Comparison of cellular and growth factor concentrations in equine Autologous Conditioned Plasma® (ACP) and manually prepared Platelet Rich Plasma (mPRP)

Abstract

Autologous Conditioned Plasma ® (ACP) is commonly used to treat orthopedic disorders in horses and is characterized by a moderate supra-physiological platelet concentration, which might however be too low to achieve optimal tissue regenerative effect. Because of considerably lower costs and potentially higher platelet concentrations, non-commercial, manual, double-centrifugation tube methods (mPRP) are often employed instead. However, mPRP preparation is tedious and not standardized. In order to determine if an "in-house" mPRP technique can be a valuable alternative to ACP in the practice, the aim of this study was to compare the manual product to the commercial method with respect to their preparation process, platelet activation level (assessed by measuring the mean platelet volume (MPV) and mean platelet component (MPC)), as well as absolute platelet, leukocyte, transforming growth factor-b1 (TGF-b1) and platelet derived growth factor-BB (PDGF-BB) concentrations. For this purpose, all these parameters were determined in ACP, mPRP and its platelet poor plasma (mPPP) obtained from venous blood samples of 10 healthy adult horses. The mean platelet concentration in mPRP reached 221.4 ± 60.3 ×10 9 /l and was 1.2-and 1.4-fold higher than in ACP and mPPP respectively. Mean leukocyte content in mPRP reached 25.8 ±10.9 ×10 9 /l and was 32.3-and 19.9-fold higher than in ACP and mPPP respectively. Mean PDGF-BB level in mPRP (1.81± 0.58 ng/ml) was 1.7-fold higher than both in ACP and mPPP. mPRP showed a 2-and 1.8-fold higher mean TGF-b1 concentration (3.62 ±1.16 ng/ml) than ACP and mPPP respectively. MPC reached 20.3 ±1.3 g/l in mPRP, 20.6 ±1.6 g/l in ACP and 20.4 ±1.7 g/l in mPPP. MPV was 8.6 ± 0.7 fl in mPRP, 8.7 ±1.0 fl in ACP and 8.4 ± 0.9 fl in mPPP. ACP preparation was easily performed, whereas mPRP processing was laborious and time-consuming. Compared to ACP, the "in house" mPRP method achieved a slightly higher mean platelet concentration in a much smaller end-volume, though. Mean leukocyte, TGF-b1 and PDGF-BB levels in mPRP were significantly above the values in ACP and mPPP, which both showed similar results. The high mean leukocyte concentration in mPRP could possibly induce unwanted local inflammatory reactions. Platelet activation degree did not differ between the three products. The mPRP processing method described in this study should therefore first be adjusted and optimized before being recommended for extensive use in horses. Compared to other equine platelet concentrates reported in the literature, mPRP and ACP both showed low absolute platelet and GF levels; further comparative clinical studies are needed to determine if these values were sufficient to induce a satisfactory clinical effect.

Scalable Production of Equine Platelet Lysate for Multipotent Mesenchymal Stromal Cell Culture

“…In a previous experiment (unpublished data), we had aimed to produce PLT concentrate by sedimentation of whole blood, followed by hard spin centrifugation of the supernatant similar to the PRP method. We had obtained higher PLT counts than with the buffy coat method presented here, but the leukocytes were also concentrated compared with the whole blood (unpublished data), which was in accordance with previous equine studies (Ionita et al, 2014 ; Bozorgmanesh et al, 2019 ). Furthermore, we did not succeed to deplete WBC using leukocyte reduction filters for the equine PLT concentrates.…”

Equine autologous platelet concentrates: A comparative study between different available systems

“…Numerous studies have quantified differences in the cellular and biochemical profiles of various human APC products , and these variations are assumed to influence their clinical effect . Similar data for horses are very sparse . The objective of the present study was therefore to determine and compare the platelet and leucocyte counts and the platelet‐derived growth factor‐BB and transforming growth factor‐β 1 concentrations in equine APCs obtained from the same horses, using 4 different commercial systems, adhering to the original manufacturers’ protocols, and one manual, noncommercial double‐centrifugation technique.…”