Equine autologous platelet concentrate is a leukocyte-rich platelet-rich plasma with a high interleukin-1Ra-to-interleukin-1β ratio and high transforming growth factor-β1 concentration.

OBJECTIVE

To quantify platelets, leukocytes, cytokines, and growth factors in ProVet autologous platelet concentrate (APC). We hypothesized that APC would contain significantly increased leukocytes and platelets compared to whole blood and significantly increased concentrations of anti-inflammatory cytokines and growth factors compared to serum.

METHODS

Blood was obtained from 6 horses and processed to produce APC. Leukocyte and platelet concentrations were quantified in whole blood and APC. Cytokines, including interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α, and IL-1Ra, and growth factors, including PDGF-BB, TGF-β1, VEGF, and IGF-1, were quantified in serum and APC using immunoassays.

RESULTS

Median leukocyte concentrations were significantly higher in APC (51.60 X 103 cells/μL) compared to blood (7.43 X 103 cells/μL; P = .0006). Median platelet concentrations (883.00 X 103 platelets/μL) were significantly higher in APC compared to blood (120.0 X 103 platelets/μL; P = .001). IL-1Ra was significantly concentrated in APC (53.12 ng/mL) compared to serum (below the limit of detection; P = .001), and the IL-1Ra:IL-1β ratio was significantly higher in APC (1,169) compared to serum (11.86; P = .0073). The median concentration of TGF-β1 was significantly higher in APC (12,480 pg/mL) compared to serum (6,943 pg/mL; P = .0003), whereas the median concentrations of IGF-1 (APC = 52.88 ng/mL and serum = 115.20 ng/mL; P = .0003) and PDGF-BB (APC = 1,388.41 pg/mL and serum = 1,707.24 pg/mL; P = .0017) were significantly lower in APC compared to serum.

CONCLUSIONS

ProVet APC is a leukocyte-rich PRP containing elevated concentrations of IL-1Ra and TGF-β1. This portable, self-contained system provides equine practitioners with an easy way of producing PRP in the field.

CLINICAL RELEVANCE: This study provides equine veterinarians with critical information about the constituents of a new orthobiologic.