA is maintained in platelet concentrates stored at 4 degrees C.
abstract: BACKGROUND
  Platelets (PLTs) contain mRNA and synthesize proteins in response to activation. Most guidelines for PLT concentrates (PCs) recommend ambient temperature for storage but the impact of the storage temperature on PLT mRNA content has not yet been investigated.
  
  
  METHODS
  Ten leukoreduced apheresis PCs were split and stored at 22 and 4 degrees C. P-selectin mRNA, its expression on PLTs, and its soluble form were quantified. In parallel, cellular (cell count, mean PLT volume), metabolic (pH, pO(2), pCO(2), HCO(3), glucose), and functional markers (swirling, hypotonic shock response, aggregation to collagen) were analyzed. Rotation thrombelastography was used to monitor the hemostatic potential of PLTs. All measurements were performed on Days 1 and 5 of storage.
  
  
  RESULTS
  After 5 days of storage at 4 degrees C, only 31 +/- 27 percent of P-selectin mRNA and 29 +/- 41 percent of glyceraldehyde-3-phosphate dehydrogenase mRNA were lost, while minute amounts of the mRNAs were detectable at 22 degrees C. In PCs stored at 4 degrees C the percentage of P-selectin-positive PLTs was significantly higher when compared to PCs stored at 22 degrees C. Soluble P-selectin concentrations did not significantly differ between both storage temperatures. Thrombelastography revealed significantly shorter reaction times in PLTs kept at 4 degrees C.
  
  
  CONCLUSIONS
  Our data indicate that storage at 4 degrees C is accompanied by maintained mRNA levels. PLTs with intact mRNA levels and short reaction times in thrombelastography might be functionally superior to PLTs that are devoid of mRNA and show less augmented P-selectin surface expression. In therapeutic applications, that is, if PLTs are transfused to control acute bleeding, PLTs kept at 4 degrees C may be advantageous.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stiegler
authors.forename: Gottfried
authors.initials: G
authors.lastname: Fischer
authors.forename: Gajalakshmi
authors.initials: G
authors.lastname: Ramanathan
authors.forename: Peter
authors.initials: P
authors.lastname: Bencur
authors.forename: Günter
authors.initials: G
authors.lastname: Weigel
authors.forename: Christine
authors.initials: C
authors.lastname: Mannhalter
mesh_terms: D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D001793:Blood Preservation / Q000379:methods*; D024601:Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / Q000235:genetics; D006487:Hemostasis; D006801:Humans; D047589:Leukocyte Reduction Procedures; D019007:P-Selectin / Q000235:genetics*; D010983:Plateletpheresis; D020871:RNA Stability; D012333:RNA, Messenger / Q000032:analysis*; D013696:Temperature; D013916:Thrombelastography
chemical_list: D019007:P-Selectin; D012333:RNA, Messenger; D024601:Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+)