Understanding the dynamics: pathways involved in the pathogenesis of rheumatoid arthritis

Leveraging Electrostatic Interactions for Drug Delivery to the Joint

Arthritis is a debilitating joint disease with a high economic burden and prevalence. There are many challenges delivering therapeutics to the joint, including low bioavailability when administered systemically and low joint retention after intra-articular injection. Therefore, drug delivery systems such as nanoparticles, liposomes, dendrimers, and carrier proteins have been utilized to overcome some of these limitations. To enhance joint tissue localization and retention, there are opportunities to leverage electrostatic interactions between drug carriers and various tissues and cells. These opportunities, as they pertain to specific joint tissues, are explored in this review. Further, the impact that electrostatic interactions has on various drug delivery parameters, such as the formation of a protein corona, the uptake and cytotoxicity, and the biodistribution of the drug delivery systems, is discussed. Lastly, this review summarizes key findings from studies that have investigated the use of electrostatic interactions to increase targeting of specific joint tissues and limitations in preclinical investigations are identified. As more novel targets are discovered in treating arthritis, there will be a continued need to localize therapeutics to specific tissues for greater therapeutic outcomes and hence attention must be paid in designing the drug delivery systems.

BioMethyl: an R package for biological interpretation of DNA methylation data

Motivation

The accumulation of publicly available DNA methylation datasets has resulted in the need for tools to interpret the specific cellular phenotypes in bulk tissue data. Current approaches use either single differentially methylated CpG sites or differentially methylated regions that map to genes. However, these approaches may introduce biases in downstream analyses of biological interpretation, because of the variability in gene length. There is a lack of approaches to interpret DNA methylation effectively. Therefore, we have developed computational models to provide biological interpretation of relevant gene sets using DNA methylation data in the context of The Cancer Genome Atlas.

Results

We illustrate that Biological interpretation of DNA Methylation (BioMethyl) utilizes the complete DNA methylation data for a given cancer type to reflect corresponding gene expression profiles and performs pathway enrichment analyses, providing unique biological insight. Using breast cancer as an example, BioMethyl shows high consistency in the identification of enriched biological pathways from DNA methylation data compared to the results calculated from RNA sequencing data. We find that 12 out of 14 pathways identified by BioMethyl are shared with those by using RNA-seq data, with a Jaccard score 0.8 for estrogen receptor (ER) positive samples. For ER negative samples, three pathways are shared in the two enrichments with a slight lower similarity (Jaccard score = 0.6). Using BioMethyl, we can successfully identify those hidden biological pathways in DNA methylation data when gene expression profile is lacking.

Availability and implementation

BioMethyl R package is freely available in the GitHub repository (https://github.com/yuewangpanda/BioMethyl).

Supplementary information

Supplementary data are available at Bioinformatics online.

Anti-inflammatory Diet In Rheumatoid Arthritis (ADIRA)-a randomized, controlled crossover trial indicating effects on disease activity

BACKGROUND

Many patients with rheumatoid arthritis (RA) report symptom relief from certain foods. Earlier research indicates positive effects of food and food components on clinical outcomes in RA, but insufficient evidence exists to provide specific dietary advice. Food components may interact but studies evaluating combined effects are lacking.

OBJECTIVES

We aimed to investigate if an anti-inflammatory diet reduces disease activity in patients with RA.

METHODS

In this single-blinded crossover trial, 50 patients with RA were randomly assigned to an intervention diet containing a portfolio of suggested anti-inflammatory foods, or a control diet similar to the general dietary intake in Sweden, for 10 wk. After a 4-mo washout period the participants switched diet. Food equivalent to ∼50% of energy requirements was delivered weekly to their homes. For the remaining meals, they were encouraged to consume the same type of foods as the ones provided during each diet. Primary outcome was change in Disease Activity Score in 28 joints-Erythrocyte Sedimentation Rate (DAS28-ESR). Secondary outcomes were changes in the components of DAS28-ESR (tender and swollen joints, ESR, and visual analog scale for general health) and DAS28-C-reactive protein.

RESULTS

In the main analysis, a linear mixed ANCOVA model including the 47 participants completing ≥1 diet period, there was no significant difference in DAS28-ESR between the intervention and control periods (P = 0.116). However, in unadjusted analyses, DAS28-ESR significantly decreased during the intervention period and was significantly lower after the intervention than after the control period in the participants who completed both periods (n = 44; median: 3.05; IQR: 2.41, 3.79 compared with median: 3.27; IQR: 2.69, 4.28; P = 0.04, Wilcoxon's Signed Rank test). No significant differences in the components were observed.

CONCLUSIONS

This trial indicates positive effects of a proposed anti-inflammatory diet on disease activity in patients with RA. Additional studies are required to determine if this diet can cause clinically relevant improvements.This trial was registered at clinicaltrials.gov as NCT02941055.

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.

Differential long non-coding RNA expression profiles in the peripheral blood and CD4+ T cells of patients with active rheumatoid arthritis

The human transcriptome is primarily composed of long non-coding RNAs (lncRNAs), which are key regulatory molecules of multiple biological processes. In the present study, the expression profiles of lncRNAs in the peripheral blood and CD4⁺ T cells of patients with active rheumatoid arthritis (RA) were determined. Based on the expression profiles, 493 lncRNAs and 374 mRNAs were identified to be differentially expressed in the peripheral blood of active RA patients and healthy donors. Further verification of lncRNAs was performed using reverse transcription-quantitative (RT-q) PCR analysis of peripheral blood from 5 healthy donors and 5 patients with active RA and 14 additional differentially expressed genes were identified. CD4⁺ T cells in peripheral blood from 12 patients with active RA and 8 healthy donors were isolated using magnetic beads and qPCR was used to assess differentially expressed lncRNAs. The results suggested that 7 lncRNAs were upregulated and 2 were downregulated. The results indicated that these 9 lncRNAs may be involved in the pathogenesis of RA. An increased ratio of Th17: T-regulatory (Treg) cells was also observed. It may be hypothesized that LncRNAs serve important roles in the differentiation of CD4⁺ T cells. Receiver operating characteristic curve analysis suggested that these 9 lncRNAs are of potential clinical diagnostic value for RA. Pearson correlation analysis indicated that the correlation coefficient between Ensembl transcript (ENST)00000569543 and complement C4 was 0.623 (P<0.05), and that between ENST00000420096 and anti-cyclic citrullinated peptide antibody or disease activity evaluation score, the correlation coefficient was 0.662 and 0.605, respectively (P<0.05 for each). In conclusion, the results of the present study suggest a possible role of lncRNAs in the differentiation of CD4⁺ T cells and the pathogenesis of RA, as well as the potential value as diagnostic biomarkers for active RA.

Sarilumab and adalimumab differential effects on bone remodelling and cardiovascular risk biomarkers, and predictions of treatment outcomes

Background

Interleukin-6 (IL-6) is a pleiotropic cytokine that plays a key role in the pathogenesis of rheumatoid arthritis. Sarilumab is a human monoclonal antibody that binds membrane-bound and soluble IL-6 receptor-α to inhibit IL-6 signalling. The aim of this study was to compare the effects of sarilumab and adalimumab (a tumour necrosis factor alpha inhibitor) monotherapy on levels of circulating biomarkers associated with the acute-phase response, bone remodelling, atherothrombosis, anaemia of chronic disease and markers purported to reflect synovial lymphoid and myeloid cell infiltrates, as well as the potential of these biomarkers to differentially predict clinical and patient-reported outcomes with sarilumab vs. adalimumab.

Methods

In this post hoc analysis, serum samples were analysed at baseline and prespecified post-treatment timepoints up to week 24 in adults with moderate-to-severe active rheumatoid arthritis intolerant of or inadequate responders to methotrexate from the MONARCH trial (NCT02332590).

Results

Greater reductions in C-reactive protein (CRP; − 94.0% vs. –24.0%), serum amyloid A (SAA; − 83.2% vs. –17.4%), total receptor activator of nuclear factor-κB ligand (RANKL; − 18.3% vs. 10.5%) and lipoprotein (a) (− 41.0% vs. –2.8%) were observed at week 24 with sarilumab vs. adalimumab, respectively (adjusted p < 0.0001). Greater increases in procollagen type 1 N-terminal propeptide (P1NP) were observed with sarilumab vs. adalimumab at week 24 (22.8% vs. 6.2%, p = 0.027). Patients with high baseline SAA, CRP and matrix metalloproteinase-3 (MMP-3) were more likely to achieve clinical efficacy, including American College of Rheumatology 20% improvement criteria and Disease Activity Score (28 joints)-CRP < 3.2, and report improvements in patient-reported outcomes, including Health Assessment Questionnaire-Disability Index and pain visual analogue scale, with sarilumab than adalimumab.

Conclusion

Sarilumab was associated with greater positive effects on bone remodelling and decreases in biomarkers of the acute-phase response, synovial inflammation and cardiovascular risk vs. adalimumab. High baseline concentrations of SAA, CRP and MMP-3 are predictive of clinical and patient-reported outcome responses to sarilumab treatment and prospective validation is warranted to confirm these results.

Trial registration

ClinicalTrials.gov, NCT02332590. Registered on 5 January 2015

Effects of overweight and underweight on the treatment outcomes of rheumatoid arthritis patients treated with biological drugs: A retrospective observational descriptive study

WHAT IS KNOWN AND OBJECTIVE

The effects of the body size condition (overweight and underweight) on the outcome of antirheumatic drugs are unclear. The aim of this study was to elucidate the relationship between body size and treatment outcomes in rheumatoid arthritis patients treated with biological antirheumatic drugs.

METHODS

A retrospective observational descriptive study was conducted at Tokyo Women's Medical University, Medical Center East, from June 2015 to May 2018. Primary and secondary outcomes were defined as antirheumatic treatment ineffectiveness and antirheumatic treatment discontinuation due to any side effects, respectively. Multivariate logistic regression analysis was used to determine the risk factors for the outcomes and to calculate the odds ratio (OR) and the 95% confidence interval (95% CI).

RESULTS AND DISCUSSION

A total of 297 patients were included. Primary and secondary outcomes were observed in 42 (14%) and 11 (4%) of the patients, respectively. Multivariate logistic regression analysis demonstrated that a body mass index (BMI) ≥25 kg/m² (OR = 4.22, 95% CI; 1.69-10.5, P = .002) was associated with rheumatoid arthritis treatment ineffectiveness and that BMI <18.5 kg/m² (OR = 5.87, 95% CI; 1.25-27.5, P = .025) and tacrolimus use (OR = 9.06, 95% CI; 1.37-60.1, P = .022) were associated with antirheumatic treatment discontinuation due to any side effects. The cut-off dose for tacrolimus was 0.5 mg/day.

WHAT IS NEW AND CONCLUSION

Overweight affects antirheumatic drug efficacy. Underweight and tacrolimus use increased the discontinuation of antirheumatic drugs due to side effects. A validation study is needed to confirm the reliability of these results.

Preferential recognition of epitopes on peroxynitrite-modified alpha-2-macroglobulin by circulating autoantibodies in rheumatoid arthritis patients

Autoimmune responses against post-translationally modified antigens are a hallmark of several autoimmune diseases. In this work, we have studied the changes in alpha-2-macroglobulin (α2M) upon modification by peroxynitrite. Furthermore, we have evaluated the immunogenicity of modified α2M in experimental rabbits and rheumatoid arthritis (RA) patients. Peroxynitrite-modified α2M showed disturbed microenvironment and altered aromatic residues under UV and fluorescence studies. Aggregation, reduction in β-sheet content, production of nitrotyrosine and shift in amide I and II bands were observed in the modified α2M by polyacrylamide gel electrophoresis besides CD and FTIR spectroscopic analysis. The exposure of hydrophobic clusters and changes in contact positions were observed in ANS and ThT binding assays. Immunological studies using ELISA showed peroxynitrite-modified α2M as highly immunogenic producing high titre of specific antibodies in immunized rabbits. Cross-reactivity studies revealed the polyspecificity of the elicited antibodies. Direct binding ELISA and competitive inhibition studies confirmed the presence of circulating antibodies in the sera of RA patients having high specificity towards the peroxynitrite-modified α2M as compared to the native α2M. Sera from healthy (normal) human subjects showed lower binding with the native and modified protein. This study confirms that peroxynitrite induces structural modifications in α2M and makes it immunogenic. The presence of neo-antigenic determinants on modified α2M with enhanced binding for circulating autoantibodies in RA patients could offer new possibilities for diagnosis and etiopathology of the disease. Communicated by Ramaswamy H. Sarma.

Heightened Levels of Antimicrobial Response Factors in Patients With Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic progressive autoimmune disease leading to considerable disability over time. The disease can be characterized by the presence of multiple autoantibodies in the serum and synovial fluid. Microbial dysbiosis is proposed to play a role in the pathogenesis of RA. Increased systemic bacterial exposure leads to elevated levels of antimicrobial response factors (ARFs) in the circulation. In the present study, we tested whether RA patients have increased levels of ARFs by analyzing the levels of multiple ARFs in serum from RA patients and healthy age and sex-matched controls. The levels of soluble CD14 (sCD14), lysozyme, and CXCL16 were significantly elevated in RA patients compared to healthy controls. Lipopolysaccharide binding protein (LBP) levels remained unchanged in RA patients compared to healthy controls. A positive correlation of LBP with rheumatoid factor (RF) was also found in RA subjects. Interestingly, the levels of anti-endotoxin core antibodies (EndoCAb) IgM, total IgM, EndoCAb IgA, and total IgA were significantly elevated in RA patients compared to healthy controls. No significant changes in the levels of EndoCAb IgG and total IgG were observed in RA patients compared to healthy controls. Furthermore, lysozyme and CXCL16 levels were positively correlated with disease severity among RA subjects. Increases in the levels of several ARFs and their correlations with clinical indices suggest systemic microbial exposure in the RA cohort. Modulation of microbial exposure may play an important role in disease pathogenesis in individuals with RA.

Mitigation of Rheumatic Arthritis in a Rat Model via Transdermal Delivery of Dapoxetine HCl Amalgamated as a Nanoplatform: In vitro and in vivo Assessment

Purpose

Dapoxetine HCl (DH), a selective serotonin reuptake inhibitor, may be useful for the treatment of rheumatic arthritis (RA). The purpose of this study was to investigate the therapeutic efficacy of transdermal delivery of DH in transethosome nanovesicles (TENVs). This novel delivery of DH may overcome the drawbacks associated with orally administered DH and improve patient compliance.

Methods

DH-TENV formulations were prepared using an injection- sonication method and optimized using a 3³ Box-Behnken-design with Design Expert^® software. The TENV formulations were assessed for entrapment efficiency (EE-%), vesicle size, zeta potential, in vitro DH release, and skin permeation. The tolerability of the optimized DH-TENV gel was investigated using a rat skin irritation test. A pharmacokinetic analysis of the optimized DH-TENV gel was also conducted in rats. Moreover, the anti-RA activity of the optimized DH-TENV gel was assessed based on the RA-specific marker anti-cyclic cirtullinated peptide antibody (anti-CCP), the cartilage destruction marker cartilage oligomeric matrix protein (COMP) and the inflammatory marker interleukin-6 (IL-6). Level of tissue receptor activator of nuclear factor kappa-Β ligand (RANKL) were also assessed.

Results

The optimized DH-TENV formulation involved spherical nanovesicles that had an appropriate EE- % and skin permeation characteristic. The DH-TENV gel was well tolerated by rats. The pharmacokinetics analysis showed that the optimized DH-TENV gel boosted the bioavailability of the DH by 2.42- and 4.16-fold compared to the oral DH solution and the control DH gel, respectively. Moreover, it significantly reduced the serum anti-CCP, COMP and IL-6 levels and decreased the RANKL levels. Furthermore, the DH-TENV gel attenuated histopathological changes by almost normalizing the articular surface and synovial fluid.

Conclusion

The results indicate that DH-TENVs can improve transdermal delivery of DH and thereby alleviate RA.

Integration of single nucleotide variants and whole-genome DNA methylation profiles for classification of rheumatoid arthritis cases from controls

This study evaluated the use of multiomics data for classification accuracy of rheumatoid arthritis (RA). Three approaches were used and compared in terms of prediction accuracy: (1) whole-genome prediction (WGP) using SNP marker information only, (2) whole-methylome prediction (WMP) using methylation profiles only, and (3) whole-genome/methylome prediction (WGMP) with combining both omics layers. The number of SNP and of methylation sites varied in each scenario, with either 1, 10, or 50% of these preselected based on four approaches: randomly, evenly spaced, lowest p value (genome-wide association or epigenome-wide association study), and estimated effect size using a Bayesian ridge regression (BRR) model. To remove effects of high levels of pairwise linkage disequilibrium (LD), SNPs were also preselected with an LD-pruning method. Five Bayesian regression models were studied for classification, including BRR, Bayes-A, Bayes-B, Bayes-C, and the Bayesian LASSO. Adjusting methylation profiles for cellular heterogeneity within whole blood samples had a detrimental effect on the classification ability of the models. Overall, WGMP using Bayes-B model has the best performance. In particular, selecting SNPs based on LD-pruning with 1% of the methylation sites selected based on BRR included in the model, and fitting the most significant SNP as a fixed effect was the best method for predicting disease risk with a classification accuracy of 0.975. Our results showed that multiomics data can be used to effectively predict the risk of RA and identify cases in early stages to prevent or alter disease progression via appropriate interventions.

Circulating IFN-γ producing CD4+ T cells and IL-17A producing CD4+ T cells, HLA-shared epitope and ACPA may characterize the clinical response to therapy in rheumatoid arthritis patients

This study analyzed the association between peripheral distributions of helper T cell subsets, HLA shared-epitope (SE), anti-cyclic citrullinated peptide antibody (ACPA) and clinical response to therapy in rheumatoid arthritis (RA) patients. Frequencies of IFN-γ-producing CD4+T (Th1) and IL-17A-producing CD4+T (Th17) cells were determined by flow cytometry in 167 patients (114 cases with good-response (GR) and 53 poor-response (PR) based on DAS28). HLA-DRB1 alleles for patients and 150 healthy controls were determined by PCR-SSP. We observed that 65.2% of RA patients were SE⁺, 63.4%ACPA⁺, 43.7%SE⁺ACPA⁺ and 14.9% were SE^-ACPA^-. Higher significantly proportions of Th1 and Th17 cells were found in RA patients than controls (P < 0.05) as well as in the SE⁺ or ACPA⁺RA patients compared to SE^- and ACPA^- patients. Increased frequencies of both Th subsets were found in SE⁺ACPA⁺ versus SE^-ACPA^- patients (P < 0.001) and in the PR versus GR group (P < 0.001). We showed significant differences for Th cells frequencies between SE⁺ and SE^- patients in both groups, and between ACPA⁺ and ACPA^- cases in the PR group. Our findings suggest a close link between Th1 and Th17 cells proportions and HLA-SE/ACPA in the RA patients and remarkably in the PR group which could be indicative for the importance of immune monitoring for evaluation of response to therapy.

The impact of Clonorchis sinensis infection on immune response in mice with type II collagen-induced arthritis

BACKGROUND

Clonorchis sinensis infection could trigger strong immune responses in mice and humans. However, whether the C.sinensis infection has an impact on arthritis is unknown. Here we investigated the effect of C.sinensis infection on type II collagen-induced arthritis in BALB/c mice.

RESULTS

The mice were firstly infected with 45 C.sinensis metacercariae by oral gavage. Four weeks later, arthritis in mice was induced by type II collagen. Joint inflammation with severe redness and swelling in hind paws was observed in type II collagen-induced arthritis (CIA) mice. Besides, the physical activity was significantly reduced, but the respiratory exchange ratio was increased in CIA mice. Compared with CIA mice, C.sinensis infection could increase the severity of arthritis in CIA mice, based on the results of disease score and pathological changes. Compared to CIA mice, increased neutrophils and Ly6C^hi monocytes, decreased B cells and CD4⁺T cells, were found in C.sinensis infected CIA mice. Besides these, C.sinensis infected mice also displayed significantly higher levels of serum IL-4 and IL-17 than those in CIA mice.

CONCLUSIONS

Taken together, our data suggest that C.sinensis infection have a bad effect on arthritis, and could induce the abnormality of the immune response in mice with CIA.

A highlight on CD4+ T-cells in the spleen in a rat model of rheumatoid arthritis and possible therapeutic effect of omega-3. Histological and Immunofluorescence study

BACKGROUND

Rheumatoid arthritis (RA), a primary chronic articular disease with wide range of extra-articular and systemic effects. The spleen is one of the most affected organs in RA. CD4⁺ T cells play an important role in initiation, maintenance and control of the disease.

AIM OF THE WORK

This work was designed to study the histological changes occurring in the spleen in a rat model of RA and to assess the effect of treatment with omega-3 alone, with special refer to the role of CD4⁺ T-cells.

MATERIALS AND METHODS

Thirty male albino rats were divided into four groups; control group, early and progressive RA groups and omega-3 treated group. RA was induced in rats of groups II, III and IV by a single subcutaneous injection of complete Freund's adjuvant (CFA). Samples were taken after two and four weeks of the CFA injection (in early and progressive RA groups respectively). Treatment with omega-3 (300 mg/kg/day in a single, daily oral dose) started two weeks after CFA injection in rats of group IV and continued for another two weeks. Spleen specimens were collected at the appropriate times and processed to obtain paraffin blocks. Sections were then stained for histological and immunofluorescence studies.

RESULTS

Both, early and progressive RA induced noticeable structural changes in the spleen. Thickened capsule and trabeculae and marked congestion of the blood sinusoids of the red pulp were evident. Expansion of the white pulp and areas of mononuclear cellular infiltration were seen, especially in progressive RA. Affection of blood vessel walls was also noticed. Immunofluorescence study showed extensive expression of Anti-CD4 Monoclonal Antibodies especially in progressive RA. Treatment with omega-3 significantly improved the structure of the spleen as detected by both histological and immunofluorescence studies.

CONCLUSION

Omega-3 treatment ameliorated the structural damage of the spleen caused by experimental induction of RA.

Chronic inflammatory diseases, myocardial function and cardioprotection

The association between chronic inflammatory diseases (CIDs) and increased cardiovascular (CV) risk is well documented and can be a most threatening complication in these patients. However, the pathogenetic mechanisms underlying increased CV risk remain elusive, especially in their cellular and biochemical pathways. Using animal models to understand mechanisms underlying cardiac involvement are limited. Additionally, treatments may influence cardiovascular events through different outcomes. Some drugs used to treat CIDs can negatively affect cardiac function by a direct toxicity, whereas others may protect the myocardium. In the present article, we focus on the cardiac manifestations and risk factors, the pathogenetic mechanisms, and the effect of treatments on myocardial function and cardioprotection for five common worldwide CIDs (rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, psoriasis and inflammatory bowel disease). We also give recommendations in order to evaluate common targets between CID and CV disease (CVD) and to design therapies to alleviate CID-related CVD. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc.

Safety and tolerability of subcutaneous sarilumab and intravenous tocilizumab in patients with rheumatoid arthritis

Objective

Safety and efficacy of mAbs blocking the IL-6 receptor have been established in RA. This is the first analysis examining safety and tolerability of sarilumab and tocilizumab administered as single or multiple doses in patients with RA within the same study.

Methods

In ASCERTAIN, patients were randomized 1: 1: 2 to 24 weeks’ double-blind sarilumab 150 or 200 mg every 2 weeks s.c. or tocilizumab 4 mg/kg every 4 weeks i.v., increased to 8 mg/kg if clinically indicated. In Study 1309, patients were randomized 1: 1: 1: 1 to single-dose open-label sarilumab 150 or 200 mg s.c. or tocilizumab 4 or 8 mg/kg i.v.

Results

In ASCERTAIN, incidence of treatment-emergent adverse events was similar between sarilumab and tocilizumab. The most common treatment-emergent adverse events were the following: sarilumab: neutropenia [6 patients (12.2%) in the 150 mg group and 8 (15.7%) in the 200 mg group], nasopharyngitis [6 (12.2%) and 3 (5.9%)], and injection-site erythema [4 (8.2%) and 4 (7.8%)]; tocilizumab: accidental overdose [9 (8.8%)], upper respiratory tract infection [7 (6.9%)] and nausea [7 (6.9%)]. Laboratory changes in both studies included decreased neutrophils and platelets and increased transaminases and lipids. In Study 1309, incidence of absolute neutrophil count <1.0 giga/l was similar between sarilumab and tocilizumab, and occurred more frequently in the higher dose groups. No association between decrease in absolute neutrophil count and increased incidence of infection was observed in either study.

Conclusion

No clinically meaningful differences in treatment-emergent adverse events were observed between sarilumab and tocilizumab. Laboratory changes with sarilumab were within the same range as those with tocilizumab.

Trial registration numbers

ASCERTAIN (NCT01768572); Study 1309 (NCT02097524).

Effects of Hyperbaric Oxygen on T helper 17/regulatory T Polarization in Antigen and Collagen-induced Arthritis: Hypoxia-inducible Factor-1α as a Target

Objectives

We sought to investigate and prove the effect of hyperbaric oxygen therapy (HBOT) on T helper 17 (Th17)/regulatory T (Treg) cell polarization through changes in the expression of hypoxia-inducible factor-1 alpha (HIF-1α) in rheumatoid arthritis (RA) animal model.

Methods

We used antigen and collagen-induced arthritis (ACIA) as a RA animal model. Sixteen male BALB/c models of ACIA mice were divided into two groups, the non-HBOT group as the control group and the HBOT group as the treatment group. Expression of HIF-1α, Th17 anti-cluster differentiation 196 (CD196), and Treg anti-interleukine 2 receptor β-chain cells (IL-2Rβ) in tissue from the left knee joint tissue were determined histologically. Oxidative stress and systemic inflammation were assessed by levels of superoxide dismutase (SOD), interleukin 17a (IL-17a), C-reactive protein (CRP), and rheumatoid factor (RF) using the enzyme-linked immune-sorbent assay. The degree of arthritis was assessed by clinical scoring of paw swelling and the diameter of paw swelling.

Results

We found a significant decrease (p < 0.050) in the expression of HIF-1α, Th17 (CD196), IL-17a, RF levels, and the clinical scores and the diameter of paw swelling when comparing both groups. There was no significant decrease in the level of CRP in the treatment group compared to the control group. The expression of Treg (IL-2Rβ) increased significantly (p < 0.050) and the level of SOD increased but not significantly (p > 0.050) in the treatment group compared to the control group.

Conclusions

HBOT has effects on the polarization of Th17 to Treg through a decrease in expression of HIF-1α in mice with ACIA. HBOT is recommended for use as a support therapy for RA in combination with drug therapy.

N-Butanol Extract of Gastrodia elata Suppresses Inflammatory Responses in Lipopolysaccharide-Stimulated Macrophages and Complete Freund's Adjuvant- (CFA-) Induced Arthritis Rats via Inhibition of MAPK Signaling Pathway

Gastrodia elata is a traditional herbal medicine that has been used for centuries to treat rheumatism. Previous studies have confirmed that ethanol extracts of Gastrodia elata have anti-inflammatory and antioxidant activities, and the n-butanol fraction exerts a higher inhibitory effect. However, the in vivo anti-inflammatory effects of Gastrodia elata have not been evaluated. Thus, we assessed the therapeutic effect of the n-butanol extract of Gastrodia elata (BGE) on complete Freund's adjuvant- (CFA-) induced arthritis rats which were separated into six groups (NOR; MODEL; CFA + dexamethasone (DEX); CFA + 25, 50, 100 mg/kg BGE). The paw swelling, joint radiology, and histology were used to analyze the effect of BGE on delaying the progression of rheumatoid arthritis. Furthermore, serum levels of inflammatory cytokines were analyzed via ELISA. In addition, the effect of BGE on nitric oxide (NO) production, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2(COX-2), and inflammatory cytokines were detected in lipopolysaccharide- (LPS-) stimulated RAW264.7 macrophage cells. Lastly, the impacts of BGE on the activation of the mitogen-activated protein kinases (MAPK) pathway in CFA rats and LPS-stimulated RAW264.7 macrophage were examined by western blot analysis. The results show that BGE can significantly reduce paw swelling without losing the body weight of rats. Imaging assessment confirms that BGE can protect cartilage from destruction, as well as reducing inflammatory cell infiltration and synovial proliferation. Moreover, BGE suppresses the production of inflammatory cytokines in serum and inhibits the activation of the phosphorylation of p38 and ERK in CFA rats. BGE was also demonstrated to decrease the production of NO and inflammatory cytokines in LPS-stimulated RAW264.7 cells. The effect of BGE in LPS-induced expression leads to reduced p38 and ERK phosphorylation and also downregulates the protein expression of iNOS and COX-2. Taken together, BGE exhibits a potential therapeutic effect on CFA rats, and its anti-inflammatory and antioxidant effects were possibly exerted by regulation of ERK/p38MAPK.

Humulus japonicus extract ameliorates collagen‑induced arthritis in mice through regulation of overall articular inflammation

Humulus japonicus (HJ) is a widely used herbal medicine in Asia with anti-oxidative, anti-microbial, and anti-inflammatory effects. We investigated the potential therapeutic effects of HJ in rheumatoid arthritis (RA) using a mouse model of collagen-induced arthritis (CIA) and a lipopolysaccharide-stimulated murine macrophage cell line (RAW 264.7). The CIA mice were administered 300 mg/kg HJ orally starting 3 days prior to second immunization. The clinical and histopathological findings were assessed in the paw of CIA mice. The levels of autoantibodies and inflammatory markers were determined in the plasma and cell culture supernatant, respectively. The expression at mRNA and protein levels was analyzed by reverse transcription quantitative-PCR and western blot analysis, respectively. HJ significantly decreased the gross arthritic scores and paw swelling in CIA mice. Furthermore, synovial inflammation, cartilage destruction, and bone erosion were markedly reduced by HJ. It also decreased the expression of inflammatory enzymes in both the paw of mice and RAW 264.7 cells. Moreover, the expression of genes related to all macrophages and pro-inflammatory M1 macrophage were significantly decreased, whereas the expression of anti-inflammatory M2 macrophage marker was markedly increased in the paw of HJ-treated CIA mice. In addition, HJ suppressed the levels of plasma anti-type II collagen antibody following the decreased expression of T helper type 1 (Th1) and Th2 cell-associated surface markers and cytokines in the paw. HJ also significantly inhibited the expression of IL-6 both in vitro and in vivo, followed by reduced STAT3 phosphorylation and expression in the paw of CIA mice. Finally, the expression of osteoclast-related genes was decreased in the paw of HJ-treated CIA mice. These findings suggest that HJ can play a role in suppressing the development of CIA by overall regulation of articular inflammation. This study should provide new insights into the use of HJ as a therapeutically effective natural product against RA.

Fluorometric Imaging for Early Diagnosis and Prognosis of Rheumatoid Arthritis

Early diagnosis and monitoring of disease progress are of significant importance in the effective treatment of rheumatoid arthritis (RA), because the continuing inflammation can lead to irreversible joint damage and systemic complications. However, applying imaging modalities for the prognosis of RA remains challenging, because no tissue-specific guidelines are available to monitor the progressive course of RA. In this study, fluorometric imaging of RA is reported using bioengineered targeted agents of the blood vessel, bone, and cartilage in combination with the customized optical fluorescence imaging system. Separate but simultaneous tissue-specific images of synovitis, cartilage destruction, and bone resorption are obtained from a mouse model of RA, which allows quantification of the prognosis of diseases at each stage. Thus, the fluorometric imaging of RA by using tissue-specific contrast agents plays a key role in the systemic treatment of RA by monitoring structural damage and disease progression.

Preclinical Evaluation of a Single Intravenous Infusion of hUC-MSC (BX-U001) in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory disease of the joints, which causes severe pain and excessive systemic circulation of harmful inflammatory cytokines. Current treatments are limited, with some patients not responding well, and some experiencing severe and detrimental side effects. Mesenchymal stem cells (MSC) are cell-based therapeutics being evaluated as potent immunomodulators in RA and may provide relief to patients not responding well to drug-based treatments. We evaluated the safety and efficacy of BX-U001 human umbilical cord tissue-derived mesenchymal stem cells (hUC-MSC) to treat RA, in support of a successful investigational new drug application. A collagen-induced arthritis (CIA) mouse model of RA was established in DBA/1 J mice. Mice from the treatment assessment group were given a tail vein infusion of hUC-MSC 24 days after primary RA induction, while control assessment (CA) group mice were given cell-free carrier solution. All animals were evaluated daily for RA symptoms via clinical scoring, blood was taken periodically for cytokine analysis, and mice were dissected at end point for histological analysis. A linear mixed model was used to compare the rate of change among groups. The clinical scores of TA group were significantly reduced compared with CA group (P < 0.01), indicating therapeutic effects. The histological scores of the joints in TA group were significantly lower than those in the CA group (P < 0.05), but had no significant difference compared with Healthy groups (P > 0.05). The concentration of (interleukin) IL-6 in TA group was significantly reduced by 80.0% (P < 0.0001) 2 days after treatment and by 93.4% at the experimental endpoint compared with levels prior to hUC-MSC injection. A single intravenous infusion of hUC-MSC (2 × 106 cells/mouse), to CIA-induced DBA/1 J mice, resulted in significant alleviation of RA symptoms and may provide significant therapeutic benefits in humans.

Diosmetin exhibits anti-proliferative and anti-inflammatory effects on TNF-α-stimulated human rheumatoid arthritis fibroblast-like synoviocytes through regulating the Akt and NF-κB signaling pathways

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation and proliferation of synovial tissues. Diosmetin is a bioflavonoid possessing an anti-inflammatory property. Herein, we aimed to study the effects of diosmetin on the inflammation and proliferation of RA fibroblast-like synoviocytes MH7A cells. MH7A cell proliferation was measured using cell counting kit-8 assay. Cell apoptosis was examined using flow cytometry. The production of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, and matrix metalloproteinase-1 (MMP-1) was measured using enzyme-linked immunosorbent assay (ELISA). Results showed that diosmetin inhibited tumor necrosis factor-α (TNF-α)-induced proliferation increase in MH7A cells in a dose-dependent manner. Diosmetin treatment resulted in an increase in apoptotic rates and a reduction in TNF-α-induced production of IL-1β, IL-6, IL-8, and MMP-1 in MH7A cells. Furthermore, diosmetin inhibited TNF-α-induced activation of protein kinase B (Akt) and nuclear factor-κB (NF-κB) pathways in MH7A cells. Suppression of Akt or NF-κB promoted apoptosis and inhibited TNF-α-induced proliferation increase and production of IL-1β, IL-6, IL-8, and MMP-1 in MH7A cells, and diosmetin treatment enhanced these effects. Taken together, these findings suggested that diosmetin exhibited anti-proliferative and anti-inflammatory effects via inhibiting the Akt and NF-κB pathways in MH7A cells.

FKB327, an adalimumab biosimilar, versus the reference product: results of a randomized, Phase III, double-blind study, and its open-label extension

Objective

To compare the efficacy, serum drug concentrations, immunogenicity, and safety of FKB327 with the adalimumab reference product (RP) in combination with methotrexate in patients with moderate-to-severe, active rheumatoid arthritis (RA).

Methods

Patients were randomized 1:1 in a double-blind study (NCT02260791), received 40 mg of FKB327 or RP by subcutaneous injection every other week for 24 weeks (Period I), then re-randomized 2:1, remaining on the same study drug or switching to the other up to week 54 in an open-label extension (Period II, NCT02405780). Efficacy was evaluated using American College of Rheumatology (ACR20) response rate difference at week 24 with equivalence margins of ± 13% and − 12% to + 15% using 95% and 90% confidence intervals (CIs), respectively. Efficacy, serum drug concentrations, immunogenicity, and safety were compared at week 54.

Results

A total of 730 patients were randomized in Period I (n = 367 FKB327, n = 363 RP), and 645 transitioned to Period II (n = 216 FKB327–FKB327, n = 108 FKB327–RP, n = 108 RP–FKB327, n = 213 RP–RP). At week 24, ACR20 response rates were 74.1% with FKB327 versus 75.7% with RP. 95% and 90% CI of the response rate difference were − 7.9 to 4.7% and − 7.3 to 3.6%, respectively, meeting predefined equivalence margins. The ACR20 response rate remained over 70% of patients to week 54 with all treatment sequences. In Period I, mean trough serum drug concentrations were slightly higher for patients receiving FKB327 than those receiving RP. Mean concentrations were stable over time and reflected steady state in Period II. The proportions of patients with samples positive for neutralizing antidrug antibodies (ADAs) were comparable (57.7% with FKB327 vs. 55.5% with RP) at week 24, and no consistent difference in ADA were seen between continuous and switched treatments in Period II. Efficacy was slightly reduced in the small proportion of patients with high ADA titers in all treatment groups. No clinically significant differences were observed in the incidence of commonly reported treatment-emergent adverse events between the treatments across Periods I and II.

Conclusion

FKB327 was equivalent to RP in clinical efficacy and demonstrated comparable safety and immunogenicity in patients with moderate-to-severe RA. No effect of switching between FKB327 and RP was observed.

Trial registration

ClinicalTrials.gov, NCT02260791, Registered 29 July 2014.

ClinicalTrials.gov, NCT02405780, Registered 17 July 2015.

An Overview of the Intrinsic Role of Citrullination in Autoimmune Disorders

A protein undergoes many types of posttranslation modification. Citrullination is one of these modifications, where an arginine amino acid is converted to a citrulline amino acid. This process depends on catalytic enzymes such as peptidylarginine deiminase enzymes (PADs). This modification leads to a charge shift, which affects the protein structure, protein-protein interactions, and hydrogen bond formation, and it may cause protein denaturation. The irreversible citrullination reaction is not limited to a specific protein, cell, or tissue. It can target a wide range of proteins in the cell membrane, cytoplasm, nucleus, and mitochondria. Citrullination is a normal reaction during cell death. Apoptosis is normally accompanied with a clearance process via scavenger cells. A defect in the clearance system either in terms of efficiency or capacity may occur due to massive cell death, which may result in the accumulation and leakage of PAD enzymes and the citrullinated peptide from the necrotized cell which could be recognized by the immune system, where the immunological tolerance will be avoided and the autoimmune disorders will be subsequently triggered. The induction of autoimmune responses, autoantibody production, and cytokines involved in the major autoimmune diseases will be discussed.

Investigation of the curative effects of palm vitamin E tocotrienols on autoimmune arthritis disease in vivo

The tocotrienol-rich fraction (TRF) from palm oil contains vitamin E, which possesses potent antioxidant and anti-inflammatory activities. Rheumatoid arthritis (RA) is a chronic joint inflammatory disease characterised by severe joint pain, cartilage destruction, and bone erosion owing to the effects of various pro-inflammatory mediators and cytokines. Here, we investigated the therapeutic effects of TRF in a rat model of collagen-induced arthritis (CIA). Arthritis was induced by a single intradermal injection of collagen type II in Dark Agouti (DA) rats. Rats were then treated with or without TRF by oral gavage from day 28 after the first collagen injection. Arthritic rats supplemented with TRF showed decreased articular index scores, ankle circumferences, paw volumes, and radiographic scores when compared with untreated rats. The untreated arthritic rats showed higher plasma C-reactive protein levels (p < 0.05) and production of pro-inflammatory cytokines than arthritic rats fed TRF. Moreover, there was a marked reduction in the severity of histopathological changes observed in arthritic rats treated with TRF compared with that in untreated arthritic rats. Overall, the results show that TRF had beneficial effects in this rat model of RA.

Nanomedicine - advantages for their use in rheumatoid arthritis theranostics

Rheumatoid arthritis (RA) is an autoimmune disease accompanies with synovial inflammation and progressive bone destruction. Currently, anti-rheumatic drugs need high dose and frequent use for a long-term, which lead to serious side effect and low patient compliance. To overcome above problems and improve clinical efficacy, nano-technology with targeting ability, sustained release and so forth, has been proposed on RA treatment and already achieved success in RA animal models. In this review, authors summarize and illustrate representative nanomedicine targeting to RA states, which is achieved either through passive or active targeting with high affinity to the receptors that are over-expressed in macrophages or angiogenesis. In particular, authors highlight the new strategies to promote the efficacy of nanoscale treatments through phototherapy and the addition of contrast elements for theranostic application. The described advances may pave the way to better understanding and designing the novel nanomedicine and multifunctional nano-system on efficient RA treatment.

The Systemic Immune Response to Collagen-Induced Arthritis and the Impact of Bone Injury in Inflammatory Conditions

Rheumatoid arthritis (RA) is a systemic disease that affects the osteoarticular system, associated with bone fragility and increased risk of fractures. Herein, we aimed to characterize the systemic impact of the rat collagen-induced arthritis (CIA) model and explore its combination with femoral bone defect (FD). The impact of CIA on endogenous mesenchymal stem/stromal cells (MSC) was also investigated. CIA induction led to enlarged, more proliferative, spleen and draining lymph nodes, with altered proportion of lymphoid populations. Upon FD, CIA animals increased the systemic myeloid cell proportions, and their expression of co-stimulatory molecules CD40 and CD86. Screening plasma cytokine/chemokine levels showed increased tumor necrosis factor-α (TNF-α), Interleukin (IL)-17, IL-4, IL-5, and IL-12 in CIA, and IL-2 and IL-6 increased in CIA and CIA+FD, while Fractalkine and Leptin were decreased in both groups. CIA-derived MSC showed lower metabolic activity and proliferation, and significantly increased osteogenic and chondrogenic differentiation markers. Exposure of control-MSC to TNF-α partially mimicked the CIA-MSC phenotype in vitro. In conclusion, inflammatory conditions of CIA led to alterations in systemic immune cell proportions, circulating mediators, and in endogenous MSC. CIA animals respond to FD, and the combined model can be used to study the mechanisms of bone repair in inflammatory conditions.

Stromal cell-derived factor-1 as a potential therapeutic target for osteoarthritis and rheumatoid arthritis

With age, joints become subject to chronic inflammatory processes that lead to degeneration of articular cartilage. Although multifactorial, cytokines have been shown to play a role in the pathogenesis of these chronic disease states. Stromal cell-derived factor 1 (SDF-1) is a chemokine that has been shown to be active in homeostatic mechanisms and developmental processes throughout the body, such as endochondral bone formation. SDF-1 plays a role in the transition from cartilage to bone. Although it has been shown to be a factor in normal development, it has also been shown to involve in the pathogenesis of rheumatoid arthritis (RA) and osteoarthritis (OA). In RA, SDF-1 has been shown to stimulate the recruitment of proinflammatory cells, as well as osteoclasts to the synovium, aiding in the facilitation of synovial degradation. Similarly, in OA, SDF-1 has been shown to regulate key proteins involved in the degradation of the cartilage of the joint. Because of its role in degenerative joint disease, SDF-1 has been investigated as a potential therapeutic target. Animal studies have been employing SDF-1 inhibitors, such as AMD3100 and T140, to study their effects on attenuating degenerative joint disease. These studies have shown promising results in slowing the progression of cartilage degradation and could potentially be used as therapeutic target for humans OA and RA.

The therapeutic effects of edaravone on collagen-induced arthritis in rats

Current research suggests that synovial phagocytic cells remove excessive amounts of free oxygen radicals (reactive oxygen species [ROS]), thereby preventing damage to synovial tissues. Moreover, ROS may affect the expression of growth arrest and DNA damage inducible α (GADD45A), thus further promoting the activation of synovial fibroblasts. Male adult rats were assessed for progression of collagen-induced arthritis (CIA) using a macroscopic arthritis scoring system of the hind paws and by measuring the changes in the rat's body weight, and activity level before and after diagnosis of CIA. Rats were intraperitoneally injected twice daily with edaravone at doses of 3, 6, and 9 mL/kg. Samples were taken at 2, 4, and 6 weeks, respectively. Edaravone was found to significantly reduce macroscopic arthritis and microscopic pathology scores in CIA rats. The concentration of endothelial nitric oxide synthase-6, glutathione, and heme oxygenase-1 in the serum of rats decreased, as was the production of ROS around the synovium and inflammatory factors. Moreover, ROS-1 increased the expression of the nuclear factor-κB (NF-κB) p65 protein by altering the expression level of GADD45A, causing aggravation of tissue damage. Edaravone also significantly improved the physiological condition of CIA rats, including appetite, weight changes, and loss of fur, as well as limb mobility. We believe that edaravone acts to reduce the expression of NF-ĸB p65 by clearing ROS, which causes reduced expression of GADD45A, and subsequently reduces the level of apoptosis and inflammatory response proteins, thereby reducing the symptoms of CIA. We, therefore, propose that edaravone is an effective option for clinical treatment of rheumatic arthritis.

Retinoic Acid Receptor-Related Receptor Alpha Ameliorates Autoimmune Arthritis via Inhibiting of Th17 Cells and Osteoclastogenesis

Rheumatoid arthritis (RA) is a chronic inflammatory polyarthritis characterized by progressive joint destruction. IL-17-producing CD4+ T (Th17) cells play pivotal roles in RA development and progression. Retinoic acid receptor-related orphan receptor alpha (RORα) is a negative regulator of inflammatory responses, whereas RORγt, another member of the ROR family, is a Th17 lineage-specific transcription factor. Here, we investigated the immunoregulatory potential of RORα in collagen-induced arthritis (CIA) mice, an experimental model of RA. Cholesterol sulfate (CS) or SR1078, a ligand of RORα, inhibited RORγt expression and Th17 differentiation in vitro. In addition, fortification of RORα in T cells inhibited the expression levels of glycolysis-associated genes. We found that RORα overexpression in CIA mice attenuated the clinical and histological severities of inflammatory arthritis. The anti-arthritic effect of RORα was associated with suppressed Th17 differentiation and attenuated mTOR-STAT3 signaling in T cells. Furthermore, altered RORα activity could directly affect osteoclastogenesis implicated in progressive bone destruction in human RA. Our findings defined a critical role of RORα in the pathogenesis of RA. These data suggest that RORα may have novel therapeutic uses in the treatment of RA.

Efficacy and safety of Ramucirumab and methotrexate co-therapy in rheumatoid arthritis experimental model: Involvement of angiogenic and immunomodulatory signaling

Rheumatoid arthritis (RA) is a chronic and progressive autoimmune inflammatory disease associated with irreversible joint destruction that leads to permanent motor disability and compromised quality of life. However, the main cause of RA is still unknown though stimulation of immune system and cells plays pivotal role in disease development and progression. Ramucirumab (RAM) is the monoclonal antibody against VEGF- receptor. This study aimed to investigate and evaluate the therapeutic effect of RAM with or without Methotrexate (MTX) against adjuvant-induced arthritis in rats. Complete Freund's adjuvant (CFA)-induced arthritic rats were treated for three consecutive weeks with MTX or RAM alone and MTX-RAM co-therapy. Arthritic score, gait score, ankle diameter, paw thickness, angiogenic, inflammatory cytokines, bone erosion markers, and apoptotic markers were assessed to evaluate the anti-arthritic effect. RAM monotherapy exhibited anti-inflammatory, anti-angiogenic and anti-apoptotic effects similar to MTX alone to treat RA in the current study. Furthermore, RAM alone had a protective effect on bone and cartilage health better than standard anti-rheumatic agent MTX. Interestingly, combined therapy of MTX and RAM produced significant differences in comparison with MTX or RAM monotherapy in all tested parameters. Moreover, the current study proved that MTX-RAM co-therapy has a synergistic effect.

Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review

Rheumatoid arthritis (RA), a chronic inflammatory autoimmune disease, affects roughly 1% of the world's population. RA pathogenesis remains unclear, but genetic factors account for 50–60% of the risk while the remainder might be linked to modifiable factors, such as infectious diseases, tobacco smoking, gut bacteria, and nutrition. Dietary triggers may play an inciting role in the autoimmune process, and a compromised intestinal barrier may allow food components or microorganisms to enter the blood stream, triggering inflammation. In addition, excessive body weight may affect pharmacotherapy response and the likelihood of disease remission, as well as the risk of disease mortality. Evidence suggests that changes in diet might play an important role in RA management and remission. Several studies have shown improvements in RA symptoms with diets excluding animal products. Studies have also shown that dietary fiber found in these plant-based foods can improve gut bacteria composition and increase bacterial diversity in RA patients, thus reducing their inflammation and joint pain. Although some of the trigger foods in RA patients are individualized, a vegan diet helps improve symptoms by eliminating many of these foods. This review examines the potential role of a plant-based diet in mediating RA symptoms. Further research is needed to test the effectiveness of plant-based diets on joint pain, inflammation, and quality of life in patients with RA.

Clinical evaluation of the safety, efficacy and tolerability of sarilumab in the treatment of moderate to severe rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that is characterised by synovial inflammation and progressive joint disorder with significant pain and stiffness, which lead to functional disability and systemic complications if left untreated. Although methotrexate (MTX) is the cornerstone in the RA therapy, it is ineffective or intolerable in up to 50% of patients. In addition, tumour necrosis factor (TNF) inhibitors which are regarded as the standard of care for those patients, have not been proven a panacea creating a therapeutic gap. In this direction, other cytokines such as the interleukin (IL)-6 in combination with MTX or as monotherapy have been approved. Sarilumab has already been approved for the treatment of moderate to severe RA, but more studies are on their way including polymyalgia rheumatica, giant cell arteritis, juvenile idiopathic arthritis, and indolent systemic mastocytosis. On the other hand, a study was prematurely discontinued after approximately 1.5 years, when the ankylosing spondylitis development program was discontinued due to lack of efficacy. Regarding safety, efficacy and tolerability of the molecule, three pivotal clinical trials have established sarilumab as one of the safe and efficacious choices for the treatment of RA (mobility, target and monarch trials). Significant decreases in progression of structural damage have been demonstrated. Infections and neutropenia are two of the most common adverse events. Sarilumab is beyond any doubt another molecule that can be added to the clinicians’ armamentarium for the treatment of patients with moderate to severe RA with a good safety and efficacy profile.

MicroRNA-27b-3p inhibits apoptosis of chondrocyte in rheumatoid arthritis by targeting HIPK2

BACKGROUND

Understanding the mechanism of chondrocytes degeneration could provide a new potential therapeutic idea for rheumatoid arthritis (RA) treatment. MicroRNA-27b-3p (miR-27b-3p) has been shown to regulate a variety of cell behaviors in various cell types. However, the role of miR-27b-3p in RA remains unknown.

MATERIALS AND METHODS

Expression of miR-27b-3p and HIPK2 in cartilage tissues and chondrocytes was characterized using qRT-PCR and Western blot. MiR-27b-3p was overexpressed or suppressed in chondrocytes to observe the potential role of miR-27b-3p.

RESULTS

We found declined miR-27b-3p and elevated HIPK2 in RA tissues and cells using qRT-PCR. Dual-luciferase reporter assay validated HIPK2 is a direct target of miR-27b-3p, confirmed by Western blot results. Pearson correlation presented that there was a significantly negative correlation between miR-27b-3p and HIPK2 mRNA. Overexpression of miR-27b-3p significantly reduced the expression of pro-apoptotic protein c-caspase3 and increased the expression of anti-apoptotic Bcl-2; however, downregulation of miR-27b-3p has a significant effect of inducing apoptosis. Furthermore, overexpression of miR-27b-3p combined with recombinant HIPK2 protein showed the inhibitory effect of miR-27b-3p was abolished by HIPK2.

CONCLUSION

We found declined miR-27b-3p and elevated HIPK2 in RA tissues and cells. Further in vitro studies demonstrated that miR-27b might inhibit chondrocyte apoptosis and thus attenuate RA development by directly inhibiting HIPK2 expression.

Meta-analysis of preclinical studies of mesenchymal stromal cells to treat rheumatoid arthritis

BACKGROUND

This study aims to evaluate the quality of preclinical data, determine the effect sizes, and identify experimental measures that inform efficacy using mesenchymal stromal (or stem) cells (MSC) therapy in animal models of rheumatoid arthritis (RA).

METHODS

Literature searches were performed on MSC preclinical studies to treat RA. MSC treatment effect sizes were determined by the most commonly used outcome measures, including paw thickness, clinical score, and histological score.

FINDINGS

A total of 48 studies and 94 treatment arms were included, among which 42 studies and 79 treatment arms reported that MSC improved outcomes. The effect sizes of RA treatments using MSC, when compared to the controls, were: paw thickness was ameliorated by 53.6% (95% confidence interval (CI): 26.7% -80.4%), histological score was decreased by 44.9% (95% CI: 33.3% -56.6%), and clinical score was decreased by 29.9% (95% CI: 16.7% -43.0%). Specifically, our results indicated that human umbilical cord derived MSC led to large improvements of the clinical score (-42.1%) and histological score (-51.4%).

INTERPRETATION

To the best of our knowledge, this meta-analysis is to quantitatively answer whether MSC represent a robust RA treatment in animal models. It suggests that in preclinical studies, MSC have consistently exhibited therapeutic benefits. The findings demonstrate a need for considering variations in different animal models and treatment protocols in future studies using MSC to treat RA in humans to maximise the therapeutic gains in the era of precision medicine.

FUNDS

NIH [1DP2CA195763], Baylx Inc.: BI-206512, NINDS/NIH Training Grant [Award# NS082174].

Immunodeficiency and autoimmunity during biological disease-modifying antirheumatic drug therapy

Biological disease-modifying antirheumatic drugs target specific components of the immune response related to pathogenesis of autoimmune and inflammatory diseases. Introduction of biologic therapies has enabled better disease control than conventional drugs and thus a reduction in comorbidity and mortality. However, there is concern about adverse effects of these drugs including infections, cancers and drug-induced autoimmune diseases. Patients undergoing biologic treatment are at small but significant risk of serious infections. The overall risk of malignancies in patients on biologics compared with the general population is not increased, but there is evidence of a higher risk of individual cancers. Surprisingly, biological treatment may induce autoantibody production and, rarely, development of autoimmune diseases. A growing body of literature has evaluated the risk of adverse effects during biologic therapies. This paper outlines adverse effects of biological disease-modifying antirheumatic drugs related to immune system disorders, both immunodeficiency and autoimmunity.

Association of biomarkers of inflammation and HLA-DRB1 gene locus with risk of developing rheumatoid arthritis in females

Rheumatoid arthritis (RA) is an autoimmune disease causing chronic inflammation of the joints. Multiple factors, including HLA-DRB1 gene variants, influence the susceptibility to RA. The HLA-DRB1 gene is part of a family of genes called the human leukocyte antigen (HLA) complex. In this study, we compared the inflammatory biomarkers values, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), between patients with RA and healthy control group of females of the Public Institution Health Centre of Sarajevo Canton. In addition, we estimated the frequencies of the HLA-DRB1 gene variants and their association with the risk for RA development in females. The haematological and biochemical tests were completed on automated analyzers. To assess the association between the HLA-DRB genes and the risk of RA in females, low-resolution genotyping of the HLA-DRB1, DRB3, DRB4, and DRB5 gene loci was performed by the sequence-specific polymerase chain reaction method (PCR-SSP). ESR and CRP were the most sensitive acute-phase reactants in females with RA and there was a correlation between ESR and CRP values in RA patients. There was significantly positive association between of the HLA-DRB1*03, *04, *08, *10, *11, and *14 variants and elevated values of ESR in RA patients, but negative between HLA-DRB1*03, *13 and *15 alleles and elevated CRP values. Furthermore, our results confirm genetic susceptibility to RA in a female population to the members of the HLA-DRB1*04 and *03 allelic groups, the DRB1*04/DRB1*04 and DRB1*03/DRB1*04 genotypes, and the DRB1*04-DRB4* or DRB1*03-DRB3* haplotypes, which, therefore, represent risk factors for the development of this disease. According to our results, the DRB1*01/DRB1*15 and DRB1*07/DRB1*16 genotypes and the HLA-DRB5 gene locus represent a protective factor for RA. The presence of specific HLA-DRB1 gene variants increases the risk of developing RA, while other variants provide protection against disease. Therefore, HLA typing could be helpful in the prediction of RA development and establishing and confirming a definitive diagnosis of autoimmune diseases in some subjects. A strong association with the higher levels of ESR and CRP could be used to establish definitive diagnosis and introduce of early treatment of RA to prevent the occurrence of RA symptoms.

Low-Dose Irradiation Differentially Impacts Macrophage Phenotype in Dependence of Fibroblast-Like Synoviocytes and Radiation Dose

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease whose main hallmark is inflammation and destruction of the joints. Two cell types within the synovium that play an important role in RA are fibroblast-like synoviocytes (FLS) and macrophages. The latter innate immune cells show a high plasticity in their phenotype and are central in inflammatory processes. Low-dose radiotherapy (LD-RT) with particularly a single dose of 0.5 Gy has been demonstrated to have a positive impact on pain, inflammation, and bone in inflamed joints. We now examined for the first time how LD-RT influences FLS and bone marrow-derived macrophages in co-culture systems of an experimental model of RA to reveal further mechanisms of immune modulatory effects of low and intermediate dose of ionizing radiation. For this, the bone marrow of hTNF-α tg mice was differentiated either with cytokines to obtain key macrophage phenotypes (M0, M1, and M2) or with supernatants (SN) of untreated or irradiated FLS. Flow cytometry analyses were used to analyse the impact of radiation (0.1, 0.5, 1.0, and 2.0 Gy) on the phenotype of macrophages in the presence or absence of SN of FLS. LD-RT had no impact on cytokine-mediated macrophage polarization in M0, M1, or M2 macrophages. However, SN of irradiated FLS particularly reduced CD206 expression on macrophages. Macrophage phenotype was stable when being in contact with SN of nonirradiated FLS, but significantly increased surface expression of CD206 and slightly decreased CD80 and CD86 expression were observed when macrophage themselves were irradiated with 0.5 Gy under these microenvironmental conditions, again highlighting discontinuous dose dependencies in the low and intermediate dose range. One can conclude that FLS-dependent microenvironmental conditions have a slight influence on the modulation of macrophage phenotype under radiation exposure conditions. Future studies are needed to reveal the impact of radiation exposure on the functions of treated macrophages under such microenvironmental conditions.

DOES THE RHEUMATOID ARTHRITIS AFFECT THE ENTERIC NERVOUS SYSTEM?

BACKGROUND

Few studies regarding arthritic diseases have been performed to verify the presence of the neurodegeneration. Given the increased oxidative stress and extra-articular effects of the rheumatoid arthritis, the gastrointestinal studies should be further investigated aiming a better understanding of the systemic effects the disease on enteric nervous system.

OBJECTIVE

To determine whether the rheumatoid arthritis affects the nitrergic density and somatic area of the nNOS- immunoreactive (IR) myenteric neurons, as well as the morphometric areas of CGRP and VIP-IR varicosities of the ileum of arthritic rats.

METHODS

Twenty 58-day-old male Holtzmann rats were distributed in two groups: control and arthritic. The arthritic group received a single injection of the Freund's Complete Adjuvant in order to induce arthritis model. The whole-mount preparations of ileum were processed for immunohistochemistry to VIP, CGRP and nNOS. Quantification was used for the nitrergic neurons and morphometric analyses were performed for the three markers.

RESULTS

The arthritic disease induced a reduction 6% in ileal area compared to control group. No significant differences were observed in nitrergic density comparing both groups. However, arthritic group yielded a reduction of the nitrergic neuronal somatic area and VIP-IR varicosity areas. However, an increase of varicosity CGRP-IR areas was also observed.

CONCLUSION

Despite arthritis resulted in no alterations in the number of nitrergic neurons, the retraction of ileal area and reduction of nitrergic somatic and VIP-IR varicosity areas may suggest a negative impact the disease on the ENS.