New therapies for treatment of rheumatoid arthritis

COVID-19 infection and rheumatoid arthritis: mutual outburst cytokines and remedies

In March 2020, COVID-19 infection caused by SARS-CoV-2 has been declared to be a global pandemic, where its complications, severity and mortality are reported to be due to the released inflammatory cytokines or the so-called cytokine storm. This is quite similar to that observed in the autoimmune and chronic inflammatory rheumatic disease, rheumatoid arthritis (RA). It was hypothesized that RA patients are at a higher risk of acquiring COVID-19; however, recent studies reported that they are not when compared to the rest of the population. In this review, we aim to highlight the mutual pathological features, cytokine profiles and risk factors between COVID-19 and RA. Also, many researchers are currently working to explore therapeutic agents that could aid in the eradication of COVID-19 infection. Due to the similarity between the inflammation status in COVID-19 and RA, many anti-rheumatic drugs such as hydroxychloroquine, tocilizumab, baricitinib and anakinra were proposed to be therapeutic modalities for COVID-19 infection.

Preferential cyclooxygenase inhibition by Jasminum sambac: A possible relationship with potent anti-arthritic activity

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Traditional claim validation.

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Molecular target identification.

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In-vitro estimation.

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In-vivo anti-arthritic activity.

Iguratimod: Novel Molecular Insights and a New csDMARD for Rheumatoid Arthritis, from Japan to the World

Iguratimod (IGU) is a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) routinely prescribed in Japan since 2012 to patients with rheumatoid arthritis (RA). Iguratimod acts directly on B cells by inhibiting the production of inflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, IL-17), thereby suppressing the production of immunoglobulin and inhibiting the activity of nuclear factor kappa-light chain enhancer of activated B cells. In Japan, it is one of the most used csDMARDs in daily practice, but it is not recommended as a treatment for RA due to the lack of large-scale evidence established overseas. However, recent reports on the novel pharmacological effects of IGU on lymphocytes and synovial fibroblasts, as well as its efficacy in daily practice, have increased its importance as a drug for the treatment of RA. In this review, we highlighted the basic and clinical studies in IGU and discuss its potential as a new therapeutic agent for the treatment of RA.

The p53 status in rheumatoid arthritis with focus on fibroblast-like synoviocytes

P53 is a transcription factor that regulates many signaling pathways like apoptosis, cell cycle, DNA repair, and cellular stress responses. P53 is involved in inflammatory responses through the regulation of inflammatory signaling pathways, induction of cytokines, and matrix metalloproteinase expression. Also, p53 regulates immune responses through modulating Toll-like receptors expression and innate and adaptive immune cell differentiation and maturation. P53 is a modulator of the apoptosis and proliferation processes through regulating multiple anti and pro-apoptotic genes. Rheumatoid arthritis (RA) is categorized as an invasive inflammatory autoimmune disease with irreversible deformity of joints and bone resorption. Different immune and non-immune cells contribute to RA pathogenesis. Fibroblast-like synoviocytes (FLSs) have been recently introduced as a key player in the pathogenesis of RA. These cells in RA synovium produce inflammatory cytokines and matrix metalloproteinases which results in synovitis and joint destruction. Besides, hyper proliferation and apoptosis resistance of FLSs lead to synovial hyperplasia and bone and cartilage destruction. Given the critical role of p53 in inflammation, apoptosis, and cell proliferation, lack of p53 function (due to mutation or low expression) exerts a prominent role for this gene in the pathogenesis of RA. This review focuses on the role of p53 in different mechanisms and cells (specially FLSs) that involved in RA pathogenesis.

Immunomodulatory nanosystems for treating inflammatory diseases

Inflammatory disease (ID) is an umbrella term encompassing all illnesses involving chronic inflammation as the central manifestation of pathogenesis. These include, inflammatory bowel diseases, hepatitis, pulmonary disorders, atherosclerosis, myocardial infarction, pancreatitis, arthritis, periodontitis, psoriasis. The IDs create a severe burden on healthcare and significantly impact the global socio-economic balance. Unfortunately, the standard therapies that rely on a combination of anti-inflammatory and immunosuppressive agents are palliative and provide only short-term relief. In contrast, the emerging concept of immunomodulatory nanosystems (IMNs) has the potential to address the underlying causes and prevent reoccurrence, thereby, creating new opportunities for treating IDs. The IMNs offer exquisite ability to precisely modulate the immune system for a therapeutic advantage. The nano-sized dimension of IMNs allows them to efficiently infiltrate lymphatic drainage, interact with immune cells, and subsequently to undergo rapid endocytosis by hyperactive immune cells (HICs) at inflamed sites. Thus, IMNs serve to restore dysfunctional or HICs and alleviate the inflammation. We identified that different IMNs exert their immunomodulatory action via either of the seven mechanisms to modulate; cytokine production, cytokine neutralization, cellular infiltration, macrophage polarization, HICs growth inhibition, stimulating T-reg mediated tolerance and modulating oxidative-stress. In this article, we discussed representative examples of IMNs by highlighting their rationalization, design principle, and mechanism of action in context of treating various IDs. Lastly, we highlighted technical challenges in the application of IMNs and explored the future direction of research, which could potentially help to overcome those challenges.

Meta-analysis of association of microRNAs genetic variants with susceptibility to rheumatoid arthritis and systemic lupus erythematosus

BACKGROUND

An increasing body of studies has investigated that genetic polymorphisms in microRNA (miRNA) may be related to susceptibility to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, some results remain controversial. Thus, a meta-analysis was embarked on assessing whether some miRNA polymorphisms are associated with the risk of RA and SLE.

METHODS

Relevant studies were acquired on PubMed, Web of Science, Cochrane Library, CNKI, and Embase electronic databases from inception to December 2019. The strength of the association of miRNA polymorphisms with the risk of RA and SLE was assessed by odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Eligible 20 articles (36 studies) involving 5 miRNAs were enrolled in the meta-analysis. For RA, the polled result showed that there was no significant relationship between miR-146a rs2910164 and RA, but subgroup analysis based on ethnicity demonstrated that CC genotype may be a genetic protect factor for RA in Caucasians (CC vs CG+GG, OR = 0.825, 95% CI: 0.684-0.996, Pz = .045, Ph = .166). Besides, statistical significance of miR-499 rs3746444 (T/C) with susceptibility to RA was observed as well in the overall population, and the association was only significant in Caucasians but not Asians. For SLE, the associations of miR-146a rs2431697 T allele/T-carrier with increased risk of SLE were observed.

CONCLUSIONS

Our results highlight that miR-499 rs3746444 may contribute to RA susceptibility, particularly in Caucasians. In addition, CC genotype in miR-146a rs2910164 may act as a protector of RA in Caucasians. For SLE, miR-146a rs2431697 (C/T) is most likely to the increased the risk of SLE. These findings do not support the genetic association between miR-196a2 rs11614913 and RA/SLE susceptibility, as well as the association of miR-146a rs2910164, miR-146a rs57095329, miR-499 rs3746444 with SLE.

Association of Rheumatoid Arthritis with Diabetic Comorbidity: Correlating Accelerated Insulin Resistance to Inflammatory Responses in Patients

Over the past two decades, with advancement of medical research and technology, treatments of many diseases including chronic disorders like rheumatoid arthritis (RA) have been revolutionized. Treatment and management of RA has been refined by advances in understanding its pathologic mechanisms, the development of drugs which target them and its association with various other chronic comorbidities like diabetes. Diabetes prevalence is closely associated with RA since elevated insulin resistance have been observed with RA. It is also associated with inflammation caused due to pro-inflammatory cytokines like tumour necrosis factor α and interleukin 6. Inflammation encourages insulin resistance and also stimulates other factors like a high level of rheumatoid factor in the blood leading to positivity of rheumatoid factor in RA patients. The degree of RA inflammation also tends to influence the criticality of insulin resistance, which increases with high activity of RA and vice versa. Markers of glucose metabolism appear to be improved by DMARDs like methotrexate, hydroxychloroquine, interleukin 1 antagonists and TNF antagonist while glucocorticoids adversely affect glycemic control especially when administered chronically. The intent of the present review paper is to understand the association between RA, insulin resistance and diabetes; the degree to which both can influence the other along with the plausible impact of RA medications on diabetes and insulin resistance.

Signalling and putative therapeutic molecules on the regulation of synoviocyte signalling in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by symmetrical and chronic polyarthritis. Fibroblast-like synoviocytes are mainly involved in joint inflammation and cartilage and bone destruction by inflammatory cytokines and matrix-degrading enzymes in RA. Approaches that induce various cellular growth alterations of synoviocytes are considered as potential strategies for treating RA. However, since synoviocytes play a critical role in RA, the mechanism and hyperplastic modulation of synoviocytes and their motility need to be addressed. In this review, we focus on the alteration of synoviocyte signalling and cell fate provided by signalling proteins, various antioxidant molecules, enzymes, compounds, clinical candidates, to understand the pathology of the synoviocytes, and finally to achieve developed therapeutic strategies of RA.

Cite this article: Bone Joint Res 2021;10(4):285–297.

Interleukin-37 as an anti-inflammatory cytokine: does its relation to disease activity suggest its potential role in rheumatoid arthritis therapy?

Background

This study aimed to measure the serum and synovial interleukin (IL)-37 levels in rheumatoid arthritis (RA) patients compared to patients with primary knee osteoarthritis (PKOA) and healthy controls and to detect its relation to RA disease activity.

Results

This cross-sectional study included 50 RA patients with a mean age of 40.24 ± 8.62 years, 50 patients with PKOA with a mean age of 56.69 ± 4.21, and 40 healthy controls with a mean age of 41.75 ± 7.38 years. The mean serum IL-37 level in the RA patients (382.6 ± 73.97 pg/ml) was statistically significantly (P < 0.001) the highest among the studied groups; however, it showed a non-significant difference between the PKOA patients (70.38 ± 27.49 pg/ml) and the healthy controls (69.97 ± 25.12 pg/ml) (P > 0.94). Both serum and synovial IL-37 levels were significantly positively correlated with disease activity scores (r = 0.92, P< 0.001 and r = 0.85, P < 0.001), tender joint counts (r = 0.83, P < 0.001 and r = 0.82, P < 0.001 ), swollen joint counts (r = 0.72, P < 0.001 and r = 0.60, P < 0.001), visual analog scale (r = 0.82, P < 0.001 and r = 0.82, P < 0.001), erythrocyte sedimentation rate (r = 0.75, P < 0.001 and r = 0.65, P < 0.001), and C-reactive protein (r = 0.93, P < 0.001 and r = 0.79, P < 0.001), respectively.

Conclusion

Serum and synovial IL-37 were significantly elevated in the RA patients, and they were closely correlated. Being less invasive, the serum IL-37 could be a marker of disease activity and could reflect the effective disease control by drugs. Having an anti-inflammatory effect could not suggest IL-37 as the key player to control inflammation alone, but its combination with other anti-proinflammatory cytokines could be investigated.

A Review on Rheumatoid Arthritis Interventions and Current Developments

Rheumatoid arthritis is a chronic autoimmune disorder characterized by inflammation, swelling, and joint destruction primarily affecting the peripheral joints. In recent years, RA has become an alarming concern affecting more than 1.5% of the population worldwide. The majority of the drugs in clinical trials for rheumatoid arthritis are immunomodulatory. The development of novel drugs for RA is impending and scientists are exploring new strategies through various innovative approaches for RA drug development. Treat-to-target and window of opportunity hypothesis are the new approaches that are used to treat, improve outcomes, and prevent long-term use of ineffective therapy, respectively. Novel therapeutic agents (e.g. GM-CSF inhibitors, Matrix metalloproteinase inhibitors) and delivery systems (e.g., Liposomes, Superparamagnetic iron oxide nano particles (SPIONs)) are under investigation for more target based therapy with reduced side effects and toxicity. The new drug discovery and repositioning of previously FDA-approved drugs are also being considered for chronic inflammatory disorder. The review encompasses a vast array of information, including genetics, etiology, clinical symptoms, current treatment, and newer therapeutics approaches, focused on the development of RA interventions. The introduction of the bioinformatics-based approach in RA has also been significantly discussed in the review. This review provides a general understanding of the challenges and uncertainties in the treatment of RA and summarizes the evolving scenario as well as innovative approaches taken into consideration for drug development in rheumatoid arthritis.

Rheumatoid cachexia: the underappreciated role of myoblast, macrophage and fibroblast interplay in the skeletal muscle niche

Although rheumatoid arthritis affects 1% of the global population, the role of rheumatoid cachexia, which occurs in up to a third of patients, is relatively neglected as research focus, despite its significant contribution to decreased quality of life in patients. A better understanding of the cellular and molecular processes involved in rheumatoid cachexia, as well as its potential treatment, is dependent on elucidation of the intricate interactions of the cells involved, such as myoblasts, fibroblasts and macrophages. Persistent RA-associated inflammation results in a relative depletion of the capacity for regeneration and repair in the satellite cell niche. The repair that does proceed is suboptimal due to dysregulated communication from the other cellular role players in this multi-cellular environment. This includes the incomplete switch in macrophage phenotype resulting in a lingering pro-inflammatory state within the tissues, as well as fibroblast-associated dysregulation of the dynamic control of the extracellular matrix. Additional to this endogenous dysregulation, some treatment strategies for RA may exacerbate muscle wasting and no multi-cell investigation has been done in this context. This review summarizes the most recent literature characterising clinical RA cachexia and links these features to the roles of and complex communication between multiple cellular contributors in the muscle niche, highlighting the importance of a targeted approach to therapeutic intervention.

Variability of rituximab and tocilizumab trough concentrations in patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) are eligible for treatment with therapeutic monoclonal antibodies (mAbs) that target tumor necrosis factor α (TNFα), as well as others, such as rituximab (RTX) and tocilizumab (TCZ). Although pharmacokinetic variability and the link between concentration-clinical response of anti-TNFα mAbs have been well-described, little is known about RTX and TCZ. We aimed to evaluate the variability of RTX and TCZ serum concentrations in RA patients treated in second-line and the relationship between RTX/TCZ concentrations and the clinical response. Serum mAb trough concentrations of RA patients treated with RTX (n = 35) or TCZ (n = 46) were determined at week 24 by liquid chromatography-tandem mass spectrometry. The clinical response was assessed at week 24 by the change in the disease activity score in the 28 joints-erythrocyte sedimentation rate from baseline (ΔDAS28-Erythrocyte Sedimentation Rate) and according to the European League Against Rheumatism (EULAR) recommendations. RTX and TCZ trough concentrations were highly variable, with a coefficient of variation of 171.3% for RTX (median [10th-90th percentiles]: <1.0 µg/mL [<1.0-5.1]) and 132.6% for TCZ (median [10th-90th percentiles]: 5.4 µg/mL [<1.0-27.8]). Univariate analysis did not identify any determinants of such variability, except cotreatment with methotrexate, which was associated with lower RTX concentrations (P = 0.03). The response to treatment was not related to the RTX or TCZ trough concentration. RTX and TCZ trough concentrations at 24 weeks were highly variable in RA patients treated in the second line, without any link concentration-clinical response having been demonstrated.

Biologic Agents Preserve the C-2 Pedicle in Patients with Rheumatoid Arthritis: A Comparative Imaging Study Using Three-Dimensional Computed Tomography

OBJECTIVE

To investigate whether biologic agents (BAs) reduce a narrow C-2 pedicle screw trajectory, which is often a key stabilizer in surgical treatment, in patients with rheumatoid arthritis (RA).

METHODS

A total of 100 patients with RA treated with and without BAs (BA [+] group [n = 50] and BA [-] group [n = 50]), respectively, were included in the present study. Computed tomography (CT) images of their cervical spine, including C-2, were analyzed. The maximum screw diameter at C-2 that could be inserted without breaching the cortex, measured on 3-dimensional images using a CT-based navigation system, was compared between the groups with and without BA administration. Furthermore, the destruction of the atlantoaxial joint was examined using CT images. The risk factors for a narrow C-2 pedicle were elucidated among the patients treated with BAs.

RESULTS

The pedicle in the BA (+) group had a significantly larger C-2 maximum screw diameter than the BA (-) group (6.00 mm vs. 5.13 mm, P < 0.001), with less destruction of the atlantoaxial joint. Among the BA (+) group, a longer period until the initial administration of BAs and RA disease duration were associated with a narrow C-2 pedicle.

CONCLUSIONS

This study suggests that BAs can maintain the trajectory for C-2 pedicle screws, which acts as a key stabilizer in surgical management for the rheumatoid cervical spine, by halting the destruction of the atlantoaxial joint. Early introduction of BAs can be especially important to prevent the narrowing of the C-2 pedicle.

Epidemiology of cardiac or orthopedic procedures in gout versus rheumatoid arthritis: a national time-trends study

Aims

To examine the secular trends in the number and rates of in-hospital cardiac and orthopedic procedures in people with gout and rheumatoid arthritis (RA), and the United States (US) general population, from 1998 to 2014.

Methods

We examined the frequency of seven common cardiac and orthopedic procedures in hospitalized people with gout, RA, or the general population using the 1998-2014 US National Inpatient Sample (NIS). Poisson regression evaluated the differences in frequencies in 1998 versus 2014, between gout and RA, and within each cohort.

Results

Both in-hospital cardiac and orthopedic procedures increased in gout and RA with time, in contrast with declining cardiac procedures in the general US population. Cardiac procedures were significantly higher in gout versus RA in 1998 (59% higher) and 2014 (92% higher). The rate of cardiac procedures increased from 36.6 to 82.8 in gout and from 20.1 to 33.1 in RA per 100,000 NIS claims from 1998 to 2014. Orthopedic procedures became more common than cardiac procedures in gout and RA by 2014. In RA, the cardiac-orthopedic procedure volume difference was significant in 1998 and 2014. We noted no significant difference between cardiac versus orthopedic procedures in 1998 in gout, but the difference was significant in 2014. Orthopedic procedures in gout were significantly lower than RA in 1998 (33% lower), but were significantly higher than RA in 2014 (5% higher).

Conclusion

Increasing in-hospital cardiac procedures in gout and RA contrasting with declining general US population rates indicated that optimal management of systemic inflammation and an early diagnosis of gout and RA are needed. The rate of increase in orthopedic procedures exceeded that in cardiac procedures. A much greater volume and rate of increase in common in-hospital cardiac and orthopedic procedures in gout compared to RA indicates that an aggressive approach to treat-to-target in gout is needed to potentially reduce the associated healthcare burden and cost.

Plain language summary

Cardiac and orthopedic procedures rising faster for gout compared to rheumatoid arthritis in the United States We performed a national US study of the most common cardiac versus orthopedic procedures from 1998 to 2014. We found that over time, the number and the rate of cardiac procedures increased in people with gout (2.2-fold higher) or rheumatoid arthritis (1.6-fold higher). This was surprising, since during the same time, we noted a decrease in cardiac procedures in the general U.S. population. The rate of cardiac procedures in gout was 2.5-fold higher than that in rheumatoid arthritis, 82.8 vs. 33.1 per 100,000 NIS claims in 2014. Interestingly, orthopedic procedures were more common than cardiac procedures in both gout and RA in all periods. Also, the difference in the numbers of cardiac vs. orthopedic procedures increased over time in both gout and RA. Gout outpaced rheumatoid arthritis for both the total number and the rate of cardiac or orthopedic procedures over time. Therefore, our study provides an understanding of an increasing procedure burden in gout compared to rheumatoid arthritis, and to the general U.S. people with these conditions.

Anti-nociceptive effect of Portulaca oleracea L. ethanol extracts attenuated zymosan-induced mouse joint inflammation via inhibition of Nrf2 expression

The aim of this study was to explore the effects of ethanol extracts from Portulaca oleracea L. (ePO) on joint inflammation and to explain the underlying mechanisms. A joint inflammation mouse model was constructed by injecting zymosan, and the Von Frey method was employed and the joint thickness measured. The numbers of leukocytes, neutrophils, and monocytes were counted in the joint cavity and the infiltration of inflammatory cells was assessed by joint histopathological analysis. The mRNA levels of inflammatory cytokines were determined by quantitative RT-PCR and their secretion levels were determined by specific ELISAs. Pre-treatment with ePO inhibited articular mechanical hyperalgesia and edema and ameliorated the recruitment of mononuclear neutrophils and leukocytes. In addition, pre-treatment with ePO improved pathological alternations in the joint tissues by reducing the number of inflammatory cells. Pre-treatment with ePO regulated the nuclear factor erythroid 2-related factor 2 (Nrf2)-related proteins and thereby inhibited oxidative stress. In addition, ePO inhibited NLR family pyrin domain containing 3 (NLRP3) inflammasome-related genes (NLRP3, ASC, pro-caspase-1 and pro-IL-1ß), modulated inflammatory cytokines and the activation of NF-κB. ePO attenuated zymosan-induced joint inflammation by regulating oxidative stress, NLRP3 inflammasome, and NF-κB.

JNK pathway-associated phosphatase associates with rheumatoid arthritis risk, disease activity, and its longitudinal elevation relates to etanercept treatment response

Background

This study aimed to investigate the relationship of serum JNK pathway‐associated phosphatase (JKAP) expression with rheumatoid arthritis (RA) risk and clinical features, also to explore the longitudinal change of JKAP during etanercept treatment and its relationship with etanercept treatment response in RA patients.

Methods

A total of 87 RA patients and 44 healthy controls (HCs) were enrolled; then, their JKAP expression in serum was determined by enzyme‐linked immunosorbent assay (ELISA). Among 87 RA patients, 42 cases further received the 24‐week etanercept treatment; then, their JKAP level in serum (detected by ELISA) and clinical response (evaluated by disease activity score in 28 joints (DAS28) score) were evaluated at week 4 (W4), week 12 (W12), and week 24 (W24) after initiation of etanercept treatment.

Results

JKAP expression was decreased in RA patients compared to HCs, which disclosed a good predictive value for RA risk. JKAP expression was negatively associated with tender joint count, swollen joint count, erythrocyte sedimentation rate, C‐reactive protein, and DAS28 in RA patients, respectively. For RA patients who received 24‐week etanercept treatment, their clinical response rate was 0.0%, 33.3%, 50.0%, and 69% at W0, W4, W12, and W24, respectively. Importantly, JKAP was gradually increased during etanercept treatment, whose longitudinal elevation positively related to etanercept treatment response in RA patients.

Conclusion

Circulating JKAP links with decreased RA risk and mild disease activity, whose longitudinal elevation positively relates to etanercept treatment response.

TNF-α-Inhibition Improves the Biocompatibility of Porous Polyethylene Implants In Vivo

Background:

To improve the biocompatibility of porous polyethylene (PPE) implants and expand their application range for reconstructive surgery in poorly vascularized environments, implants were coated with tumor necrosis factor α (TNFα) inhibitor Etanercept. While approved for systemic application, local application of the drug is a novel experimental approach. Microvascular and mechanical integration as well as parameters of inflammation were analyzed in vivo.

Methods:

PPE implants were coated with Etanercept and extracellular matrix (ECM) components prior to implantation into dorsal skinfold chambers of C57BL/6 mice. Fluorescence microscopy analyses of angiogenesis and local inflammatory response were thrice performed in vivo over a period of 14 days to assess tissue integration and biocompatibility. Uncoated implants and ECM-coated implants served as controls.

Results:

TNFα inhibition with Etanercept led to a reduced local inflammatory response: leukocyte-endothelial cell adherence was significantly lowered compared to both control groups (n = 6/group) on days 3 and 14, where the lowest values were reached: 3573.88 leukocytes/mm-2 ± 880.16 (uncoated implants) vs. 3939.09 mm-2 ± 623.34 (Matrigel only) vs. 637.98 mm-2 + 176.85 (Matrigel and Etanercept). Implant-coating with Matrigel alone and Matrigel and Etanercept led to significantly higher vessel densities 7 and 14 days vs. 3 days after implantation and compared to uncoated implants. Mechanical implant integration as measured by dynamic breaking strength did not differ after 14 days.

Conclusion:

Our data show a reduced local inflammatory response to PPE implants after immunomodulatory coating with Etanercept in vivo, suggesting improved biocompatibility. Application of this tissue engineering approach is therefore warranted in models of a compromised host environment.

Electronic supplementary material

The online version of this article (10.1007/s13770-020-00325-w) contains supplementary material, which is available to authorized users.

Rosuvastatin Attenuates Rheumatoid Arthritis-Associated Manifestations via Modulation of the Pro- and Anti-inflammatory Cytokine Network: A Combination of In Vitro and In Vivo Studies

The current investigation employed rosuvastatin for evaluation as an antiarthritic agent by in vitro and in vivo studies. In vitro studies comprised egg albumin and bovine serum albumin protein denaturation assays along with membrane stabilization assays, while in vivo studies comprised formaldehyde and complete Freund's adjuvant (CFA)-provoked arthritis. The antioxidant potential was estimated via DPPH free radical scavenging and ferric reducing assays. Rosuvastatin significantly inhibited heat-provoked protein denaturation of egg albumin and bovine serum in a concentration-dependent way with the highest inhibition of 1225 ± 9.83 and 82.80 ± 4.03 at 6400 μg/mL. The percentage protection of the RBC membrane from hypotonicity-prompted lysis was found to be 80.67 ± 2.7. Rosuvastatin promisingly subdued formaldehyde-provoked arthritis, with maximum reduction (65.47%) of the paw volume being observed at a dose of 40 mg/kg. Rosuvastatin also significantly (p < 0.001) attenuated arthritis induced by CFA injection by reducing the paw volume and arthritic index. The reduction in the body weight due to CFA injection was also preserved by rosuvastatin treatment. Hematological and biochemical changes due to arthritis induction by CFA injection were also maintained near normal values by rosuvastatin. The histopathological and radiographic investigation also revealed the protective effect of rosuvastatin on preventing structural changes. Gene expression of IL-1β, TNF-α, and IL-6 was reduced, while IL-4 and IL-10 levels were elevated by rosuvastatin in comparison to those for the disease control group. Concentration-dependent antioxidant potential was shown by rosuvastatin. Thus, rosuvastatin possesses a notable antiarthritic potential as evidenced via in vitro and in vivo studies.

Relationship Between Inflammation and Metabolism in Patients With Newly Presenting Rheumatoid Arthritis

Background

Systemic inflammation in rheumatoid arthritis (RA) is associated with metabolic changes. We used nuclear magnetic resonance (NMR) spectroscopy-based metabolomics to assess the relationship between an objective measure of systemic inflammation [C-reactive protein (CRP)] and both the serum and urinary metabolome in patients with newly presenting RA.

Methods

Serum (n=126) and urine (n=83) samples were collected at initial presentation from disease modifying anti-rheumatic drug naïve RA patients for metabolomic profile assessment using 1-dimensional ¹H-NMR spectroscopy. Metabolomics data were analysed using partial least square regression (PLS-R) and orthogonal projections to latent structure discriminant analysis (OPLS-DA) with cross validation.

Results

Using PLS-R analysis, a relationship between the level of inflammation, as assessed by CRP, and the serum (p=0.001) and urinary (p<0.001) metabolome was detectable. Likewise, following categorisation of CRP into tertiles, patients in the lowest CRP tertile and the highest CRP tertile were statistically discriminated using OPLS-DA analysis of both serum (p=0.033) and urinary (p<0.001) metabolome. The most highly weighted metabolites for these models included glucose, amino acids, lactate, and citrate. These findings suggest increased glycolysis, perturbation in the citrate cycle, oxidative stress, protein catabolism and increased urea cycle activity are key characteristics of newly presenting RA patients with elevated CRP.

Conclusions

This study consolidates our understanding of a previously identified relationship between serum metabolite profile and inflammation and provides novel evidence that there is a relationship between urinary metabolite profile and inflammation as measured by CRP. Identification of these metabolic perturbations provides insights into the pathogenesis of RA and may help in the identification of therapeutic targets.

The effectiveness and safety of Tripterygium wilfordii glycosides combined with disease-modifying anti-rheumatic drugs in the treatment of rheumatoid arthritis: A systematic review and meta-analysis of 40 randomized controlled trials

OBJECTIVE

This systematic review and meta-analysis were performed to investigate the efficacy and safety of Tripterygium wilfordii glycosides (TG) for rheumatoid arthritis (RA) from the current literature.

METHODS

An electronic search was conducted in eight databases (PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, Chinese VIP Database, and Wanfang Database) from inception until September 2020. Randomized controlled trials (RCTs) with risk of bias (RoB) score ≥ 4 according to the Cochrane RoB tool were included for the analyses. The primary outcome measures were duration of morning stiffness (DMS), tender joint count (TJC), swollen joint count (SJC), visual analog score (VAS), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF). The secondary outcome measures were the total clinical effective rate and adverse events. All the analyses were used by the random effects models. The meta-analysis was performed using RevMan 5.3 and STATA 14.0.

RESULTS

A total of 40 RCTs with 3092 patients met our inclusion criteria. This meta-analysis showed that TG plus DMARDs for RA could decrease the DMS (p < .001), TJC (p < .001), SJC (p < .001), VAS (p < .001), serum CRP (p < .001), ESR (p < .001), and RF (p < .001) and improve total effective rate (p < .001). In addition, TG was generally safe and well tolerated in RA patients.

CONCLUSION

Despite the limitations, the present evidence supports, at least to an extent, that TG can be recommended for routine use for RA patients. More large multicenter and high-quality RCTs are required for further research.

Current Evidence of Interleukin-6 Signaling Inhibitors in Patients With COVID-19: A Systematic Review and Meta-Analysis

Background: Interleukin-6 (IL-6) is known to be detrimental in coronavirus disease 2019 (COVID-19) because of its involvement in driving cytokine storm. This systematic review and meta-analysis aimed to assess the safety and efficacy of anti-IL-6 signaling (anti-IL6/IL-6R/JAK) agents on COVID-19 based on the current evidence. Methods: Studies were identified through systematic searches of PubMed, EMBASE, ISI Web of Science, Cochrane library, ongoing clinical trial registries (clinicaltrials.gov), and preprint servers (medRxiv, ChinaXiv) on August 10, 2020, as well as eligibility checks according to predefined selection criteria. Statistical analysis was performed using Review Manager (version 5.3) and STATA 12.0. Results: Thirty-one studies were included in the pooled analysis of mortality, and 12 studies were identified for the analysis of risk of secondary infections. For mortality analysis, 5630 COVID-19 cases including 2,132 treated patients and 3,498 controls were analyzed. Anti-IL-6 signaling agents plus standard of care (SOC) significantly decreased the mortality rate compared to SOC alone (pooled OR = 0.61, 95% CI 0.45-0.84, p = 0.002). For the analysis of secondary infection risk, 1,624 patients with COVID-19 including 639 treated patients and 985 controls were included, showing that anti-IL-6 signaling agents did not increase the rate of secondary infections (pooled OR = 1.21, 95% CI 0.70-2.08, p = 0.50). By contrast, for patients with critical COVID-19 disease, anti-IL-6 signaling agents failed to reduce mortality compared to SOC alone (pooled OR = 0.75, 95% CI 0.42-1.33, p = 0.33), but they tended to increase the risk of secondary infections (pooled OR = 1.85, 95% CI 0.95-3.61, p = 0.07). A blockade of IL-6 signaling failed to reduce the mechanical ventilation rate, ICU admission rate, or elevate the clinical improvement rate. Conclusion: IL-6 signaling inhibitors reduced the mortality rate without increasing secondary infections in patients with COVID-19 based on current studies. For patients with critical disease, IL-6 signaling inhibitors did not exhibit any benefit.

Au@polydopamine nanoparticles/tocilizumab composite as efficient scavengers of oxygen free radicals for improving the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is the most common chronic autoimmune disorder associated with high-cost, side effects, and low therapeutic effects. To improve the treatment of RA, we originally developed a novel anti-RA Au@polydopamine nanoparticles (PDANPs)/TCZ composite using PDANPs as the binding sites of gold nanoparticles (AuNPs) and the drug carries of tocilizumab (TCZ) through a facile and environmentally-friend method, aiming to effectively scavenge oxygen free radicals (OFR) and inhibit the formation of related inflammatory factors. Characterizations showed that AuNPs with the size of 11.4 ± 2.9 nm randomly distributed onto the surface of PDANPs (145.8 ± 31.9 nm), meanwhile TCZ was chemically cross-linked to PDANPs through Schiff base linkage. The synthesized composite had good biocompatibility that can promote the proliferation and growth of chondrocytes and fibroblasts. More importantly, Au@PDANPs/TCZ composite showed more excellent abilities to scavenge OFR and inhibit the related inflammatory factors in vitro and in vivo than that of AuNPs and PDANPs owing to the synergistic scavenging effect, ensuring its best therapeutic effect in RA therapy. This new composite will have application potential in the treatment of RA related disease.

Prediction of Targets of Curculigoside A in Osteoporosis and Rheumatoid Arthritis Using Network Pharmacology and Experimental Verification

Purpose

Network pharmacology is considered to be the next-generation drug development model that uses bioinformatics to predict and identify multiple drug targets and interactions in diseases. Here, network pharmacology was used to investigate the mechanism by which Curculigoside A (CA) acts in rheumatoid arthritis (RA) and osteoporosis.

Methods

First, TCMSP and SwissADME were applied to predict the druggability of CA. Then, potential targets were identified from overlapping data in SwissTarget and TargetNet, and targets were analyzed using Genemania and DAVID6.8 to obtain information about the GO and KEGG pathways. Ultimately, the drug-target-pathway network was identified after using Cytoscape 3.0 for visualization. Besides, qPCR was used to validate the predicted five major genes targets (EGFR, MAP2K1, MMP2, FGFR1, and MCL1).

Results

The results of TCMSP and SwissADME demonstrated that CA exhibits good druggability; 26 potential protein targets were classified by SwissTarget and TargetNet. The results of Genemania and DAVID6.8 indicated that CA probably caused anti-osteoporosis and anti-RA effects by regulating some biological pathways, especially nitrogen metabolism, estrogen signaling pathway, Rap1 signaling pathway, and PI3K/Akt signaling pathway. Besides, the result of Cytoscape 3.0 showed that the 26 targets participate in osteoporosis and RA-related pathways, metabolism, and other physiological processes. In vitro induced inflammation cell model experiments, the qPCR results showed that CA pretreatment significantly decreased the expression of EGFR, MAP2K1, MMP2, FGFR1, and MCL1 genes.

Conclusion

These results suggested that network pharmacology may provide possible mechanism of how CA exerts therapeutic effects in osteoporosis and RA.

The Expression of von Willebrand Factor-Binding Protein Determines Joint-Invading Capacity of Staphylococcus aureus, a Core Mechanism of Septic Arthritis

Septic arthritis, one of the most dangerous joint diseases, is predominantly caused by Staphylococcus aureus In contrast, coagulase-negative staphylococci are rarely found in septic arthritis. We hypothesize that coagulases released by S. aureus, including coagulase (Coa) and von Willebrand factor-binding protein (vWbp), play potent roles in the induction of septic arthritis. Four isogenic S. aureus strains differing in expression of coagulases (wild-type [WT] Newman, Δcoa, Δvwb, and Δcoa Δvwb) were used to induce septic arthritis in both wild-type and von Willebrand factor (vWF)-deficient mice. Septic arthritis severity was greatly reduced when wild-type mice were infected with the Δcoa Δvwb and Δvwb variants compared to WT or Δcoa strains, suggesting that vWbp rather than Coa is a major virulence factor in S. aureus septic arthritis. vWF-deficient mice were more susceptible to bone damage in septic arthritis, especially when the Δvwb strain was used. Importantly, no difference in arthritis severity between the Δvwb and WT strains was observed in vWF-deficient mice. Collectively, we conclude that vWbp production by S. aureus enhances staphylococcal septic arthritis.IMPORTANCE Septic arthritis remains one of the most dangerous joint diseases with a rapidly progressive disease character. Despite advances in the use of antibiotics, permanent reductions in joint function due to joint deformation and deleterious contractures occur in up to 50% of patients with septic arthritis. So far, it is still largely unknown how S. aureus initiates and establishes joint infection. Here, we demonstrate that von Willebrand factor-binding protein expressed by S. aureus facilitates the initiation of septic arthritis. Such effect might be mediated through its interaction with a host factor (von Willebrand factor). Our finding contributes significantly to the full understanding of septic arthritis etiology and will pave the way for new therapeutic modalities for this devastating disease.

Causal Inference between Rheumatoid Arthritis and Breast Cancer in East Asian and European Population: A Two-Sample Mendelian Randomization

Simple Summary

Rheumatoid arthritis (RA) is one of the chronic autoimmune diseases that affects about 0.5 to 1.0% of the general population worldwide. The main symptom of RA is the destruction of the synovial joint, leading to a reduced quality of life and increased mortality. RA may be accompanied by several comorbidities, on which several studies have been conducted on the association between RA and breast cancer. However, the association between RA and breast cancer has shown different directions and has not been clearly established. In this study, we tried to determine whether RA had a causal effect on breast cancer using Mendelian randomization (MR) analysis, but causal evidence was not found. Therefore, additional studies are needed to determine whether RA patients are at high risk of breast cancer, based on large-scale cohorts to validate these results.

Abstract

Previous studies have been reported that the association between rheumatoid arthritis (RA) and breast cancer remains inconclusive. A two-sample Mendelian randomization (MR) analysis can reveal the potential causal association between exposure and outcome. A two-sample MR analysis using the penalized robust inverse variance weighted (PRIVW) method was performed to analyze the association between RA and breast cancer risk based on the summary statistics of six genome-wide association studies (GWAS) targeting RA in an East Asian population along with summary statistics of the BioBank Japan (BBJ), Breast Cancer Association Consortium (BCAC), and Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) targeting breast cancer. We found that the direction of the effect of RA on breast cancer varied among GWAS-summary data from BBJ, BCAC, and CIMBA. Significant horizontal pleiotropy based on a penalized robust MR-Egger regression was observed only for BBJ and CIMBA BRCA2 carriers. As the results of the two-sample MR analyses were inconsistent, the causal association between RA and breast cancer was inconclusive. The biological mechanisms explaining the relationship between RA and breast cancer were unclear in Asian as well as in Caucasians. Further studies using large-scale patient cohorts are required for the validation of these results.

Update on the diagnosis and management of early rheumatoid arthritis

The clinical spectrum of rheumatoid arthritis (RA) presentation is heterogeneous, with wide variation in age of onset, degree of joint involvement and severity. Delayed rheumatological referral is associated with less favourable long-term outcomes. Multidisciplinary teamwork is key to the success of a holistic approach to patient care and addressing issues that are important to the person. Pharmacological treatment of early RA aims to optimally suppress the inflammatory component of the disease with an ideal treatment target of remission. The overarching aim of management of early RA is to achieve a quality of life that permits the individual to pursue normal work, domestic and social activity.

Near-Infrared Plasmon-Boosted Heat/Oxygen Enrichment for Reversing Rheumatoid Arthritis with Metal/Semiconductor Composites

Rheumatoid arthritis (RA) is an autoimmune disease that often causes progressive joint dysfunction, even disability and death in severe cases. The radical improvement of inflammatory cell infiltration and the resulting disorder in oxygen supply is a novel therapeutic direction for RA. Herein, a near-infrared-absorbing metal/semiconductor composite, polyethylene glycol-modified ceria-shell-coated gold nanorod (Au@CeO₂), is fabricated for topical photothermal/oxygen-enriched combination therapy for RA in a mouse model. Upon laser irradiation, the photothermal conversion of Au@CeO₂ is exponentially enhanced by the localized surface plasma resonance-induced light focusing. The elevated temperature can not only remarkably obliterate hyperproliferative inflammatory cells gathered in diseased joints but also vastly increase the catalase-like activity of ceria to accelerate the decomposition of H₂O₂ to produce much oxygen, which relieves hypoxia. Significantly, RA-induced lesions are improved, and the expression of proinflammatory cytokines and hypoxia-inducible factors is effectively repressed under the cooperation of heat and oxygen. Overall, the core/shell-structured Au@CeO₂ is a promising nanotherapeutic platform that can well realize light-driven heat/oxygen enrichment to completely cure RA from the perspective of pathogenesis.

Challenges for biosimilars: focus on rheumatoid arthritis

Healthcare systems worldwide are struggling to find ways to fund the cost of innovative treatments such as gene therapies, regenerative medicine, and monoclonal antibodies (mAbs). As the world's best known mAbs are close to facing patent expirations, the biosimilars market is poised to grow with the hope of bringing prices down for cancer treatment and autoimmune disorders, however, this has yet to be realized. The development costs of biosimilars are significantly higher than their generic equivalents due to therapeutic equivalence trials and higher manufacturing costs. It is imperative that academics and relevant companies understand the costs and stages associated with biologics processing. This article brings these costs to the forefront with a focus on biosimilars being developed for Rheumatoid Arthritis (RA). mAbs have remarkably changed the treatment landscape, establishing their superior efficacy over traditional small chemicals. Five blockbuster TNFα mAbs, considered as first line biologics against RA, are either at the end of their patent life or have already expired and manufacturers are seeking to capture a significant portion of that market. Although in principle, market-share should be available, withstanding that the challenges regarding the compliance and regulations are being resolved, particularly with regards to variation in the glycosylation patterns and challenges associated with manufacturing. Glycan variants can significantly affect the quality attributes requiring characterization throughout production. Successful penetration of biologics can drive down prices and this will be a welcome change for patients and the healthcare providers. Herein we review the biologic TNFα inhibitors, which are on the market, in development, and the challenges being faced by biosimilar manufacturers.

Intracytoplasmic Expression of IL-6 and IL-17A in Circulating CD4+ T Cells Are Strongly Associated with and Predict Disease Activity in Rheumatoid Arthritis: A Case-Control Study in Ghana

Background

T cell cytokines play important roles in the development and progression of rheumatoid arthritis (RA). Loss of Th1/Th2 and Th17/Treg balance has been reported in several inflammatory autoimmune diseases. However, their role in RA within hitherto rare Ghanaian context has not been explored. Here, we evaluated the intracytoplasmic CD4+ T cell cytokine patterns in rheumatoid arthritis patients in Ghana and determined their relationship with disease activity.

Methods

This case-control study included 48 newly diagnosed RA patients and 30 apparent healthy controls from two major hospitals in Ghana. Validated structured questionnaires were administered to obtain demographic data; blood samples were collected and processed for flow cytometric analysis.

Results

IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, IL-6/IL-4, and IL-17/IL-10 expressions were significantly higher in RA cases compared to the healthy controls. The expression of IL-6 (0.00 (0.00-0.98) vs. 0.82 (0.34-1.10) vs. 1.56 (1.39-1.68), p < 0.0001), IL-17A (0.00 (0.00-0.02) vs. 0.19 (0.09-0.30) vs. 0.99 (0.64-1.25), p < 0.0001), and IL-17A/IL-10 (0.00 (0.00-0.39) vs. 0.15 (0.09-0.26) vs. 0.88 (0.41-1.47), p < 0.0001) increased significantly from the healthy controls through RA patients with low DAS scores to RA patients with moderate DAS scores. IL-6 (β = 0.681, r² = 0.527, p < 0.0001), IL-17A (β = 0.770, r² = 0.593, p < 0.0001), and IL-17A/IL-10 (β = 0.677, r² = 0.452, p < 0.0001) expressions were significantly directly associated with DAS28 scores. IL-6 (cutoff = 1.32, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) and IL-17A (cutoff = 0.58, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) presented with the best discriminatory power in predicting moderate DAS scores from low DAS scores.

Conclusion

Th1- and Th17-related cytokines predominate in the pathophysiology of RA, with IL-6 and IL-17 being principally and differentially expressed based on the severity of the disease. IL-6 and IL-17A could serve as useful prognostic and disease-monitoring markers in RA in the African context.

Anti-angiogenic effect of Shikonin in rheumatoid arthritis by downregulating PI3K/AKT and MAPKs signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Zicao is the dried root of Lithospermum erythrorhizon Sieb, et Zucc, Arnebia euchroma (Royle) Johnst, or Arnebia guttata Bunge and commonly used to treat viral infection, inflammation, arthritis and cancer in China.Shikonin (SKN) is a major active chemical component isolated from zicao. Previous research showed that SKN has anti-inflammatory, immunomodulatory and analgesic effects, and inhibits the development of arthritis and the condition of collagen arthritis (CIA) mice; nevertheless, its role in the angiogenesis of rheumatoid arthritis (RA) has not been elucidated.

AIM OF THE STUDY

The purpose of this study was to investigate the antiangiogenic activity of SKN in CIA rats and various angiogenesis models.

MATERIAL AND METHODS

The anti-arthritic effect of SKN on CIA rats was tested by arthritis score, arthritis incidence, radiological observation and histopathology evaluation of inflamed joints. Vessel density evaluated with CD31 immunohistochemistry/immunofluorescence in joint synovial membrane tissues of CIA rats, chick chorioallantoic membrane assay, rat aortic ring assay, and the migration, invasion, adhesion and tube formation of human umbilical vein endothelial (HUVEC) cells induced by tumor necrosis factor (TNF)-α were used to measured the antiangiogenenic activity of SKN. Moreover, the effect of SKN on the expression of angiogenic mediators, such as vascular endothelial growth factor (VEGF), VEGFR2, TNF-α, interleukin (IL)-1β, platelet derived growth factor (PDGF) and transforming growth factor (TGF)-β in sera and joint synovia of rats, and in TNF-α-induced MH7A/HUVEC cells were measured by immunohistochemistry, enzyme linked immunosorbent assay, Western blot and/or real-time polymerase chain reaction (PCR). Through the analysis of protein and mRNA levels of phosphoinositide 3-kinase (PI3K), Akt and PTEN, and the autophosphorylation of ERK1/2, JNK and p38 in joint synovia of rats and in TNF-α-induced HUVEC cells, the molecular mechanism of its inhibition was elucidated by using Western blot and/or real-time PCR.

RESULTS

SKN significantly reduced the arthritis score and arthritis incidence, and inhibited inflammation, pannus formation, cartilage and bone destruction of inflamed joints in CIA rats. Partially, SKN remarkably decreased the immature blood vessels in synovial membrane tissues of inflamed joints from CIA rats. It also suppressed in vivo angiogenesis in chick embryo and VEGF₁₆₅-induced microvessel sprout formation ex vivo. Meanwhile, SKN inhibited TNF-α-induced migration, invasion, adhesion and tube formation of HUVEC cells. Moreover, SKN significantly decreased the expression of angiogenic activators including VEGF, VEGFR2, TNF-α, IL-1β, PDGF and TGF-β in synovia of CIA rats and/or in MH7A/HUVEC cells. More interestingly, SKN downregulated PI3K and Akt, and simultaneously upregulated PTEN both at protein and mRNA levels in synovia tissues and/or in TNF-α-induced HUVEC cells. It also suppressed the phosphorylation and gene level of TNF-α-induced signaling molecules, as ERK1/2, JNK, and p38 in synovium and/or in TNF-α-induced HUVEC cells.

CONCLUSION

These findings indicate for the first time that SKN has the anti-angiogenic effect in RA in vivo, ex vivo and in vitro by interrupting the PI3K/AKT and MAPKs signaling pathways.

Virtual Screening Technique Used to Estimate the Mechanism of Adhatoda vasica Nees for the Treatment of Rheumatoid Arthritis Based on Network Pharmacology and Molecular Docking

Adhatoda vasica Nees (AVN) is commonly used to treat joint diseases such as rheumatoid arthritis (RA) in ethnic minority areas of China, especially in Tibetan and Dai areas, and its molecular mechanisms on RA still remain unclear. Network pharmacology, a novel strategy, utilizes bioinformatics to predict and evaluate drug targets and interactions in disease. Here, network pharmacology was used to investigate the mechanism by which AVN acts in RA. The chemical compositions and functional targets of AVN were retrieved using the systematic pharmacological analysis platform PharmMapper. The targets of RA were queried through the DrugBank database. The protein-protein interaction network (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of key targets were constructed in the STRING database, and the network visualization analysis was performed in Cytoscape. Maestro 11.1, a type of professional software, was used for verifying prediction and analysis based on network pharmacology. By comparing the predicted target information with the targets of RA-related drugs, 25 potential targets may be related to the treatment of RA, among which MAPK1, TNF, DHODH, IL2, PTGS2, and JAK2 may be the main potential targets for the treatment of RA. Finally, the chemical components and potential target proteins were scored by molecular docking, and compared with the ligands of the protein, the prediction results of network pharmacology were preliminarily verified. The active ingredients and mechanism of AVN against RA were firstly investigated using network pharmacology. Additionally, this research provided a solid foundation for further experimental studies.

Targeted silver nanoparticles for rheumatoid arthritis therapy via macrophage apoptosis and Re-polarization

Infiltration of inflammatory cells, especially the M1 macrophages that secrete various types of inflammation cytokines, play crucial roles in the pathogenesis of rheumatoid arthritis (RA). To relief synovial inflammation, M1 macrophages must be eliminated or switched to anti-inflammatory M2 phenotype. We herein developed folic acid modified silver nanoparticles (FA-AgNPs) that can actively deliver into M1 macrophages to synergistically induce M1 macrophages reduction and M2 macrophages polarization for effective RA treatment. The AgNPs was facilely prepared, PEGylated and modified with FA to realize M1 macrophages targeting delivery via folate receptor overexpressed on M1 macrophages surface. After entering cells, FA-AgNPs dissolved and released Ag⁺ in response to intracellular glutathione (GSH), which is the key element to exert a series of anti-inflammatory functions, such as M1 macrophages apoptosis and reactive oxygen species (ROS) scavenging to facilitate M2 macrophages polarization, both of which contributed to RA treatment. This nano-system could passively accumulate into inflamed joints, permit potent anti-inflammatory activity, and impose strong therapeutic efficacy in mice RA models with high biosafety. After treatment, FA-AgNPs could be gradually cleared from the body mainly via feces without tissue accumulation, and did not show any appreciable long-term toxicity. This work declares the first example of using bio-active nanoparticles for RA treatment without loading any drugs, and highlights the potential of FA-AgNPs for targeted RA therapy via simultaneous M1 macrophage apoptosis and M1-to-M2 macrophages re-polarization.

Tocilizumab Was Effective in Repairing the Large Geode in a Patient with Rheumatoid Arthritis

Rheumatoid arthritis is characterized by multiple chronic arthritis subsequently inducing joint destruction. Although subchondral geode is a well-known feature of high-disease activity, a large geode is rare. Moreover, the treatment effect of biologic agents in the repair of large geode has not been reported. The present report shows the significant effect of interleukin-6 receptor blocker, tocilizumab, in repairing the large geode in the left humeral lateral epicondyle. This case implies that tocilizumab might be an effective treatment in patients with rheumatoid arthritis even with large geode.

Repository corticotropin injection attenuates collagen-induced arthritic joint structural damage and has enhanced effects in combination with etanercept

Background

Melanocortin receptor (MCR) agonists have anti-inflammatory and immunomodulatory properties mediated by receptors expressed on cells relevant to arthritis. Repository corticotropin injection (RCI; Acthar® Gel), an MCR agonist preparation, is approved as adjunctive therapy for rheumatoid arthritis (RA), but its mechanism of action in RA is unclear. This study explored the efficacy of RCI as monotherapy or adjunctive therapy with etanercept (ETN) in an established animal model of collagen-induced arthritis (CIA).

Methods

After induction of CIA, rats (n = 10 per group) were randomized to receive subcutaneous RCI (40, 160, or 400 U/kg twice daily) alone or in combination with ETN (10 mg/kg 3 times daily), ETN alone, or vehicle (on days 13 through 19). Inflammation was assessed via changes in paw edema. Bone damage was determined by microfocal computed tomography histopathology, and immunohistochemistry. Statistical analyses were performed using a 2-way analysis of variance (ANOVA) followed by the Newman-Keuls, Dunn’s, or Dunnett’s multiple comparisons test or a 1-way ANOVA followed by the Dunnett’s or Holm-Sidak multiple comparisons test.

Results

RCI administration resulted in dose-dependent decreases in ankle edema and histopathologic measures of inflammation, pannus formation, cartilage damage, bone resorption, and periosteal bone formation. RCI and ETN showed combined benefits on all parameters measured. Radiographic evidence of bone damage was significantly reduced in rats that received RCI alone or in combination with ETN. This reduction in bone density loss correlated with decreases in the number of CD68-positive macrophages and cathepsin K–positive osteoclasts within the lesions.

Conclusions

As monotherapy or adjunctive therapy with ETN, RCI attenuated CIA-induced joint structural damage in rats. These data support the clinical efficacy of RCI as adjunctive therapy for patients with RA.

The Derivative of Tripterygium wilfordii Hook F-Kunxian Capsule, Attenuated Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

The study aimed to explore the efficacy and safety of Kunxian Capsule (KXC) in the treatment of rheumatoid arthritis (RA). The randomized controlled trials (RCTs) comparing the effects of KXC in patients with RA were included in this study. Weighted mean differences (MDs) were calculated for net changes by employing Review Manager meta-analysis software. Nine RCTs were included in the systematic review with a total of 747 patients. The overall effects showed that KXC alone or combined with disease-modifying antirheumatic and drugs decreased tender joint counts (P=0.02, MD = −1.07, 95% CI: −1.95 to −0.18), shortened duration of morning stiffness (P < 0.0001, MD = −9.01, 95% CI: −13.08 to −4.93), lowered erythrocyte sedimentation rate (P < 0.00001, MD = −5.27, 95% CI: −6.78 to −3.77), and reduced C-reactive protein (P < 0.0001, MD = −5.04, 95% CI: −7.28 to −2.80). The most common adverse events were gastrointestinal disturbances and abnormal liver function. These results suggest that KXC is likely to be a more effective and safe candidate for treating RA compared with conventional therapies.

Deciphering the Molecular Targets and Mechanisms of HGWD in the Treatment of Rheumatoid Arthritis via Network Pharmacology and Molecular Docking

Background

Huangqi Guizhi Wuwu Decoction (HGWD) has been applied in the treatment of joint pain for more than 1000 years in China. Currently, most physicians use HGWD to treat rheumatoid arthritis (RA), and it has proved to have high efficacy. Therefore, it is necessary to explore the potential mechanism of action of HGWD in RA treatment based on network pharmacology and molecular docking methods.

Methods

The active compounds of HGWD were collected, and their targets were identified from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and DrugBank database, respectively. The RA-related targets were retrieved by analyzing the differentially expressed genes between RA patients and healthy individuals. Subsequently, the compound-target network of HGWD was constructed and visualized through Cytoscape 3.8.0 software. Protein-protein interaction (PPI) network was constructed to explore the potential mechanisms of HGWD on RA using the plugin BisoGenet of Cytoscape 3.8.0 software. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed in R software (Bioconductor, clusterProfiler). Afterward, molecular docking was used to analyze the binding force of the top 10 active compounds with target proteins of VCAM1, CTNNB1, and JUN.

Results

Cumulatively, 790 active compounds and 1006 targets of HGWD were identified. A total of 4570 differentially expressed genes of RA with a p value <0.05 and |log 2(fold change)| > 0.5 were collected. Moreover, 739 GO entries of HGWD on RA were identified, and 79 pathways were screened based on GO and KEGG analysis. The core target gene of HGWD in RA treatment was JUN. Other key target genes included FOS, CCND1, IL6, E2F2, and ICAM1. It was confirmed that the TNF signaling pathway and IL-17 signaling pathway are important pathways of HGWD in the treatment of RA. The molecular docking results revealed that the top 10 active compounds of HGWD had a strong binding to the target proteins of VCAM1, CTNNB1, and JUN.

Conclusion

HGWD has important active compounds such as quercetin, kaempferol, and beta-sitosterol, which exert its therapeutic effect on multiple targets and multiple pathways.

The endocannabinoid signaling pathway as an emerging target in pharmacotherapy, earmarking mitigation of destructive events in rheumatoid arthritis

Rheumatoid arthritis is an inflammatory autoimmune disease, characterized by synovial proliferation, destruction to articular cartilage and severe pain. The cannabinoids obtained from Cannabis sativa exhibited their actions via cannabinoid-1 and -2 receptors, which also provides a platform for endocannabinoids to act. The endocannabinoid system comprises endocannabinoid molecules involved in signaling processes, along with G-protein coupled receptors and enzymes associated with ligand biosynthesis, activation and degradation. The action of endocannabinoid system in immune system regulation, via primary CB2 activation, followed by inhibition of production of pro-inflammatory cytokines, auto-antibodies and MMPs, FLSs proliferation and T-cell mediated immune response, are elaborated as potential therapeutic regimes in rheumatoid arthritis. The involvement of endocannabinoid system in immune cells like, B cells, T cells and macrophages, as well as regulatory actions on sensory noniceptors to ameliorate pain is significantly highlighted in the review, elaborating the actions of endocannabinoid signaling in mitigating the disease events. The review also focuses on enhancement of endocannabinoid tone, either by inhibiting the degradation enzymes, like FAAH, MAGL, COX, CytP450, LOX, etc. or by retarding cellular uptake processes. Moreover, the review portrays the optimizing role of endocannabinoid system, in abbreviating the symptoms and complications of rheumatoid arthritis in patients and mitigating inflammation, pain and immune mediated effects significantly.

Trigger-responsive engineered-nanocarriers and image-guided theranostics for rheumatoid arthritis

Rheumatoid Arthritis (RA), one of the leading causes of disability due to progressive autoimmune destruction of synovial joints, affects ∼1% of the global population. Standard therapy helps in reducing inflammation and delaying the progression of RA but is limited by non-responsiveness on long-term use and several side-effects. The conventional nanocarriers (CNCs), to some extent, minimize toxicity associated with free drug administration while improving the therapeutic efficacy. However, the uncontrolled release of the encapsulated drug even at off-targeted organs limits the application of CNCs. To overcome these challenges, trigger-responsive engineered nanocarriers (ENCs) have been recently explored for RA treatment. Unlike CNCs, ENCs enable precise control over on-demand drug release due to endogenous triggers in arthritic paws like pH, enzyme level, oxidative stress, or exogenously applied triggers like near-infrared light, magnetic field, ultrasonic waves, etc. As the trigger is selectively applied to the inflamed joint, it potentially reduces toxicity at off-target locations. Moreover, ENCs have been strategically coupled with imaging probe(s) for simultaneous monitoring of ENCs inside the body and facilitate an 'image-guided-co-trigger' for site-specific action in arthritic paws. In this review, the progress made in recently emerging 'trigger-responsive' and 'image-guided theranostics' ENCs for RA treatment has been explored with emphasis on the design strategies, mechanism, current status, challenges, and translational perspectives.

TonEBP in dendritic cells mediates pro-inflammatory maturation and Th1/Th17 responses

Dendritic cells (DCs) are potent antigen-presenting cells that link the innate and adaptive immune responses; as such they play pivotal roles in initiation and progression of rheumatoid arthritis (RA). Here, we report that the tonicity-responsive enhancer-binding protein (TonEBP or NFAT5), a Rel family protein involved in the pathogenesis of autoimmune disease and inflammation, is required for maturation and function of DCs. Myeloid cell-specific TonEBP deletion reduces disease severity in a murine model of collagen-induced arthritis; it also inhibits maturation of DCs and differentiation of pathogenic Th1 and Th17 cells in vivo. Upon stimulation by TLR4, TonEBP promotes surface expression of major histocompatibility complex class II and co-stimulatory molecules via p38 mitogen-activated protein kinase. This is followed by DC-mediated differentiation of pro-inflammatory Th1 and Th17 cells. Taken together, these findings provide mechanistic basis for the pathogenic role of TonEBP in RA and possibly other autoimmune diseases.

An herbal formula inhibits STAT3 signaling and attenuates bone erosion in collagen-induced arthritis rats

BACKGROUND

Receptor activator of NF-κB ligand (RANKL) facilitates differentiation of osteoclast precursors into osteoclasts, resulting in bone erosion in rheumatoid arthritis (RA) patients. Fibroblast-like synoviocytes (FLS) are the main cells for producing RANKL. Signal transducer and activator of transcription 3 (STAT3) signaling is activated in FLS of RA patients (RA-FLS), which has been linked to RANKL production. A two-herb formula (RL) comprising Rosae Multiflorae Fructus and Lonicerae Japonicae Flos is traditionally used for treating RA in China. We have found that a standardized ethanolic extract of RL (RLE for short) alleviates bone erosion in collagen-induced arthritis (CIA) rats.

PURPOSE

This study aimed to determine whether RLE inhibits RANKL production and osteoclastogenesis in cell and rat models, and to explore the involvement of the STAT3 pathway in this inhibition.

STUDY DESIGN AND METHODS

A CIA rat model, interleukin-6/soluble interleukin-6 receptor (IL-6/sIL-6R)-stimulated RA-FLS and a co-culture system (IL-6/sIL-6R-stimulated RA-FLS/peripheral blood mononuclear cells) were used to evaluate the effects of RLE. Micro-computed tomography analysis was used to observe bone erosion in CIA rats. Tartrate-resistant acid phosphatase staining was used to evaluate osteoclastogenesis. Western blotting and ELISA assays were employed to examine protein levels. RT-qPCR was used to detect mRNA levels. STAT3-over-activated RA-FLS were used to investigate the involvement of STAT3 signaling in the anti-osteoclastogenic effects of RLE.

RESULTS

RLE alleviated bone erosion in joints of CIA rats. In both synovial tissues of CIA rats and IL-6/sIL-6R-stimulated RA-FLS, RLE downregulated the protein level of RANKL. In the co-culture system, RLE significantly and dose-dependently inhibited IL-6/sIL-6R-induced osteoclastogenesis. Mechanistic studies revealed that RLE lowered the protein level of phospho-STAT3 (Tyr705) in synovial tissues of CIA rats. In IL-6/sIL-6R-stimulated RA-FLS, RLE inhibited the activation/phosphorylation of a STAT3 upstream kinase Janus kinase 2 (Tyr1007/1008) and STAT3 (Tyr705), decreased the nuclear localization of STAT3, lowered mRNA levels of STAT3-transcriptionally regulated genes IL-1β and TNF-α. RLE's inhibitory effects on RANKL production in RA-FLS gradually decreased when IL-6/sIL-6R doses increased. Over-activation of STAT3 diminished the inhibitory effects of RLE on RANKL production in IL-6/sIL-6R-stimulated RA-FLS, and attenuated the anti-osteoclastogenic effects of RLE in the co-culture system.

CONCLUSION

We, for the first time, demonstrated that suppressing STAT3 signaling contributes to the inhibition of RANKL production and osteoclastogenesis, and thereby supports the mechanisms responsible for the reduction in bone erosion in RLE-treated CIA rats. This study provides further pharmacological groundwork for developing RLE as a modern anti-arthritic drug, and supports the notion that targeting STAT3 signaling is a viable strategy for managing bone erosion.

Effect of phenolic compounds from Oenothera rosea on the kaolin-carrageenan induced arthritis model in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Oenothera rosea (Onagraceae), commonly known as "hierba del golpe" in Mexico, is an herbaceous plant widely used in Mexican traditional medicine for the treatment of pain and inflammation.

AIM OF THE STUDY

The aim of this study was to assess the effect of extracts and compounds isolated from O. rosea in kaolin-carrageenan induced arthritis.

MATERIALS AND METHODS

Hydroalcoholic extract from aerial parts of O. rosea was obtained and chemically separated in order to obtain OrEA and isolated compounds using column chromatography, HPLC, UPLC and NMR analysis. O. rosea extract and derivatives were tested on the kaolin/carrageenan (K/C) induced arthritis model on ICR mice. Knee inflammation and paw withdrawal threshold were assessed following intraarticular administration of kaolin and carrageenan (4% and 2%, respectively) and subsequent oral administration of O. rosea. TNF-α, IL-1β, IL-6 and IL-10 levels from synovial capsule were measured using ELISA kits. NF-κB activity was also measured using the RAWBlue™ cell line. Finally, spleen and lungs were dissected to investigate body index.

RESULTS

Oral administration of the O. rosea ethyl acetate fraction (25, 50 and 100 mg/kg) and isolated compounds (2 mg/kg) reduced the edema induced by kaolin/carrageenan, similar to the effect of methotrexate (1 mg/kg). Hyperalgesia but not allodynia was observed during this experiment. O. rosea derivatives reduced this behavior. The quantification of cytokines showed a reduction in TNF-α, IL-1β and IL-6, as well as an increase of IL-10. NF-κB production was also reduced by administering O. rosea derivatives. Chemical analysis of O. rosea derivatives showed that the major compounds present in the ethyl acetate fraction were phenolic compounds. Gallic acid, quercetin glucoside and quercetin rhamnoside were separated and identified by UPLC-UV-MS, and myricetin glycoside and tamarixetin glucoside using ¹H and ¹³C NMR.

CONCLUSIONS

O. rosea produces different phenolic compounds capable of reducing the inflammation and secondary mechanical hyperalgesia produced by K/C administration. They also reduced proinflammatory cytokines and increased anti-inflammatory cytokines. Finally, NF-κB modulation was reduced by the administration of O. rosea. Therefore, O. rosea could be considered of interest in inflammatory and painful diseases.

Rhoifolin regulates oxidative stress and proinflammatory cytokine levels in Freund's adjuvant-induced rheumatoid arthritis via inhibition of NF-κB

Rheumatoid arthritis (RA) is an autoimmune disease of knee joints involving pain and inflammation. Rhoifolin is a plant flavonoid known to have antioxidant and anti-inflammatory properties. This study was taken to identify the effect of rhoifolin on complete Freund’s adjuvant (CFA)-induced arthritis in the rat model. Treatment with rhoifolin (10 and 20 mg/kg) showed a significant improvement in the overall health parameters such as paw edema and weight loss. This improvement in morphological parameters corroborated the findings with gross morphological changes observed in the histopathological analysis. Rhoifolin treatment also caused a significant decrease in oxidative stress, evident from changes in intracellular levels of glutathione, glutathione peroxidase, malondialdehyde, and superoxide dismutase in the articular cartilage tissue. Moreover, proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin(IL)-1β, and IL-6 showed a significant downregulation of gene expression and intracellular protein concentration levels. The NF-κB pathway showed a significant attenuation as evident in the significant reduction in the levels of NF-κB p65 and p-IκB-α. These results indicated that rhoifolin can be a natural therapeutic alternative to the extant regimens, which include non-steroidal anti-inflammatory drugs and immunosuppressants. Additionally, the antioxidant and anti-inflammatory action of rhoifolin was probably mediated by the NF-κB pathway. However, the exact target molecules of this pathway need to be determined in further studies.

Chinese Herbal Medicines for Rheumatoid Arthritis: Text-Mining the Classical Literature for Potentially Effective Natural Products

Background

Rheumatoid arthritis (RA) is an autoimmune disease characterized by multijoint swelling, pain, and destruction of the synovial joints. Treatments are available but new therapies are still required. One source of new therapies is natural products, including herbs used in traditional medicines. In China and neighbouring countries, natural products have been used throughout recorded history and are still in use for RA and its symptoms. This study used text-mining of a database of classical Chinese medical books to identify candidates for future clinical and experimental investigations of therapeutics for RA.

Methods

The database Encyclopaedia of Traditional Chinese Medicine (Zhong Hua Yi Dian) includes the full texts of over 1,150 classical books. Eight traditional terms were searched. All citations were assessed for relevance to RA. Results and Conclusions. After removal of duplications, 3,174 citations were considered. After applying the exclusion and inclusion criteria, 548 citations of traditional formulas were included. These derived from 138 books written from 206 CE to 1948. These formulas included 5,018 ingredients (mean, 9 ingredients/formula) comprising 243 different natural products. When these text-mining results were compared to the 18 formulas recommended in a modern Chinese Medicine clinical practice guideline, 44% of the herbal formulas were the same. This suggests considerable continuity in the clinical application of these herbs between classical and modern Chinese medicine practice. Of the 15 herbs most frequently used as ingredients of the classical formulas, all have received research attention, and all have been reported to have anti-inflammatory effects. Two of these 15 herbs have already been developed into new anti-RA therapeutics—sinomenine from Sinomenium acutum (Thunb.) Rehd. & Wils and total glucosides of peony from Paeonia lactiflora Pall. Nevertheless, there remains considerable scope for further research. This text-mining approach was effective in identifying multiple natural product candidates for future research.

Synovial Fluid Cell Proteomic Analysis Identifies Upregulation of Alpha-Taxilin Proteins in Rheumatoid Arthritis: A Potential Prognostic Marker

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease affecting the joints and surrounding tissue. Identification of novel proteins associated with the progression of a disease is a prerequisite for understanding the pathogenesis of RA. The present study was undertaken to identify the potential biomarkers from a less explored biological sample such as synovial fluid (SF) cells which is specific for RA and to analyze their functional aspects using proteomic approach. Two-dimensional gel electrophoresis (2-DE) was performed using synovial fluid cells of RA and osteoarthritis (OA) patients, and 7 differentially expressed proteins were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS). Αlpha-Taxilin (α-Taxilin) has been found as one of the novel, significantly up regulated protein in RA. It has been validated in the synovium, synovial fluid (SF), SF cells, and plasma samples by Western blot, enzyme-linked immunosorbent assay (ELISA), fluorescence-activated cell sorting (FACS), immunohistochemistry (IHC), and real-time PCR. The identification of autoantibody against α-Taxilin and in silico studies has further helped us to understand its involvement in disease mechanism. The present study will therefore provide knowledge towards the etiology of RA that pave the way for suitable prognostic marker identification along with other clinical parameters.

Evaluation of Risk Factors for Falls in Patients with Rheumatoid Arthritis

Background

The aim of our study was to investigate the risk factors for falls in the rheumatoid arthritis (RA) patient population in Poland. This would be a major step towards the development of new fall prevention programs.

Material/Methods

There were 450 RA patients who met the criteria of the American College of Rheumatology who participated in this study. The average age of patient participants was 54.2 years; the average RA duration was 15.1 years. All patients filled out the study questionnaire regarding falls, medications, and diseases, and they filled out the Polish version of the Health Assessment Questionnaire (HAQ).

Results

Of the 400 patients, 203 patients (51%) experienced falls. Out of the 268 falls experienced by study patients, 113 falls (42%) were due to an environmental cause, the remainder 155 falls were caused by health conditions. The number of falls positively correlated with HAQ scores (r=0.42, P<0.01) and the duration of RA (r=0.39, P<0.05). For individuals who had fallen 3 or more times, there was a stronger positive correlation between the number of falls and the total HAQ score (r=0.61, P<0.01). The main risk factors for falls in the study group were dizziness (odds ratio [OR]=3.42), the use of hypotensive medication (OR=2.82), foot deformities (OR=4.09), and a high HAQ score (OR=2.59). Other factors such as drug use (e.g., glucocorticoids), pain, and duration of RA were measured using a visual analogue scale, and were found not to have increased the risk for falls and fractures (P>0.05).

Conclusions

Knowledge about risk factors can help identify high-risk patients to help decrease their risk of falling, thus preventing fall-related injuries.

CXCR3 antagonist AMG487 inhibits glucocorticoid-induced tumor necrosis factor-receptor-related protein and inflammatory mediators in CD45 expressing cells in collagen-induced arthritis mouse model

Rheumatoid arthritis (RA) is an autoimmune disease classified by uncontrolled joint inflammation leading to the destruction of both cartilage and joints. Despite progress made in RA treatment in the past decade, new drugs with high efficacy and fewer long-term adverse effects are still needed; thus, safe anti-inflammatory therapies for RA are urgently needed. Previous results demonstrated that the CXCR3 antagonist is an extremely attractive therapeutic target for the treatment of several autoimmune diseases, suggesting that it might have an inhibitory effect on RA. In this study, we investigated the effect of AMG487, a selective CXCR3 antagonist, on collagen-induced arthritis (CIA) in mice and evaluated its potential therapeutic mechanism.Following induction of CIA, mice were treated with AMG487 (5 mg/kg, intraperitoneally), to investigate their protective effects against CIA. CD4, CD25, CCR6, IL-9, NF-κB, IL-6, IL-17A, IL-21, STAT6 and Foxp3 expressing GITR⁺ and CD45⁺ cells were measured in the spleen using flow cytometry to assess anti-inflammatory effects of AMG487. The mRNA and protein expression of GITR, CCR6, IL-9, and IL-21 were measured using quantitative real-time PCR and western blot analysis in knee tissue. AMG487 significantly alleviated joint inflammation by decreasing GITR⁺CD25⁺, GITR⁺CD45⁺, GITR⁺IL-9⁺, GITR⁺NF-κB⁺ CD45⁺CD4⁺, CD45⁺CCR6⁺, CD45⁺IL-6⁺ cells, CD45⁺IL-17A⁺, and CD45⁺IL-21⁺, and increasing GITR⁺Foxp3⁺ and GITR⁺STAT6⁺ cells. There was a significant decrease in mRNA and protein expression of GITR, CD4, CCR6, IL-6, IL-9, and IL-21 in knee tissue of CIA mice. This study demonstrates that AMG487 has a potential therapeutic effect on RA and could explore novel anti-inflammatory therapies for its treatment.

Precision medicine and management of rheumatoid arthritis

Precision medicine (PM) is a very commonly used term that implies a highly individualized and tailored approach to patient management. There are, however, many layers of precision, as for example taking an appropriate patient history, or performing additional lab or imaging tests are already helping to better tailor treatments to the right patient. All this adds to the narrower definition of PM, which implies using the unique molecular characteristics of a patient for management decisions. Big data has become an essential part of PM, including as much information as possible to improve precision of disease management, although integration of multi-source data continues to be a challenge in practical application. In research big data can identify new (sub-)phenotypes in unsupervised analyses, which ultimately advance precision by allowing new targeted therapeutic approaches. We will discuss the current status of PM in rheumatoid arthritis (RA) in the management areas of diagnosis, prognosis, selection of therapy, and decision to reduce therapy. PM markers for diagnosis of RA are usually markers of RA classification rather than diagnosis, and subtypes of RA are potentially underrecognized. Prognostic precision is well established for RA, including markers of disease activity or structure, as well as autoantibodies and genetics. The choice of the right compound in a patient identified to have a poor prognosis, however, remains widely arbitrary. Finally and most recently, the most reliable markers for a safe withdrawal of therapy continue to be lower levels of disease activity and longer presence of remission.