title: Preparation of highly concentrated and white cell-poor platelet-rich plasma by plateletpheresis.
abstract: OBJECTIVE
  Contaminating white blood cells (WBC) contribute remarkably to the overall growth factor content of locally applicable platelet-rich plasma (PRP) or platelet (PLT) gel and change the relative proportions of the contained growth factors.
  
  
  METHODS
  To study the independent effects of locally applicated highly concentrated PLTs, the development of preparations is needed that contain large amounts of PLTs and no or at least very few leucocytes. Therefore, 20 plateletpheresis procedures were performed in voluntary blood donors to get highly concentrated and extremely WBC-poor plateletpheresis concentrates. The degree of spontaneous PLT activation, the PLT aggregation response to agonists and the level of the growth factor TGF-beta1 (transforming growth factor beta1) were measured immediately after the donation and 1 day later.
  
  
  RESULTS
  The concentrates contained 1.96 +/- 0.36 x 10e11 PLTs per unit in 55.2 +/- 7.9 ml, respectively. In comparison to the donors' blood, the PLT-enrichment factor was 15.3 +/- 5.4. At the same time, the concentrates contained extremely low residual numbers of WBCs (0.8 +/- 3.3 x 10e3/ml). The concentration of the growth factor TGF-beta1 was 743.2 +/- 243.9 ng/ml. On day 1, the PLT concentration and the TGF-beta1 content of the PLT concentrates had not decreased.
  
  
  CONCLUSIONS
  In summary, plateletpheresis is suited to provide PRP products with higher concentrations of human platelets and platelet-derived growth factors than previously reported PRP preparation methods but with extremely low numbers of contaminating leucocytes.
authors.affiliation: Department of Transfusion Medicine and Haemostaseology, University Hospital Erlangen, Friedrich-Alexander-Universitaet Erlangen- Nuernberg, Krankenhausstrasse 12, 91054 Erlangen, Germany. robert.zimmermann@uk-erlangen.de
authors.forename: R
authors.initials: R
authors.lastname: Zimmermann
authors.forename: S
authors.initials: S
authors.lastname: Reske
authors.forename: P
authors.initials: P
authors.lastname: Metzler
authors.forename: A
authors.initials: A
authors.lastname: Schlegel
authors.forename: J
authors.initials: J
authors.lastname: Ringwald
authors.forename: R
authors.initials: R
authors.lastname: Eckstein
mesh_terms: D001772:Blood Cell Count; D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D007962:Leukocytes; D015539:Platelet Activation; D010974:Platelet Aggregation; D010982:Platelet-Derived Growth Factor / Q000032:analysis; D010983:Plateletpheresis / Q000379:methods / Q000592:standards*; D053773:Transforming Growth Factor beta1 / Q000032:analysis
chemical_list: D010982:Platelet-Derived Growth Factor; D053773:Transforming Growth Factor beta1