Joost Peerbooms

24 Chapter 2 Table 2 Preparation Protocols and Costs for the Different PRP Separation Systems* * NP, not provided by manufacturer (unknown); PRP, platelet-rich plasma Laboratory Results Platelets, Leukocytes, and Platelet Enrichment Factors. The concentrations of platelets and leukocytes found in the included studies are presented in Figure 2. The concentration of platelets in PRP differed largely between, and to a lesser extent within, the studied PRP separation systems. The highest concentration of platelets was produced by the Cascade system; the lowest concentration of platelets was produced by the ACP system. Regarding the concentration of leukocytes in PRP, large differences were found between, but not within, the separation systems. The highest concentration of leukocytes was found in PRP produced by the GPS III system; PRP produced by the ACP system contained the lowest number of leukocytes. Although only reported in 4 studies, large differences between PRP separation systems were found for the platelet enrichment factor. The highest platelet enrichment factors were found for the GPS III and SmartPrep systems (3.93 32 and 3.79 30 , respectively) and the lowest for the ACP, RegenPRP, and Cascade systems (1.31 32 , 1.59 32 and 1.62 7 , respectively). Growth Factors. The concentrations of the growth factors PDGF-AB, TGF-ß1, and VEGF found in the included studies are presented in Figure 3. Large differences both between and within the studied PRP separation systems were found for all the growth factors. Additionally, no differences in the concentrations of PDGF-AB and TGF-ß1 were found between the higher (GPS III, SmartPrep, and Magellan) and lower platelet-yielding devices (ACP, Cascade, Endoret, and RegenPRP) as for the higher (GPS III, SmartPrep, Magellan, and RegenPRP) and lower leukocyte-yielding devices (ACP and Cascade). However, the concentration of VEGF tended to be higher in PRP produced by systems that yield higher concentrations of platelets and leukocytes (GPS III and Magellan).