Comparison between platelet-rich plasma (PRP) and vascular endothelial growth factor-111 (VEGF-111) as a therapeutic tool in tendon healing process

Poster (2010, March 20)

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the ... [more ▼]

Introduction In spite of the availability of various treatments for tendinopathy, this pathology often becomes chronic. For this reason, it is of interest to develop new treatments. Among them, the injection of platelet-rich plasma (PRP) seems to be a promising one. Indeed, several animal models have demonstrated that injection of blood platelets can initiate and stimulate tendon and ligament repair by releasing growth factors (GF) locally. Among all the GF released by activated platelets, the vascular endothelial growth factor-A (VEGF-A) is known to induce positive effects on vascular function and angiogenesis, and could be implicated in the healing process of tendons. Recently, a novel VEGF-A isoform was identified, the VEGF-111, a biologically active and proteolysis-resistant VEGF-A isoform, also known to present beneficial effects on ischemic diseases. This prompted us to evaluate whether VEFF-111 would have a therapeutic interest within the framework of the tendon pathology. Aim of the study: We hypothesized that the healing of ruptured Achilles tendons, which is the last stage of the Blazina’s classification, could be improved by injection of VEGF-111 that was compared to the potential effect of PRP injections using a rat model. Methods: A 5mm defect was surgically induced in rat Achilles tendon after resection of plantaris tendon. Rats were divided into 3 groups: A: control (no injection), B: PRP treatment and C: VEGF-111 treatment. Rats received a local injection of PRP (50µL) or VEGF-111 (100ng) in situ after the surgery and were placed in their cage without immobilization. After 5, 15 and 30 days, the rats were euthanized in each group. The traumatized Achilles tendon of each rat was removed and dissected during the healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Results: Our results show that developed force necessary to induce tendon rupture during biomechanical tensile test was more important for tendons which had received an injection of PRP or VEGF-111. Moreover, the tensile force necessary to break tendons is higher with PRP than with VEGF-111. These results were already noticed from day 5 onwards. Conclusion: This experimentation has shown that both PRP and VEGF-111 injections stimulated tendon healing process as suggested by the increased force needed to break tendons during its healing process. Furthermore, this acceleration of the cicatrisation process was more significant with PRP than with VEGF-111. This could be explained by the release from platelets of a “cocktail” of growth factors acting in synergy on the healing process. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

GPS™ II and GPS™ III: comparison of obtained platelets concentrations

Poster (2010, March 20)

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study ... [more ▼]

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study is to compare the obtained platelets concentration between the new GPS™ III and GPS™ II. Methods: Two blood samples of 52 mL were taken in 5 volunteers and transferred respectively in both GPS™ II and GPS™ III. These devices were centrifuged at 3200 RPM during 15 min. The platelet-rich plasma (PRP) was thus collected and transferred in 6 mL test tubes. Cells count was done using an analyser ABX Micros 60. Results and conclusion: Platelets concentrations were more important from 6.2 up to 9.2 times with GPS™ II and from 7.3 up to 8.3 times with GPS™ III compared to blood samples. Efficiency of the collected platelets was around 92% for GPS™ II and 96% for GPS™ III. Both techniques made it possible to collect platelets but, unfortunately, also a lot of red and white blood cells. None of these parameters showed any significant difference (p>0.05). Conflicts of interests: The 10 devices GPS™ II and GPS™ III were provided gracefully by the firm Biomet Biologics TTC. [less ▲]

Sport et Biologie Clinique

Conference (2010, February 11)

Evaluation biologique du stress oxydant : application en routine clinique.

in Nutritions & Endocrinologie (2009), HS Stress Oxydant

Cholestérol total, HDL, LDL et LDL oxydées : implications cardiovasculaires

Poster (2009, November 03)

Comparaison de 5 techniques de prération du PRP (Platelet-Rich Plasma ou plasma)

in Annales de Réadaptation et de Médecine Physique (2009, October), 52(Sup. 1), 109

Introduction : Depuis une vingtaine d’années, le développement des activités sportives s’accompagne d’une incidence accrue de diverses tendinopathies, souvent rebelles aux traitements conservateurs ... [more ▼]

Introduction : Depuis une vingtaine d’années, le développement des activités sportives s’accompagne d’une incidence accrue de diverses tendinopathies, souvent rebelles aux traitements conservateurs classiques (anti-inflammatoires non stéroïdiens, orthèses, kinésithérapie, infiltrations…). De nouvelles thérapeutiques, dont l’injection de concentrés plaquettaires (plasma riche en plaquettes ou PRP), sont actuellement en cours d’évaluation clinique. Objectifs : L’injection de PRP fait actuellement l’objet de recherche comme thérapeutique des tendinopathies chroniques. L’injection intra-tendineuse nécessite idéalement un volume minimal afin de diminuer la pression lors de l’injection et minimiser les douleurs, mais il doit également présenter une concentration plaquettaire élevée ; par ailleurs, la quantité de facteurs de croissance libérés pourrait être liée au système de préparation. Méthodes : Après avoir prélevés divers échantillons de sang veineux chez 5 patients, nous avons comparé 5 techniques de préparation du PRP : celle du Service d’Hématologie Biologique du CHU de Liège, le PRP Kit de Curasan®, les techniques Plateltex®, GPS®II et RegenLab®. Résultats : Les différentes techniques permettent d’obtenir des concentrations plaquettaires plus importantes que dans le sang avec des volumes variables (de 0,3 mL à 6 mL) et un nombre de globules rouges et globules blancs limité (sauf pour GPS® II). Le nombre de plaquettes/µL apparaît plus élevé avec la technique Plateltex® et obtient le plus petit volume à injecter. Les autres techniques permettent également d’obtenir de petits volumes sauf avec le GPS®II. Le nombre de plaquettes collectées dans le PRP apparaît donc plus élevé avec cette technique mais avec une concentration faible. Discussion – Conclusion : La technique décrite par Plateltex® permet de recueillir le PRP le plus concentré dans le volume le plus faible. [less ▲]

Le cas clinique du mois. Osteogenesis imperfecta

in Revue Médicale de Liège (2009)

We report the case of a young boy who had had multiple bone fractures (more than 10) since the age of 19 months. The father had the same clinical history. The clinical examination was normal for his age ... [more ▼]

We report the case of a young boy who had had multiple bone fractures (more than 10) since the age of 19 months. The father had the same clinical history. The clinical examination was normal for his age except blue sclera. The bone densitometry showed a severe osteoporosis for his age. Biological exam swere correct. The genetic exploration revealed mutation of COL1A2 gene. With this clinical history, the diagnosis of Osteogenesis imperfecta (OI) was retained. OI is a hereditary dystrophy with abnormal synthesis or metabolism of collagen with, often, mutation of COL1A1 or COL1A2 genes. There are 7 different forms. We consider the possible differential diagnoses. The goal of any treatment is to promote bone remineralisation and to decrease the fracture frequency. The treatment includes calcium and vitamin D, and in the presence of some precise criteria, biphosphonate therapy. [less ▲]

Comparison of two immunoassays for quantitative measurement of oxydized-LDL

in Immuno-Analyse & Biologie Spécialisée [=IBS] (2009), 24

Comparison of BNP and NT-proBNP performances for assessing heart failure in a population of patients with high incidence of with renal insufficiency

in Annales de Biologie Clinique (2009), 67(1),

Comment j'explore... Revue des principaux auto-anticorps

in Revue Médicale de Liège (2008), 63(1), 43-9

Auto-immune diseases represent the 3rd cause of morbidity after cardiovascular and oncologic diseases. They often occur in young subjects. Their presence is not synonymous of disease and must be ... [more ▼]

Auto-immune diseases represent the 3rd cause of morbidity after cardiovascular and oncologic diseases. They often occur in young subjects. Their presence is not synonymous of disease and must be associated to clinical signs to be pathological. However, their discovery can require a complement of investigations and the possibility of a follow-up because some auto-antibodies are predictive of disease. This paper is concerned with the main autoantibodies that can be picked out at the laboratory of immunology. Some technical explanations and INAMI rules are explained too. [less ▲]