https://www.cell.com/trends/biotechnology/pdf/S0167-7799(09)00015-8.pdf

Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF).

Background: Platelet-rich plasma (PRP) has shown to be a general stimulation for repair. Purpose: To determine the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis. Study Design: Randomized controlled trial; Level of evidence, 1. Patients: The trial was conducted in 2 teaching hospitals in the Netherlands. One hundred patients with chronic lateral epicondylitis were randomly assigned in the PRP group (n 5 51) or the corticosteroid group (n 5 49). A central computer system carried out randomization and allocation to the trial group. Patients were randomized to receive either a corticosteroid injection or an autologous platelet concentrate injection through a peppering technique. The primary analysis included visual analog scores and DASH Outcome Measure scores (DASH: Disabilities of the Arm, Shoulder, and Hand). Results: Successful treatment was defined as more than a 25% reduction in visual analog score or DASH score without a reintervention after 1 year. The results showed that, according to the visual analog scores, 24 of the 49 patients (49%) in the corticosteroid group and 37 of the 51 patients (73%) in the PRP group were successful, which was significantly different (P \ .001). Furthermore, according to the DASH scores, 25 of the 49 patients (51%) in the corticosteroid group and 37 of the 51 patients (73%) in the PRP group were successful, which was also significantly different (P 5 .005). The corticosteroid group was better initially and then declined, whereas the PRP group progressively improved. Conclusion: Treatment of patients with chronic lateral epicondylitis with PRP reduces pain and significantly increases function, exceeding the effect of corticosteroid injection. Future decisions for application of the PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits.

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Positive Effect of an Autologous Platelet Concentrate in Lateral Epicondylitis in a Double-Blind Randomized Controlled Trial Platelet-Rich Plasma Versus Corticosteroid Injection With a 1-Year Follow-up

In Europe and the United States, there is an increasing prevalence of the use of autologous blood products to facilitate healing in a variety of applications. Recently, we have learned more about specific growth factors, which play a crucial role in the healing process. With that knowledge there is abundant enthusiasm in the application of concentrated platelets, which release a supra-maximal quantity of these growth factors to stimulate recovery in non-healing injuries. For 20 years, the application of autologous PRP has been safely used and documented in many fields including; orthopedics, sports medicine, dentistry, ENT, neurosurgery, ophthalmology, urology, wound healing, cosmetic, cardiothoracic, and maxillofacial surgery. This article introduces the reader to PRP therapy and reviews the current literature on this emerging treatment modality. In summary, PRP provides a promising alternative to surgery by promoting safe and natural healing. However, there are few controlled trials, and mostly anecdotal or case reports. Additionally the sample sizes are frequently small, limiting the generalization of the findings. Recently, there is emerging literature on the beneficial effects of PRP for chronic non-healing tendon injuries including lateral epicondylitis and plantar fasciitis and cartilage degeneration (Mishra and Pavelko, The American Journal of Sports Medicine 10(10):1–5, 2006; Barrett and Erredge, Podiatry Today 17:37–42, 2004). However, as clinical use increases, more controlled studies are needed to further understand this treatment.

/pdf/platelet-rich-plasma-injection-grafts-for-musculoskeletal-5g5chs38cl.pdf

Platelet rich plasma injection grafts for musculoskeletal injuries: a review

Background: Platelet-rich plasma (PRP) has been shown to be a general stimulation for repair and 1-year results showed promising success percentages. Purpose: This trial was undertaken to determine the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis with a 2-year follow-up. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: The trial was conducted in 2 Dutch teaching hospitals. One hundred patients with chronic lateral epicondylitis were randomly assigned to a leukocyte-enriched PRP group (n = 51) or the corticosteroid group (n = 49). Randomization and allocation to the trial group were carried out by a central computer system. Patients received either a corticosteroid injection or an autologous platelet concentrate injection through a peppering needling technique. The primary analysis included visual analog scale (VAS) pain scores and Disabilities of the Arm, Shoulder and Hand (DASH) outcome scores. Results: The PRP group was more often successfully treated than the corticosteroid group (P\.0001). Success was defined as a reduction of 25% on VAS or DASH scores without a reintervention after 2 years. When baseline VAS and DASH scores were compared with the scores at 2-year follow-up, both groups significantly improved across time (intention-to-treat principle). However, the DASH scores of the corticosteroid group returned to baseline levels, while those of the PRP group significantly improved (as-treated principle). There were no complications related to the use of PRP. Conclusion: Treatment of patients with chronic lateral epicondylitis with PRP reduces pain and increases function significantly, exceeding the effect of corticosteroid injection even after a follow-up of 2 years. Future decisions for application of PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits.

/pdf/ongoing-positive-effect-of-platelet-rich-plasma-versus-212qfavttw.pdf

Ongoing Positive Effect of Platelet-Rich Plasma Versus Corticosteroid Injection in Lateral Epicondylitis: A Double-Blind Randomized Controlled Trial With 2-year Follow-up

Platelet concentrates for surgical topical applications are nowadays often used, but quantification of the long-term growth factor release from these preparations in most cases is impossible. Indeed, in most protocols, platelets are massively activated and there is no significant fibrin matrix to support growth factor release and cell migration. Choukroun's platelet-rich fibrin (PRF), a second generation platelet concentrate, is a leucocyte- and platelet-rich fibrin biomaterial. Here, we show that this dense fibrin membrane releases high quantities of three main growth factors (Transforming Growth Factor b-1 (TGFbeta-1), platelet derived growth factor AB, PDGF-AB; vascular endothelial growth factor, VEGF) and an important coagulation matricellular glycoprotein (thrombospondin-1, TSP-1) during 7 days. Moreover, the comparison between the final released amounts and the initial content of the membrane (after forcible extraction) allows us to consider that the leucocytes trapped in the fibrin matrix continue to produce high quantities of TGFbeta-1 and VEGF during the whole experimental time.

Slow release of growth factors and thrombospondin-1 in Choukroun's platelet-rich fibrin (PRF): a gold standard to achieve for all surgical platelet concentrates technologies.

Strategies to reduce blood loss and transfusion of al- logeneic blood products during surgical procedures are impor- tant in modern times. The most important and well-known au- tologous techniques are preoperative autologous predonation, hemodilution, perioperative red cell salvage, postoperative wound blood autotransfusion, and pharmacologic modulation of the hemostatic process. At present, new developments in the preparation of preoperative autologous blood component therapy by whole blood platelet-rich plasma (PRP) and platelet- poor plasma (PPP) sequestration have evolved. This technique has been proven to reduce the number of allogeneic blood trans- fusions during open heart surgery and orthopedic operations. Moreover, platelet gel and fibrin sealant derived from PRP and PPP mixed with thrombin, respectively, can be exogenously ap- plied to tissues to promote wound healing, bone growth, and tissue sealing. However, to our disappointment, not many well- designed scientific studies are available, and many anecdotic sto- ries exist, whereas questions remain to be answered. We there- fore decided to study perioperative blood management in more detail with emphasis on the application and production of au- tologous platelet gel and the use of fibrin sealant. This review addresses a large variety of aspects relevant to platelets, platelet- rich plasma, and the application of platelet gel. In addition, an overview of recent animal and human studies is presented. Key- words: platelets, platelet-rich plasma, platelet gel, platelet growth factors, thrombin. JECT. 2006;38:174-187

Platelet-rich plasma and platelet gel: a review.

Antimicrobial activity of platelet-leukocyte gel against Staphylococcus aureus.

Background: The therapeutic use of autologously prepared, platelet-leukocyte-enriched gel (PLG) is a relatively new technology for the stimulation and acceleration of soft tissue and bone healing. The effectiveness of this procedure lies in the delivery of a wide range of platelet growth factors mimicking the physiologic wound healing and reparative tissue processes. Despite an increase in PLG applications, the structures and kinetics of this autogenously derived biologic material have not been observed. Methods: A review of the most recent literature was performed to evaluate the use of PLG in various surgical disciplines. Results: The review showed that the application of PLG has been extended to various surgical disciplines including orthopedics, cardiac surgery, plastic and maxillofacial surgery, and recently also endoscopic surgery. Conclusion: This review demonstrates the usefulness of PLG in a wide range of clinical applications for improvement of healing after surgical procedures.

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The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review.

The therapeutic use of autologously prepared platelet-leukocyte gel (PLG) is a relatively new technology which might stimulate and accelerate soft-tissue and bone healing. The effectiveness of this pr

/pdf/reviewing-the-structural-features-of-autologous-platelet-17l0tirj8p.pdf

Reviewing the structural features of autologous platelet-leukocyte gel and suggestions for use in surgery.

The use of platelet-leukocyte gel (PLG), made from platelet rich plasma, to stimulate bone formation and wound healing has been investigated extensively. As leukocytes play an important role in the innate host-defence, we hypothesised that PLG might also have antimicrobial properties. The purpose of this study was to investigate the antimicrobial activity of PLG against Staphylococcus aureus in an in vitro experiment. To determine the contribution of myeloperoxidase (MPO), present in leukocytes, in this process, MPO release was measured. Platelet rich plasma (PRP) was prepared from whole blood of 6 donors. In this process platelet poor plasma (PPP) was obtained as well. PLG was prepared by mixing PRP with either autologous (PLG-AT) or bovine thrombin (PLG-BT). The antimicrobial activity of PLG-AT, PLG-BT, PRP and PPP was determined in a bacterial kill assay, containing 1x106 CFU/ml of Staphylococcus aureus, during a 24-hour period. MPO release was measured by ELISA. Cultures showed a rapid decrease in the number of bacteria in the presence of both PLG-AT and PLG-BT, which was maximal between 4 and 8 hours, to approximately 1% of the bacteria in controls. Also PRP and PPP induced a statistically significant bacterial kill, but the effect of PLG-AT was the largest (p=0.093 vs. PLG-BT; p=0.004 vs. PRP and p PLG appears to have potent antimicrobial capacity, but the role of MPO in this activity is questionable. PLG might represent a useful strategy against postoperative infections. Further research should investigate its antimicrobial capacity in the in vivo situation.

E.P. Overdevest

Papers

Platelet-rich plasma and platelet gel: a review.

Antimicrobial activity of platelet-leukocyte gel against Staphylococcus aureus.

The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review.

Reviewing the structural features of autologous platelet-leukocyte gel and suggestions for use in surgery.

Antimicrobial activity of platelet-leukocyte gel against staphylococcus aureus