Commercial Separation Systems Designed for Preparation of Platelet-Rich Plasma Yield Differences in Cellular Composition

Background The role of platelet-rich plasma (PRP) in the treatment of sport-related injuries is unclear, largely due to the heterogeneity of clinical results. This may relate to compositional differences in PRP from different separation systems. Questions/Purposes This study aims to compare the composition of PRP produced with five different commercially available systems, focusing on cellular concentrations and pH. Methods Seven donors (41 ± 12 years) provided blood for PRP preparation using five systems (Arthrex Angel, Emcyte Genesis CS, Arteriocyte Magellan, Harvest SmartPrep, and Biomet GPS III). Post processing, cellular composition was measured including platelets (PLT), white blood cells (WBC), neutrophils (NE), and red blood cells (RBC), as well as pH. Results Platelet concentration and capture efficiency were similar between systems, except the Angel 7% preparation had a greater concentration than Genesis CS (2310 ± 524 vs. 1129 ± 264 k/μL). WBC concentration was variable between systems; however, significant differences were only found between the Angel 2% and GPS III preparations (11.0 ± 4.5, 27.3 ± 7.1 k/μL). NE concentration was significantly lower in the Angel 2% and 7% preparations compared with GPS III (0.6 ± 0.6 and 1.8 ± 1.3 k/μL vs. 9.4 ± 7.0 k/μL). RBC concentration was highest in SmartPrep (3.2 ± 0.6 M/μL) and Genesis CS systems (3.1 ± 0.6 M/μL) compared with all other systems (≤1.1 ± 1.2 M/μL). Finally, pH was significantly lower with the SmartPrep system (6.95 ± 0.06) compared with all others (≥7.26 ± 0.06). Conclusion Aside from platelet concentration and capture efficiency, significant compositional differences were identified between preparation systems. Caution should be employed when interpreting clinical results of studies utilizing PRP, as the role of compositional differences and their effect on outcome are unknown. Further study is necessary to determine the clinical significance of these differences.