Uso de concentrados autólogos de plaquetas como terapia regenerativa de enfermedades crónicas del aparato musculoesquelético equino

Antimicrobial Activity of Plasma Rich in Platelets (PRP) on the Ocular Microbiota of Healthy Horses from Minas Gerais: In Vitro Study

In equine ophthalmology, ulcerative keratitis is among the most common conditions and, in general, arises as a consequence of some trauma suffered. Secondarily, subsequent contamination by pathogenic or resident bacteria of the horse's ocular microbiota may have undesirable consequences. Under physiological conditions, the normal microbiota coexists with the immune status of the host, serving as a barrier, ensuring the health of the ocular surface, and inhibiting the proliferation of pathogens. However, in the imbalance of immune barriers, the normal microbiota can become pathogenic and lead to infection, acting as an opportunistic agent. The present study aims to demonstrate the antimicrobial effect of platelet-rich plasma (PRP), its time of action, and its correlation with the concentration of its same components in vitro on Staphylococcus sciuri, a bacterium with high prevalence in the normal ocular microbiota of horses in the municipality of Minas Gerais. For the preparation of the PRP, eight adult Quarter Horse (QH) horses were used. The individual PRP was prepared by the double centrifugation protocol, and then, the PRPs were added to a pool, followed by testing their interaction in culture with Brain Heart Infusion (BHI) broth at different dilutions against five strains collected from different animals. After 3, 6, 12, and 18 hours, the colony formation units (CFU) count on a 5% horse blood agar plate was evaluated for each time point. Our study showed that Staphylococcus sciuri, the resident microorganism of the ocular conjunctival microbiota of horses, is more susceptible when compared to the standard strain "American Type Culture Collection" (ATCC-29213) Staphylococcus aureus, a pathogenic microorganism, which was used for the validation of our study. The antibacterial effect shown in this study was bacteriostatic for up to 6 hours. The most concentrated PRP dilutions, 1 : 1 and 1 : 2, were also most effective, suggesting that the antibacterial effect is volume dependent.

Simple Tube Centrifugation Method for Platelet-Rich Plasma (PRP) Preparation in Catalonian Donkeys as a Treatment of Endometritis-Endometrosis

Simple Summary

Platelet-rich plasma (PRP) is used to improve the regenerative capacity of damaged tissues in different species. In equine medicine, PRP is commonly used to treat joint diseases, tendinitis, ligamentous lesions, and persistent endometritis. Jenny endometrium shows a high sensitivity to endometritis. There are important differences between donkey and horse blood characteristics. Several protocols to obtain horse PRP have been reported, but no protocols have yet been reported for obtaining donkey PRP. Our study shows that single-spin tube centrifugation at 133× g for 10 min is appropriate to obtain donkey PRP with therapeutic potential in jenny endometritis-endometriosis.

Abstract

The aim of this study was to standardize a simple, manual platelet-rich plasma (PRP) protocol in Catalonian donkeys using single-spin tube centrifugation as a treatment for jenny endometritis. The objective was to obtain a blood product with a moderate concentration of platelets (2 or 3 times baseline physiologic values) and a low WBC (White Blood Cells) concentration. Blood was drawn from six Catalonian donkeys using acid citrate dextrose (ACD) as an anticoagulant, and then processed by single centrifugation at 133× g for two different centrifugation times (10 and 15 min). The PRP samples were evaluated by flow cytometry, and TGF-β1 (Transforming Growth Factor-Beta1) concentrations were determined by enzyme-linked immunosorbent assay (ELISA). The 10 min centrifugation protocol resulted in a slightly greater release of TGF-β1 (6044.79 ng/mL), a 2.06-fold increase in platelet concentration, and a 15-fold reduction in leukocyte concentration when compared to the initial values. The 15 min centrifugation time resulted in a 2.44-fold increase in baseline platelet concentration, a reduction in WBC count by a factor of 20, and slightly lower TGF levels (5206 ng/mL). We conclude that both protocols are adequate for the obtention of PRP, and both may have an acceptable therapeutic potential for use in this species, although this needs to be further validated.

Endothelial cells and angiogenesis in the horse in health and disease-A review

The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progenitor cells; equine endothelial cells and angiogenesis (heterogeneity, markers and assessment); endothelial regulatory molecules in equine angiogenesis; angiogenesis research in equine reproduction (ovary, uterus, placenta and conceptus, testis); angiogenesis research in pathological conditions (tumours, ocular pathologies, equine wound healing, musculoskeletal system and laminitis). The review also includes a table that summarizes in vitro studies on equine endothelial cells, either describing the isolation procedure or using previously isolated endothelial cells. A particular challenge of the review was that results published are fragmentary and sometimes even contradictory, raising more questions than they answer. In conclusion, angiogenesis is a major factor in several diseases frequently occurring in horses, but relatively few studies focus on angiogenesis in the horse. The challenge for the future is therefore to continue exploring new therapeutic angiogenesis strategies for horses to fill in the missing pieces of the puzzle.

Effects of sodium citrate and acid citrate dextrose solutions on cell counts and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel

Background

There is a lack information on the effects of the most commonly used anticoagulants for equine platelet rich plasmas (PRPs) elaboration on cell counts and growth factor release from platelet rich gels (PRGs). The aims of this study were 1) to compare the effects of the anticoagulants sodium citrate (SC), acid citrate dextrose solution A (ACD-A) and ACD-B on platelet (PLT), leukocyte (WBC) and on some parameters associated to platelet activation including mean platelet volume (MPV) and platelet distribution width (PDW) between whole blood, pure PRP (P-PRP) and platelet-poor plasma (PPP); 2) to compare transforming growth factor beta 1 (TGF-β₁) and platelet-derived growth factor isoform BB (PDGF-BB) concentrations in supernatants from pure PRG (P-PRG), platelet-poor gel (PPG), P-PRP lysate (positive control) and plasma (negative control); 3) to establish the possible correlations between all the studied cellular and molecular parameters.

Results

In all cases the three anticoagulants produced P-PRPs with significantly higher PLT counts compared with whole blood and PPP. The concentrations of WBCs were similar between P-PRP and whole blood, but significantly lower in PPP. The type of anticoagulant did not significantly affect the cell counts for each blood component. The anticoagulants also did not affect the MPV and PDW parameters. Independently of the anticoagulant used, all blood components presented significantly different concentrations of PDGF-BB and TGF-β₁. The highest growth factor (GF) concentrations were observed from P-PRP lysates, followed by PRG supernatants, PPP lysates, PPG supernatants and plasma. Significant correlations were observed between PLT and WBC counts (ρ = 0.80), PLT count and TGF-β₁ concentration (ρ = 0.85), PLT count and PDGF-BB concentration (ρ = 0.80) and PDGF-BB and TGF-β₁ concentrations (ρ = 0.75). The type of anticoagulant was not correlated with any of the variables evaluated.

Conclusions

The anticoagulants did not significantly influence cell counts or GF concentrations in equine PRP. However, ACD-B was apparently the worst anticoagulant evaluated. It is necessary to perform additional research to determine the effect of anticoagulants on the kinetics of GF elution from P-PRG.

Plasma rico em plaquetas no tratamento de lesões condrais articulares induzidas experimentalmente em equinos: avaliação clínica, macroscópica, histológica e histoquímica

Estudou-se a eficácia do plasma rico em plaquetas (PRP) no tratamento de lesões condrais articulares, experimentalmente induzidas em equinos. Para isso, foi induzida uma lesão condral, na tróclea medial femoral dos dois membros pélvicos de quatro animais. Após 30 dias da indução, as oito articulações foram divididas em dois grupos. Os animais do grupo 1 receberam o tratamento intralesional e intra-articular com PRP, e os do grupo 2 foram tratados apenas com solução fisiológica. As avaliações clínicas, constituídas de exames de claudicação e análises do líquido sinovial, foram realizadas antes da indução da lesão - tempo zero -, quinzenalmente, até 120 dias e aos 150 dias. Avaliações macroscópicas, histológicas e histoquímicas foram realizadas no tempo zero e aos 150 dias. Os equinos do grupo 1 apresentaram melhora do grau de claudicação em relação aos do grupo 2. Os exames macroscópicos, histológicos e histoquímicos revelaram melhor tecido de reparação igualmente no grupo 1. Concluiu-se que a administração de PRP apresentou efeitos benéficos no tratamento de lesões condrais experimentais de equinos.