Evaluation of polysulfated glycosaminoglycan or sodium hyaluronan administered intra-articularly for treatment of horses with experimentally induced osteoarthritis

Study of the Early Effects of Chitosan Nanoparticles with Glutathione in Rats with Osteoarthrosis

Due to cartilage's limited capacity for regeneration, numerous studies have been conducted to find new drugs that modify osteoarthrosis's progression. Some evidence showed the capability of chitosan nanoparticles with glutathione (Np-GSH) to regulate the oxide-redox status in vitro in human chondrocytes. This work aimed to evaluate the capacity of Np-GSH in vivo, using Wistar rats with induced surgical osteoarthritis. Radiographic, biochemical (GSH and TBARS quantification), histopathological, and immunohistochemical (Col-2 and MMP-13) analyses were performed to evaluate the progress of the osteoarthritic lesions after the administration of a single dose of Np-GSH. According to the results obtained, the GSH contained in the NPs could be vectored to chondrocytes and used by the cell to modulate the oxidative state reduction, decreasing the production of ROS and free radicals induced by agents oxidizing xenobiotics, increasing GSH levels, as well as the activity of GPx, and decreasing lipid peroxidation. These results are significant since the synthesis of GSH develops exclusively in the cell cytoplasm, and its quantity under an oxidation-reduction imbalance may be defective. Therefore, the results allow us to consider these nanostructures as a helpful study tool to reduce the damage associated with oxidative stress in various diseases such as osteoarthritis.

A Double-Blinded Positive Control Study Comparing the Relative Efficacy of 2.5% Polyacrylamide Hydrogel (PAAG) Against Triamcinolone Acetonide (TA) And Sodium Hyaluronate (HA) in the Management of Middle Carpal Joint Lameness in Racing Thoroughbreds

The purpose of this prospective double-blinded positive control study was to compare the efficacy of 2.5% polyacrylamide hydrogel (2.5% PAAG) in the management of middle carpal joint lameness in Thoroughbreds against treatments of triamcinolone acetonide (TA) or sodium hyaluronate (HA). A total of 31 flat-racing Thoroughbreds with lameness (grade 1-3/5) localized to the carpus by intra-articular analgesia were selected. Following a radiological assessment of the carpi confirming the absence of fragment/fracture, the horses were randomly assigned for intra-articular treatment with either 2 ml of 2.5% PAAG, 12 mg TA or 20 mg HA (followed by two further intravenous treatments of 40 mg, at weekly intervals in the HA group only), by a treating veterinarian. All horses were rested for 48 hours post-treatment and then re-entered an unaltered training regimen. Subsequent examinations at 2, 4, and 6 weeks were performed by a blinded examining veterinarian for all groups, while horses treated with 2.5% PAAG were monitored for 12 weeks for recurrence of lameness. Significantly more joints treated with 2.5% PAAG were lame free (83%) at 6 weeks compared to TA (27%; P = .007) and to HA (40%; P = .04). There was no significant difference between TA and HA groups at any time. All the joints treated within 2.5% PAAG that were lame free at 6 weeks (10/12) were still lame-free at 12 weeks. In conclusion, treatment with 2.5% PAAG led to statistically superior results compared to TA and HA in the management of selected middle carpal joint lameness in flat-racing Thoroughbreds, with therapeutic effects persisting up to 12 weeks.

Effect of intravenous tiludronate disodium administration on the radiographic progression of osteoarthritis of the fetlock joint in Standardbred racehorses

OBJECTIVE

To compare the effects of tiludronate disodium and 3 other medical treatments on clinical and radiographic findings and biomarkers of disease progression in horses with osteoarthritis of the fetlock joint.

ANIMALS

100 Standardbred racehorses with spontaneous traumatic injury of the fetlock joint.

PROCEDURES

Horses were retrospectively grouped by whether they received tiludronate IV or triamcinolone acetonide and hyaluronan, polysulfated glycosaminoglycan, or interleukin-1 receptor antagonist protein intra-articularly. Data were collected on clinical, radiographic, and ultrasonographic findings and results for serum and synovial samples obtained before and 6 months after treatment. Lameness score, joint flexion test response, radiographic score, serum concentrations of tumor necrosis factor-α and carboxy-terminal telopeptides of collagen types I and II (CTX-I and II, respectively), and synovial fluid concentrations of interleukin-1β, prostaglandin E₂, and CTX-II were compared among treatments.

RESULTS

All treatments resulted in a significant improvement in lameness score and joint flexion test response at 6 months. In horses that received triamcinolone acetonide and hyaluronan, synovial fluid interleukin-1β, prostaglandin E₂, and CTX-II concentrations decreased after treatment, suggesting this treatment inhibited progression of hyaline cartilage degeneration and inflammatory processes. Horses that received tiludronate were the only group that had a decrease in radiographic score and serum CTX-I concentration after treatment, supporting the effect of tiludronate on bone metabolism. Tiludronate treatment was also followed by increases in serum and synovial fluid concentrations of CTX-II, a marker of cartilage damage.

CONCLUSIONS AND CLINICAL RELEVANCE

Tiludronate appeared to inhibit the radiographic progression of osteoarthritis in high-motion joints of racehorses at 6 months after treatment by inhibiting subchondral bone remodeling. Whether this effect was associated with a worsening of progressive cartilage damage remains to be ascertained.

Antimicrobial prescribing patterns in equine ambulatory practice

Antimicrobial resistance is one of the most important public health risks facing our world today. Antimicrobials are commonly prescribed in equine veterinary medicine, but limited information exists documenting their use in practice. The goal of this study was to investigate antimicrobial prescription patterns in regards to prescription frequency, duration, drug class, clinician and affected body system in an equine ambulatory setting via retrospective analysis of billing and electronic medical records. Risk factors associated with antimicrobial prescription including the nature of the visit, submission of a culture, body system affected and clinician were assessed using multivariable regression. We found that antimicrobials were prescribed in 8.5 % of visits with a median number of 3.5 (IQR 0.8-12.2) animal-defined daily doses (ADD), defined as the number of daily doses of all antimicrobials prescribed to a patient at a single visit. Aminoglycosides were the most common class of antimicrobials prescribed and trimethoprim sulfamethoxazole was the most common drug prescribed overall. Amikacin was primarily used for patients presenting with musculoskeletal signs, and the median number of ADDs for visits where amikacin was prescribed was 1 (IQR 0.9-1.9), while the median number of antimicrobial ADDs for all other visits was 4.4 (IQR 0-14.1). Statistically significant differences in antimicrobial use patterns existed across clinicians, months, years and affected body systems. Horses presenting with ocular (OR 1199; 95 % CI 204-7,037; p < 0.001) and integumentary (OR 365; 95 % CI 87.2-1532; p < 0.001) signs were most likely to be prescribed an antimicrobial. Emergency visits (OR 5.61; 95 % CI 3.19-9.89; p < 0.001) and submission of a bacterial culture (OR 3.58; 95 % CI 2.11-6.09; p < 0.001) were associated with an increased likelihood of an antimicrobial prescription. This observational study was the first to quantitatively characterize antimicrobial use patterns in equine ambulatory practice in the United States, which is an important step needed to determine appropriateness of use and develop and evaluate antimicrobial stewardship guidelines.

Effect of parasitic infestation on carpal synovial constituents in donkeys (Equus asinus)

The present study was carried out to examine the physical, microscopical and biochemical parameters of the synovial fluid from the carpal joints of donkeys suffering from Strongylus spp. and Parascaris equorum infestation. Forty-five donkeys were selected out from a total of sixty animals based on faecal analysis. Animals were divided into 3 groups, which included Strongylus spp. (n=23), mixed infestation (n=17, Strongylus spp. and Parascaris equorum) and control (n=5) groups. The aspirated synovial fluid from all animals (n=45) was examined physically and microscopically. Then, the total protein, albumin, globulins, calcium, phosphorus, magnesium, glucose levels, and gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) activities were measured in the serum and synovial fluid of all animals. The results revealed no changes of the physical and microscopical features of the synovial fluid of the infested and control animals but there were significant decreases in total protein, albumin, globulin, glucose and magnesium levels in the serum of Strongylus and mixed infection groups. The synovial fluid analysis exhibited an increase of calcium and phosphorus levels, and ALP activity, and decreased levels of total protein, glucose and GGT in Strongylus and mixed groups. The results of this study suggested significant changes in some biochemical parameters in both serum and synovial fluids in donkeys suffering from parasitic infestation.

An assessment of the effectiveness of hyaluronic acid and polyacrylamide hydrogel in horses with osteoarthritis: Systematic review and network meta-analysis

For several years, hyaluronic acid (HyA) and, more recently, polyacrylamide hydrogel (PHyd) have been used to reduce lameness and pain caused by osteoarthritis. However, there is still a lack of scientific evidence of the efficacy of these substances to allow veterinary experts to make decisions about their use in horses. The objective of this study was to evaluate, through a systematic review and network meta-analysis (NMA), the efficacy of HyA, associated or not with other drugs, and PHyd in relieving lameness in horses with osteoarthritis. The searches for primary studies were conducted on four search platforms. The efficacy of HyA and PHyd was estimated through the relative risk difference method. Heterogeneity was observed in the efficacy of HyA, indicating long-term ineffectiveness of this drug when associated or not with anti-inflammatory drugs. In contrast, the results indicate that PHyd is an effective alternative therapy, with a long period of action in reducing lameness in horses with osteoarthritis. This study provides evidence that the application of PHyd and HyA is effective in reducing lameness caused by osteoarthritis in horses at different time periods, where PHyd has a longer time of action.

Evaluation of the inflammatory response to two intra-articular hyaluronic acid formulations in normal equine joints

Intra-articular (IA) hyaluronic acid (HA) is commonly used to treat equine arthritis. Inflammatory response or "joint flare" is a recognized potential side effect. However, the incidence and severity of inflammation following IA HA injection in horses is not well documented. This study compared the effects of two IA HA formulations of different molecular weight (MW) and a saline control on clinical signs and synovial fluid markers of inflammation in normal equine joints. Eight adult horses each had three healthy fetlock joints randomly assigned to treatment with either 1.4 mega Dalton HA, 0.8 mega Dalton HA or saline control once weekly for three weeks. Clinical evaluation and synovial fluid analysis were performed by blinded assessors. Outcomes of interest were lameness score, joint effusion score and synovial fluid white cell count and differential, total protein, viscosity and serum amyloid A. Joints injected with HA developed significant mild-to-moderate inflammatory responses often associated with lameness and joint effusion compared with saline control joints. The higher MW HA formulation elicited a significantly greater inflammatory response than the lower MW HA after the first injection. In HA injected joints, viscosity remained poor for the entire study. Both IA HA formulations in this study induced an inflammatory response in healthy equine joints. This may have implications for the use of HA in equine joints. The findings in this study are limited to the two HA formulations used. Further investigation of different HA formulations and the use of HA in normal and arthritic equine joints is warranted.

Osteochondral fragments of the pastern joint at the origin of the collateral ligament of the distal sesamoid bone: performance after arthroscopic removal (2000-2015)

OBJECTIVE

To describe the presence of fragments in the dorsal proximal interphalangeal (PIP) joint and to report flat racing performance after surgical treatment.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Thirty-nine affected thoroughbred flat racehorses and 169 age- and sex-matched maternal siblings.

METHODS

Medical records from 2000 to 2015 were reviewed for thoroughbred horses that underwent arthroscopic removal of osteochondral fragments in the dorsal aspect of the PIP joint. The horses' 2-year-old year, 3-year-old year, and career athletic performances were compared with their matched siblings.

RESULTS

Thirty-nine thoroughbred horses were included, varying in age from 4 months to 4 years, with osteochondral fragments in 42 PIP joints. Hind limbs (92%) were more commonly affected than forelimbs (8%). Fragments were located within the origin of the collateral ligament of the distal sesamoid (navicular) bone. After surgery, the likelihood of starting a race did not differ between treated horses (27/39 [69%]) and maternal siblings (129/169 [76%], P = .15). Race earnings did not differ between treated horses and their siblings during their 2-year-old year (P = .66), 3-year-old year (P = .43), or career (P = .60).

CONCLUSION

Removing osteochondral fragments from the origin of the collateral ligament of the distal sesamoid bone did not impair the ability to race or earning potential for affected thoroughbred racehorses compared with their maternal siblings.

CLINICAL SIGNIFICANCE

Fragments from the dorsal aspect of the PIP joint in racehorses can be removed arthroscopically resulting in a good clinical outcome and future flat racing performance comparable to matched controls.

Long-term outcome after stifle arthroscopy in 82 Western performance horses (2003-2010)

OBJECTIVE

To report the outcome of horses engaged in Western performance disciplines after stifle arthroscopy and identify prognostic factors for return to performance.

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Eighty-two Western performance horses undergoing stifle arthroscopy.

METHODS

Medical records were reviewed for horses involved in athletic performance/training for various Western performance disciplines and undergoing arthroscopy for lameness localized to the stifle. Follow-up was obtained ≥2 years postoperatively by telephone interviews with the owners. Preoperative and intraoperative findings as well as postoperative treatment were analyzed for their association with return to athletic performance as the primary outcome of interest.

RESULTS

The most common disciplines represented were cutting (n = 38), Western pleasure (n = 13), and reining (n = 13). Approximately 40% (32/82) of horses returned to intended use after surgery. Increased age, higher degree of lameness, longer duration of lameness, and the presence of partial-thickness cartilage lesions decreased the odds of returning to athletic performance. Postoperative therapies (intra-articular: stem cells, corticosteroids, interleukin-1 receptor antagonist protein, hyaluronic acid/polysulfated glycosaminoglycans; systemic: nonsteroid anti-inflammatory drugs, hyaluronic acid/polysulfated glycosaminoglycans, oral joint supplements) did not affect the odds of returning to intended use.

CONCLUSION

Less than half of the Western performance horses that underwent stifle arthroscopy returned to intended use. Older age, longer duration of lameness, and presence of partial-thickness cartilage lesions affected the odds of a horse returning to intended use. Postoperative therapies did not affect the outcome in this population.

CLINICAL SIGNIFICANCE

The prognosis of Western performance horses undergoing stifle arthroscopy is as guarded as that previously reported in horses of other disciplines.

Evaluation of the effect of experimentally induced cartilage defect and intra-articular hyaluronan on synovial fluid biomarkers in intercarpal joints of horses

BACKGROUND

Inflammatory and degenerative activity inside the joint can be studied in vivo by analysis of synovial fluid biomarkers. In addition to pro-inflammatory mediators, several anabolic and anti-inflammatory substances are produced during the disease process. They counteract the catabolic effects of the pro-inflammatory cytokines and thus diminish the cartilage damage. The response of synovial fluid biomarkers after intra-articular hyaluronan injection, alone or in combination with other substances, has been examined only in a few equine studies. The effects of hyaluronan on some pro-inflammatory mediators, such as prostaglandin E2, have been documented but especially the effects on synovial fluid anti-inflammatory mediators are less studied. In animal models hyaluronan has been demonstrated to reduce pain via protecting nociceptive nerve endings and by blocking pain receptor channels. However, the results obtained for pain-relief of human osteoarthritis are contradictory. The aim of the study was to measure the synovial fluid IL-1ra, PDGF-BB, TGF-β1 and TNF-α concentrations before and after surgically induced cartilage defect, and following intra-articular hyaluronan injection in horses. Eight Standardbred horses underwent bilateral arthroscopic surgeries of their intercarpal joints under general anaesthesia, and cartilage defect was created on the dorsal edge of the third carpal bone of one randomly selected intercarpal joint of each horse. Five days post-surgery, one randomly selected intercarpal joint was injected intra-articular with 3 mL HA (20 mg/mL).

RESULTS

Operation type had no significant effect on the synovial fluid IL-1ra, PDGF-BB, TGF-β1 and TNF-α concentrations but compared with baseline, synovial fluid IL-1ra and TNF-α concentrations increased. Intra-articular hyaluronan had no significant effect on the biomarker concentrations but a trend of mild improvement in the clinical signs of intra-articular inflammation was seen.

CONCLUSIONS

Creation of the cartilage defect and sham-operation lead to an increase of synovial fluid IL-1ra and TNF-α concentrations but changes in concentrations of anabolic growth factors TGF-β1 and PDGF-BB could not be documented 5 days after the arthroscopy. Intra-articular hyaluronan was well tolerated. Further research is needed to document possible treatment effects of intra-articular hyaluronan on the synovial fluid biomarkers of inflammation and cartilage metabolism.

Changes in biomarkers in equine synovial fluid two weeks after intra-articular hyaluronan treatment: a randomised double-blind clinical trial

BACKGROUND

Inflammatory and degenerative activity inside the joint can be studied in vivo via analysis of synovial fluid (SF) biomarkers, which are molecular markers of inflammatory processes and tissue turnover. The aim of this study was to investigate the response of selected biomarkers in the SF after an intra-articular (IA) high-molecular-weight non-animal stabilized hyaluronic acid (NASHA) treatment. Our hypothesis was that prostaglandin E₂ (PGE₂), substance P, aggrecan chondroitin sulfate 846 epitope (CS846), and carboxypeptide of type II collagen (CPII) concentrations in SF would decrease more in the NASHA than in the placebo group. Twenty-eight clinically lame horses with positive responses to diagnostic IA anaesthesia of the metacarpophalangeal or metatarsophalangeal joints were randomized into treatment (n = 15) and control (n = 13) groups. After collection of baseline SF samples followed by IA diagnostic anaesthesia, horses in the treatment group received 3 ml of a NASHA product IA. Those in the placebo group received an equivalent volume of sterile 0.9% saline solution. The horses were re-evaluated and a second SF sample was obtained after a 2-week period.

RESULTS

CS846 concentration decreased in the NASHA group only (P = 0.010). Both PGE₂ and CPII concentrations decreased within the groups (PGE₂, P = 0.010 for the NASHA group; P = 0.027 for the placebo group; CPII, P < 0.001 for NASHA group; P = 0.009 for placebo group). No significant treatment effect for any biomarker was found between groups. NASHA induced an increase in white blood cell count; this was significant compared with baseline (P = 0.021) and the placebo group (P = 0.045).

CONCLUSIONS

Although the SF concentration of the cartilage-derived biomarker CS846 decreased in the NASHA group, no statistically significant treatment effect of any of the biomarkers were observed between treatment groups. The significant increase in SF white blood cell count after IA NASHA may indicate a mild inflammatory response. However, as no clinical adverse effects were observed, we conclude that IA NASHA was well tolerated.

Effects of hyaluronan alone or in combination with chondroitin sulfate and N-acetyl-d-glucosamine on lipopolysaccharide challenge-exposed equine fibroblast-like synovial cells

OBJECTIVE To investigate effects of hyaluronic acid (HA) or HA combined with chondroitin sulfate (CS) and N-acetyl-d-glucosamine (NAG) by use of a lipopolysaccharide (LPS) in vitro method. SAMPLE Monolayer cultures of synovial cells from 4 adult horses. PROCEDURES Synovial cell cultures were untreated or treated with HA alone or HA-CS-NAG for 24 hours, subsequently unchallenged or challenge-exposed with 2 LPS concentrations (20 and 50 ng/mL) for 2 hours, and retreated with HA or HA-CS-NAG for another 24 hours. Cellular morphology of cultures was evaluated at 0, 24 (before LPS), 26 (after LPS), and 50 (24 hours after end of LPS) hours. At 50 hours, cell number and viability and prostaglandin (PG) E₂, interleukin (IL)-6, matrix metalloproteinase (MMP)-3, and cyclooxygenase (COX)-2 production were measured. RESULTS LPS challenge exposure induced a significant loss of characteristic synovial cell morphology, decrease in cell viability, and increases in concentrations of PGE₂, IL-6, MMP-3, and COX-2. Cells treated with HA or HA-CS-NAG had significantly better viability and morphology scores and lower concentrations of PGE₂, MMP-3, IL-6, and COX-2 than untreated LPS challenge-exposed cells. Cells treated with HA had significantly better morphology scores at 50 hours than cells treated with HA-CS-NAG. Cells treated with HA-CS-NAG had significantly superior suppression of LPS-induced production of PGE₂, IL-6, and MMP-3 than cells treated with HA alone. CONCLUSIONS AND CLINICAL RELEVANCE HA and HA-CS-NAG protected synovial cells from the effects of LPS. Treatment with HA-CS-NAG had the greatest anti-inflammatory effect. These results supported the protective potential of HA and HA-CS-NAG treatments.

Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint

OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse. Beginning on day 15, horses were assigned to exercise in a UWT or in the UWT without water (simulating controlled hand walking) at the same speed, frequency, and duration. Thoracic and pelvic limb ground reaction forces, thoracic limb kinematics, and electromyographic results for select thoracic limb muscles acting on the carpi were collected on days -7 (baseline), 14, 42, and 70. Weekly evaluations included clinical assessments of lameness, response to carpal joint flexion, and goniometric measurements of thoracic limb articulations. At study conclusion, articular cartilage and synovial membrane from the middle carpal joints was histologically examined. RESULTS Exercise in a UWT significantly reduced synovial membrane inflammation and resulted in significant clinical improvements with regard to symmetric thoracic limb loading, uniform activation patterns of select thoracic limb muscles, and return to baseline values for carpal joint flexion, compared with results for horses with simulated hand walking. CONCLUSIONS AND CLINICAL RELEVANCE Overall improvements in thoracic limb function, joint range of motion, and synovial membrane integrity indicated that exercise in a UWT was a potentially viable therapeutic option for the management of carpal joint osteoarthritis in horses.

A randomised, double-blinded, placebo-controlled clinical study on intra-articular hyaluronan treatment in equine lameness originating from the metacarpophalangeal joint

Background

Intra-articular inflammation resulting in lameness is a common health problem in horses. Exogenous intra-articular hyaluronic acid has been shown to provide an analgesic effect and reduce pain in equine and human osteoarthritis. High molecular weight non-animal stabilized hyaluronic acid (NASHA) has gained popularity in the treatment of human arthritic conditions due to its long-acting pain-relieving effects. The aim of this study was to compare the response to treatment of lameness localized in the equine metacarpophalangeal joint injected with non-animal stabilized hyaluronic acid (NASHA) and placebo (saline). Twenty-seven clinically lame horses with a positive response to diagnostic intra-articular anaesthesia of the metacarpophalangeal joint and with no, or at most mild, radiographic changes in this joint were included in the study. Horses in the treatment group (n = 14) received 3 mL of a NASHA product intra-articularly, and those in the placebo group (n = 13) received an equivalent volume of sterile 0.9 % saline solution.

Results

The change in the lameness score did not significantly differ between NASHA and placebo groups (P = 0.94). Scores in the flexion test improved more in the NASHA group compared with placebo (P = 0.01). The changes in effusion and pain in flexion were similar (P = 0.94 and P = 0.27, respectively) when NASHA and placebo groups were compared. A telephone interview follow-up of the owners three months post-treatment revealed that 14 of the 21 horses (67 %) were able to perform at their previous level of exercise.

Conclusions

In the present study, a single IA NASHA injection was not better than a single saline injection for reducing lameness in horses with synovitis or mild osteoarthritis. However, the results of this study indicate that IA NASHA may have some beneficial effects in modifying mild clinical signs but more research is needed to evaluate whether the positive effect documented ie. reduced response in the flexion test is a true treatment effect.

Unravelling osteoarthritis-related synovial fibrosis: a step closer to solving joint stiffness

Synovial fibrosis is often found in OA, contributing heavily to joint pain and joint stiffness, the main symptoms of OA. At this moment the underlying mechanism of OA-related synovial fibrosis is not known and there is no cure available. In this review we discuss factors that have been reported to be involved in synovial fibrosis. The aim of the study was to gain insight into how these factors contribute to the fibrotic process and to determine the best targets for therapy in synovial fibrosis. In this regard, the following factors are discussed: TGF-β, connective tissue growth factor, procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2, tissue inhibitor of metalloproteinase 1, A disintegrin and metalloproteinase domain 12, urotensin-II, prostaglandin F2α and hyaluronan.

scAAVIL-1ra dosing trial in a large animal model and validation of long-term expression with repeat administration for osteoarthritis therapy

A gene therapeutic approach to treat osteoarthritis (OA) appears to be on the horizon for millions of people who suffer from this disease. Previously we described optimization of a scAAVIL-1ra gene therapeutic vector and initially tested this in an equine model verifying long-term intrasynovial IL-1ra protein at therapeutic levels. Using this vector, we carried out a dosing trial in six horses to verify protein levels and establish a dose that would express relevant levels of therapeutic protein for extended periods of time (8 months). A novel arthroscopic procedure used to detect green fluorescence protein (GFP) fluorescence intrasynovially confirmed successful transduction of the scAAVGFP vector in both the synovial and cartilage tissues. No evidence of intra-articular toxicity was detected. Immune responses to vector revealed development of neutralizing antibodies (Nabs) within 2 weeks of administration, which persisted for the duration of the study but did not lower protein expression intra-articularly. Re-dosing with a different serotype to attain therapeutic levels of protein confirmed establishment of successful transduction. This is the first study in an equine model to establish a dosing/redosing protocol, as well as examine the Nab response to capsid and supports further clinical investigation to determine the clinical efficacy of scAAVIL-1ra to treat OA.

An international multi-centre prospective study on the efficacy of an intraarticular polyacrylamide hydrogel in horses with osteoarthritis: a 24 months follow-up

BACKGROUND

Polyacrylamide hydrogel (PAAG) was evaluated recently to treat osteoarthritis (OA) in horses with highly encouraging results; however no long term field-study was done to explore its clinical efficacy and lasting effect. The objective of this study was to evaluate the efficacy of PAAG in improving clinical signs of OA in horses. We hypothesized that lameness grade would significantly improve and the effect would last at least 2 years in osteoarthritic joints treated with PAAG. Forty three horses older than 2 years with OA in only one joint based on clinical evaluation, intra-articular anaesthesia and imaging (radiography) were included in this study. Horses were injected with 2 ml of PAAG into the affected joint and were followed up at 1, 3, 6, 12 and 24 months. Efficacy of PAAG was evaluated by blinded clinical assessment of lameness. Adverse reactions to joint injection were assessed. Data relating to case details, type of activity, joint and limb involved, lameness duration, lameness grading, previous joint treatment, joint effusion grading, radiographic grading, and owner assessment were recorded. Factors associated with the outcome measure "lameness grading" were analyzed using generalized linear mixed model for logistic regression.

RESULTS

At 1, 3, 6, 12 and 24 months follow-up, 59%, 69%, 79%, 81/% and 82.5% of horses were non-lame respectively. Reduction of joint effusion was observed over time. No side effect was observed in the treated joints. There was a significant decrease in lameness grade from baseline to 1, 3, 6, 12 and 24 months (P < 0.0001) and a significant positive association with joint effusion (P < 0.0001). Estimates for odds ratio (OR) showed that the effect of treatment increased over time (OR for lower lameness from month 1 to month 24 relative to baseline increased from 20 to 58).

CONCLUSIONS

PAAG significantly alleviated lameness and joint effusion in osteoarthritic joints. PAAG is a safe and lasting (at least 24 months) OA treatment in horses. PAAG is a promising new treatment for OA in horses.

Treatment of experimentally induced osteoarthritis in horses using an intravenous combination of sodium pentosan polysulfate, N-acetyl glucosamine, and sodium hyaluronan

OBJECTIVE

To assess the effects of sodium pentosan polysulfate (PPS), N-acetyl glucosamine (NAG), and sodium hyaluronan (HA) in horses with induced osteoarthritis (OA).

STUDY DESIGN

Experimental.

ANIMALS

Adult Standard bred horses (n = 16).

METHODS

OA was induced arthroscopically in 1 intercarpal joint; 8 horses were administered 3 mg/kg PPS, 4.8 mg/kg NAG, and 0.12 mg/kg HA (PGH), intravenously (IV), weekly and 8 horses were administered an equivalent volume of saline IV until study completion (day 70). Horses underwent a standardized treadmill exercise program. Clinical and radiographic findings and synovial fluid analysis were evaluated throughout the study. Macroscopic, histologic, histochemical, and biochemical findings were evaluated after necropsy. Comparisons of interest included OA and non-OA joints of saline treated horses and OA joints of PGH treated horses and OA joints of saline treated horses. Results were statistically analyzed with significance set at P < .05.

RESULTS

OA caused increases in clinical assessment scores, synovial fluid variables, radiographic, macroscopic, and histologic cartilage scores, synovial fluid and cartilage chondroitin sulfate 846-epitope and glycosaminoglycan concentration. Total radiographic scores, total macroscopic joint pathology and macroscopic cartilage pathology scores were significantly reduced in horses treated with PGH compared with saline treated horses. Synovial fluid total protein concentration and white blood cell count were higher in OA joints of PGH treated horses compared with saline treated horses. There were no other significant differences between treatment groups.

CONCLUSIONS

Improvements in macroscopic variables were not supported by other outcomes. Further evidence is needed before PGH can be recommended as a therapeutic option for osteoarthritis in horses.

Evaluation of a single intra-articular injection of autologous protein solution for treatment of osteoarthritis in horses

OBJECTIVE

To evaluate intra-articular autologous protein solution (APS) for the treatment of osteoarthritis in horses. Animals-40 client-owned horses with naturally occuring osteoarthritis.

PROCEDURES

APS was generated from a dual-device system that concentrated plasma and WBC proteins and enriched platelet growth factors. Horses were randomly assigned to receive an intra-articular injection of 5 mL of saline (0.9% NaCl) solution (n = 20) or APS (20), exercised on a treadmill, and evaluated on the basis of lameness grades, kinetic gait analysis, joint circumference, and range of motion for 14 days. Horses that received saline solution were administered APS at termination of the study, and clients scored horses for lameness and discomfort before, 12 weeks after, and 52 weeks after the APS injection.

RESULTS

The APS group had significant improvements in lameness grade, asymmetry indices of vertical peak force, and range of joint motion by 14 days, compared with baseline or control group values. No adverse effects associated with APS treatment were evident. Clients assessed lameness and comfort as improved at 12 and 52 weeks. The APS had greater likelihood (OR, 4.3 to 30.0) of a therapeutic response in horses with a lameness score < 4, < 10% vertical force asymmetry, or absence of marked osteophyte formation, subchondral sclerosis, or joint space narrowing. Concentration of interleukin-1 receptor antagonist in APS was 5.8 times that in blood.

CONCLUSIONS AND CLINICAL RELEVANCE

Intra-articular administration of APS can be considered an effective treatment option for equine osteoarthritis, with the potential for disease-modifying effects.

Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury

OBJECTIVE

Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA).

METHODS

An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) were graded. At week 16, synovium and cartilage biopsies were taken arthroscopically from OC injured and sham joints for histologic evaluation and the OC fragment was removed.

RESULTS

OC fragments were successfully created and horses were free of clinical lameness after fragment removal. Forelimb gait asymmetry was observed at week 2 (P = 0.0012), while joint circumference (P < 0.0001) and effusion scores (P < 0.0001) were increased in injured limbs compared to baseline from weeks 2 to 16. Positive flexion response of injured limbs was noted at multiple time points. Capsular enthesophytes were seen radiographically in injured limbs. Articular cartilage damage was demonstrated arthroscopically as mild wear-lines and histologically as superficial zone chondrocyte death accompanied by mild proliferation. Synovial hyperemia and fibrosis were present at the site of OC injury.

CONCLUSION

Acute OC injury to the MCP joint resulted in clinical, imaging, and histologic changes in cartilage and synovium characteristic of early PTOA. This model will be useful for defining biomarkers of early osteoarthritis and for monitoring response to therapy and surgery.

Optimization of scAAVIL-1ra In Vitro and In Vivo to Deliver High Levels of Therapeutic Protein for Treatment of Osteoarthritis

Osteoarthritis (OA) affects over 40 million people annually. We evaluated interleukin-1 receptor antagonist (IL-1ra) gene transfer in an equine model based on IL-1ra protein therapy which inhibits inflammation through blocking IL-1. Using the self-complementary adeno-associated virus (scAAV)IL-1ra equine gene as a starting construct, we optimized the transgene cassette by analyzing promoters (cytomegalovirus (CMV) versus chicken β-actin hybrid (CBh)), coding sequences (optimized versus unoptimized), vector capsid (serotype 2 versus chimeric capsid), and biological activity in vitro. AAV serotypes 2 and 2.5 CMV scAAVoptIL-1ra were tested in equine joints. We evaluated two doses of scAAVIL-1ra, scAAVGFP, and saline. We developed a novel endoscopy procedure and confirmed vector-derived transgene expression (GFP) in chondrocytes 6 months post-injection. AAVIL-1ra therapeutic protein levels were 200-800 ng/ml of synovial fluid over 23 and 186 days, respectively. No evidence of intra-articular toxicity was detected and no vector genomes were found in contralateral joints based on GFP fluorescence microscopy and quantitative PCR. Finally, we assayed vector-derived IL-1ra activity based on functional assays which supported anti-inflammatory activity of our protein. These studies represent the first large animal intra-articular gene transfer approach with a therapeutic gene using scAAV and demonstrate high levels of protein production over extended time supporting further clinical investigation using scAAV gene therapy for OA.Molecular Therapy - Nucleic Acids (2013) 2, e70; doi:10.1038/mtna.2012.61; published online 5 February 2013.

The horse as a model of naturally occurring osteoarthritis

Osteoarthritis (OA) is an important cause of pain, disability and economic loss in humans, and is similarly important in the horse. Recent knowledge on post-traumatic OA has suggested opportunities for early intervention, but it is difficult to identify the appropriate time of these interventions. The horse provides two useful mechanisms to answer these questions: 1) extensive experience with clinical OA in horses; and 2) use of a consistently predictable model of OA that can help study early pathobiological events, define targets for therapeutic intervention and then test these putative therapies. This paper summarises the syndromes of clinical OA in horses including pathogenesis, diagnosis and treatment, and details controlled studies of various treatment options using an equine model of clinical OA.

Evaluation of intramuscularly administered sodium pentosan polysulfate for treatment of experimentally induced osteoarthritis in horses

OBJECTIVE

To assess clinical, radiographic, histologic, and biochemical effects of sodium pentosan polysulfate (NaPPS) administered IM for treatment of experimentally induced osteoarthritis in horses.

ANIMALS

18 horses.

PROCEDURES

Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. Nine horses received NaPPS (3 mg/kg, IM) on study days 15, 22, 29, and 36. Nine control horses received the same volume of saline (0.9% NaCl) solution IM on study days 15, 22, 29, and 36. Clinical, radiographic, gross, histologic, histochemical, and biochemical findings as well as findings of synovial fluid analysis were evaluated.

RESULTS

No adverse treatment-related events were detected. Induced osteoarthritis caused a substantial increase in lameness, response to flexion, joint effusion, radiographic findings, synovial membrane inflammation, and articular cartilage fibrillation. Articular cartilage fibrillation was substantially reduced by NaPPS treatment, and concentrations of chondroitin sulfate 846 epitope were significantly increased in the synovial fluid of osteoarthritic and non-osteoarthritic joints of treated horses.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that NaPPS has some beneficial disease-modifying effects and may be a therapeutic option for osteoarthritis in horses.

Viscosupplementation with hyaluronic acid in the treatment for cartilage lesions: a review of current evidence and future directions

Diseases involving the articular cartilage are one of the leading causes of physical impairment among the adult population. While surgical technique and advancement have allowed us effective means at treating these diseases, this is not without significant risk and morbidity. With a very solid safety profile, viscosupplementation with hyaluronic acid (HA) derivatives has become an excellent modality for treating diseased articular cartilage. Recent literature supports the use of HA not only in the management of the pain associated with osteoarthritis but also as a disease-modifying agent as well. Further studies have started to define exciting new roles for viscosupplementation in the treatment for acute injuries to the joint microenvironment.

Osteomyelitis of the patella in eight foals

OBJECTIVE

To describe the characteristics of osteomyelitis lesions of the patella and to report short- and long-term outcome after treatment in 8 foals.

STUDY DESIGN

Retrospective case series.

ANIMALS

Foals (n = 8).

METHODS

Medical records (2003-2007) and radiographs of foals that had osteomyelitis of the patella were reviewed. Inclusion criteria included clinical, radiographic, and surgical findings consistent with osteomyelitis of the patella, and a long-term follow-up of >15 months. Information acquired included signalment, hematologic and serum biochemical profile results, clinical and radiographic signs, surgical technique and perioperative treatment. Follow-up radiographs were evaluated and outcome was determined from veterinary examination, race records, and telephone questionnaire.

RESULTS

Six foals survived long term (15 months-4 years); all had intralesional and systemic antimicrobial therapy, along with synovial lavage and antimicrobial medication. All were sound and achieved either yearling sales (n=3), show hunter or racing (2). Two foals died in the short term from renal failure and suppurative peritonitis secondary to cecal perforation, 1 remaining lame with suppurative osteonecrosis confirmed at necropsy. This foal was not administered intralesional antimicrobial therapy.

CONCLUSIONS

Prompt medical and surgical therapy for osteomyelitis of the patella can result in a good prognosis for soundness and a potential athletic career. Concurrent septicemia or other systemic perinatal disease can result in prolonged therapy and delayed recovery.

Intra-articular drug delivery: the challenge to extend drug residence time within the joint

The rationale behind developing sustained release microsphere formulations of non-steroidal anti-inflammatory drugs (NSAIDs) administered via the intra-articular (IA) route is to minimise the systemic bioavailability and attendant side-effects associated with oral drug administration. Overall dose is reduced whilst therapeutic benefit within the joint is maintained. The potential benefits of IA therapy for osteoarthritis (OA) are not achieved using currently available medications and delivery vehicles due to the rapid clearance of therapeutic substances from the synovial space. There is a need for sustained release delivery systems if the potential of IA drug administration is to be realised. Rationally designed microspheres taken up by synovial macrophages offer a strategy to sustain drug delivery within the joint, and to deliver NSAIDs directly to pivotal inflammatory cells. The efficacy of microsphere candidates may be evaluated in large animal models of OA. The principles of IA microsphere drug delivery may also be applicable to other classes of drugs.