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Introduction: It is important to know the current status of hemophilic arthropathy diagnoses, treatments, complications, and outcomes in developed countries., Areas Covered: A bibliographic search in PubMed for articles published from 1 January 2019 through 12 June 2023 was performed., Expert Opinion: In developed countries with specialized hemophilia treatment centers, primary hematological prophylaxis (started before the age of 2 years and after no more than one joint bleed) has almost completely eliminated the joint-related problems of the disease. The ideal goal of zero hemarthroses can be achieved only with intense and well-dosed prophylaxis: intravenous infusion of coagulation factor - standard half-life or extended half-life; periodic or subcutaneous injections of nonfactor products (emicizumab or fitusiran). However, hemophilic arthropathy continues to occur due to subclinical joint hemorrhages. In one study, 16% of the joints without reported hemarthroses showed signs of previous subclinical bleeding (hemosiderin deposits with/without synovial hypertrophy on magnetic resonance imaging were deemed signs of previous subclinical bleeding), rendering evidence for subclinical bleeding in people with severe hemophilia with lifelong prophylaxis treatment. Subclinical joint hemorrhages can be averted only by employing accurate and tailored prophylaxis.

The purpose of this study was to clarify the histological effect of reducing the loading to knee on cartilage degeneration, osteophyte formation, and synovitis in early-stage osteoarthritis (OA) using a post-traumatic rat model. Ten male rats were randomly allocated into two experimental groups: OA induction by surgical destabilization of medial meniscus (DMM, OA group) and hindlimb suspension after OA induction by DMM (OAHS group). The articular cartilage, osteophyte formation, and synovial membrane in the medial tibiofemoral joint were analyzed histologically and histomorphometrically at 2 and 4 weeks after surgery. The histological scores and changes in articular cartilage and osteophyte formation were significantly milder and slower in the OAHS group than in the OA group. At 2 and 4 weeks, there were no significant differences in cartilage thickness and matrix staining intensity between both the groups, but chondrocytes density was significantly lower in the OA group. Synovitis was milder in OAHS group than in OA group at 2 weeks. Reducing knee joint loading inhibited histological OA changes in articular cartilage, osteophyte formation, and synovial inflammation. This result supports the latest clinical guidelines for OA treatment. Further studies using biochemical and mechanical analyses are necessary to elucidate the mechanism underlying delayed OA progression caused by joint-load reduction., Competing Interests: The authors have declared that no competing interests exist.

G protein-coupled receptor kinase 5 (GRK5) regulates inflammatory responses via the nuclear factor-kappa B (NF-κB) pathway. This study investigated the functional involvement of GRK5 in the pathogenesis of inflammatory arthritis. Immunohistochemically, rheumatoid arthritis (RA) synovium had a significantly higher proportion of GRK5-positive cells in the synovial lining layer than healthy control synovium. Gene expression and NF-κB activation in lipopolysaccharide-stimulated human SW982 synovial cells were significantly suppressed by silencing of the GRK5 gene. Similarly, GRK5 kinase activity inhibition in human primary RA synovial cells attenuated gene expressions of inflammatory factors. In a murine model of collagen antibody-induced arthritis, arthritis scores and serum IL6 production of GRK5 knockout (GRK5 -/- ) mice were significantly lower than those of wild-type mice. Histologically, the degree of synovitis and cartilage degeneration in GRK5 -/- mice was significantly lower than in wild-type mice. In in vitro analyses using activated murine macrophages and fibroblast-like synoviocytes, gene expression of inflammatory factors and p65 nuclear translocation were significantly lower in GRK5 -/- mice compared to wild-type mice. In conclusion, our results suggested that GRK5 is deeply involved in the pathogenesis of inflammatory arthritis, therefore, GRK5 inhibition could be a potential therapeutic target for types of inflammatory arthritis such as RA.

An established lipopolysaccharide (LPS) model previously described in Warmbloods, was inconsistent in Standardbred horses, where lameness was not detected despite the presence of synovitis. The present study aimed to determine the dose of LPS from E. coli O55:B5 required to induce mild to moderate lameness following middle carpal joint injection in Standardbred horses and to quantitate the induced lameness over time, with and without anti-inflammatory pre-treatment. In a baseline trial, eight healthy, clinically sound Standardbred horses were used in a rule-based dose-escalation design trial, starting at a dose of 10 endotoxin units (EU). Lameness at trot was evaluated visually and quantitatively (using an inertial-sensor system and pressure plate analysis). Synovial fluid aspirates were analysed for total nucleated cell counts, total protein and prostaglandin E 2 (PGE 2 ). Following 2 months wash-out, the effective LPS-dose determined in the baseline trial was used to evaluate the effect of anti-inflammatory treatment. A mixed model for repeated measures with horse as random effect was used for analysis. After injection of 10 EU LPS, the desired degree of lameness was observed in the baseline trial, with maximal lameness at post-injection hour (PIH) 4, followed by a rapid decline and return to baseline by PIH 48. No lameness was observed following pre-treatment with meloxicam. In synovial fluid, PGE 2 was significantly higher at PIH 8 and PIH 24 in the baseline trial compared with following meloxicam pre-treatment. In conclusion, injection of the middle carpal joint with 10 EU LPS consistently induces a transient lameness and synovitis in Standardbred horses., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

We recently showed that clotting factor VIIa (FVIIa) binding to endothelial cell protein C receptor (EPCR) induces anti-inflammatory signaling and protects vascular barrier integrity. Inflammation and vascular permeability are thought to be major contributors to the development of hemophilic arthropathy following hemarthrosis. The present study was designed to investigate the potential influence of FVIIa interaction with EPCR in the pathogenesis of hemophilic arthropathy and its treatment with recombinant FVIIa (rFVIIa). For this, we first generated hemophilia A (FVIII-/-) mice lacking EPCR (EPCR-/-FVIII-/-) or overexpressing EPCR (EPCR++ FVIII-/-). Joint bleeding was induced in FVIII-/-, EPCR-/-FVIII-/-, and EPCR++FVIII-/- mice by needle puncture injury. Hemophilic synovitis was evaluated by monitoring joint bleeding, change in joint diameter, and histopathological analysis of joint tissue sections. EPCR deficiency in FVIII-/- mice significantly reduced the severity of hemophilic synovitis. EPCR deficiency attenuated the elaboration of interleukin-6, infiltration of macrophages, and neoangiogenesis in the synovium following hemarthrosis. A single dose of rFVIIa was sufficient to fully prevent the development of milder hemophilic synovitis in EPCR-/-FVIII-/- mice. The development of hemophilic arthropathy in EPCR-overexpressing FVIII-/- mice did not significantly differ from that of FVIII-/- mice, and 3 doses of rFVIIa partly protected against hemophilic synovitis in these mice. Consistent with the data that EPCR deficiency protects against developing hemophilic arthropathy, administration of a single dose of EPCR-blocking monoclonal antibodies markedly reduced hemophilic synovitis in FVIII-/- mice subjected to joint bleeding. The present data indicate that EPCR could be an attractive new target to prevent joint damage in hemophilia patients., (© 2020 by The American Society of Hematology.)

Betulinic acid (BA) inhibits the migration, invasion, and cytoskeletal reorganization of fibroblast-like synoviocytes (RA-FLS) in patients with rheumatoid arthritis. Here, to further explore the mechanism of action of BA in collagen-induced arthritis (CIA) rats, we investigated the pharmacodynamic effects of BA on synovial inflammation in a rat model of type II CIA. After inducing hind paw swelling, the rats were divided into four groups: healthy controls (normal), and rats that underwent CIA and received methotrexate treatment (MTX), BA treatment (BA), or no treatment (CIA). Body weight and hind paw swelling were determined regularly, and arthritis scores were calculated weekly. On day 35, rats were sacrificed and their hind ankle joints sectioned and stained with hematoxylin and eosin for histopathological evaluation. BA significantly reduced CIA-induced hind paw swelling, synovial tissue proliferation, cartilage destruction, and vasospasm. BA treatment also decreased serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) levels in rats with CIA. The CCK-8 assay was used to detect the proliferation of isolated vimentin + CD68 - RA-FLS; RA-FLS were stimulated with TNF-α in vitro. BA significantly inhibited TNF-α-stimulated RA-FLS proliferation, as well as IL-1β and IL-6 secretion. BA also downregulated the transcription of vascular endothelial growth factor (VEGF) and transforming growth factor β (TGF-β) and decreased the expression of the NF-кB pathway proteins (NF-kB-P65, IkBα, and IKKα/β) in the TNF-α-stimulated RA-FLS. These results indicate that BA alleviated the symptoms of CIA by inhibiting synoviocyte proliferation, modifying TNF-α- and NF-кB-related inflammatory pathways, and downregulating inflammatory mediators and growth factors including IL-1β, IL-6, VEGF, and TGF-β.

Current studies focused on the effects of all-trans-retinoic acid (ATRA) on synovial explants from rats with rheumatoid arthritis (RA) induced by lipopolysaccharides (LPS). In our study, synovial membranes were extracted aseptically from the quadriceps femoris of the knee joint of rats, and then incubated in medium containing 10% neonate bovine serum for 24 h adaptive culture. We first measured variations of correlation factors in synovium at 24, 48, 72, 96 and 120 h in control medium or in medium containing 20 ng/mL tumor necrosis factor alpha (TNF-α) (TNF-α-experiment). Then, we investigated the synovium exposed to three ATRA concentrations after 48 h incubation (ATRA-experiment). The effects of ATRA on synovitis were evaluated by observing the expression of inflammatory cytokines, angiogenic factors and the production of proteases in nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway and apoptosis and autophagy. In TNF-α-experiment, the secretion of nitric oxide (NO), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and matrix metalloproteinase-9 (MMP-9) increased significantly after TNF-α stimulation without pathological damage to the synovium. Hence, we successfully obtained the synovial explants model, which had longer inflammatory response time. In the ATRA-experiment, ATRA suppressed the secretion of IL-6 and NO, downregulated the NF-κB P65 and Bcl-2, increased levels of autophagy marker protein LC3, but different doses of ATRA showed inconsistent regulatory effects on VEGF and MMP-9. In short, ATRA inhibited TNF-α induced synovitis by the regulation of inflammatory cytokines and inhibiting NF-κB signal transduction and potentially promoting autophagy, apoptosis and angiogenesis, displaying its role in alleviating synovial inflammation in patients with RA.

The polyphenolic extract (PE) from extra virgin olive oil (EVOO) has been shown to possess important anti-inflammatory and joint protective properties in murine models of rheumatoid arthritis (RA). This study was designed to evaluate the effects of PE on IL-1β-activated human synovial fibroblasts SW982 cell line. PE from EVOO treatment inhibited IL-1β-induced matrix metalloproteases (P<0·001), TNF-α and IL-6 production (P<0·001). Similarly, IL-1β-induced cyclo-oxygenase-2 and microsomal PGE synthase-1 up-regulations were down-regulated by PE (P<0·001). Moreover, IL-1β-induced mitogen-activated protein kinase (MAPK) phosphorylation and NF-κB activation were ameliorated by PE (P<0·001). These results suggest that PE from EVOO reduces the production of proinflammatory mediators in human synovial fibroblasts; particularly, these protective effects could be related to the inhibition of MAPK and NF-κB signalling pathways. Taken together, PE from EVOO probably could provide an attractive complement in management of diseases associated with over-activation of synovial fibroblasts, such as RA.

Rheumatoid arthritis (RA) is a systemic autoimmune disease primarily affecting joints and is featured by chronic synovial inflammation and angiogenesis. We employed a bovine type-II collagen (BIIC)-induced Sprague-Dawley rat arthritis model and an in vitro RA model based on interleukin (IL)-1β-stimulated rat synovial cells (RSC-364) to explore the preventive effect of resveratrol on RA and the underlying mechanisms. We found that resveratrol ameliorated BIIC-elicited synovitis and RA-related pathological hallmarks such as inflammatory cell infiltration and angiogenesis in the synovial tissue. Also, BIIC-stimulated rats displayed increased serum levels of proinflammatory cytokines and reactive oxygen species (ROS), as manifested by elevated serum malonaldehyde contents combined with reduced superoxide dismutase activity. It is noteworthy that resveratrol abolished BIIC-induced ROS and inflammation, confirming the antioxidative and anti-inflammatory actions of resveratrol in the context of RA. Furthermore, immunoblotting indicated that resveratrol downregulated the increase in the levels of hypoxia-inducible factor-1α (HIF-1α) and that of the activated phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase in IL-1β-stimulated RSC-364 cells. Moreover, we observed that resveratrol-treated RSC-364 cells displayed both G 0 /G 1 cell-cycle arrest and enhanced levels of apoptosis. Altogether, the present evidence established the preventive role of resveratrol in RA progression. Mechanistically, resveratrol inhibits MAPK signaling pathways, likely by reducing ROS accumulation, to suppress the inflammatory response and cell proliferation and to provoke cell apoptosis in the synovial tissue, along with mitigation of HIF-1α-mediated angiogenesis. Thus resveratrol appears to hold great potential for clinical translation as a novel RA therapeutic.

Purpose: Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease characterized by aggressive and symmetric polyarthritis. Mammalian target of rapamycin (mTOR) was reported to be a new target for RA therapy and its inhibitor rapamycin can significantly reduce the invasive force of fibroblast-like synoviocytes. Here, we determined the effect of curcumin to alleviate inflammation and synovial hyperplasia for the therapy of RA., Materials and Methods: Collagen-induced arthritis (CIA) was developed in Wistar rats and used as a model resembling RA in humans. Rats were treated with curcumin (200 mg/kg) and the mTOR inhibitor rapamycin (2.5 mg/kg) daily for 3 weeks. Effects of the treatment on local joint, peripheral blood, and synovial hyperplasia in the pathogenesis of CIA were analyzed., Results: Curcumin and rapamycin significantly inhibited the redness and swelling of ankles and joints in RA rats. Curcumin inhibited the CIA-induced mTOR pathway and the RA-induced infiltration of inflammatory cells into the synovium. Curcumin and rapamycin treatment inhibited the increased levels of proinflammatory cytokines including IL-1β, TNF-α, MMP-1, and MMP-3 in CIA rats., Conclusion: Our findings show that curcumin alleviates CIA-induced inflammation, synovial hyperplasia, and the other main features involved in the pathogenesis of CIA via the mTOR pathway. These results provide evidence for the anti-arthritic properties of curcumin and corroborate its potential use for the treatment of RA., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Background and Objective: Rheumatoid arthritis (RA) is a predominant inflammatory autoimmune disorder. The incidence and prevalence of RA is increasing with considerable morbidity and mortality worldwide. The pathophysiology of RA has become clearer due to many significant research outputs during the last two decades. Many inflammatory cytokines involved in RA pathophysiology and the presence of autoantibodies are being used as potential biomarkers via the use of effective diagnostic techniques for the early diagnosis of RA. Currently, several disease-modifying anti-rheumatic drugs are being prescribed targeting RA pathophysiology, which have shown significant contributions in improving the disease outcomes., Discussion: Even though innovations in treatment strategies and monitoring are helping the patients to achieve early and sustained clinical and radiographic remission, the high cost of drugs and limited health care budgets are restricting the easy access of RA treatment. Both direct and indirect high cost of treatment are creating economic burden for the patients and affecting their quality of life., Conclusion: The aim of this review is to describe the updated concept of RA pathophysiology and highlight current diagnostic tools used for the early detection as well as prognosis - targeting several biomarkers of RA. Additionally, we explored the updated treatment options with side effects besides discussing the global economic burden., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Dried plum (DP), a rich source of polyphenols has been shown to have bone-preserving properties in both animal models of osteoporosis and postmenopausal women. We evaluated if DP alleviated the destruction of joints in transgenic mice (TG) that overexpress human tumor necrosis factor (TNF), a genetic model of rheumatoid arthritis (RA). A four-week treatment of 20% DP diet in TG slowed the onset of arthritis and reduced bone erosions in the joints compared to TG on a regular diet. This was associated with fewer tartrate-resistant acid phosphatase (TRAP) positive cells, suggesting decreased osteoclastogenesis. A DP diet also produced significant protection of articular cartilage and reduction of synovitis. Cultures of human synovial fibroblast in the presence of TNF showed a significant increase in inflammatory interleukin (IL)-1β, chemokines (monocyte chemoattractant protein-1: MCP1 & macrophage inflammatory protein-1 alpha: MIP1α), cartilage matrix metalloproteinases (MMP1&3), and an osteoclastogenic cytokine (receptor activator of nuclear factor-κB ligand: RANKL) compared to controls. Addition of neochlorogenic acid (NC), a major polyphenol in DP to these cultures resulted in down-regulation of these genes. In the cultures of mouse bone marrow macrophage, NC also repressed TNF-induced formation of osteoclasts and mRNA levels of cathepsin K and MMP9 through inhibition of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) expression and nuclear factor kappa B (NF-κB) activation. Our data suggested that dietary supplementation with DP inhibited TNF singling; leading to decreased erosions of bone and articular cartilage as well as synovitis., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: To develop a measure of knee joint effusion-synovitis volume and to examine the effect of vitamin D supplementation on effusion-synovitis in people with knee osteoarthritis (OA) and low vitamin D levels over 24 months., Method: Symptomatic knee OA patients with low 25-(OH)D levels (12.5-60 nmol/l) were recruited for a multi-centre, randomised, placebo-controlled and double-blind trial. Participants (age 63 ± 7 years, 208 females) were allocated to either 50,000 IU monthly vitamin D 3 (n = 209) or placebo (n = 204) for 24 months. Knee effusion-synovitis volume in suprapatellar and other regions was measured on magnetic resonance imaging (MRI) using OsiriX software. The intra-class correlation coefficients (ICCs) were used to test inter- and intra-rater reliabilities. The least significant change criterion was used to define the increase/decrease in effusion-synovitis volume., Result: The reproducibilities of effusion-synovitis volume measurement were high with ICCs ranging from 0.93 to 0.99. Over 24 months, effusion-synovitis volume remained stable in the vitamin D group but increased in placebos with a significant between-group difference (-1.94 ml, 95% confidence interval (CI): -3.54, -0.33). This effect was evident in those with baseline effusion-synovitis and with suprapatellar effusion-synovitis. The proportion with an increase in effusion-synovitis volume was lower in the vitamin D group than placebo (risk ratio (RR): 0.87, 95% CI: 0.77, 0.97)., Conclusion: This highly reproducible effusion-synovitis volume measurement could be a promising outcome measure in OA trials. Vitamin D supplementation could retard the progression of effusion-synovitis which can potentially benefit people with an inflammatory OA phenotype., (Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Background: Nutraceuticals are often used in the management of equine osteoarthritis, but scientific evidence of their efficacy is lacking., Objectives: To study the preventive effects of two new nutraceuticals after the experimental induction of synovitis in comparison with positive and negative control treatments., Study Design: Blinded, controlled, randomised experiment., Methods: Twenty-four healthy Standardbred horses were randomly allocated to supplement AT (multi-ingredient, 28 days), supplement HP (collagen hydrolysate, 60 days), meloxicam (4 days) or placebo (60 days). Synovitis was induced in the right intercarpal joint by intra-articular injection of 0.5 ng lipopolysaccharide (LPS) of Escherichia coli while treatments were continued. Blood and synovial fluid were sampled before treatment, immediately prior to LPS injection, and at 8, 24 and 48 h post-injection. Synovial fluid samples were analysed for total nucleated cell count (TNCC), total protein (TP) and selected biomarkers (prostaglandin E 2 [PGE 2 ], interleukin-6 [IL-6], glycosaminoglycans [GAGs], type II collagen synthesis [CPII], matrix metalloproteinase [MMP]). Lameness was scored by visual examination and pressure plate analysis immediately prior to LPS injection, and at 8, 24 and 48 h post-injection. Clinical examinations were performed before treatment, immediately prior to LPS injection, at 2, 4 and 6 h post-injection, and then twice per day during the test period., Results: Before treatment and intra-articular challenge, there were no statistically significant differences among the treatment groups for any of the parameters. After intra-articular challenge, the placebo group showed significantly higher synovial fluid TP, TNCC and PGE 2 compared with the meloxicam group, although the model did not induce a relevant amount of lameness. Both nutraceuticals resulted in significantly lower synovial fluid TP, TNCC and PGE 2 compared with placebo. No statistical differences in IL-6, GAGs, CPII or MMPs were observed among treatment groups. No adverse effects were observed., Main Limitations: Despite evidence of synovitis, lameness was too mild to detect., Conclusions: The preventive administration of these nutraceuticals showed anti-inflammatory effects in this validated synovitis model. Therefore, further studies of their clinical applicability are warranted., (© 2016 The Authors Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Objective: To investigate the impact of systemic inhibition of interleukin 6 (IL-6) or signal transducer and activator of transcription (Stat3) in an experimental model of osteoarthritis (OA)., Methods: Expression of major catabolic and anabolic factors of cartilage was determined in IL-6-treated mouse chondrocytes and cartilage explants. The anti-IL-6-receptor neutralising antibody MR16-1 was used in the destabilisation of the medial meniscus (DMM) mouse model of OA. Stat3 blockade was investigated by the small molecule Stattic ex vivo and in the DMM model., Results: In chondrocytes and cartilage explants, IL-6 treatment reduced proteoglycan content with increased production of matrix metalloproteinase (MMP-3 and MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-4 and ADAMTS-5). IL-6 induced Stat3 and extracellular signal-regulated kinase (ERK) 1/2 signalling but not p38, c-Jun N-terminal kinase or Akt. In the DMM model, Stat3 was activated in cartilage, but neither in the synovium nor in the subchondral bone. Systemic blockade of IL-6 by MR16-1 alleviated DMM-induced OA cartilage lesions, impaired the osteophyte formation and the extent of synovitis. In the same model, Stattic had similar beneficial effects on cartilage and osteophyte formation. Stattic, but not an ERK1/2 inhibitor, significantly counteracted the catabolic effects of IL-6 on cartilage explants and suppressed the IL-6-induced chondrocytes apoptosis., Conclusion: IL-6 induces chondrocyte catabolism mainly via Stat3 signalling, a pathway activated in cartilage from joint subjected to DMM. Systemic blockade of IL-6 or STAT-3 can alleviate DMM-induced OA in mice., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune inflammatory disease. Typical pathological findings of RA include persistent synovitis and bone degradation in the peripheral joints. Equol, a metabolite of the major soybean isoflavone daidzein, shows superior bioactivity than other isoflavones. We investigated the effects of equol administration on inflammatory response and bone erosion in mice with collagen-induced arthritis (CIA). The severity of arthritis symptoms was significantly low in the equol-administered CIA mice. In addition, equol administration improved the CIA-induced bone mineral density decline. In the inflamed area of CIA mice, equol administration suppressed the expression of interleukin-6 and its receptor. Furthermore, equol reduced the expression of genes associated with bone formation inhibition, osteoclast and immature osteoblast specificity and cartilage destruction. These results suggest that equol suppresses RA development and RA-induced bone erosion by regulating inflammation and bone metabolism., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: Tropomyosin receptor kinase A (TrkA) mediates nociceptor sensitisation by nerve growth factor (NGF), but it is unknown whether selective TrkA inhibition will be an effective strategy for treating osteoarthritis (OA) pain. We determined the effects of a TrkA inhibitor (AR786) on pain behaviour, synovitis and joint pathology in two rat OA models., Methods: Knee OA was induced in rats by intra-articular monosodium-iodoacetate (MIA) injection or meniscal transection (MNX) and compared with saline-injected or sham-operated controls. Pain behaviour was assessed as weight-bearing asymmetry and paw withdrawal threshold to punctate stimulation. Oral doses (30 mg/kg) of AR786 or vehicle were administered twice daily in either preventive (day -1 to -27) or treatment (day 14-28) protocols. Effect maintenance was evaluated for 2 weeks after treatment discontinuation. Alterations in knee structure (cartilage, subchondral bone and synovium) were examined by macroscopic visualisation of articular surfaces and histopathology., Results: Preventive AR786 treatment inhibited pain behaviour development and therapeutic treatment attenuated established pain behaviour. Weight-bearing asymmetry increased 1 week after treatment discontinuation, but remained less than in vehicle-treated arthritic rats, whereas paw withdrawal thresholds returned to levels of untreated rats within 5 days of treatment discontinuation. AR786 treatment reduced MIA-induced synovitis and did not significantly affect osteochondral pathology in either model., Conclusions: Blocking NGF activity by inhibiting TrkA reduced pain behaviour in two rat models of OA. Analgesia was observed both using preventive and treatment protocols, and was sustained after treatment discontinuation. Selective inhibitors of TrkA therefore hold potential for OA pain relief., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Objective: To assess the outcome and adverse-effects of the radioisotope synoviorthesis in paediatric and adolescent patients with haemophilia., Material and Methods: Prospective study of historical cohort was conducted. A total of 20 consecutive haemophiliacs with a mean age of 13.1 years (range 4-17) were included with a mean follow-up of 64.9 months (range 18-109). The diagnosis of synovitis was established on the basis of clinical follow-up including radiological images (radiography and/or MRI). For evaluation, the classification proposed by Fernandez-Palazzi was used., Inclusion Criteria: Patients aged less than 18 years old with haemophilia and more than one haemarthrosis in less than 3 months remaining a chronic synovitis despite prophylactic therapy intensification., Exclusion Criteria: Any contraindication for radionuclide synoviorthesis. Twenty-seven radioisotope synoviorthesis with (90)Y-citrate-colloid and/or (186)Re-sulphide-colloid were done. The effectiveness of the procedure was assessed through pre and posttreatment clinical comparison at 6 months after radioisotope synoviorthesis., Results: Nineteen of the 27 synoviorthesis (70.3%) had a good or excellent response and 8 joints (29.7%) had partial response. It was necessary to repeat the procedure in 3 joints in 3 different patients, obtaining in all cases a good or excellent response. We appreciated inflammatory reaction after procedure in 4 cases (14.8%), which improved with analgesics and nonsteroidal anti-inflamatory drugs. None of the patients presented malignant or premalignant lesions during the follow-up., Conclusion: The radionuclide synoviorthesis is a very effective procedure in paediatric and adolescent patients with hemophilia, being a minimally invasive procedure, easy to perform, safe and with minimal side effects., (Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.)

The aim of the present study was to assess the effects of pro-protein convertase subtilisin/kexin type 6 (PCSK6), a proteinase implicated in the proteolytic activity of various precursor proteins and involved in the regulation of protein maturation, in fibroblast‑like synoviocytes (FLS) of a rat model of collagen‑induced arthritis (CIA). Cultured FLS from CIA models were subjected to small interfering RNA mediated PCSK6 knockdown, followed by assessment of the proliferation, invasive and migratory capacity, the secretion of inflammation factors and the cell cycle. Expression of genes associated with proliferation, invasion, migration and inflammation was detected by reverse transcription polymerase chain reaction. The results showed that PCSK6 knockdown significantly decreased the cell proliferation, invasion and migration of FLS from rats with CIA. ELISA showed an obvious decrease of tumor necrosis factor α and interleukin 1β secretion, and flow cytometric analysis revealed G0/G1 arrest of FLS following PCSK6 knockdown. Furthermore, a decrease in the mRNA levels of inflammation‑associated chemokine CXCL9, angiogenesis‑associated genes MMP‑2, MMP‑9 and NOSTRIN, hypoxia‑associated gene HIF‑1α, adhesion‑associated gene MPZL2, proliferation‑associated gene IGF‑2 and citrullination‑associated gene PADI4 was detected after PCSK6 knockdown. The results of the present study indicated that inhibition of PCSK6 may have a protective role against synovitis in rheumatoid arthritis.

Aim: To investigate the effects of Tubastatin A, a selective histone deacetylase-6 inhibitor, on synovial inflammation and joint destruction in a collagen antibody-induced arthritis (CAIA) mouse model., Methods: Collagen antibody-induced arthritis mice were given daily intraperitoneal injections of various concentrations of Tubastatin A (0, 10, 50, 100 mg/kg). The clinical score and paw thickness were measured. Mice were sacrificed on day 15, and the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1 and IL-6 in the serum were analyzed using enyme-linked immunosorbent assay (ELISA). Two pathologists independently measured the synovitis score. Micro-computed tomography (CT) scans of the joints were performed to quantify joint destruction. The expression of IL-6 from human fibroblast-like synoviocytes (FLSs) after incubation with various doses of Tubastatin A (0, 0.75, 1.5, 3 μmol/L) was measured using ELISA., Results: The clinical arthritis score was significantly attenuated and paw thickness was lower in the group treated with 100 mg/kg Tubastatin A compared with those treated with vehicle alone. The synovitis score was significantly reduced in the 100 mg/kg Tubastatin A-treated group compared with the control group. Micro-CT showed that quantitative measures of joint destruction were significantly attenuated in the 100 mg/kg Tubastatin A-treated group compared with the control. The expression of IL-6 in the sera was lower in the mice treated with Tubastatin A compared with the control. The expression of IL-6 in human FLSs decreased dose-dependently after incubation with Tubastatin A without affecting cell viability., Conclusions: Tubastatin A successfully ameliorated synovial inflammation and protected against joint destruction in CAIA mice, at least in part, by modulating IL-6 expression., (© 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.)

Introduction: During the progression of rheumatoid arthritis (RA), there are frequent but intermittent flares in which the joint becomes acutely inflamed and painful. Although a number of drug therapies are currently used to treat RA, their effectiveness is variable and side effects are common. Endocannabinoids have the potential to ameliorate joint pain and inflammation, but these beneficial effects are limited by their rapid degradation. One enzyme responsible for endocannabinoid breakdown is fatty acid amide hydrolase (FAAH). The present study examined whether URB597, a potent and selective FAAH inhibitor, could alter inflammation and pain in a mouse model of acute synovitis., Methods: Acute joint inflammation was induced in male C57BL/6 mice by intra-articular injection of 2% kaolin/2% carrageenan. After 24 hr, articular leukocyte kinetics and blood flow were used as measures of inflammation, while hindlimb weight bearing and von Frey hair algesiometry were used as measures of joint pain. The effects of local URB597 administration were then determined in the presence or absence of either the cannabinoid (CB)1 receptor antagonist AM251, or the CB2 receptor antagonist AM630., Results: URB597 decreased leukocyte rolling and adhesion, as well as inflammation-induced hyperaemia. However, these effects were only apparent at low doses and the effects of URB597 were absent at higher doses. In addition to the anti-inflammatory effects of URB597, fatty acid amide hydrolase (FAAH) inhibition improved both hindlimb weight bearing and von Frey hair withdrawal thresholds. The anti-inflammatory effects of URB597 on leukocyte rolling and vascular perfusion were blocked by both CB1 and CB2 antagonism, while the effect on leukocyte adherence was independent of cannabinoid receptor activation. The analgesic effects of URB597 were CB1 mediated., Conclusions: These results suggest that the endocannabinoid system of the joint can be harnessed to decrease acute inflammatory reactions and the concomitant pain associated with these episodes.

Introduction: Post-traumatic arthritis (PTA) is a progressive, degenerative response to joint injury, such as articular fracture. The pro-inflammatory cytokines, interleukin 1(IL-1) and tumor necrosis factor alpha (TNF-α), are acutely elevated following joint injury and remain elevated for prolonged periods post-injury. To investigate the role of local and systemic inflammation in the development of post-traumatic arthritis, we targeted both the initial acute local inflammatory response and a prolonged 4 week systemic inflammatory response by inhibiting IL-1 or TNF-α following articular fracture in the mouse knee., Methods: Anti-cytokine agents, IL-1 receptor antagonist (IL-1Ra) or soluble TNF receptor II (sTNFRII), were administered either locally via an acute intra-articular injection or systemically for a prolonged 4 week period following articular fracture of the knee in C57BL/6 mice. The severity of arthritis was then assessed at 8 weeks post-injury in joint tissues via histology and micro computed tomography, and systemic and local biomarkers were assessed in serum and synovial fluid., Results: Intra-articular inhibition of IL-1 significantly reduced cartilage degeneration, synovial inflammation, and did not alter bone morphology following articular fracture. However, systemic inhibition of IL-1, and local or systemic inhibition of TNF provided no benefit or conversely led to increased arthritic changes in the joint tissues., Conclusion: These results show that intra-articular IL-1, rather than TNF-α, plays a critical role in the acute inflammatory phase of joint injury and can be inhibited locally to reduce post-traumatic arthritis following a closed articular fracture. Targeted local inhibition of IL-1 following joint injury may represent a novel treatment option for PTA.

Background: Blood-induced joint damage is characterized by synovitis and cartilage damage. Recently, we demonstrated that joint bleeding in hemophilic mice results in elevated synovial levels of urokinase plasminogen activator (u-PA) and plasmin, and in plasmin-mediated cartilage damage., Objective: To evaluate whether treatment with amiloride (an inhibitor of u-PA) or antiplasmin attenuates synovitis and cartilage damage following joint bleeding in hemophilic mice., Methods: Following the induction of joint bleeding, hemophilic mice were randomized between daily oral treatment with amiloride (1 mg kg⁻¹) or control, or weekly intra-articular treatment with amiloride (2.5 mg mL⁻¹), antiplasmin (2.5 mg mL⁻¹), or control. After 5 weeks of treatment, synovitis and cartilage damage were determined on hematoxylin and eosin-stained (Valentino score) and Safranin O-stained sections, respectively., Results: No effects of oral and intra-articular treatment with amiloride were found. In contrast, intra-articular treatment with antiplasmin resulted in significant (P < 0.01) reductions in both synovitis (score 1, 11.1% vs. 0%; score 2, 11.1% vs. 4.2%; score 3, 61.1% vs. 16.7%; score 4, 5.6% vs. 29.2%; score 5, 11.1% vs. 20.8%; score 6, 7.7% vs. 8.3%; score 7, 0% vs. 8.3%; and score 8, 0% vs. 12.5%) and cartilage damage (score 2, 10% vs. 8.3%; score 3, 50% vs. 12.5%; score 4, 30% vs. 33.3%; score 5, 10% vs. 33.3%; and score 6, 0% vs. 16.7%) as compared with controls., Conclusions: Intra-articular treatment with antiplasmin (but not amiloride) following joint bleeding prevented synovitis and cartilage damage in hemophilic mice. These data offer promise for the use of antiplasmin as a new therapeutic intervention for patients who suffer from joint bleeds despite administration of clotting factor., (© 2013 International Society on Thrombosis and Haemostasis.)

Physical medicine and rehabilitation aim to evaluate, diagnose and treat disability in haemophiliac patients, while preventing injury or deterioration. They also aim to maintain the greatest degree of functional capacity and independence in patients with haemophilia, or to return them to that state. Rehabilitation, together with clotting factor replacement therapy, has revolutionized the management of these patients in developed countries and reduced their morbidity/mortality rates. A knowledge of the musculoskeletal signs and symptoms of haemophilia is essential for providing a treatment which is suitable and customized. Physical medicine and rehabilitation techniques, which are based on physical means, are intended to reduce the impact which these injuries and their consequences or sequelae can have on the quality of life of patients with haemophilia. Under ideal haemostatic control conditions (primary prophylaxis), people with haemophilia could achieve good physical condition which will allow them to enjoy both physical activity and a daily life without limitations. Currently, children undergoing primary prophylaxis are quite close to this ideal situation. For these physical activities to be carried out, the safest possible situations must be sought.

Hemophilia is an inherited recessive, sex-linked bleeding disorder. The lack of sufficient coagulation factor VIII produces hemophilia A, and the lack of factor IX causes hemophilia B. The prevention and treatment of the disease requires intravenous infusion of the deficient factor. Hemophilic patients present with multiarticular joint degeneration (hemophilic arthropathy), secondary to recurrent hemarthroses. With the availability of deficient factors, hemophilic patients requiring elective ankle surgery can undergo such surgery with a high expectation of success. A thorough analysis of each case by a multidisciplinary team will increase the likelihood of successful surgical intervention in the hemophilic patient. Radiosynovectomy decreases both the frequency and the intensity of recurrent ankle bleeding episodes related to ankle synovitis. The general recommendation is that when 3 early consecutive radiosynovectomies (repeated every 6 months) fail to halt synovitis, arthroscopic synovectomy should be considered. For advanced hemophilic arthropathy of the ankle, the first alternative for treatment, in our opinion, is arthroscopic ankle debridement. In the most severe cases, we recommend either ankle arthrodesis or total ankle replacement. In every other case, we feel that the best therapy is prophylaxis and radiosynovectomy in order to avoid hemophilic synovitis and ankle arthropathy., (Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Hemophilia is caused by a deficiency of clotting factor VIII or IX and is inherited by a sex-linked recessive pattern. von Willebrand disease, a common, moderate bleeding disorder, is caused by a quantitative or qualitative protein deficiency of von Willebrand factor and is inherited in an autosomal dominant or recessive manner. The most important clinical strategy for the management of patients with hemophilia is the avoidance of recurrent hemarthrosis by continuous, intravenous hematologic prophylaxis. Early hemarthrosis should be aggressively managed with aspiration and clotting factor concentrate until the joint examination is normal. Starting prophylactic factor replacement in infancy may prevent chronic synovitis and arthropathy. The natural history of poorly controlled disease is polyarticular hemophilic arthropathy; functional prognosis is poor. Patients with chronic synovitis may be treated effectively with radiosynovectomy; those who develop joint surface erosions may require realignment osteotomies, joint arthroplasty, and treatment of pseudotumors. Reconstructive surgery for hemophilic arthropathy, especially in patients with factor inhibitor, requires careful hematologic management by an experienced, multidisciplinary team.

Haemophilia has been recognized as the most severe among the inherited disorders of blood coagulation since the beginning of the first millennium. Joint damage is the hallmark of the disease. Despite its frequency and severity, the pathobiology of blood-induced joint disease remains obscure. Although bleeding into the joint is the ultimate provocation, the stimulus within the blood inciting the process and the mechanisms by which bleeding into a joint results in synovial inflammation (synovitis) and cartilage and bone destruction (arthropathy) is unknown. Clues from careful observation of patient material, supplemented with data from animal models of joint disease provide some clues as to the pathogenesis of the process. Among the questions that remain to be answered are the following: (i) What underlies the phenotypic variability in bleeding patterns of patients with severe disease and the development of arthropathy in some but not all patients with joint bleeding? (ii) What is the molecular basis underlying the variability? (iii) Are there strategies that can be developed to counter the deleterious effects of joint bleeding and prevent blood-induced joint disease? Understanding the key elements, genetic and/or environmental, that are necessary for the development of synovitis and arthropathy may lead to rational design of therapy for the targeted prevention and treatment of blood-induced joint disease., (© 2011 Blackwell Publishing Ltd.)

Osteoarthritis (OA) is currently a major health problem, both with an important individual and socio-economical impact. The diagnostic of osteoarthritis is both clinical and radiological, without a strong correlation between symptoms and radiographic findings. Participation in sports increases the risk of joint overuse or injuries potentially leading to posttraumatic osteoarthritis. Conversely, sport is a recognized therapeutic and probably also a preventive tool against osteoarthritis, with a positive influence on weight, muscle strength and possibly synovial inflammation. In general, sport should be encouraged individually with an appropriate program and a correct intensity.

Based on genetic studies that establish the role of spleen tyrosine kinase (Syk) in immune function, inhibitors of this kinase are being investigated as therapeutic agents for inflammatory diseases. Because genetic studies eliminate both adapter functions and kinase activity of Syk, it is difficult to delineate the effect of kinase inhibition alone as would be the goal with small-molecule kinase inhibitors. We tested the hypothesis that specific pharmacological inhibition of Syk activity retains the immunomodulatory potential of Syk genetic deficiency. We report here on the discovery of (4-(3-(2H-1,2,3-triazol-2-yl)phenylamino)-2-((1R,2S)-2-aminocyclohexylamino) pyrimidine-5-carboxamide acetate (P505-15), a highly specific and potent inhibitor of purified Syk (IC50 1-2 nM). In human whole blood, P505-15 potently inhibited B cell antigen receptor-mediated B cell signaling and activation (IC50 0.27 and 0.28 μM, respectively) and Fcε receptor 1-mediated basophil degranulation (IC50 0.15 μM). Similar levels of ex vivo inhibition were measured after dosing in mice (Syk signaling IC50 0.32 μM). Syk-independent signaling and activation were unaffected at much higher concentrations, demonstrating the specificity of kinase inhibition in cellular systems. Oral administration of P505-15 produced dose-dependent anti-inflammatory activity in two rodent models of rheumatoid arthritis. Statistically significant efficacy was observed at concentrations that specifically suppressed Syk activity by ∼67%. Thus specific Syk inhibition can mimic Syk genetic deficiency to modulate immune function, providing a therapeutic strategy in P505-15 for the treatment of human diseases.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by chronic inflammation and joint destruction. In this study, we investigated whether dietary supplementation with alpha lipoic acid (ALA) suppresses collagen-induced arthritis (CIA) in mice. Mice were randomly divided into three groups: (1) a control CIA group was fed a normal diet, (2) a CIA group was fed a 0.1% ALA diet (average ALA intake of 160 mg/kg/day), and (3) a CIA group was fed a 0.5% ALA diet (average ALA intake of 800 mg/kg/day). The ALA-fed mice showed a decreased incidence and severity of arthritis compared to the normal diet group. Radiographic findings revealed a dramatic decrease in bone destruction, and histological findings showed extensively suppressed pathological changes in the ALA-fed mice. The ALA-fed mice exhibited inhibited generation of tartrate resistant acid phosphatase (TRAP)-positive osteoclasts in vivo. Additionally, ALA-fed mice reduced production of various proinflammatory cytokines and the soluble receptor activator of NF-κB ligand (sRANKL) in the joint tissues and the sera. In conclusion, dietary supplementation with ALA attenuated inflammatory responses and bone destruction in CIA mice.

Rheumatoid arthritis (RA) is a chronic, destructive autoimmune disease that can cause disability and have a negative socioeconomic impact. Despite significant advances in therapeutic options, limitations on the routes of administration and the requirement for frequent and long-term dosing often lead to systemic adverse effects and patient non-compliance. Micro and nanoparticle systems that selectively deliver drugs to inflamed synovium have the potential to improve drug efficacy while leaving extrasynovial tissues unaffected. This review summarizes key design parameters of RA-targeted drug carriers and discusses design considerations for improving RA therapies.

Background: The importance of the radial head to elbow function and stability is increasingly apparent. Although preservation of the native radial head is preferred, severely comminuted fractures may necessitate resection or arthroplasty. Silastic radial head arthroplasty has been condemned on the basis of several sporadic reports of silicone synovitis. However, problems of "overstuffing," cartilage wear, and motion loss are becoming apparent with metal prostheses, indicating this also is not an ideal solution. Thus, the choices remain controversial., Questions/purposes: We asked whether intact or reconstructed primary elbow stabilizers permit use of silastic radial head implants without fragmentation, failure, and silicone synovitis., Methods: We retrospectively reviewed 23 patients with unreconstructable radial head fractures who were treated with silastic radial head arthroplasty and concomitant repair and/or reconstruction of the medial ulnar collateral ligament and/or lateral ulnar collateral ligament. Analysis included range of motion, pain, stability, and radiographic assessments; Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire; and Mayo Elbow Performance Score (MEPS). The minimum followup was 16 months (average, 69.6 months; range, 16-165 months)., Results: At last followup, the mean elbow flexion was 145°, extension 11°, supination 80°, and pronation 83°. The mean MEPS score was 88.9. The mean DASH score was 11.8. There were eight reoperations, none resulting from failure of the radial head implants., Conclusions: These results demonstrate silastic radial heads can be used with low complication rates and without evidence of synovitis when concomitant elbow ligament repair or reconstruction is performed., Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Objectives: (1) To show that a single-chain Fv antibody (scFv) against tumour necrosis factor alpha (TNFalpha) (ESBA105) has efficacy comparable to a full length anti-TNFalpha IgG (infliximab); (2) to evaluate whether ESBA105 has all the properties required for the local treatment of arthritis; and (3) to investigate its discriminative tissue penetration properties., Methods: In vivo efficacy was measured in arthritis of the knee joint induced by the intra-articular injection of recombinant human TNFalpha (rhTNFalpha) in Lewis rats. Cartilage penetration of scFv (ESBA105) and full length IgG (infliximab) were studied in bovine cartilage specimens ex vivo. Tissue penetration, biodistribution and pharmacokinetics of ESBA105 were followed and compared after intra-articular and intravenous administration., Results: In cell culture, ESBA105 showed similar TNFalpha inhibitory potency to infliximab. In vivo, ESBA105 inhibited rhTNFalpha-induced synovial inflammation in rats with efficacy again comparable to infliximab. An 11-fold molar excess of ESBA105 over rhTNFalpha resulted in 90% inhibition of knee joint swelling, inflammatory infiltrates and proteoglycan loss from cartilage. In ex vivo studies of bovine cartilage, ESBA105 penetrated well into the cartilage whereas infliximab remained on the surface. In vivo, rapid penetration into the synovial tissue, cartilage and surrounding tissues was observed following intra-articular injection of [(125)I]-ESBA105 into the knee joint of rabbits., Conclusions: ESBA105 potently inhibits inflammation and prevents cartilage damage triggered by TNFalpha. In contrast to a full length IgG, ESBA105 also penetrates into cartilage and can be expected to reverse the TNFalpha-induced catabolic state of articular cartilage in arthritides.

Background: Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystal-induced interleukin 1 beta (IL1beta) release contributes to inflammation in subcutaneous air pouch and peritoneal models of acute gout and pseudogout. However, consequences of IL1 inhibition have not been explored in more clinically relevant models of crystal-induced arthritis., Objective: To develop a novel mouse model of acute gouty ankle arthritis and use it to assess the effects of genetic deletion of IL1 receptor type (IL1R1) and of exogenous mIL1 Trap (a high-affinity blocker of mouse IL1alpha and IL1beta) on pain, synovitis and systemic inflammatory biomarkers., Methods: MSU crystals were injected into the mouse ankle joint and pain and ankle swelling were measured over 4 days. The effects of IL1 inhibition were determined in this model, and in the comparator models of crystal-induced peritonitis and subcutaneous air pouch inflammation., Results: Both IL1R1-null mice and mice pretreated with mIL1 Trap showed reduced neutrophil influx in MSU and CPPD crystal-induced peritonitis and air pouch models (p<0.05). In the ankle joint model, both IL1R1 knockout mice and pretreatment with mIL1 Trap were associated with significant reductions in MSU crystal-induced elevations in hyperalgesia, inflammation, serum amyloid A and the levels of multiple inflammatory cytokines and chemokines (p<0.05). Additionally, it was found that administration of mIL1 Trap after MSU crystal injection reduced established hyperalgesia and ankle swelling., Conclusions: IL1 inhibition both prevented and relieved pain and ankle joint inflammation in response to intra-articular MSU crystals in mice. Results suggested that IL1 Trap has the potential to both prevent and treat gouty arthritis.

Objective: To examine the therapeutic efficacy of an HMG-CoA reductase inhibitor (statin) in rabbit osteoarthritis (OA) in vitro and in vivo., Methods: In the presence or absence of mevastatin, rabbit chondrocytes and synoviocytes were incubated with Interleukin-1beta (IL-1beta), and analyzed by biochemical methods. Thirty-two mature rabbits that underwent bilateral anterior cruciate ligament transaction (ACLT) received six consecutive weekly intra-articular injections of mevastatin at three different concentrations or a control solution. All animals were sacrificed 6 weeks after ACLT, and the knee joints were assessed by morphological, histological, immunohistochemical, and biochemical methods., Results: Mevastatin inhibited IL-1beta stimulation of gene expression of monocyte chemoattractant protein-1 (MCP-1) and matrix-metalloproteinases 3 (MMP-3), in synoviocytes but not chondrocytes. The levels of MCP-1 and MMP-3 productions in synoviocytes were significantly reduced by statin-treatment. In rabbit with OA, intra-articular injection of mevastatin significantly reduced cartilage degradation, as assessed by morphological and histological examinations. Synovial tissues of knees treated with mevastatin showed less severe inflammatory responses with reduced thickness of synovial cell lining and less infiltration of subsynovial CD68+monocyte lineage cells compared to untreated control knees. Relative mRNA expressions of MCP-1, IL-1beta, MMP-3, and MMP-13 were reduced in synovial tissues, but not articular cartilage, of knees treated with mevastatin compared with untreated control knees., Conclusion: During the development of experimental OA, intra-articular administration of HMG-CoA reductase inhibitor (statin) reduces inflammatory cell infiltration and matrix-degrading enzyme expression, thus limiting cartilage degradation.

The aim of the present study is to investigate the potential therapeutic action of RvCSd, an oriental herbal mixture, in an experimental model of rheumatoid arthritis (RA). DBA/1J mice were immunized with type II collagen. After a second collagen immunization, mice were treated with RvCSd or methotrexate (MTX) orally once a day for 35 days, and the incidence, clinical score, and joint histopathology were evaluated. The inflammatory response cytokines and cartilage protection effect were determined by measuring the levels in the joints and sera. The Th1/Th2-mediated auto-reactive response was evaluated by determining the proliferative response and cytokines of drained spleen cells stimulated with type II collagen. RvCSd treatment significantly reduced the incidence and severity of CIA, markedly abrogating joint swelling, synovial hyperplasia, and cartilage destruction. RvCSd significantly inhibited the production of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha and IL-6, IL-2, interferon (IFN)-gamma, and matrix metalloproteinases (MMP)-1 and up-regulated anti-inflammatory cytokines IL-4, IL-10, and metalloproteinase (TIMP)-1 in mice with CIA. In conclusion, RvCSd has therapeutic effects exerted through inhibition of inflammatory and Th1 responses, regulation of MMP/TIMP, and induction of regulatory T cells in CIA; these effects make RvCSd an outstanding candidate for use as an immune suppressive and cartilage protective medicine in RA patients.

Objective: Investigation of the effects of diallyl sulfide (DAS), a garlic sulfur compound, on joint tissue inflammatory responses induced by monosodium urate (MSU) crystals and interleukin-1beta (IL-1beta)., Design: The HIG-82 synovial cell line was used to establish the experimental model and DAS regime. Primary cultures of articular chondrocytes and synovial fibroblasts obtained from patients undergoing joint replacement for osteoarthritis were used in experimental studies. Cyclooxygenase (COX) expression following MSU crystal and IL-1beta stimulation with/without DAS co-incubation was assessed by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunocytochemistry and nuclear factor-kappa B (NF-kappaB) activation determined by electrophoretic mobility shift assay. Prostaglandin E2 (PGE(2)) production was measured by enzyme-linked immunosorbent assay (ELISA). DAS effects on COX gene expression in an MSU crystal-induced acute arthritis in rats were assessed by RT-PCR., Results: MSU crystals upregulated COX-2 expression in HIG-82 cells and this was inhibited by co-incubation with DAS. DAS inhibited MSU crystal and IL-1beta induced elevation of COX-2 expression in primary synovial cells and chondrocytes. Production of PGE(2) induced by crystals was suppressed by DAS and celecoxib. MSU crystals had no effect on expression of COX-1 in synovial cells. NF-kappaB was activated by MSU crystals and this was blocked by DAS. Increased expression of COX-2 in synovium following intraarticular injection of MSU crystals in a rat model was inhibited by co-administration of DAS., Conclusions: DAS prevents IL-1beta and MSU crystal induced COX-2 upregulation in synovial cells and chondrocytes and ameliorates crystal induced synovitis potentially through a mechanism involving NF-kappaB. Anti-inflammatory actions of DAS may be of value in treatment of joint inflammation.

Recently, it has been demonstrated that oxygen free radicals have an important role as a signaling messenger in the development of inflammation and osteoclastogenesis, suggesting the implication of oxygen free radicals in the pathogenesis of arthritis. The aim of this study was to examine the potential of a strong free-radical scavenger, water-soluble fullerene (C60), as a protective agent against synovitis in arthritis, both in vitro and in vivo. In the presence or absence of C60 (0.1, 1.0, 10.0 muM), human synovial fibroblasts, synovial infiltrating lymphocytes or macrophages were incubated with tumor necrosis factor-alpha (TNF-alpha) (10.0 ng/mL), and the production of proinflammatory cytokines by the individual cells were analyzed. C60 significantly suppressed the TNF-alpha-induced production of proinflammatory cytokines in synovial fibroblasts, synovial infiltrating lymphocytes and macrophages in vitro. Adjuvant induced arthritic rats were used as an animal model of arthritis. Rats were divided into two subgroups: control and treatment with C60 at 10.0 muM. The left ankle joint was injected intraarticularly with water-soluble C60 (20 mul) in the C60-treated group, while, as a control, the left ankle joint in the control rats received phosphate-buffered saline (20 mul), once weekly for eight weeks. Ankle joint tissues were prepared for histological analysis. In adjuvant-induced arthritic rats, intra-articular treatment with C60 in vivo reduced synovitis and alleviated bone resorption and destruction in the joints, while control ankle joints showed progression of synovitis and joint destruction with time. These findings indicate that C60 is a potential therapeutic agent for inhibition of arthritis.

Preservation of normal joint function in patients with haemophilia is a goal of modern therapy. Regular injections of anti-haemophilic factor concentrate reduce the risk of joint bleeding, the optimal regimen for which remains under investigation. The goals of the experiment described here are: (i) to assess the capacity of a murine model of severe haemophilic arthropathy to predict the likelihood of success of a test product to prevent joint bleeding and the complications that follow and (ii) to compare the effectiveness of recombinant human activated factor VII (rFVIIa) to recombinant human factor VIII (rFVIII) to prevent acute joint bleeding in the mouse model of haemarthrosis. Mice lacking expression of FVIII received a single intravenous injection of human rFVIII (280 U kg(-1)), rFVIIa (10 mg kg(-1)) or vehicle prior to blunt trauma injury to the knee joint. Mice receiving rFVIII and rFVIIa developed less injury-induced joint bleeding, swelling and loss of range of motion compared to mice pretreated with vehicle. Despite the reduction in clinical symptoms, synovial hyperplasia was evident in all groups after 7 days although less pronounced in mice receiving rFVIII and rFVIIa. The data under these experimental conditions demonstrate: (i) that this model can be used to evaluate novel therapies designed to prevent joint bleeding (prophylaxis) and (ii) both rFVIII and rFVIIa reduced acute haemarthrosis but did not completely prevent synovitis, the sequelae of blood induced joint injury.

Hemophilic bleeding into joints causes synovial and microvascular proliferation and inflammation (hemophilic synovitis) that contribute to end-stage joint degeneration (hemophilic arthropathy), the major morbidity of hemophilia. New therapies are needed for joint deterioration that progresses despite standard intravenous (IV) clotting factor replacement. To test whether factor IX within the joint space can protect joints from hemophilic synovitis, we established a hemophilia B mouse model of synovitis. Factor IX knockout (FIX(-/-)) mice received a puncture of the knee joint capsule with a needle to induce hemarthrosis; human factor IX (hFIX) was either injected through the needle into the joint space (intraarticularly) or immediately delivered IV. FIX(-/-) mice receiving intraarticular FIX protein were protected from synovitis compared with mice receiving same or greater doses of hFIX IV. Next, adeno-associated virus (AAV) gene transfer vectors expressing hFIX were injected into knee joints of FIX(-/-) mice. Joints treated with 10(10) vector genomes (vg)/joint AAV2-, AAV5-, or AAV8-hFIX or 2.5 x 10(9) vg/joint AAV5-hFIX developed significantly fewer pathologic changes 2 weeks after injury compared with the pathology of control injured contralateral hind limbs. Extravascular factor activity and joint-directed gene transfer may ameliorate hemophilic joint destruction, even in the absence of circulating FIX.

Recurrent haemarthrosis results in chronic synovitis and destructive arthropathy. The long-term effect of a single haemorrhage is not known. To investigate the histopathological changes following a single, but major joint haemorrhage, an animal model of massive haemarthrosis without mechanical trauma was developed and is described in this manuscript. The knee joint capsule of mice deficient in coagulation factor VIII or IX and non-haemophilic wild type mice was punctured to induce a one time, but massive haemorrhage. The single joint puncture resulted in acute haemarthrosis in both types of haemophilic mice but not in wild type mice. Subsequent to injury, the changes in the knee joints were analysed using gross, histological and radiographic assessments and compared with the uninjured knee. In addition, a novel imaging modality, micro-computed tomography, was used to document the structural damage to the joint. Our results indicate that the long-term changes classically observed in patients with advanced haemophilic arthropathy are evident following a single massive haemarthrosis. This model will allow a thorough investigation of the pathobiology of blood-induced joint disease and will be useful to test the efficacy of innovative therapeutic strategies to prevent haemophilic synovitis and arthropathy.

Objective: To investigate the effect of the histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), on joint inflammation and cartilage degeneration in a collagen antibody-induced arthritis (CAIA) mouse model., Methods: CAIA mice were given daily subcutaneous injections of various concentrations of TSA (0, 0.5, 1.0, and 2.0 mg/kg) and various parameters were monitored for 14 days. On Day 15, the hind paws were examined histologically. To investigate the effects of TSA on the expressions of matrix metalloproteinase (MMP)-3, MMP-13, tissue inhibitor of MMP-1 (TIMP-1), and acetyl-H4 by chondrocytes, another group of mice was sacrificed on Day 6. In vitro direct effect of TSA was examined by real-time PCR for mRNA of type II collagen, aggrecan, MMP-3, and MMP-13 in murine chondrogenic ATDC5 cells after pro-inflammatory cytokine stimulation., Results: In the TSA-treated group, clinical arthritis was significantly ameliorated in a dose-dependent manner. The severity of synovial inflammation and the cartilage destruction score were significantly lower in the TSA 2.0 mg/kg group compared to the other TSA-treated groups. On immunohistochemistry, the number of MMP-3 and MMP-13-positive chondrocytes was significantly lower in the TSA 2.0 mg/kg group than in the control group. In contrast, the number of TIMP-1-positive cells and acetyl-histone H4-positive cells was significantly higher in the TSA 2.0mg/kg group than in the control group. TSA suppressed interleukin 1-beta and tumor necrosis factor-alpha-stimulated up-regulation of MMP-3, but not MMP-13 mRNA expression by ATDC5., Conclusion: The systemic administration of TSA ameliorated synovial inflammation in CAIA mice. Subsequently cartilage destruction was also suppressed by TSA, at least in part, by modulating chondrocyte gene expression.

The most frequent, severe clinical manifestation of hemophilia is hemarthrosis, which often develops at a young age and is initiated by repeated joint bleeds. Blood within a joint results in inflammation and hypertrophy of synovial membranes, causing increased vascularization of the joint and bone degeneration. In addition, hemarthrosis is associated with pain, impaired mobility, and reduced health-related quality of life (HRQoL). Although data on the effect of joint pain on pediatric HRQoL are currently lacking, both health-related outcome and treatment-experience studies reported the benefits of early identification, assessment, and treatment of pain in improving patient outcome and HRQoL. Ultimately, prevention of bleeding through aggressive treatment of joint bleeds and prophylaxis with factor concentrates are key to ensuring the best musculoskeletal outcome for pediatric patients with hemophilia.

Osteoarthritis is primarily characterized by areas of destruction of articular cartilage and by synovitis. Articular damage and synovitis are secondary to local increase of pro-inflammatory cytokines (interleukin-1beta and tumor necrosis factor-alpha), enzymes with proteolytic activity (matrix metalloproteinases), and enzymes with pro-inflammatory activity (cyclooxygenase-2 and nitric oxide synthase-2). Enhanced expression of these proteins in chondrocytes and in synovial membrane appears associated to the activation and nuclear translocation of nuclear factor-kappaB (NF-kappaB). Chondroitin sulfate (CS) prevents joint space narrowing and reduces joint swelling and effusion. To produce these effects, CS elicits an anti-inflammatory effect at the chondral and synovial levels. CS and its disaccharides reduce NF-kappaB nuclear translocation, probably by diminishing extracellular signal-regulated kinase1/2, p38mitogen-activated protein kinase and c-Jun N-terminal kinase activation. This review discusses the evidence supporting that CS pleiotropic effects in chondrocytes and synoviocytes are primarily due to a common mechanism, e.g., the inhibition of NF-kappaB nuclear translocation.

Patients with severe haemophilia A (HA) can either be treated by regular FVIII infusions twice or three times per week (prophylaxis), or only in case of bleeding episodes (on-demand). Whereas prophylaxis reduces the number of bleeding episodes and may therefore prevent the development of haemophilic arthropathy, there is still a lot of controversy surrounding recommendations on age and dose at start of prophylactic regimens. The present database study was performed to investigate the role of primary versus secondary prophylaxis in HA children. The outcome variable was imaging-proven haemophilic joint damage. Forty-two children were initially treated with primary prophylaxis following the first bleeding episode, and were frequency-matched (year of birth, catchment area) to 67 patients receiving "on-demand" therapy with an early switch to "secondary prophylaxis". In multivariate analysis adjusted for the HA mutation type and the presence or absence of thrombophilia, the Pettersson score investigated at a median age of 12.5 years in joints with at least one documented bleeding episode was not significantly different between the two patient groups (p = 0.944), and no statistically significant differences were found in patients with target joints (p = 0.3), nor in children in whom synovitis had occurred (p = 0.77). No conclusion can be drawn from the data presented herein whether primary prophylaxis or an early start of secondary prophylaxis is superior with respect to joint outcome in children with severe HA.

Objectives: All complement pathways lead to the formation of C5a, which is believed to contribute to the influx and activation of C5a-receptor (C5aR) bearing cells into the joints of patients with rheumatoid arthritis (RA). Studies in animal models of RA have suggested therapeutic potential of C5aR blockade. In this study, we examined the effects of the C5aR blockade on synovial inflammation in RA patients., Methods: We performed a double-blind, placebo-controlled study using an orally administered C5aR-antagonist. Twenty-one patients with active RA were randomized 2:1 to treatment with a C5aR-antagonist AcF- (OpdChaWR) (PMX53) vs placebo for 28 days. Serum concentrations of PMX53 were determined. Synovial tissue was obtained at baseline and after 28 days of treatment for pharmacodynamic analysis using immunohistochemistry and digital image analysis., Results: All patients completed the study. Areas under the curve (AUCs) of PMX53 in patients' blood samples showed a mean of 40.8 nmol h/l. There was neither decrease in cell infiltration, nor changes in key biomarkers associated with clinical efficacy after active treatment. In addition, there was no trend towards clinical improvement in the C5aR-antagonist-treated group compared with placebo nor was there a correlation between the AUC and clinical response., Conclusions: Treatment with PMX53 did not result in a reduction of synovial inflammation despite reaching serum levels of PMX53 that block C5aR-mediated cell activation in vitro. The data suggest that C5aR blockade does not result in reduced synovial inflammation in RA patients.

Prophylaxis is paramount to try to avoid the development of haemophilic synovitis. The best treatment for synovitis in patients with inhibitors is radioactive synoviorthesis (rhenium for ankle and elbows, yttrium for knees). With both methods (prohylaxis and radioactive synoviorthesis), we can delay the development of severe haemophilic arthropathy, that eventually will require major orthopaedic surgery.

It has been proven that early prophylactic therapy can prevent bleeding and arthropathy. Numerous retrospective non-randomized cohort studies have demonstrated that prophylaxis, if started early in life, is associated with a considerable reduction of the mean number of joint bleeds and the rate of joint deterioration. It is quite extraordinary that despite the considerable evidence base it has been considered necessary by investigators to pursue the ideal of the controlled randomized trial and expose children to the risk of cerebral bleed. This questionable ethical approach is driven by the reluctance of the 'willingness to pay' but it is important that patients are not subjected to unnecessary investigation at either the behest of the Cochrane Database or those who control the financing of haemophilia care.