Etanercept in patients with inflammatory hand osteoarthritis (EHOA): a multicentre, randomised, double-blind, placebo-controlled trial

Inflammation as a therapeutic target for osteoarthritis: A literature review of clinical trials

The burden of osteoarthritis (OA) is rapidly increasing with population aging, but there are still no approved disease-modifying drugs available. Accumulating evidence has shown that OA is a heterogeneous disease with multiple phenotypes, and it is unlikely to respond to one-size-fits-all treatments. Inflammation is recognized as an important phenotype of OA and is associated with worse pain and joint deterioration. Therefore, it is believed that anti-inflammatory treatments may be more effective for OA with an inflammatory phenotype. In this review, we summarized clinical trials that evaluated anti-inflammatory treatments for OA and discussed whether these treatments are more effective in inflammatory OA phenotypes compared to general OA patients.

Hand osteoarthritis: A fresh look

Hand osteoarthritis (OA) has been the subject of numerous publications in recent years, particularly in the fields of imaging and therapeutics. The imaging studies revealed a good correlation between the presence of synovitis and/or subchondral edema and arthritic joint pain. Several randomized controlled trials (RCTs) have assessed the efficacy of biologics and conventional DMARDs in patients with symptomatic hand OA. No less than six RCTs have evaluated the symptomatic and, in some cases, structural efficacy of anti-IL-1, anti-TNF or anti-IL-6 drugs. Overall, the results of these trials were disappointing - none of them demonstrated superiority over placebo. There were also two negative trials with hydroxychloroquine. In the end, the only trial that was positive evaluated 10mg oral prednisone versus placebo for 6 weeks in patients with flares of hand OA and synovitis visible on ultrasound. While that trial confirms the role of inflammation in hand OA, it should obviously not encourage the long-term use of corticosteroids as a symptomatic treatment.

Repurposing drugs for the treatment of osteoarthritis

OBJECTIVE

Currently, no disease-modifying therapies for osteoarthritis (OA) exist, and attempts to identify novel cellular targets have been challenging. Risk factors for OA include advanced age, obesity, and metabolic syndrome. This creates an attractive opportunity to repurpose existing drugs that are used to treat comorbidities commonly encountered in patients with OA, if those drugs possess OA disease modifying properties.

METHODS

This narrative review incorporates findings from knee or hand OA randomized clinical trials, post-hoc clinical trial analyses, prospective cohort studies, and observational data.

RESULTS

Drugs used for the treatment of rheumatoid arthritis (methotrexate; TNFa, IL-1, and IL-6 pathway inhibitors; hydroxychloroquine), atopic/allergic disease (anti-histamines), osteoporosis (bisphosphonates and vitamin D), type 2 diabetes (metformin and GLP-1 agonists), and cardiovascular disease (atorvastatin, fish oil, and beta blockers) were reviewed for their potential benefit in OA. This review outlines the successful attributes of repurposed drugs, the challenges in repurposing drugs, and strategies for future clinical trials to support OA drug repurposing. Potential drug candidates for OA may be identified through the use of existing datasets and via collaborations with researchers in other fields to include OA endpoints in future clinical trials.

CONCLUSION

Given the association of OA with several commonly treated comorbidities, drug repurposing is an appealing approach that could provide a favorable benefit-to-risk ratio for chronic OA treatment.

Systematic review and network meta-analysis on the efficacy and safety of parmacotherapy for hand osteoarthritis

OBJECTIVE

Hand osteoarthritis poses a significant health challenge globally due to its increasing prevalence and the substantial burden on individuals and the society. In current clinical practice, treatment options for hand osteoarthritis encompass a range of approaches, including biological agents, antimetabolic drugs, neuromuscular blockers, anti-inflammatory drugs, hormone medications, pain relievers, new synergistic drugs, and other medications. Despite the diverse array of treatments, determining the optimal regimen remains elusive. This study seeks to conduct a network meta-analysis to assess the effectiveness and safety of various drug intervention measures in the treatment of hand osteoarthritis. The findings aim to provide evidence-based support for the clinical management of hand osteoarthritis.

METHODS

We performed a comprehensive search across PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials was conducted until September 15th, 2022, to identify relevant randomized controlled trials. After meticulous screening and data extraction, the Cochrane Handbook's risk of bias assessment tool was applied to evaluate study quality. Data synthesis was carried out using Stata 15.1 software.

RESULTS

21 studies with data for 3965 patients were meta-analyzed, involving 20 distinct Western medicine agents. GCSB-5, a specific herbal complex that mainly regulate pain in hand osteoarthritis, showed the greatest reduction in pain [WMD = -13.00, 95% CI (-26.69, 0.69)]. CRx-102, s specific medication characterized by its significant effect for relieving joint stiffness symptoms, remarkably mitigated stiffness [WMD = -7.50, 95% CI (-8.90, -6.10)]. Chondroitin sulfate displayed the highest incidence of adverse events [RR = 0.26, 95% CI (0.06, 1.22)]. No substantial variation in functional index for hand osteoarthritis score improvement was identified between distinct agents and placebo.

CONCLUSIONS

In summary, GCSB-5 and CRx-102 exhibit efficacy in alleviating pain and stiffness in HOA, respectively. However, cautious interpretation of the results is advised. Tailored treatment decisions based on individual contexts are imperative.

Erosive Hand Osteoarthritis: Recent Advances and Future Treatments

PURPOSE OF THE REVIEW

Erosive hand osteoarthritis (EHOA) is an aggressive form of hand osteoarthritis that leads to significant disability, and recent data suggests that it is increasing in prevalence. This review provides an update of our current understanding of epidemiology, genetic associations, biomarkers, pathogenesis, and treatment of EHOA, with particular focus on studies published within the last 5 years.

RECENT FINDINGS

New studies of EHOA have identified new genetic loci associated with disease, including variants in genes involved in inflammation and bone remodeling. Preclinical studies implicate pathways of innate immunity, including some that may be causal in the condition. Recent novel studies showed that inflammatory features identified by ultrasound and MRI are associated with development of erosive lesions over time on conventional radiography. In the future, these imaging modalities may be useful in identifying patients at risk of adverse outcomes. Promising new findings in genetics, biomarkers, and treatment targets will hopefully allow for future therapeutic options for this debilitating condition.

Immunomodulatory Strategies for Cartilage Regeneration in Osteoarthritis

Osteoarthritis (OA) is the most prevalent musculoskeletal disorder and a leading cause of disability globally. Although many efforts have been made to treat this condition, current tissue engineering (TE) and regenerative medicine strategies fail to address the inflammatory tissue environment that leads to the rapid progression of the disease and prevents cartilage tissue formation. First, this review addresses in detail the current anti-inflammatory therapies for OA with a special emphasis on pharmacological approaches, gene therapy, and mesenchymal stromal cell (MSC) intra-articular administration, and discusses the reasons behind the limited clinical success of these approaches at enabling cartilage regeneration. Then, we analyze the state-of-the-art TE strategies and how they can be improved by incorporating immunomodulatory capabilities such as the optimization of biomaterial composition, porosity and geometry, and the loading of anti-inflammatory molecules within an engineered structure. Finally, the review discusses the future directions for the new generation of TE strategies for OA treatment, specifically focusing on the spatiotemporal modulation of anti-inflammatory agent presentation to allow for tailored patient-specific therapies. Impact statement Osteoarthritis (OA) is a prevalent and debilitating musculoskeletal disorder affecting millions worldwide. Despite significant advancements in regenerative medicine and tissue engineering (TE), mitigating inflammation while simultaneously promoting cartilage tissue regeneration in OA remains elusive. In this review article, we discuss current anti-inflammatory therapies and explore their potential synergy with cutting-edge cartilage TE strategies, with a special focus on novel spatiotemporal and patient-specific anti-inflammatory strategies.

Senescence-regulatory factors as novel circulating biomarkers and therapeutic targets in regenerative medicine for osteoarthritis

Recent discoveries reveal that the chronic presence of senescent cells in osteoarticular tissues provides a focal point of disease development for osteoarthritis (OA). Nevertheless, senescence-regulatory factors associated with OA still need to be identified. Furthermore, few diagnostic- and prognostic-validated biochemical markers (biomarkers) are currently used in clinics to evaluate OA patients. In the future, alongside imaging and clinical examination, detecting senescence-regulatory biomarkers in patient fluids could become a prospective method for disease: diagnosis, monitoring, progression and prognosis following treatment. This review summarizes a group of circulating OA biomarkers recently linked to senescence onset. Remarkably, these factors identified in proteomics, metabolomic and microRNA studies could also have deleterious or protective roles in osteoarticular tissue homeostasis. In addition, we discuss their potentially innovative modulation in combination with senotherapeutic approaches, for long-lasting OA treatment.

Advancing Rheumatology Care Through Machine Learning

Rheumatologic diseases are marked by their complexity, involving immune-, metabolic- and mechanically mediated processes which can affect different organ systems. Despite a growing arsenal of targeted medications, many rheumatology patients fail to achieve full remission. Assessing disease activity remains challenging, as patients prioritize different symptoms and disease phenotypes vary. This is also reflected in clinical trials where the efficacy of drugs is not necessarily measured in an optimal way with the traditional outcome assessment. The recent COVID-19 pandemic has catalyzed a digital transformation in healthcare, embracing telemonitoring and patient-reported data via apps and wearables. As a further driver of digital medicine, electronic medical record (EMR) providers are actively engaged in developing algorithms for clinical decision support, heralding a shift towards patient-centered, decentralized care. Machine learning algorithms have emerged as valuable tools for handling the increasing volume of patient data, promising to enhance treatment quality and patient well-being. Convolutional neural networks (CNN) are particularly promising for radiological image analysis, aiding in the detection of specific lesions such as erosions, sacroiliitis, or osteoarthritis, with several FDA-approved applications. Clinical predictions, including numerical disease activity forecasts and medication choices, offer the potential to optimize treatment strategies. Numeric predictions can be integrated into clinical workflows, allowing for shared decision making with patients. Clustering patients based on disease characteristics provides a personalized care approach. Digital biomarkers, such as patient-reported outcomes and wearables data, offer insights into disease progression and therapy response more flexibly and outside patient consultations. In association with patient-reported outcomes, disease-specific digital biomarkers via image recognition or single-camera motion capture enables more efficient remote patient monitoring. Digital biomarkers may also play a major role in clinical trials in the future as continuous, disease-specific outcome measurement facilitating decentralized studies. Prediction models can help with patient selection in clinical trials, such as by predicting high disease activity. Efforts are underway to integrate these advancements into clinical workflows using digital pathways and remote patient monitoring platforms. In summary, machine learning, digital biomarkers, and advanced imaging technologies hold immense promise for enhancing clinical decision support and clinical trials in rheumatology. Effective integration will require a multidisciplinary approach and continued validation through prospective studies.

RANKL blockade for erosive hand osteoarthritis: a randomized placebo-controlled phase 2a trial

Erosive hand osteoarthritis (OA) is a prevalent and disabling disease with limited treatment options. Here we present the results of a monocentric, placebo-controlled, double-blind, randomized phase 2a clinical trial with denosumab, a receptor activator of nuclear factor-κB ligand inhibitor, evaluating the effects on structure modification in erosive hand OA. Patients were randomized to 48 weeks treatment with denosumab 60 mg every 3 months (n = 51, 41 females) or placebo (n = 49, 37 females). The primary (radiographic) endpoint was the change in the total Ghent University Scoring System (GUSS) at week 24, where positive changes correspond to remodeling and negative changes to erosive progression. Secondary endpoints were the change in the GUSS at week 48 and the number of new erosive joints at week 48 by the anatomical phase scoring system. Baseline mean GUSS (standard deviation) of target joints was 155.9 (69.3) in the denosumab group and 158.7 (46.8) in the placebo group. The primary endpoint was met with an estimated difference between groups of 8.9 (95% confidence interval (CI) 1.0 to 16.9; P = 0.024) at week 24. This effect was confirmed at week 48 (baseline adjusted GUSS (standard error of the mean) denosumab and placebo were 163.5 (2.9) and 149.2 (3.9), respectively; with an estimated difference between groups of 14.3 (95% CI 4.6 to 24.0; P = 0.003)). At patient level, more new erosive joints were developed in the placebo group compared with denosumab at week 48 (odds ratio 0.24 (95% CI 0.08 to 0.72); P = 0.009). More adverse events occurred in the placebo group (125 events in 44 patients (90%)) compared with the denosumab group (97 events in 41 patients (80%)). These results demonstrate that denosumab has structure modifying effects in erosive hand OA by inducing remodeling and preventing new erosive joints. EU Clinical Trials Register identifier 2015-003223-53 .

Could sex-specific subtypes of hand osteoarthritis exist? A retrospective study in women presenting to secondary care

Introduction

Hand osteoarthritis is more common in women, and its risk increases around the time of the menopause. We set out to describe the timing between menopause and the onset of symptomatic hand osteoarthritis (OA), and associations with the use of hormone replacement therapy (HRT) or its discontinuation, describing any identifiable subgroups of women.

Methods

Retrospective healthcare-records study of sequential women referred to a specialist hand OA clinic, 2007-2015. Confirmation of hand OA diagnosis was by clinican, by accepted criteria. Demographics and clinical variables were from healthcare-records, recorded by standardised proforma. Outcomes of interest were reported age of onset of hand symptoms, reported age at final menstrual period (FMP), time from FMP to reported onset of hand symptoms and time from cessation of HRT to reported onset of hand symptoms. Exposure categories for systemic HRT use were never users, current users, previous users. Analysis of Variance compared groups; linear regression analysed associations of exposure with outcome.

Results

82/92(89%) of eligible women were post-menopausal, mean age at FMP 49.9 years (SD5.4). In these post-menopausal women, median time from FMP to hand symptom onset was 3 years. 48/82 (59%) developed hand symptoms within the defined peri-menopausal period (FMP ± 4 years), whilst some women developed their symptoms before or after (range -25, 30 years). In women who discontinued HRT prior to symptom onset, the median time from HRT cessation to onset of hand symptoms was 6 months. Past HRT users were older at hand symptom onset than women who had not taken HRT [coeff.4.7 years (0.92, 8.39); P = 0.015].

Conclusions

This study adds to evidence associating the menopause/sex hormone deficiency with hand OA symptom onset in a sizeable subgroup of women (but not all). HRT use/cessation appears to influence the timing of onset of hand OA symptoms. It is not possible to interpret from this type of study whether sex hormone deficiency is causative of disease or modulates its symptoms. It is also not possible to judge whether painful hand osteoarthritis in post-menopausal women is a subtype of disease. Further investigation is indicated of sex-specific subtypes and potential for personalised medicine for post-menopausal women with hand osteoarthritis, as a clearly definable high-risk subgroup.

Synovial inflammation in osteoarthritis. A treatable target?

Synovial inflammation is present in osteoarthritis and associated with pain and structural damage, so it is hypothesized that anti-inflammatory drugs might be of use in osteoarthritis. However, nine randomized clinical trials targeting pro-inflammatory cytokines, especially IL-1 and TNFα, did not show an effect on short-term pain relief (as primary end-points). These results were rather disappointing. The questions is whether the results reflect a true lack of effect of anti-inflammatory drugs in osteoarthritis, or whether there are alternative explanations. Currently, we lack insight in the pathobiology of the synovitis-driven endotype and in cross-talk between tissues in the osteoarthritic joint, complicating identification of the appropriate patients for trials and of the best outcome measures. Furthermore we lack classification criteria to define inflammatory osteoarthritis complicating selection of patients. We do know that anti-inflammatory corticosteroids alleviate pain in osteoarthritis, warranting further investigation of other mediators than IL-1 and TNFα. Now, trials are set up with short follow-up aiming for short-term pain alleviation. For investigation of pain alleviation in the context of disease modification, trials with at least one year follow-up should be performed.

Efficacy of Herbal Medicine in Hand Osteoarthritis: A Narrative Review

OBJECTIVE

Osteoarthritis (OA) is one of the most prevalent joint disorders in the world that has placed an enormous economic and social burden on governments and healthcare sectors in many countries. Hand OA (HOA) is the most common peripheral arthritis, which is less investigated than knee and hip OA. Due to limited approved drug choices and adverse effects of long-term use of current regimens, we aimed to review the existing evidence that were used as oral herbal medicine to treat HOA.

METHODS

The PubMed database was searched for both observational and interventional studies that have investigated herbal medicine safety and efficacy in HOA, written in English and published between 2010 and 2022.

RESULTS

A total of 5 original articles fulfilled the inclusion criteria, and each article assessed a different herbal regimen. Overall, it seems desirable to add specific herbal treatments to the regimen of HOA patients, specifically in case of early stages of HOA.

CONCLUSION

Currently, the need for a low-risk alternative treatment in HOA patients is felt more than ever. There are reliable references relating to the safety of Korean red ginseng, GCSB-5, XLGB, and GS-GCu in these patients, although their efficacy was limited. Additionally, herbs like curcumin and Boswellia serrata have positively affected patients with knee osteoarthritis. However, there is a lack of strong evidence supporting their effectiveness in hand osteoarthritis (HOA). This emphasizes the potential benefits that these herbs may have for HOA patients.

CircIRAK3 exerts negative feedback regulation on inflammation by binding to HNRNP U and destabilizing proinflammatory cytokine mRNA in osteoarthritis and chondrogenesis

Osteoarthritis (OA) is the most prevalent age-related and degenerative joint disease with limited treatment options. Previous studies have identified the therapeutic effects of mesenchymal stem cells (MSCs) therapy. Nevertheless, chronic inflammation impedes MSCs therapeutic effect. There have been reports suggesting that circular RNAs (circRNAs) are involved in OA and chondrogenesis. The combination of MSCs and circRNAs in therapies appears to be a promising option. In this study, we identified circIRAK3 as a significant regulator in cartilage degeneration and chondrogenesis through high-throughput sequencing analyses. We observed increased circIRAK3 in OA cartilage and during MSCs chondrogenesis. Knockdown of circIRAK3 resulted in excessive apoptosis, inhibited proliferation, and degradation of chondrocytes, along with the inhibition of MSCs chondrogenesis. Mechanistically, circIRAK3 bound to HNRNP U and competitively prevented its binding to IL-1β, TNFα, and IL6 mRNA, thereby promoting mRNA degradation. Notably, circIRAK3 expression in plasma increased with higher OARSI scores. Intra-articular injection of adeno-associated virus-circIRAK3 delayed cartilage degeneration and reduced inflammation in DMM mouse model. Our study highlights a compensatory regulation network of circIRAK3 in chondrocytes in response to inflammation. CircIRAK3 has the potential to serve as a new therapeutic target for OA. Furthermore, therapies targeting circIRAK3 combined with MSCs hold promise.

Evaluating the potential of Vitamin D and curcumin to alleviate inflammation and mitigate the progression of osteoarthritis through their effects on human chondrocytes: A proof-of-concept investigation

Osteoarthritis (OA) is a chronic degenerative joint disorder primarily affecting the elderly, characterized by a prominent inflammatory component. The long-term side effects associated with current therapeutic approaches necessitate the development of safer and more efficacious alternatives. Nutraceuticals, such as Vitamin D and curcumin, present promising therapeutic potentials due to their safety, efficacy, and cost-effectiveness. In this study, we utilized a proinflammatory human chondrocyte model of OA to assess the anti-inflammatory properties of Vitamin D and curcumin, with a particular focus on the Protease-Activated Receptor-2 (PAR-2) mediated inflammatory pathway. Employing a robust siRNA approach, we effectively modulated the expression of PAR-2 to understand its role in the inflammatory process. Our results reveal that both Vitamin D and curcumin attenuate the expression of PAR-2, leading to a reduction in the downstream proinflammatory cytokines, such as Tumor Necrosis Factor-alpha (TNF-α), Interleukin 6 (IL-6), and Interleukin 8 (IL-8), implicated in the OA pathogenesis. Concurrently, these compounds suppressed the expression of Receptor Activator of Nuclear Factor kappa-Β Ligand (RANKL) and its receptor RANK, which are associated with PAR-2 mediated TNF-α stimulation. Additionally, Vitamin D and curcumin downregulated the expression of Interferon gamma (IFN-γ), known to elevate RANKL levels, underscoring their potential therapeutic implications in OA. This study, for the first time, provides evidence of the mitigating effect of Vitamin D and curcumin on PAR-2 mediated inflammation, employing an siRNA approach in OA. Thus, our findings pave the way for future research and the development of novel, safer, and more effective therapeutic strategies for managing OA.

Efficacy of tumor necrosis factor inhibitors in hand osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

Objectives

This study aimed at systematically review the evidence for the efficacy of Tumor Necrosis Factor (TNF) inhibitors on symptoms and structural outcomes in hand osteoarthritis.

Methods

Three databases were searched for randomized controlled trials examining the efficacy of TNF inhibitors in hand osteoarthritis. Two authors extracted data and assessed the risk of bias. The mean difference (MD) was calculated, and a random-effects meta-analysis was performed.

Results

Four studies were identified involving 276 participants. Meta-analysis showed that TNF inhibitors had no effect on pain at 4-6 weeks (MD -0.93, 95%CI -7.41 to 5.55; 2 studies) and 24-26 weeks (MD -3.82, 95%CI -11.46 to 3.83; 2 studies) and no effect on grip strength at 12 months (MD -0.35, 95%CI -1.08 to 0.37; 2 studies). There was limited evidence for the effect of TNF inhibitors on structural outcomes at 12 months. Subgroup analysis from 2 studies showed beneficial effect of TNF inhibitors on reducing the progression of structural outcomes in hand OA patients with signs of inflammation but not in those without inflammation. The certainty of the evidence was low for the effect of TNF inhibitor on pain and moderate for the effect on grip strength.

Conclusion

This study found no effect of TNF inhibitors on clinical outcomes in hand osteoarthritis over the short term (<6 weeks) and within one year, with some evidence for beneficial effect on structural outcomes.

Methotrexate to treat hand osteoarthritis with synovitis (METHODS): an Australian, multisite, parallel-group, double-blind, randomised, placebo-controlled trial

BACKGROUND

Hand osteoarthritis is a disabling condition with few effective therapies. Hand osteoarthritis with synovitis is a common inflammatory phenotype associated with pain. We aimed to examine the efficacy and safety of methotrexate at 6 months in participants with hand osteoarthritis and synovitis.

METHODS

In this multisite, parallel-group, double-blind, randomised, placebo-controlled trial, participants (aged 40-75 years) with hand osteoarthritis (Kellgren and Lawrence grade ≥2 in at least one joint) and MRI-detected synovitis of grade 1 or more were recruited from the community in Melbourne, Hobart, Adelaide, and Perth, Australia. Participants were randomly assigned (1:1) using block randomisation, stratified by study site and self-reported sex, to receive methotrexate 20 mg or identical placebo orally once weekly for 6 months. The primary outcome was pain reduction (measured with a 100 mm visual analogue scale; VAS) in the study hand at 6 months assessed in the intention-to-treat population. Safety outcomes were assessed in all randomly assigned participants. This trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12617000877381).

FINDINGS

Between Nov 22, 2017, and Nov 8, 2021, of 202 participants who were assessed for eligibility, 97 (48%) were randomly assigned to receive methotrexate (n=50) or placebo (n=47). 68 (70%) of 97 participants were female and 29 (30%) were male. 42 (84%) of 50 participants in the methotrexate group and 40 (85%) of 47 in the placebo group provided primary outcome data. The mean change in VAS pain at 6 months was -15·2 mm (SD 24·0) in the methotrexate group and -7·7 mm (25·3) in the placebo group, with a mean between-group difference of -9·9 (95% CI -19·3 to -0·6; p=0·037) and an effect size (standardised mean difference) of 0·45 (0·03 to 0·87). Adverse events occurred in 31 (62%) of 50 participants in the methotrexate group and 28 (60%) of 47 participants in the placebo group.

INTERPRETATION

Treatment of hand osteoarthritis and synovitis with 20 mg methotrexate for 6 months had a moderate but potentially clinically meaningful effect on reducing pain, providing proof of concept that methotrexate might have a role in the management of hand osteoarthritis with an inflammatory phenotype.

FUNDING

National Health and Medical Research Council of Australia.

Combining single-cell RNA sequencing and population-based studies reveals hand osteoarthritis-associated chondrocyte subpopulations and pathways

Hand osteoarthritis is a common heterogeneous joint disorder with unclear molecular mechanisms and no disease-modifying drugs. In this study, we performed single-cell RNA sequencing analysis to compare the cellular composition and subpopulation-specific gene expression between cartilage with macroscopically confirmed osteoarthritis (n = 5) and cartilage without osteoarthritis (n = 5) from the interphalangeal joints of five donors. Of 105 142 cells, we identified 13 subpopulations, including a novel subpopulation with inflammation-modulating potential annotated as inflammatory chondrocytes. Fibrocartilage chondrocytes exhibited extensive alteration of gene expression patterns in osteoarthritic cartilage compared with nonosteoarthritic cartilage. Both inflammatory chondrocytes and fibrocartilage chondrocytes showed a trend toward increased numbers in osteoarthritic cartilage. In these two subpopulations from osteoarthritic cartilage, the ferroptosis pathway was enriched, and expression of iron overload-related genes, e.g., FTH1, was elevated. To verify these findings, we conducted a Mendelian randomization study using UK Biobank and a population-based cross-sectional study using data collected from Xiangya Osteoarthritis Study. Genetic predisposition toward higher expression of FTH1 mRNA significantly increased the risk of hand osteoarthritis (odds ratio = 1.07, 95% confidence interval: 1.02-1.11) among participants (n = 332 668) in UK Biobank. High levels of serum ferritin (encoded by FTH1), a biomarker of body iron overload, were significantly associated with a high prevalence of hand osteoarthritis among participants (n = 1 241) of Xiangya Osteoarthritis Study (P-for-trend = 0.037). In conclusion, our findings indicate that inflammatory and fibrocartilage chondrocytes are key subpopulations and that ferroptosis may be a key pathway in hand osteoarthritis, providing new insights into the pathophysiology and potential therapeutic targets of hand osteoarthritis.

Pharmatherapeutic Treatment of Osteoarthrosis-Does the Pill against Already Exist? A Narrative Review

The aim of this narrative review is to summarize the current pharmacotherapeutic treatment options for osteoarthritis (OA). Is therapy still mainly symptomatic or does the pill against arthrosis already exist? Causal and non-causal, as well as future therapeutic approaches, are discussed. Various surgical and non-surgical treatment options are available that can help manage symptoms, slow down progression, and improve quality of life. To date, however, therapy is still mainly symptomatic, often using painkilling and anti-inflammatory drugs until the final stage, which is usually joint replacement. These "symptomatic pills against" have side effects and do not alter the progression of OA, which is caused by an imbalance between degenerative and regenerative processes. Next to resolving mechanical issues, the goal must be to gain a better understanding of the cellular and molecular basis of OA. Recently, there has been a lot of interest in cartilage-regenerative medicine and in the current style of treating rheumatoid arthritis, where drug therapy ("the pill against") has been established to slow down or even stop the progression of rheumatoid arthritis and has banned the vast majority of former almost regular severe joint destructions. However, the "causal pill against" OA does not exist so far. First, the early detection of osteoarthritis by means of biomarkers and imaging should therefore gain more focus. Second, future therapeutic approaches have to identify innovative therapeutic approaches influencing inflammatory and metabolic processes. Several pharmacologic, genetic, and even epigenetic attempts are promising, but none have clinically improved causal therapy so far, unfortunately.

Osteoarthritic chondrocytes undergo a glycolysis-related metabolic switch upon exposure to IL-1b or TNF

BACKGROUND

Osteoarthritis is an age-related disease that currently faces a lack of symptomatic treatment. Inflammation, which is mainly sustained by pro-inflammatory cytokines such as IL-1b, TNF, and IL-6, plays an important role in osteoarthritis progression. In this context, pro-inflammatory cytokines are widely used to mimic the inflammatory component of osteoarthritis in vitro. However, the therapeutic failures of clinical trials evaluating anti-cytokines drugs highlight the lack of overall understanding of the effects of these cytokines on chondrocytes.

METHODS

Here, we generated a comprehensive transcriptomic and proteomic dataset of osteoarthritic chondrocytes treated with these cytokines to describe their pro-inflammatory signature and compare it to the transcriptome of non-osteoarthritic chondrocytes. Then, the dysregulations highlighted at the molecular level were functionally confirmed by real-time cellular metabolic assays.

RESULTS

We identified dysregulation of metabolic-related genes in osteoarthritic chondrocytes but not in non-osteoarthritic chondrocytes. A metabolic shift, toward increased glycolysis at the expense of mitochondrial respiration, was specifically confirmed in osteoarthritic chondrocytes treated with IL-1b or TNF.

CONCLUSION

These data show a strong and specific association between inflammation and metabolism in osteoarthritic chondrocytes, which was not found in non-osteoarthritic chondrocytes. This indicates that the link between inflammation and metabolic dysregulation may be exacerbated during chondrocyte damage in osteoarthritis. Video Abstract.

What is new in pharmacological treatment for osteoarthritis?

Osteoarthritis (OA) is a degenerative joint disease in which structural changes of hyaline articular cartilage, subchondral bone, ligaments, capsule, synovium, muscles, and periarticular changes are involved. The knee is the most commonly affected joint, followed by the hand, hip, spine, and feet. Different pathological mechanisms are at play in each of these various involvement sites. Although systemic inflammation is more prominent in hand OA, knee and hip OA have been associated with excessive joint load and injury. As OA has varied phenotypes and the primarily affected tissues differ, treatment options must be tailored accordingly. In recent years, ongoing efforts have been made to develop disease-modifying options that halt or slow disease progression. Many are still in clinical trials, and as insights into the pathogenesis of OA evolve, novel therapeutic strategies will be developed. In this chapter, we provide an overview of the novel and emerging strategies in the management of OA.

Comprehensive analysis of arachidonic acid metabolism-related genes in diagnosis and synovial immune in osteoarthritis: based on bulk and single-cell RNA sequencing data

BACKGROUND

Osteoarthritis (OA) is one of degenerative-related arthritis, which can be aggravated by low-grade synovitis. It is known that arachidonic acid (AA) dysmetabolism brings OA synovitis. However, the impact of synovial AA metabolism pathway (AMP) related genes on OA remains uncovered.

METHODS

Here, we conducted a comprehensive analysis to explore the impact of AA metabolism genes in OA synovium. We obtained transcriptome expression profiles from three raw datasets related to OA synovium (GSE12021, GSE29746, GSE55235) and identified the hub genes of AA metabolism pathways (AMP) in OA synovium. An OA occurrence diagnostic model was constructed and validated based on the identified hub genes. Then, we explored the correlation between hub gene expression and the immune-related module using CIBERSORT and MCP-counter analysis. The unsupervised consensus clustering analysis and weighted correlation network analysis (WGCNA) were utilized to identify robust clusters of identified genes in each cohort. Moreover, the interaction between the hub genes of AMP and immune cells was elucidated through single-cell RNA (scRNA) analysis by scRNA sequencing data from GSE152815.

RESULTS

We found that the expression of AMP-related genes was up-regulated in OA synovium, and seven hub genes (LTC4S, PTGS2, PTGS1, MAPKAPK2, CBR1, PTGDS, and CYP2U1) were identified. The diagnostic model that combined the identified hub genes showed great clinical validity in diagnosing OA (AUC = 0.979). Moreover, significant associations were noticed between the hub genes' expression, immune cell infiltration, and inflammatory cytokine levels. The 30 OA patients were randomized and clustered into three groups using WGCNA analysis based on the hub genes, and diverse immune status was found in different clusters. Of interest, older patients were more likely to be classified into a cluster with higher levels of inflammatory cytokines IL-6 and less infiltration of immune cells. Based on the scRNA-sequencing data, we found that the hub genes had relatively higher expression in macrophages and B cells than other immune cells. Moreover, inflammation-related pathways were significantly enriched in macrophages.

CONCLUSION

These results suggest that AMP-related genes are closely involved in alterations of OA synovial inflammation. The transcriptional level of hub genes could serve as a potential diagnostic marker for OA.

Recent Advances in Small Molecule Inhibitors for the Treatment of Osteoarthritis

Osteoarthritis refers to a degenerative disease with joint pain as the main symptom, and it is caused by various factors, including fibrosis, chapping, ulcers, and loss of articular cartilage. Traditional treatments can only delay the progression of osteoarthritis, and patients may need joint replacement eventually. As a class of organic compound molecules weighing less than 1000 daltons, small molecule inhibitors can target proteins as the main components of most drugs clinically. Small molecule inhibitors for osteoarthritis are under constant research. In this regard, by reviewing relevant manuscripts, small molecule inhibitors targeting MMPs, ADAMTS, IL-1, TNF, WNT, NF-κB, and other proteins were reviewed. We summarized these small molecule inhibitors with different targets and discussed disease-modifying osteoarthritis drugs based on them. These small molecule inhibitors have good inhibitory effects on osteoarthritis, and this review will provide a reference for the treatment of osteoarthritis.

Osteoarthritis: pathogenic signaling pathways and therapeutic targets

Osteoarthritis (OA) is a chronic degenerative joint disorder that leads to disability and affects more than 500 million population worldwide. OA was believed to be caused by the wearing and tearing of articular cartilage, but it is now more commonly referred to as a chronic whole-joint disorder that is initiated with biochemical and cellular alterations in the synovial joint tissues, which leads to the histological and structural changes of the joint and ends up with the whole tissue dysfunction. Currently, there is no cure for OA, partly due to a lack of comprehensive understanding of the pathological mechanism of the initiation and progression of the disease. Therefore, a better understanding of pathological signaling pathways and key molecules involved in OA pathogenesis is crucial for therapeutic target design and drug development. In this review, we first summarize the epidemiology of OA, including its prevalence, incidence and burdens, and OA risk factors. We then focus on the roles and regulation of the pathological signaling pathways, such as Wnt/β-catenin, NF-κB, focal adhesion, HIFs, TGFβ/ΒΜP and FGF signaling pathways, and key regulators AMPK, mTOR, and RUNX2 in the onset and development of OA. In addition, the roles of factors associated with OA, including MMPs, ADAMTS/ADAMs, and PRG4, are discussed in detail. Finally, we provide updates on the current clinical therapies and clinical trials of biological treatments and drugs for OA. Research advances in basic knowledge of articular cartilage biology and OA pathogenesis will have a significant impact and translational value in developing OA therapeutic strategies.

Recombinant protein drugs-based intra articular drug delivery systems for osteoarthritis therapy

Osteoarthritis (OA) is the most prevalent chronic degenerative joint disease. It weakens the motor function of patients and imposes a significant economic burden on society. The current medications commonly used in clinical practice do not meet the need for the treatment of OA. Recombinant protein drugs (RPDs) can treat OA by inhibiting inflammatory pathways, regulating catabolism/anabolism, and promoting cartilage repair, thereby showing promise as disease-modifying OA drugs (DMOADs). However, the rapid clearance and short half-life of them in the articular cavity limit their clinical translation. Therefore, the reliable drug delivery systems for extending drug treatment are necessary for the further development. This review introduces RPDs with therapeutic potential for OA, and summarizes their research progress on related drug delivery systems, and make proper discussion on the certain keys for optimal development of this area.

Osteoarthritis today: Lost in translation?

Osteoarthritis (OA) is a highly prevalent joint disease that is associated with pain, loss of function, and high direct and indirect economic costs. The current therapeutic options are inadequate, providing only a moderate symptom relief without the possibility of disease modification. While treatment options and personalized medicines are increasing for many complex diseases, OA drug development has been impeded by the advanced state of disease at the time of diagnosis and intervention, heterogeneity in both symptoms and rates of progression, and a lack of validated biomarkers and relevant outcome measures. This review article summarizes the OA landscape, including therapies in development as potential OA treatments, potential biomarkers undergoing evaluation by the US Food and Drug Administration, and a summary of current OA treatment guidelines, with a particular focus on the knee OA.

Latest insights in disease-modifying osteoarthritis drugs development

Osteoarthritis (OA) is a prevalent and severely debilitating disease with an unmet medical need. In order to alleviate OA symptoms or prevent structural progression of OA, new drugs, particularly disease-modifying osteoarthritis drugs (DMOADs), are required. Several drugs have been reported to attenuate cartilage loss or reduce subchondral bone lesions in OA and thus potentially be DMOADs. Most biologics (including interleukin-1 (IL-1) and tumor necrosis factor (TNF) inhibitors), sprifermin, and bisphosphonates failed to yield satisfactory results when treating OA. OA clinical heterogeneity is one of the primary reasons for the failure of these clinical trials, which can require different therapeutic approaches based on different phenotypes. This review describes the latest insights into the development of DMOADs. We summarize in this review the efficacy and safety profiles of various DMOADs targeting cartilage, synovitis, and subchondral bone endotypes in phase 2 and 3 clinical trials. To conclude, we summarize the reasons for clinical trial failures in OA and suggest possible solutions.

Small molecule inhibitors of osteoarthritis: Current development and future perspective

Osteoarthritis (OA) is one of the common degenerative joint diseases in clinic. It mainly damages articular cartilage, causing pain, swelling and stiffness around joints, and is the main cause of disability of the elderly. Due to the unclear pathogenesis of osteoarthritis and the poor self-healing ability of articular cartilage, the treatment options for this disease are limited. At present, NSAIDs, Glucocorticoid and Duloxetine are the most commonly used treatment choice for osteoarthritis. Although it is somewhat effective, the adverse reactions are frequent and serious. The development of safer and more effective anti-osteoarthritis drugs is essential and urgent. This review summarizes recent advances in the pharmacological treatment of OA, focusing on small molecule inhibitors targeting cartilage remodeling in osteoarthritis as well as the research idea of reducing adverse effects by optimizing the dosage form of traditional drugs for the treatment of osteoarthritis. It should provide a reference for exploration of new potential treatment options.

An update on the use of conventional and biological disease-modifying anti-rheumatic drugs in hand osteoarthritis

Osteoarthritis (OA) is a highly prevalent condition worldwide associated with pain, progressive disability, reduced participation in social activities, and impaired quality of life. Despite its growing burden, the therapeutic options are still limited and almost exclusively addressed to symptoms' management, while no disease-modifying OA drugs able to prevent or retard disease progression are actually available. For these reasons, in the last decades, relevant efforts to find new potential therapeutic targets in OA have been made and a number of existing conventional and biological disease-modifying anti-rheumatic drugs (DMARDs), including hydroxychloroquine (HCQ), methotrexate (MTX), tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6 inhibitors, commonly used to treat inflammatory rheumatic diseases, have been repurposed for the treatment of OA and explored also in hand osteoarthritis (HOA). The current narrative review was aimed to provide a comprehensive and updated understanding of the possibilities and the criticisms related to the treatment of HOA with conventional and biological DMARDs. Unfortunately, therapy with conventional and biologic drugs in HOA has not achieved the expected success, despite a rationale for their use exists. Thus, our findings outline the urgent need to enhance the exploration of HOA basic molecular mechanisms to find new potential therapeutic targets, personalized for each patient, and appropriate for the different subsets of HOA and for the different phases of disease.

Osteoarthritis of hand joints: prevalence, risk factors, phenotypes, diagnosis, treatment

Osteoarthritis is the most common rheumatic disease, accompanied by constant pain and dysfunction of the joints, the progression of which leads to a deterioration in the quality of life and often to disability of patients. The article presents the prevalence, predictors of development and progression of osteoarthritis of the hand joints (OHJ). Clinical classification of OHJ, clinical picture depending on the localization of the process, topical features of involvement of the hand joints in different types of OHJ are given. Clinical, laboratory and instrumental methods for diagnosing of the disease, classification and diagnostic criteria are described, much attention is paid to modern principles of OHJ therapy in accordance with Russian clinical guidelines, as well as EULAR and ACR recommendations.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

Tissue-Protective and Anti-Inflammatory Landmark of PRP-Treated Mesenchymal Stromal Cells Secretome for Osteoarthritis

Bone-marrow-mesenchymal-stromal-cells (BMSCs)- and platelet-rich-plasma (PRP)-based therapies have shown potential for treating osteoarthritis (OA). Recently, the combination of these two approaches was proposed, with results that overcame those observed with the separate treatments, indicating a possible role of PRP in ameliorating BMSCs' regenerative properties. Since a molecular fingerprint of BMSCs cultivated in the presence of PRP is missing, the aim of this study was to characterize the secretome in terms of soluble factors and extracellular-vesicle (EV)-embedded miRNAs from the perspective of tissues, pathways, and molecules which frame OA pathology. One hundred and five soluble factors and one hundred eighty-four EV-miRNAs were identified in the PRP-treated BMSCs' secretome, respectively. Several soluble factors were related to the migration of OA-related immune cells, suggesting the capacity of BMSCs to attract lympho-, mono-, and granulocytes and modulate their inflammatory status. Accordingly, several EV-miRNAs had an immunomodulating role at both the single-factor and cell level, together with the ability to target OA-characterizing extracellular-matrix-degrading enzymes and cartilage destruction pathways. Overall, anti-inflammatory and protective signals far exceeded inflammation and destruction cues for cartilage, macrophages, and T cells. This study demonstrates that BMSCs cultivated in the presence of PRP release therapeutic molecules and give molecular ground for the use of this combined and innovative therapy for OA treatment.

Effect of disease-modifying anti-rheumatic drugs in osteoarthritis: A meta-analysis

OBJECTIVE

Osteoarthritis (OA) displays features of systemic and local inflammation, suggesting that DMARDs used in rheumatoid arthritis could potentially also be effective in OA. However, studies of the effects of DMARDs in OA have yielded conflicting data, and have been insufficiently large to draw conclusions. In this meta-analysis, we aimed to estimate the effect of DMARDs - such as methotrexate, hydroxychloroquine, TNF, and IL-1 inhibitors - on OA.

METHODS

We searched for relevant articles of randomized controlled trials published up to March 2022, using Pubmed, EMBASE, and the Cochrane Library. Studies were reviewed in accordance with PRISMA 2020 guidelines. The effects of DMARDs on OA outcomes (symptoms, quality of life, ESR) were expressed as the standardized mean difference.

RESULTS

We retrieved 29 references. Among these, 23 randomized controlled trials compared the effects of DMARDs versus placebo or other treatments on disease activity, including 1143 DMARD-treated OA patients and 1155 OA patients in the control group. We found statistically significant improvement of pain and stiffness with methotrexate, especially in knee OA. TNF inhibitors improved the swollen joint count in hand OA, and inflammation parameters, without change in pain, stiffness, or function. Hydroxychloroquine and IL-1 inhibitors were not effective.

CONCLUSION

Overall, the presently available data regarding the effects of DMARDs on OA symptoms intensity are disappointing. Only methotrexate might have an analgesic effect, especially in knee OA, which warrants further investigation.

Hormone replacement therapy (conjugated oestrogens plus bazedoxifene) for post-menopausal women with symptomatic hand osteoarthritis: primary report from the HOPE-e randomised, placebo-controlled, feasibility study

Background

Symptomatic hand osteoarthritis is more common in women than in men, and its incidence increases around the age of menopause, implicating oestrogen deficiency. No randomised controlled trials of hormone replacement therapy (HRT) have been done in people with hand osteoarthritis. We aimed to determine the feasibility and acceptability of a form of HRT (conjugated oestrogens plus bazedoxifene) in post-menopausal women with painful hand osteoarthritis.

Methods

The HOPE-e feasibility study was a randomised, double-blind, placebo-controlled trial, for which we recruited women aged 40-65 years, for whom 1-10 years had passed after their final menstrual period, with definite hand osteoarthritis and at least two painful hand joints. Participants were recruited across three primary or secondary care sites and from the community and were randomly assigned (1:1) to receive conjugated oestrogens plus bazedoxifene or placebo, orally once every day for 24 weeks, before weaning for 4 weeks until the end of the study. The primary feasibility outcomes were rates of identification, recruitment, randomisation, retention, and compliance of eligible participants, and the likelihood of unmasking. The secondary objective was to generate proof-of-concept quantitative and qualitative data on the acceptability of proposed clinical outcomes for a full trial and adverse events. We used an intention-to-treat analysis, and criteria for progression to a full trial were pre-defined as recruitment of at least 30 participants across all sites in 18 months; a dropout rate of less than or equal to 30% of randomised individuals; and acceptability to the majority of participants, including acceptable rates of adverse events. Due to the COVID-19 pandemic, the recruitment window was reduced to 12-15 months. A proportionately reduced minimum sample size of 22 was judged to be sufficient to test feasibility. This trial was registered at ISRCTN, ISRCTN12196200.

Findings

From May 9, 2019 to Dec 31, 2020, 434 enquiries or referrals were received. We did 96 telephone pre-screens; of the 35 eligible participants, seven were excluded as ineligible at the telephone or face-to-face screening and 28 (80% [95% CI 63-92]) were randomly assigned. Of the 406 who were not randomly assigned, 250 (62%) were ineligible (with contraindicated medications accounting for 50 [20%] of these), 101 (25%) did not respond to further enquiries, and 55 (14%) chose not to proceed (with the most common reason being not wanting to take a hormone-based drug). All 28 randomised participants completed all follow-up assessments with high compliance and outcome measure completeness. All three adverse event-related treatment withdrawals were in the placebo group. No serious adverse events were reported. Participants and investigators were successfully masked (participant Bang's blinding index placebo group 0·50 [95% CI 0·25-0·75]). The trial met the prespecified criteria for progression to a full trial.

Interpretation

This first-ever feasibility study of a randomised controlled trial of HRT for post-menopausal women with painful hand osteoarthritis met its progression criteria, although it was not powered to detect a clinical effect. This outcome indicates that a full trial of an HRT in this population is feasible and acceptable and identifies potential refinements with regard to the design of such a trial.

Funding

Research for Patient Benefit programme, National Institute for Health Research.

Dorso-ventral osteophytes of interphalangeal joints correlate with cartilage damage and synovial inflammation in hand osteoarthritis: a histological/radiographical study

Objective

To detect dorsally located osteophytes (OP) on lateral x-ray views and to correlate their presence with the extent of structural joint damage, determined by histologic grading (cartilage damage and synovial inflammation) and radiographic scoring in hand osteoarthritis (HOA).

Methods

Distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were obtained from post mortem specimens (n = 40). Multiplanar plain x-rays were taken (dorso/palmar (dp) and lateral views). Radiographic OA was determined by the Kellgren and Lawrence classification. Joint samples were prepared for histological analysis and cartilage damage was graded according to the Mankin scoring system. Inflammatory changes of the synovial membrane were scored using the general synovitis score (GSS). Spearman’s correlation was applied to examine the relationship between histological and radiographical changes. Differences between groups were determined by Mann-Whitney test.

Results

Bony proliferations that were only detectable on lateral views but reminiscent of OPs on dp images were termed dorso-ventral osteophytes (dvOPs). All joints displaying dvOPs were classified as OA and the presence of dvOPs in DIP and PIP joints correlated with the extent of histological and radiographic joint damage, as well as with patient age. Joint damage in osteoarthritic DIP and PIP joints without any dvOPs was less severe compared to joints with dvOPs. Synovial inflammation was mainly present in joints displaying dvOPs and correlated with joint damage.

Conclusion

dvOPs are associated with increasing structural alterations in DIP and PIP joints and can be seen as markers of advanced joint damage. Detecting dvOPs can facilitate the diagnosis process and improve damage estimation in HOA.

Current understanding of osteoarthritis pathogenesis and relevant new approaches

Osteoarthritis (OA) is the most common degenerative joint disease that causes painful swelling and permanent damage to the joints in the body. The molecular mechanisms of OA are currently unknown. OA is a heterogeneous disease that affects the entire joint, and multiple tissues are altered during OA development. To better understand the pathological mechanisms of OA, new approaches, methods, and techniques need to be used to understand OA pathogenesis. In this review, we first focus on the epigenetic regulation of OA, with a particular focus on DNA methylation, histone modification, and microRNA regulation, followed by a summary of several key mediators in OA-associated pain. We then introduce several innovative techniques that have been and will continue to be used in the fields of OA and OA-associated pain, such as CRISPR, scRNA sequencing, and lineage tracing. Next, we discuss the timely updates concerning cell death regulation in OA pathology, including pyroptosis, ferroptosis, and autophagy, as well as their individual roles in OA and potential molecular targets in treating OA. Finally, our review highlights new directions on the role of the synovial lymphatic system in OA. An improved understanding of OA pathogenesis will aid in the development of more specific and effective therapeutic interventions for OA.

Management of hand osteoarthritis: from an US evidence-based medicine guideline to a European patient-centric approach

Hand osteoarthritis is the most common joint condition and is associated with significant morbidity. It is of paramount importance that patients are thoroughly assessed and examined when complaining of hand stiffness, pain, deformity or disability and that the patient's concerns and expectations are addressed by the healthcare professional. In 2019 the American College of Rheumatology and Arthritis Foundation (ACR/AF) produced guidelines which included recommendations for the treatment of hand osteoarthritis. An ESCEO expert working group (including patients) was convened and composed this paper with the aim to assess whether these guidelines were appropriate for the treatment of hand osteoarthritis therapy in Europe and whether they met with the ESCEO patient-centered approach. Indeed, patients are the key stakeholders in healthcare and eliciting the patient's preference is vital in the context of an individual consultation but also for informing research and policy-making. The patients involved in this working group emphasised the often-neglected area of aesthetic changes in hand osteoarthritis, importance of developing pharmacological therapies which can alleviate pain and disability and the need of the freedom to choose which approach (out of pharmacological, surgical or non-pharmacological) they wished to pursue. Following robust appraisal, it was recommended that the ACR/AF guidelines were suitable for a European context (as described within the body of the manuscript) and it was emphasised that patient preferences are key to the success of individual consultations, future research and future policy-making.

Emerging injectable therapies for osteoarthritis

Osteoarthritis (OA) affects more than 240 million people worldwide. In 2016, the Osteoarthritis Research Society International submitted a report to the United States Food and Drug Administration highlighting OA as a 'serious' disease, and appealed for the urgent development and review of new therapies to address a significant unmet need. Despite this, international guidelines for the treatment of OA have been largely unchanged for over a decade. There is now an updated understanding that OA is more than simply a non-inflammatory 'wear-and-tear' process involving articular cartilage. Based on this, potential emerging therapies are being developed that target novel inflammatory, pain, and regeneration pathways. Drugs targeting the latter are being lauded as 'Disease-Modifying Osteoarthritis Drugs' - a concept which has so far proved elusive in OA research. While this review does not recommend a change in current practice, it should prompt readers to rethink the OA treatment paradigm. The global pandemic has added another layer of consideration when managing patients with OA. At a time when there is more strain on hospital systems, there is a need to expand our pharmacological armamentarium in order to manage OA without elective surgery and hospital admission.

A review of osteoarthritis signaling intervention using small-molecule inhibitors

Numerous small-molecule inhibitors (SMIs) have been approved as adjuvant or first-line therapies for malignancies. Based on cancer treatment using SMIs, next-generation SMIs that can be used to optimize the therapeutic index, overcome drug resistance, and establish combination therapies are in development. Osteoarthritis (OA) is the most common chronic joint disease with senescence, and there are various approaches to OA treatment; however, the gold standard treatment is controversial. Therefore, in this manuscript, we demonstrated the potential of using SMIs in OA treatment and described the general strategies for using SMIs in OA treatment.

Thermosensitive Injectable Hydrogels for Intra-Articular Delivery of Etanercept for the Treatment of Osteoarthritis

The intra-articular administration of drugs has attracted great interest in recent decades for the treatment of osteoarthritis. The use of modified drugs has also attracted interest in recent years because their intra-articular administration has demonstrated encouraging results. The objective of this work was to prepare injectable-thermosensitive hydrogels for the intra-articular administration of Etanercept (ETA), an inhibitor of tumor necrosis factor-α. Hydrogels were prepared from the physical mixture of chitosan and Pluronic F127 with β-glycerolphosphate (BGP). Adding β-glycerolphosphate to the system reduced the gelation time and also modified the morphology of the resulting material. In vitro studies were carried out to determine the cytocompatibility of the prepared hydrogels for the human chondrocyte line C28/I2. The in vitro release study showed that the incorporation of BGP into the system markedly modified the release of ETA. In the in vivo studies, it was verified that the hydrogels remained inside the implantation site in the joint until the end of the study. Furthermore, ETA was highly concentrated in the blood of the study mice 48 h after the loaded material was injected. Histological investigation of osteoarthritic knees showed that the material promotes cartilage recovery in osteoarthritic mice. The results demonstrate the potential of ETA-loaded injectable hydrogels for the localized treatment of joints.

Synovial Fluid-Derived Extracellular Vesicles of Patients with Arthritides Contribute to Hippocampal Synaptic Dysfunctions and Increase with Mood Disorders Severity in Humans

Arthritides are a highly heterogeneous group of disorders that include two major clinical entities, localized joint disorders such as osteoarthritis (OA) and systemic autoimmune-driven diseases such as rheumatoid arthritis (RA). Arthritides are characterized by chronic debilitating musculoskeletal conditions and systemic chronic inflammation. Poor mental health is also one of the most common comorbidities of arthritides. Depressive symptoms which are most prevalent, negatively impact patient global assessment diminishing the probability of achieving the target of clinical remission. Here, we investigated new insights into mechanisms that link different joint disorders to poor mental health, and to this issue, we explored the action of the synovial fluid-derived extracellular vesicles (EVs) on neuronal function. Our data show that the exposure of neurons to different concentrations of EVs derived from both RA and OA synovial fluids (RA-EVs and OA-EVs) leads to increased excitatory synaptic transmission but acts on specific modifications on excitatory or inhibitory synapses, as evidenced by electrophysiological and confocal experiments carried out in hippocampal cultures. The treatment of neurons with EVs membrane is also responsible for generating similar effects to those found with intact EVs suggesting that changes in neuronal ability arise upon EVs membrane molecules′ interactions with neurons. In humans with arthritides, we found that nearly half of patients (37.5%) showed clinically significant psychiatric symptoms (CGIs score ≥ 3), and at least mild anxiety (HAM-A ≥ 7) or depression (MADRS and HAM-D ≥ 7); interestingly, these individuals revealed an increased concentration of synovial EVs. In conclusion, our data showing opposite changes at the excitatory and inhibitory levels in neurons treated with OA- and RA-EVs, lay the scientific basis for personalized medicine in OA and RA patients, and identify EVs as new potential actionable biomarkers in patients with OA/RA with poor mental health.

Relative Efficacy and Safety of Anti-Inflammatory Biologic Agents for Osteoarthritis: A Conventional and Network Meta-Analysis

Previous studies have consistently revealed that both local and systemic inflammations are the key to the onset and progression of osteoarthritis (OA). Thus, anti-inflammatory biologic agents could potentially attenuate the progression of OA. We conducted this meta-analysis to examine the efficacy and safety of ant-inflammatory biologic agents among OA patients. Methods: Five databases were searched for randomized controlled trials (RCTs) comparing biologics with placebo or each other in OA patients. Data of pain, physical function, stiffness, and adverse events (AEs) were extracted for a conventional and a Bayesian network meta-analysis. Results: 15 studies with data for 1566 patients were analyzed. In the conventional meta-analysis, etanercept (SMD −0.47; 95% CI −0.89, −0.05) and infliximab (SMD −2.04; CI −2.56, −1.52) were superior to placebo for knee pain. In the network meta-analysis, infliximab was superior to all the other biologic agents in improving pain (vs. hyaluronic acid (SMD −22.95; CI −34.21, −10.43), vs. adalimumab (SMD −21.71; CI −32.65, −11.00), vs. anakinra (SMD −24.63; CI −38.79, −10.05), vs. canakinumab (SMD −32.83; CI −44.45, −20.68), vs. etanercept (SMD −18.40; CI −29.93, −5.73), vs. lutikizumab (SMD −25.11; CI −36.47, −14.78), vs. naproxen (SMD −30.16; CI −41.78, −17.38), vs. tocilizumab (SMD −24.02; CI −35.63, −11.86) and vs. placebo (SMD −25.88; CI −34.87, −16.60)). No significant differences were observed between biologics and placebo regarding physical function, stiffness, and risk of AEs. Conclusions: The findings suggest that infliximab may relieve pain more than other biological agents in OA patients. No significant differences were observed between biologics and placebo regarding physical function, stiffness, and risk of AEs. The results must be interpreted cautiously; therefore, further randomized controlled trials are warranted.

Obesity, Inflammation, and Immune System in Osteoarthritis

Obesity remains the most important risk factor for the incidence and progression of osteoarthritis (OA). The leading cause of OA was believed to be overloading the joints due to excess weight which in turn leads to the destruction of articular cartilage. However, recent studies have proved otherwise, various other factors like adipose deposition, insulin resistance, and especially the improper coordination of innate and adaptive immune responses may lead to the initiation and progression of obesity-associated OA. It is becoming increasingly evident that multiple inflammatory cells are recruited into the synovial joint that serves an important role in pathological changes in the synovial joint. Polarization of macrophages and macrophage-produced mediators are extensively studied and linked to the inflammatory and destructive responses in the OA synovium and cartilage. However, the role of other major innate immune cells such as neutrophils, eosinophils, and dendritic cells in the pathogenesis of OA has not been fully evaluated. Although cells of the adaptive immune system contribute to the pathogenesis of obesity-induced OA is still under exploration, a quantity of literature indicates OA synovium has an enriched population of T cells and B cells compared with healthy control. The interplay between a variety of immune cells and other cells that reside in the articular joints may constitute a vicious cycle, leading to pathological changes of the articular joint in obese individuals. This review addresses obesity and the role of all the immune cells that are involved in OA and summarised animal studies and human trials and knowledge gaps between the studies have been highlighted. The review also touches base on the interventions currently in clinical trials, different stages of the testing, and their shortcomings are also discussed to understand the future direction which could help in understanding the multifactorial aspects of OA where inflammation has a significant function.

Prescription-grade crystalline glucosamine sulfate as an add-on therapy to conventional treatments in erosive osteoarthritis of the hand: results from a 6-month observational retrospective study

Objective

To evaluate the efficacy of prescription-grade Crystalline Glucosamine Sulfate (pCGS) as an add-on treatment to conventional therapy, compared to usual therapy alone, in patients with erosive osteoarthritis of the hand (EHOA).

Methods

This 6-month retrospective case–control study included patients with concomitant knee osteoarthritis and symptomatic EHOA. Participants were stratified into two groups based on whether or not pCGS (1500 mg/day) was added to the conventional therapy (education and training in ergonomic principles, exercise and use on-demand of symptomatic drugs) for hand osteoarthritis. Patients were evaluated at baseline, after 3 and 6 months. Primary outcomes were the change from baseline to month 6 in Visual Analogue Scale (VAS) hand pain and in Functional Index for Hand Osteoarthritis (FIHOA) score. A set of secondary parameters was also evaluated.

Results

123 patients were included as follows: 67 treated with pCGS in addition to conventional therapy (pCGS Group) and 56 with conventional therapy alone (Control Group). After 6 months a significant difference in VAS and in FIHOA score (p < 0.01 and p < 0.001, respectively) was observed in favor of pCGS Group. Similar results were found for morning stiffness duration (p < 0.05), health assessment questionnaire (p < 0.01) and physical and mental component score of 36-item short form (p < 0.05 and p < 0.001, respectively). A significant reduction of symptomatic drug consumption at 3 and 6 months was reported in the pCGS Group (p < 0.001). No serious adverse event was recorded in both groups.

Conclusions

Despite all the limitations inherent to an observational study, our results suggest the potential effectiveness of pCGS, when used in combination with conventional therapy in EHOA. Further randomized placebo-controlled trials are needed to confirm these positive findings.

Trial Registration

ClinicalTrials.gov, http://www.clinicaltrials.gov, date of registration: February 2, 2022, NCT05237596. The present trial was retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-022-02151-7.

Repurposed and investigational disease-modifying drugs in osteoarthritis (DMOADs)

In spite of a major public health burden with increasing prevalence, current osteoarthritis (OA) management is largely palliative with an unmet need for effective treatment. Both industry and academic researchers have invested a vast amount of time and financial expense to discover the first diseasing-modifying osteoarthritis drugs (DMOADs), with no regulatory success so far. In this narrative review, we discuss repurposed drugs as well as investigational agents which have progressed into phase II and III clinical trials based on three principal endotypes: bone-driven, synovitis-driven and cartilage-driven. Then, we will briefly describe the recent failures and lessons learned, promising findings from predefined post hoc analyses and insights gained, novel methodologies to enhance future success and steps underway to overcome regulatory hurdles.

Peedanil Gold, Herbo-Mineral Formulation, Moderates Cytokine Levels and Attenuates Pathophysiology in Monosodium Iodoacetate Induced Osteoarthritis in SD Rat Model

The inflammatory cartilaginous degeneration of the articular joints, mostly those of knee, hips and hands, is osteoarthritis (OA). The available treatment strategies for osteoarthritis are designed for pain relief, molecular targeting, cartilage regeneration and surgical intervention. However, meta-analysis of clinical trials has shown these strategies to be sub-optimal, thereby, eliciting a need for investigating alternative options. The herbo-mineral formulation, Peedanil Gold (PN-G) has been used against joint pains and inflammation. In the current study, anti-osteoarthritic effects of PN-G were investigated in rat model of OA, induced by intra-articular injection of monosodium-iodoacetate. PN-G treatment improved the clinical and Kellgren &amp; Lawrence scores; and rescued the osteoarthritic rats from hyperalgesia and allodynia. Besides, PN-G treatment ameliorated joint inflammation and abrogated in vivo osteoarthritic pathology through effective cartilage regeneration, measured radiologically and histopathologically. PN-G also reduced the levels of interleukin-6 (IL-6) and interleukin-1 beta (IL-1β), in a dose dependent manner, in inflamed human macrophagic THP-1 cells, thereby, reaffirming its anti-inflammatory property at cytosafe concentrations. Ultra High performance liquid chromatography (UHPLC) revealed the presence of several analgesic and anti-inflammatory phytocompounds, like ellagic acid, guggulsterone E, guggulsterone Z, 5-(hydroxymethyl) furfural, corilagin, cinnamic acid, ferulic acid, gallic acid and protocatechuic acid in PN-G. In conclusion, this study has succinctly demonstrated that PN-G is capable of relieving the clinical symptoms of osteoarthritis, which is measurable through the established osteoarthritic serum biomarker, Cartilage Oligomeric Matrix Protein (COMP).

Targeting cellular senescence as a novel treatment for osteoarthritis

Cellular senescence is associated with normal development and wound healing, but has also been implicated in the pathogenesis of numerous aging-related diseases including osteoarthritis (OA). Treatment strategies for OA are being developed that target senescent cells and the paracrine and autocrine secretions of the senescence-associated secretory phenotype (SASP). The field of potential therapies continues to expand as new mechanistic targets of cell senescence and the SASP are identified. Ongoing pre-clinical and clinical studies of drugs targeting cellular senescence yield significant promise, but have yet to demonstrate long-term efficacy. Therapeutic targeting of senescence is challenged by the diverse phenotypes of senescent cells, which can vary depending on age, species, tissue source, and type of physiologic stressor. Accordingly, there remains considerable demand for more studies to further develop and assess senotherapeutics as disease-modifying treatments for OA.

Efficacy and safety of biologic agents for the treatment of osteoarthritis: a meta-analysis of randomized placebo-controlled trials

Background:

We aimed to evaluate the efficacy and safety of biologic agents targeting three main cytokines, that is, nerve growth factor (NGF), interleukin-1 (IL-1), and tumor necrosis factor-α (TNF-α), for osteoarthritis (OA) treatment.

Methods:

Databases (PubMed, Embase, and Cochrane Library) and ClinicalTrials.gov were systematically searched for randomized placebo-controlled trials (RCTs) of biologic agents from inception to November 15, 2020. The outcomes were the mean change in pain, function scores, and the risk of adverse effects (AEs).

Results:

Out of the 28 studies with 29 RCTs (8555 individuals) included, biologic agents were superior to placebo in pain relief (standardized mean difference [SMD] = 0.28, 95% confidence interval [CI] = 0.17–0.38, p < 0.001) and function improvement (SMD = 0.30, 95% CI = 0.18–0.43, p < 0.001). The incidence of any AEs (risk ratio [RR] = 1.09, 95% CI = 1.05–1.14, p < 0.001) and discontinuations due to AEs (RR = 1.39, 95% CI = 1.05–1.83, p = 0.021) were higher following treatment with biologic agents while no significant difference was found in serious AEs. Subgroup analyses showed that NGF inhibitors provided superior pain relief (SMD = 0.36, 95% CI = 0.26–0.47, p < 0.001) and function improvement (SMD = 0.41, 95% CI = 0.30–0.51, p < 0.001), whereas IL-1 inhibitors and TNF-α inhibitors did not. Meanwhile, NGF inhibitors increased the incidence of any AEs (RR = 1.12, 95% CI = 1.07–1.17, p < 0.001) and discontinuations due to AEs (RR = 1.48, 95% CI = 1.07–2.06, p = 0.018). IL-1 inhibitors and TNF-α inhibitors showed no difference in safety compared with placebo.

Conclusions:

The efficacy and safety of biologic agents vary by mechanism of action. NGF inhibitors can relieve OA-related pain and improve function but involve safety concerns. IL-1 inhibitors and TNF-α inhibitors are relatively safe options but with limited efficacy.

Erosive Hand OsteoArthritis (EHOA): analysis of consecutive patients presenting with EHOA in a hospital-based rheumatology practice and its implications for an upcoming interventional study

INTRODUCTION

Erosive Hand OsteoArthritis (EHOA) is a common rheumatological problem. We aim to determine characteristics of EHOA patients: comorbidities, radiographic erosivity and pain experienced after being diagnosed, in order to find which of these are potentially relevant in upcoming interventional trials.

METHOD

Retrospective analysis of EHOA patients within the electronic database in one centre, with a telephone interview on pain as experienced even exceeding 12 months after being diagnosed.

RESULTS

Eighty-four non-academic EHOA patients were found: 89% females (median age 69 years), 11% males (similar age distribution). Kellgren-Lawrence (KL) erosivity scores in both sexes were comparable; DIPs scored higher than PIP's. Comorbid conditions were crystal-induced arthritis, rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in 8%, 5% and 1%, respectively; seropositivity for rheumatoid factor and anti-citrullinated protein antibodies in 8% and 1% respectively. Pain worst experienced often exceeded a visual analogue score of 5.0, but was unrelated to the total KL score. Some pain reduction was reached with non-steroidals (perorally/transcutaneously) as deduced from continued use in 1 in 3.

CONCLUSIONS

In many EHOA patients, there is an unmet need regarding the treatment of pain, which per se was not directly correlated with erosivity score. Future studies may be designed considering the aforementioned characteristics, acting on the inflammatory process resulting in PIP/DIP erosions, with the exclusion of RA and PsA in order to get a clean study on EHOA. Several studies with monoclonal antibodies have been performed but demonstrated ineffectivity on the outcome of pain. Hope glooms with the arrival of innovative small molecules that may reach EHOA target cells. Key Points • Erosive handOA is a common problem in non-academic rheumatology; it is often associated with significant pain in both sexes exceeding a VASpain of 5.0 even years after being diagnosed; 1 in 3 found some relief in non-steroidals perorally/transcutaneously. • Future studies will have to focus on (episodic) inflammatory hand OA resulting in proven erosivity (EHOA) located in PIP plus DIP joints and may have to exclude comorbid active crystal-induced arthritis as well as rheumatoid/psoriatic arthritis and possibly even RF/ACPA seropositivity in order to get a clean study on EHOA. • As several big monoclonals have failed in EHOA, we may have to search for promising new drugs within the group of small molecules. These will have to show a significant pain-reducing effect and preferably also a disease-modifying osteoarthritis drug (DMOAD) effect.

Erosive hand osteoarthritis: latest findings and outlook

Osteoarthritis (OA) most commonly affects knee joints, and the next most commonly affected sites are the hands and hips. Three distinct hand OA phenotypes have been described: erosive hand OA (EHOA), nodal hand OA - also known as non-erosive hand OA (non-EHOA) - and first carpometacarpal joint OA. EHOA predominantly affects women and is the most aggressive form of hand OA, characterized by a severe clinical onset and progression, leading to joint damage, disability and reduction of quality of life. Clinical signs of inflammation associated with EHOA include the acute onset of pain, swelling and redness. Moreover, EHOA is characterized by radiographic features such as central erosion, saw-tooth and gull-wing lesions and, rarely, ankylosis. The aim of this Review is to report the latest findings on epidemiology, clinical features, pathology and aetiopathogenesis, biomarkers, imaging modalities and treatments for EHOA. The ongoing development of new hand OA classification criteria should facilitate standardization between studies.