Differences in platelet growth factor release and leucocyte kinetics during autologous platelet gel formation

Abstract

Three commercial systems for whole blood separation were compared to obtain the buffy coat composed of platelet-rich plasma (BC-PRP) and leucocytes . These samples of the buffy coat were used to make a platelet gel (PG), which was used to measure platelet growth factor (PGF) release, to perform a white blood cell (WBC) count and to measure myeloperoxidase (MPO) release from WBCs. Aliquots of whole blood obtained from ten volunteers were distributed either to a blood cell separator (The Electa Cell-Separator, E-CS) or to a tabletop centrifuge (Gravitational Platelet Sequestration System, GPS) to prepare the BC-PRP. The third system combines the BC-PRP production by E-CS with a micro porous filter (Autologous Growth Factor filter, AGF) to enrich for the BC-PRP. Autologous thrombin was used to activate the BC-PRP and to prepare the PG and subsequently to degranulate the platelet concentrate. Platelet-derived growth factor-AB and transforming growth factor-beta1 were present in high levels after thrombin activation of the E-CS or GPS prepared samples. However, the AGF prepared samples released their growth factors before thrombin activation. The WBCs were significantly increased with each of the three systems. Contrary to the AGF, no leucocyte degranulation occurred with the E-CS or GPS prepared samples, based upon the low MPO concentrations in the BC-PRP. The three types of apparatus had different harvesting capacities for collecting the enriched platelets and the release of high concentrations of PGF. When the E-CS and GPS, but not the AGF, were used, low levels of MPO were maintained in the PG, which potentially contributes to antimicrobial properties of platelet gel at the site of application.

Exogenous Application of Platelet-Leukocyte Gel during Open Subacromial Decompression Contributes to Improved Patient Outcome

“…These growth factors augment the wound healing process [7,8] . The high concentration of non-activated leukocytes, present in the PLG, promotes anti-microbial activity at the wound site through destruction of bacteria and foreign materials and removal of damaged tissue [9,10] .…”

Effects of Autologous Conditioned Plasma® (ACP) on the healing of surgically induced core lesions in equine superficial digital flexor tendon

“…There are conflicting opinions about the role of leukocytes in blood products used to treat tendinopathy and how they affect tendon healing , Sundman et al 2011, Everts et al 2006. There are indications, that in vivo, the leucocytes may have positive effects, such as promote healing, modulate the immune response, anti-inflammatory Effects of Autologous Conditioned Plasma ® (ACP) R. J.…”

“…There are indications, that in vivo, the leucocytes may have positive effects, such as promote healing, modulate the immune response, anti-inflammatory Effects of Autologous Conditioned Plasma ® (ACP) R. J. Estrada et al Pferdeheilkunde 30 (2014) 638 action and release of anti-microbial substances (Everts et al 2006). On the other hand, recent studies have claimed that platelet concentrates with reduced leukocyte concentration might be a suitable option for improving tissue repair, since high leukocyte counts in PRP induce an increase in the production of catabolic and inflammatory cytokines (McCarrel et al 2012, Sundman et al 2011.…”

“…In vitro studies have shown that ACP allows concentration of platelets and growth factors while at the same time decreasing WBC counts , Kissich et al 2012. Even though there are conflicting reports about the role that WBC counts in blood products play on tendon healing , Sundman et al 2011, Everts et al 2006, several in vitro studies have demonstrated that lower WBC counts in the platelet concentrates are directly correlated to a lower concentration of catabolic enzymes , Sundman et al 2011. Therefore, it has been suggested that leukocyte-reduced platelet concentrates might be superior than platelet rich plasma (PRP) in stimulating tendon healing, since persistent inflammation incited by the high concentration of WBC may result in scar tissue formation .…”

Untitled

“…The various studies on platelet-derived products were simply divided into two generations, and then, according to the huge concentrations on PCs, researchers subsequently divided the products into four main families based on their endogenous fibrin and cell content: [26][27][28][29] (1) Pure PRP (P-PRP); (2) leukocyte PRP (L-PRP); (3) pure-platelet-rich fibrin (P-PRF); and (4) leukocyte-PRF (L-PRF). 1.…”