Platelet-Rich Plasma Content of Active Spinal Cord Injured Patients: A Controlled Laboratory Study.

OBJECTIVE: Platelet-rich plasma has potential uses for patients with spinal cord injuries. However, no study has quantified the cellular and growth factor content of platelet-rich plasma in this population. This study aimed to analyze (1) platelet-rich plasma content of spinal cord injury subjects and (2) the effect of high-intensity interval exercise on their platelet-rich plasma. DESIGN: Ten spinal cord injury patients and 10 controls were enrolled. At rest, platelet-rich plasma was created from both groups. The spinal cord injury group then performed high-intensity interval exercise and underwent a second blood draw to create post-high-intensity interval exercise platelet-rich plasma. Complete blood counts and growth factor analysis (via enzyme-linked immunosorbent assay) was performed on all platelet-rich plasma. RESULTS: The spinal cord injury group had lower platelets (305,700 ± 85,697/µl vs 380,800 ± 57,301/µl, P = 0.015) and transforming growth factor ß (12.84 ± 1.58 vs 14.33 ± 0.63 ng/ml, P = 0.023). Four minutes of high-intensity interval exercise increased the platelets (305,700 ± 85,697/µl to 399,200 ± 96,251/µl, P = 0.004), leukocytes (906 ± 930 vs 2504 ± 3765/µl, P = 0.002) and transforming growth factor ß (12.84 ± 1.58 to 14.28 ± 1.21 ng/ml, P = 0.020). CONCLUSIONS: Spinal cord injury patients have fewer platelets and transforming growth factor ß in their platelet-rich plasma at baseline compared with controls. Exercise increased platelet, leukocyte, and transforming growth factor ß yield, compensating for the baseline deficits.

High Intensity Interval Exercise Increases Platelet and Transforming Growth Factor-ß Yield in Platelet-Rich Plasma.

BACKGROUND: Platelet-rich plasma (PRP) is an emerging orthobiologic treatment for musculoskeletal conditions like osteoarthritis. Two studies have demonstrated the influence of longer duration exercise on PRP composition, but no study has ever explored the impact of high intensity interval exercise (HIIE) on PRP content. OBJECTIVE: To quantify cellular and growth factor content changes in PRP after 4 minutes of HIIE. DESIGN: Controlled laboratory pilot study. SETTING: Academic sports medicine center. PARTICIPANTS: Ten healthy volunteers (5 male, 5 female). INTERVENTION: Volunteers had PRP prepared from 15 mL of whole blood using a single spin, plasma-based system (autologous conditioned plasma [ACP]) immediately before and after 4 minutes of HIIE on a stationary exercise bike (Tabata protocol). MAIN OUTCOME MEASURE: The PRP was sent for complete blood counts and enzyme-linked immunosorbent assay (ELISA) to quantify transforming growth factor (TGF)-ß, platelet-derived growth factor (PDGF), insulin-like growth factor (IGF)-1, and vascular endothelial growth factor (VEGF). RESULTS: Mean platelet count in PRP increased from 367.4 ± 57.5 k/µL to 497.7 ± 93.3 k/µL after 4 minutes of HIIE (P < .001). TGF-ß also increased from 8237.2 ± 7676.5 pg/mL to 21 535.7 ± 4062.6 pg/mL postexercise (P = .004). The other cellular components (leukocytes, red blood cells, and mean platelet volume) and growth factors (PDGF, IGF-1, and VEGF) were not significantly changed. CONCLUSIONS: A short 4-minute bout of HIIE significantly increased the total platelet count and TGF-ß concentration in PRP.