Short- and long-term effects of platelet-rich plasma upon healthy equine joints: Clinical and laboratory aspects.

This study aimed to verify whether transient inflammatory reactions incited by the administration of intra-articular platelet-rich plasma (PRP) affected joint components through short- and long-term in vivo evaluation of inflammatory biomarkers and extracellular matrix degradation products in synovial fluid. The effects of PRP were analyzed in a short phase protocol (SPP) and in a prolonged phase protocol (PPP), using saline-injected joints as controls. In the SPP, higher white blood cell counts and prostaglandin E2 and total protein concentrations were observed in the synovial fluid of PRP-treated joints (P < 0.05). There were no differences between the interleukin-1ß, interleukin-1 receptor antagonist protein, tumor necrosis factor-α, chondroitin sulfate, or hyaluronic acid concentrations between PRP and saline injected joints. In the PPP, there were no differences in evaluated parameters between groups. PRP injection elicits a mild and self-limiting inflammatory response shortly after administration, without long-term deleterious effects on joint homeostasis.

Effets à court et à long terme de le plasma riche en plaquettes sur les articulations sains chez les équines : aspects cliniques et laboratoiren. Cette étude a pour but de vérifier si les réactions inflammatoires passagères induites par l'administration intra articulaire de Plasma Enrichi en Plaquettes (PRP) affectent les composants articulaires. Les bio-marqueurs de l'inflammation et les produits de dégradation de la matrice extracellulaire ont été évalués in vivo, dans le liquide synovial, à court et long terme. Les effets du PRP ont été analysés lors d'un protocole court terme et lors d'un protocole long terme et les articulations contrôles ont été injectées avec du liquide physiologique. Le protocole court terme a révélé des comptages de globules blancs et de prostaglandine E2, ainsi que des concentrations en protéines totales plus élevés dans le liquide synovial des articulations traitées au PRP (P < 0,05). Cependant, aucune différence de concentration en interleukine-1 bêta, en protéine antagoniste des récepteurs à l'interleukine-1, en facteur de nécrose tumorale alpha, en chondroïtine sulfate et en acide hyaluronique n'a été notée entre les articulations injectées au PRP et les articulations contrôles. Le protocole long terme n'a démontré aucune différence des paramètres évalués entre les deux groupes. L'injection de PRP provoque une réponse inflammatoire légère et auto-limitante rapidement après l'administration, sans effet délétère sur l'homéostasie de l'articulation à long terme.(Traduit par les auteurs).

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions.

BACKGROUND: This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included independently of their design. Experimental studies relevant to the clarification of PRP's effects and mechanisms of action in tissues of interest, conducted in any animal species, were selected. RESULTS: This review included 123 studies. PRP's beneficial effects were observed in 46.7% of the clinical studies, while the absence of positive effects was observed in 43.3%. Among experimental studies, 73% yielded positive results, and 7.9% yielded negative results. The most frequent flaws in the clinical trials' designs were the lack of a true placebo group, poor product characterization, insufficient blinding, small sampling, short follow-up periods, and adoption of poor outcome measures. The methods employed for PRP preparation and administration and the selected outcome measures varied greatly. Poor study design was a common feature of equine clinical trials. From studies in which PRP had beneficial effects, 67.8% had an overall high risk of bias. From the studies in which PRP failed to exhibit beneficial effects, 67.8% had an overall low risk of bias. CONCLUSIONS: Most experimental studies revealed positive effects of PRP. Although the majority of equine clinical studies yielded positive results, the human clinical trials' results failed to corroborate these findings. In both species, beneficial results were more frequently observed in studies with a high risk of bias. The use of PRP in musculoskeletal lesions, although safe and promising, has still not shown strong evidence in clinical scenarios.

Autologous processed plasma: cytokine profile and effects upon injection into healthy equine joints.

This experimental controlled study was performed to evaluate the composition of autologous processed plasma (APP), and the effects of APP intra-articular injection into healthy equine metacarpophalangeal joints. The effects on joints were analysed with a short-phase protocol and a prolonged-phase protocol using saline-injected joints as controls. For the short protocol, horses received one intra-articular APP injection. Synovial fluid samples were collected prior to the injection and 3, 6, 24, 48, and 16 h after treatment. For the prolonged protocol, the joints received three weekly injections of APP, and samples were collected at 0, 7, 14, 21, and 28 days before APP administration. IL1-ra level was found to be increased in APP compared to plasma. Upon intra-articular administration of APP, transient (up to 24 h) increases in white blood cell (WBC) counts along with elevated protein and prostaglandin E2 (PGE2) concentrations were observed in the treated joints. Over the 28-day observation period, APP did not elicit changes relative to baseline levels, but WBC counts, PGE2 and chondroitin sulphate concentrations were lower than those found in the control. In conclusion, APP intra-articular injection induced a mild and transitory inflammatory response but no inflammation reaction was observed over a longer period of treatment and observation.

Do blood components affect the production of reactive oxygen species (ROS) by equine synovial cells in vitro? / Os componentes do sangue afetam a produção de (ERO) pelas células sinoviais de equinos in vitro?

Blood-derived products are commonly administered to horses and humans to treat many musculoskeletal diseases, due to their potential antioxidant and anti-inflammatory effects. Nevertheless, antioxidant effects have never been shown upon horse synovial fluid cells in vitro. If proved, this could give a new perspective to justify the clinical application of blood-derived products. The aim of the present study was to investigate the antioxidant effects of two blood-derived products - plasma (unconditioned blood product - UBP) and a commercial blood preparation (conditioned blood product - CBP)¹ - upon stimulated equine synovial fluid cells. Healthy tarsocrural joints (60) were tapped to obtain synovial fluid cells; these cells were pooled, processed, stimulated with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA), and evaluated by flow cytometry for the production of reactive oxygen species (ROS). Upon addition of any blood-derived product here used - UBP and CBP - there was a significant decrease in the oxidative burst of synovial fluid cells (P<0.05). There was no difference between UBP and CBP effects. In conclusion, treatment of stimulated equine synovial cells with either UBP or CBP efficiently restored their redox equilibrium.

Produtos derivados do sangue são comumente usados, tanto no homem como em cavalos, para tratar diversas doenças musculoesqueléticas, principalmente devido a seus efeitos antioxidantes e anti-inflamatórios. Contudo, efeitos antioxidantes nunca foram demonstrados em células de líquido sinovial in vitro. Caso esses efeitos sejam efetivamente demonstrados, uma nova perspectiva para justificar a aplicação clínica desses produtos poderia surgir. Sendo assim, o objetivo do presente estudo foi investigar os efeitos antioxidantes de dois produtos derivados de sangue - plasma (produto de sangue não condicionado - UBP) e uma preparação comercial de sangue (produto de sangue condicionado - CBP)¹ - sobre células estimuladas extraídas do líquido sinovial de equinos. Articulações tibiotársicas saudáveis (60) foram puncionadas para a obtenção de células de líquido sinovial; essas células foram concentradas, processadas, estimuladas com lipopolissacarídeos (LPS) ou forbol 12-miristato 13-acetato (PMA), e avaliadas por citometria de fluxo quanto à produção de espécies reativas de oxigênio (ROS). Após a adição de ambos os produtos derivados do sangue - UBP ou CBP - ocorreu uma significativa queda no burst oxidativo em células do líquido sinovial (P<0,05). Não houve diferença entre os efeitos de UBP e CBP. Em conclusão, tratamento de células estimuladas do líquido sinovial de equinos com UBP ou CBP restaurou eficientemente o equilíbrio redox das células.