title: Analysis of Platelet-Rich Plasma Extraction: Variations in Platelet and Blood Components Between 4 Common Commercial Kits.
abstract: BACKGROUND
  Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP.
  
  
  OBJECTIVE
  To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine.
  
  
  RESULTS
  Three kits taking samples from the "buffy coat layer" were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples.
  
  
  CONCLUSIONS
  This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored, being considered insignificant. The lack of standardization of PRP preparation for clinical use has contributed at least in part to the varying clinical efficacy in PRP use.
  
  
  CONCLUSIONS
  The variation of platelet and other blood component concentrations between commercial PRP kits may affect clinical treatment outcomes. There is a need for standardization of PRP for clinical use.
authors.affiliation: School of Surgery, The University of Western Australia, Crawley, Western Australia, Australia.; QEII Medical Centre, Nedlands, Western Australia, Australia.
authors.forename: Jane
authors.initials: J
authors.lastname: Fitzpatrick
authors.affiliation: Chair in Biostatistics, Institute for Health Research, University of Notre Dame, Fremantle, Western Australia, Australia.
authors.forename: Max K
authors.initials: MK
authors.lastname: Bulsara
authors.affiliation: Florey Neurosciences Institutes, University of Melbourne, Melbourne Brain Centre, Heidelberg, Victoria, Australia.
authors.forename: Paul Robert
authors.initials: PR
authors.lastname: McCrory
authors.affiliation: Department of Surgery, Orthopaedics Epworth Hospital, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Richardson
authors.affiliation: QEII Medical Centre, Nedlands, Western Australia, Australia.; Research Centre for Translational Orthopaedic, School of Surgery, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Ming Hao
authors.initials: MH
authors.lastname: Zheng
keywords: PRP; leukocyte; osteoarthritis; platelet-rich plasma; tendinopathy