Baseline CXCL10 and CXCL13 levels are predictive biomarkers for tumor necrosis factor inhibitor therapy in patients with moderate to severe rheumatoid arthritis: a pilot, prospective study

Towards Personalized Medicine in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, incurable, multisystem, inflammatory disease characterized by synovitis and extra-articular features. Although several advanced therapies targeting inflammatory mechanisms underlying the disease are available, no advanced therapy is universally effective. Therefore, a ceiling of treatment response is currently accepted where no advanced therapy is superior to another. The current challenge for medical research is the discovery and integration of predictive markers of drug response that can be used to personalize medicine so that the patient is started on "the right drug at the right time". This review article summarizes our current understanding of predicting response to anti-rheumatic drugs in RA, obstacles impeding the development of personalized medicine approaches and future research priorities to overcome these barriers.

Natural carboxyterminal truncation of human CXCL10 attenuates glycosaminoglycan binding, CXCR3A signaling and lymphocyte chemotaxis, while retaining angiostatic activity

BACKGROUND

Interferon-γ-inducible protein of 10 kDa (IP-10/CXCL10) is a dual-function CXC chemokine that coordinates chemotaxis of activated T cells and natural killer (NK) cells via interaction with its G protein-coupled receptor (GPCR), CXC chemokine receptor 3 (CXCR3). As a consequence of natural posttranslational modifications, human CXCL10 exhibits a high degree of structural and functional heterogeneity. However, the biological effect of natural posttranslational processing of CXCL10 at the carboxy (C)-terminus has remained partially elusive. We studied CXCL10(1-73), lacking the four endmost C-terminal amino acids, which was previously identified in supernatant of cultured human fibroblasts and keratinocytes.

METHODS

Relative levels of CXCL10(1-73) and intact CXCL10(1-77) were determined in synovial fluids of patients with rheumatoid arthritis (RA) through tandem mass spectrometry. The production of CXCL10(1-73) was optimized through Fmoc-based solid phase peptide synthesis (SPPS) and a strategy to efficiently generate human CXCL10 proteoforms was introduced. CXCL10(1-73) was compared to intact CXCL10(1-77) using surface plasmon resonance for glycosaminoglycan (GAG) binding affinity, assays for cell migration, second messenger signaling downstream of CXCR3, and flow cytometry of CHO cells and primary human T lymphocytes and endothelial cells. Leukocyte recruitment in vivo upon intraperitoneal injection of CXCL10(1-73) was also evaluated.

RESULTS

Natural CXCL10(1-73) was more abundantly present compared to intact CXCL10(1-77) in synovial fluids of patients with RA. CXCL10(1-73) had diminished affinity for GAG including heparin, heparan sulfate and chondroitin sulfate A. Moreover, CXCL10(1-73) exhibited an attenuated capacity to induce CXCR3A-mediated signaling, as evidenced in calcium mobilization assays and through quantification of phosphorylated extracellular signal-regulated kinase-1/2 (ERK1/2) and protein kinase B/Akt. Furthermore, CXCL10(1-73) incited significantly less primary human T lymphocyte chemotaxis in vitro and peritoneal ingress of CXCR3+ T lymphocytes in mice. In contrast, loss of the four endmost C-terminal residues did not affect the inhibitory properties of CXCL10 on migration, proliferation, wound closure, phosphorylation of ERK1/2, and sprouting of human microvascular endothelial cells.

CONCLUSION

Our study shows that the C-terminal residues Lys74-Pro77 of CXCL10 are important for GAG binding, signaling through CXCR3A, T lymphocyte chemotaxis, but dispensable for angiostasis.

Definition of follicular helper T cell and cytokines expression in synovial fluid of rheumatoid arthritis

OBJECTIVE

This study aimed to assess the role of synovial fluid (SF) CD4+T, CD19+B, follicular helper cells (Tfh), and cytokines in the pathogenesis of rheumatoid arthritis (RA).

METHODS

This study enrolled 16 patients with RA and 8 patients with osteoarthritis (OA). The frequencies of the SF CD4+ T, CD19+ B, Tfh cells, and Tfh subsets were assessed using flow cytometry. The medical condition in patients with RA was evaluated using The Disease Activity Score 28 (DAS28), the Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide (anti-CCP), and rheumatoid factor (RF) were measured. The cytokines IL-4, IL-13, IL-21, and BLyS were measured by ELISA test.

RESULTS

The percentages of SF CD4+T, CD19+B, and PD-1+CXCR5+ Tfh in RA patients were higher than those in OA patients. And the Tfh2 was the main subset among Tfh subsets. In addition, levels of IL-21 and BLyS were higher in patients with RA compared to patients with OA. Furthermore, the treatment of TNF-α inhibitors may be associated with decreased levels of SF Tfh.

CONCLUSIONS

Elevated SF Tfh, B cell, and cytokines expression profiles were observed in RA patients. Tfh2 was the major subset of the Tfh, and IL-21 and BLyS were significantly enhanced. Additionally, TNF-α inhibitors reduced Tfh in SF. Therefore, Tfh, B, and Tfh2 cells could play a significant role in the progression of RA. Key Points •Tfh cells in the synovial fluid are significantly higher in RA patients and are dominated by the Tfh2 subpopulation. •Synovial fluid Tfh cells decrease in RA patients after anti-TNF-α treatment.

A review of the pleiotropic actions of the IFN-inducible CXC chemokine receptor 3 ligands in the synovial microenvironment

Chemokines are pivotal players in instigation and perpetuation of synovitis through leukocytes egress from the blood circulation into the inflamed articulation. Multitudinous literature addressing the involvement of the dual-function interferon (IFN)-inducible chemokines CXCL9, CXCL10 and CXCL11 in diseases characterized by chronic inflammatory arthritis emphasizes the need for detangling their etiopathological relevance. Through interaction with their mutual receptor CXC chemokine receptor 3 (CXCR3), the chemokines CXCL9, CXCL10 and CXCL11 exert their hallmark function of coordinating directional trafficking of CD4+ TH1 cells, CD8+ T cells, NK cells and NKT cells towards inflammatory niches. Among other (patho)physiological processes including infection, cancer, and angiostasis, IFN-inducible CXCR3 ligands have been implicated in autoinflammatory and autoimmune diseases. This review presents a comprehensive overview of the abundant presence of IFN-induced CXCR3 ligands in bodily fluids of patients with inflammatory arthritis, the outcomes of their selective depletion in rodent models, and the attempts at developing candidate drugs targeting the CXCR3 chemokine system. We further propose that the involvement of the CXCR3 binding chemokines in synovitis and joint remodeling encompasses more than solely the directional ingress of CXCR3-expressing leukocytes. The pleotropic actions of the IFN-inducible CXCR3 ligands in the synovial niche reiteratively illustrate the extensive complexity of the CXCR3 chemokine network, which is based on the intercommunion of IFN-inducible CXCR3 ligands with distinct CXCR3 isoforms, enzymes, cytokines, and infiltrated and resident cells present in the inflamed joints.

Dynamics of Type I and Type II Interferon Signature Determines Responsiveness to Anti-TNF Therapy in Rheumatoid Arthritis

The factors influencing long-term responses to a tumor necrosis factor inhibitor (TNFi) in rheumatoid arthritis (RA) patients currently remain unknown. Therefore, we herein conducted a multi-omics analysis of TNFi responses in a Japanese RA cohort. Blood samples were collected from 27 biological disease-modifying antirheumatic drug (DMARD)-naive RA patients at the initiation of and after three months of treatment with TNFi. Treatment responses were evaluated at one year. Differences in gene expression levels in peripheral blood mononuclear cells (PBMCs), plasma protein levels, drug concentrations, and the presence/absence of anti-drug antibodies were investigated, and a cell phenotypic analysis of PBMCs was performed using flow cytometry. After one year of treatment, thirteen patients achieved clinical remission (responders), while the others did not or switched to other biologics (non-responders). Differentially expressed genes related to treatment responses were enriched for the interferon (IFN) pathway. The expression of type I IFN signaling-related genes was higher in non-responders than in responders before and after treatment (P = 0.03, 0.005, respectively). The expression of type II IFN signaling-related genes did not significantly differ before treatment; however, it increased in non-responders and decreased in responders, with a significant difference being observed after three months of treatment (P = 1.2×10^-3). The total number of lymphocytes and C-X-C Motif Chemokine Ligand 10 (CXCL10) protein levels were associated with the type I IFN signature (P = 6.7×10^-7, 6.4×10^-3, respectively). Hepatocyte growth factor (HGF) protein levels before treatment predicted fold increases in type II IFN (P = 0.03). These IFN signature-related indices (the number of lymphocytes, CXCL10, and HGF) significantly differed between responders and non-responders (P = 0.01, 0.01, and 0.04, respectively). A single-cell analysis revealed that the type I IFN signature was more highly enriched in monocytes than in other cell types. A deconvolution analysis of bulk-RNA sequence data identified CD4+ and CD8+ T cells as the main sources of the type II IFN signature in non-responders. Collectively, the present results demonstrated that the dynamics of the type I and II IFN pathways affected long-term responses to TNFi, providing information on its biological background and potential for clinical applications.

T peripheral helper cells in autoimmune diseases

Pathologic T cell-B cell interactions underlie many autoimmune diseases. The T cells that help B cells in autoimmune diseases vary in phenotype and include T cells that lack typical features of T follicular helper cells, such as expression of CXCR5 and BCL6. A population of PD-1hi CXCR5- T peripheral helper (Tph) cells has now been recognized in multiple autoantibody-associated diseases. Tph cells display a distinctive set of features, merging the ability to provide B cell help with the capacity to migrate to inflamed peripheral tissues. Here, we review the scope of immune-related conditions in which Tph cells have been implicated and provide a perspective on their potential contributions to pathologic B cell activation in autoimmune diseases. We discuss Tph cells as a promising therapeutic strategy in autoimmunity and consider the utility of tracking Tph cells in blood as a biomarker to quantify aberrant T cell-B cell activation in patients with autoimmune diseases.

The interferon gene signature as a clinically relevant biomarker in autoimmune rheumatic disease

The interferon gene signature (IGS) is derived from the expression of interferon-regulated genes and is classically increased in response to type I interferon exposure. A raised whole blood IGS has increasingly been reported in rheumatic diseases as sequencing technology has advanced. Although its role remains unclear, we explore how a raised IGS can function as a clinically relevant biomarker, independent of whether it is a bystander effect or a key pathological process. For example, a raised IGS can act as a diagnostic biomarker when predicting rheumatoid arthritis in patients with arthralgia and anti-citrullinated protein antibodies, or predicting systemic lupus erythematous (SLE) in those with antinuclear antibodies; a theragnostic biomarker when predicting response for patients receiving disease modifying therapy, such as rituximab in rheumatoid arthritis; a biomarker of disease activity (early rheumatoid arthritis, dermatomyositis, systemic sclerosis, SLE); or finally a predictor of clinical characteristics, such as lupus nephritis in SLE or disease burden in primary Sjögren's syndrome. A high IGS does not uniformly predict worse clinical phenotypes across all diseases, as demonstrated by a reduced disease burden in primary Sjögren's syndrome, nor does it predict a universally poorer response to all therapies, as shown in rheumatoid arthritis. This dichotomy highlights both the complexity of type I interferon signalling in vivo and the current lack of standardisation when calculating the IGS. The IGS as a biomarker warrants further exploration, with beneficial clinical applications anticipated in multiple rheumatic diseases.

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

Infliximab for reversible dementia in acute onset of neuro-Behçet's disease: A case report and cytokine analysis

We describe a 49-year-old female patient with neuro-Behçet's disease (NBD) with acute onset of fever and symptoms of dementia. High-dose glucocorticoid was partially effective for cognitive impairment, and infliximab, an anti-TNF-α antibody, gradually improved the symptoms. An analysis of cytokines showed that IP-10 in the cerebrospinal fluid was higher than that in the peripheral blood, and both decreased after treatment. This is the first known case of NBD wherein the patient with acute onset of dementia responded to a treatment with infliximab. In glucocorticoid-resistant patients, it is important to consider the introduction of infliximab to prevent irreversible brain dysfunction.

Potential clinical biomarkers in rheumatoid arthritis with an omic approach

Objective

To aid in the selection of the most suitable therapeutic option in patients with diagnosis of rheumatoid arthritis according to the phase of disease, through the review of articles that identify omics biological markers.

Methods

A systematic review in PubMed/Medline databases was performed. We searched articles from August 2014 to September 2019, in English and Spanish, filtered by title and full text; and using the terms "Biomarkers" AND “Rheumatoid arthritis".

Results

This article supplies an exhaustive review from research of objective measurement, omics biomarkers and how disease activity appraise decrease unpredictability in treatment determinations, and finally, economic, and clinical outcomes of treatment options by biomarkers’ potential influence. A total of 122 articles were included. Only 92 met the established criteria for review purposes and 17 relevant references about the topic were included as well. Therefore, it was possible to identify 196 potential clinical biomarkers: 22 non-omics, 20 epigenomics, 33 genomics, 21 transcriptomics, 78 proteomics, 4 glycomics, 1 lipidomics and 17 metabolomics.

Conclusion

A biomarker is a measurable indicator of some, biochemical, physiological, or morphological condition; evaluable at a molecular, biochemical, or cellular level. Biomarkers work as indicators of physiological or pathological processes, or as a result of a therapeutic management. In the last five years, new biomarkers have been identified, especially the omics, which are those that proceed from the investigation of genes (genomics), metabolites (metabolomics), and proteins (proteomics). These biomarkers contribute to the physician choosing the best therapeutic option in patients with rheumatoid arthritis.

Novel approaches to develop biomarkers predicting treatment responses to TNF-blockers

Introduction: Chronic inflammatory diseases (CIDs) cause significant morbidity and are a considerable burden for the patients in terms of pain, impaired function, and diminished quality of life. Important progress in CID treatment has been obtained with biological therapies, such as tumor-necrosis-factor blockers. However, more than a third of the patients fail to respond to these inhibitors and are exposed to the side effects of treatment, without the benefits. Therefore, there is a strong interest in developing tools to predict response of patients to biologics. Areas covered: The authors searched PubMed for recent studies on biomarkers for disease assessment and prediction of therapeutic responses, focusing on the effect of TNF blockers on immune responses in spondyloarthritis (SpA), and other CID, in particular rheumatoid arthritis and inflammatory bowel disease. Conclusions will be drawn about the possible development of predictive biomarkers for response to treatment. Expert opinion: No validated biomarker is currently available to predict treatment response in CID. New insight could be generated through the development of new bioinformatic modeling approaches to combine multidimensional biomarkers that explain the different genetic, immunological and environmental determinants of therapeutic responses.

Adipocytokines in Untreated Newly Diagnosed Rheumatoid Arthritis: Association with Circulating Chemokines and Markers of Inflammation

Adiponectin, leptin, and resistin are adipocytokines whose levels are elevated in blood and synovial fluid from patients with rheumatoid arthritis (RA). However, their role in RA pathogenesis is unclear. Here, we examined whether adipocytokines are associated with circulating chemokines, markers of inflammation and RA disease activity in patients with untreated newly diagnosed RA. Plasma levels of 15 chemokines, adiponectin, leptin, and resistin were measured using flow cytometry bead-based immunoassay or enzyme-linked immunosorbent assay (ELISA) in a cohort of 70 patients with untreated newly diagnosed RA. Markers of inflammation and disease activity were also assessed in all patients. Positive association was found between total adiponectin and CXCL10 (β = 0.344, p = 0.021), CCL2 (β = 0.342, p = 0.012), and CXCL9 (β = 0.308, p = 0.044), whereas high-molecular weight (HMW) adiponectin associated only with CXCL9 (β = 0.308, p = 0.033). Furthermore, both total and HMW adiponectin were associated with C-reactive protein (β = 0.485, p = 0.001; β = 0.463, p = 0.001) and erythrocyte sedimentation rate (β = 0.442, p = 0.001; β = 0.507, p < 0.001). Leptin and resistin were not associated with plasma chemokines, markers of inflammation, or disease activity scores. Our study shows an association between circulating adiponectin and pro-inflammatory chemokines involved in RA pathogenesis as well as markers of inflammation in a well-characterized cohort of patients with untreated newly diagnosed RA.

Protein array-based companion diagnostics in precision medicine

INTRODUCTION

The development of companion diagnostics (CDx) will increase efficacy and cost-benefit markedly, compared to the currently prevailing trial-and-error approach for treatment. Recent improvements in high-throughput protein technology have resulted in large amounts of predictive biomarkers that are potentially useful components of future CDx assays. Current high multiplex protein arrays are suitable for discovery-based approaches, while low-density and more simple arrays are suitable for use in point-of-care facilities.

AREA COVERED

This review discusses the technical platforms available for protein array focused CDx, explains the technical details of the platforms and provide examples of clinical use, ranging from multiplex arrays to low-density clinically applicable arrays. We thereafter highlight recent predictive biomarkers within different disease areas, such as oncology and autoimmune diseases. Lastly, we discuss some of the challenges connected to the implementation of CDx assays as point-of-care tests.

EXPERT OPINION

Recent advances in the field of protein arrays have enabled high-density arrays permitting large biomarker discovery studies, which are beneficial for future CDx assays. The density of protein arrays range from a single protein to proteome-wide arrays, allowing the discovery of protein signatures that may correlate with drug response. Protein arrays will undoubtedly play a key role in future CDx assays.

A systematic review of CXCL13 as a biomarker of disease and treatment response in rheumatoid arthritis

BACKGROUND

The B cell chemoattractant CXCL13 is a promising biomarker in rheumatoid arthritis (RA), with a plausible role in supporting diagnosis, monitoring disease activity and as a prognostic value. It is a key chemokine driving the formation of lymphoid follicles within the inflamed synovium. The objective of this systematic review was to evaluate the role of CXCL13 as a viable biomarker in RA.

METHODS

We conducted a systematic literature review of all published cohort and randomised controlled trials evaluating the role of CXCL13 in RA. The primary outcomes were; i) CXCL13 levels in RA patients compared to healthy controls, ii) the correlation between CXCL13 and markers of disease activity, and iii) the association between CXCL13 and treatment response.

RESULTS

The search produced 278 articles, of which 31 met the inclusion criteria. Of the 12 studies evaluating CXCL13 expression in early or established RA, all reported higher levels than that seen in healthy controls. Twelve of sixteen studies reported a weakly positive correlation between CXCL13 and markers of disease activity including DAS28 and swollen joint count, with rho values between 0.20-0.67. In 2 studies, CXCL13 levels correlated with ultrasonographic evidence of synovitis. Eighteen studies assessed CXCL13 in response to therapeutic intervention. The majority signified a fall in levels in response to treatment including biologics and Janus kinase (JAK) inhibition. In some, this reduction was only seen in treatment responders. High CXCL13 levels predicted failure to achieve disease remission with csDMARDs. The evidence for treatment prediction with biologics was conflicting.

CONCLUSION

Despite evidence to suggest a role in diagnosing RA and in detecting synovitis, the heterogeneity of studies included in this review limit our ability to draw robust conclusions. At present there are inadequate results to justify the routine use of CXCL13 as a biomarker in RA routine clinical practice.

T helper cells in synovial fluid of patients with rheumatoid arthritis primarily have a Th1 and a CXCR3+Th2 phenotype

Background

The majority of CD4⁺ T helper (Th) cells found in the synovial fluid (SF) of patients with rheumatoid arthritis (RA) express CXCR3, a receptor associated with Th1 cells. In blood, subsets of Th2 and Th17 cells also express CXCR3, but it is unknown if these cells are present in RA SF or how cytokines from these subsets affect cytokine/chemokine secretion by fibroblast-like synoviocytes (FLS) from patients with RA.

Methods

We examined the proportions of Th1, Th2, CXCR3⁺Th2, Th17, CXCR3⁺Th17, Th1Th17, peripheral T helper (TPh) and T follicular helper (TFh) cells in paired SF and blood, as well as the phenotype of TPh and TFh cells in RA SF (n = 8), by the use of flow cytometry. We also examined the cytokine/chemokine profile in paired SF and plasma (n = 8) and in culture supernatants of FLS from patients with chronic RA (n = 7) stimulated with Th-associated cytokines, by the use of cytometric bead arrays and ELISA. Cytokine receptor expression in FLS (n = 3) were assessed by the use of RNA sequencing and qPCR.

Results

The proportions of Th1 and CXCR3⁺Th2 cells were higher in SF than in blood (P < 0.05). TPh and PD-1^highTFh in RA SF were primarily of a Th1 and a CXCR3⁺Th2 phenotype. Moreover, the levels of CXCL9, CXCL10, CCL20, CCL2, CXCL8, IL-6 and IL-10 were higher in SF than in plasma (P < 0.05). Lastly, IL-4, IL-13 and IL-17A induced RA FLS to secrete proinflammatory IL-6, CCL2, CXCL1 and CXCL8, while IFNγ mainly induced CXCL10.

Conclusion

These findings indicate that not only Th1 but also CXCR3⁺Th2 cells may have a pathogenic role in RA synovial inflammation.

Converging pathways in pulmonary fibrosis and Covid-19 - The fibrotic link to disease severity

As Covid-19 affects millions of people worldwide, the global health care will encounter an increasing burden of the aftermaths of the disease. Evidence shows that up to a fifth of the patients develop fibrotic tissue in the lung. The SARS outbreak in the early 2000 resulted in chronic pulmonary fibrosis in a subset (around 4%) of the patients, and correlated to reduced lung function and forced expiratory volume (FEV). The similarities between corona virus infections causing SARS and Covid-19 are striking, except that the novel coronavirus, SARS-CoV-2, has proven to have an even higher communicability. This would translate into a large number of patients seeking care for clinical signs of pulmonary fibrosis, given that the Covid-19 pandemic has up till now (Sept 2020) affected around 30 million people. The SARS-CoV-2 is dependent on binding to the angiotensin converting enzyme 2 (ACE2), which is part of the renin-angiotensin system (RAS). Downregulation of ACE2 upon virus binding disturbs downstream activities of RAS resulting in increased inflammation and development of fibrosis. The poor prognosis and risk of developing pulmonary fibrosis are therefore associated with the increased expression of ACE2 in risk groups, such as obesity, heart disorders and aging, conferring plenty of binding opportunity for the virus and subsequently the internalization of ACE2, thus devoiding the enzyme from acting counter-inflammatory and antifibrotic. Identifying pathways that are associated with Covid-19 severity that result in pulmonary fibrosis may enable early diagnosis and individualized treatment for these patients to prevent or reduce irreversible fibrotic damage to the lung.

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Covid-19 may lead to pulmonary fibrosis.

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Urgency to monitor severe cases of Covid-19 longitudinally post-infection.

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Convergent pathways in idiopathic pulmonary fibrosis and Covid-19.

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Antifibrotic treatment in Covid-19.

Nasal Chondrocyte-Derived Soluble Factors Affect Chondrogenesis of Cocultured Mesenchymal Stem Cells

To investigate the effect of soluble factors released from human nasal chondrocytes (NCs) on cocultured human bone marrow mesenchymal stem cells (MSCs) and NC tissue-engineered constructs. Cartilage engineered from pure NCs on a three-dimensional (3D) porous collagen scaffold was cultured indirectly in a Transwell system with cartilage engineered from a direct coculture of human bone marrow-derived MSCs and NCs on a 3D porous collagen scaffold. The soluble factors were measured in the conditioned media from the different chambers of the Transwell system. Engineered cartilage from cocultures exposed to the pure NC construct exhibited reduced chondrogenic potential relative to control constructs, shown by reduced extracellular matrix deposition and increased expression of hypertrophic markers. Analysis of the soluble factors within the conditioned media showed an increase in inflammatory cytokines in the coculture chamber exposed to the pure NC construct. Principal component analysis revealed that the majority of the data variance could be explained by proinflammatory factors and hypertrophic chondrogenesis. In conclusion, our data suggest that inflammatory cytokines derived from NCs reduce the chondrogenic potential of coculture engineered cartilage through the induction of hypertrophic chondrogenesis. Impact statement The use of engineered cartilage from cocultured nasal chondrocytes (NCs) and mesenchymal stem cells for nasal cartilage reconstruction may be problematic. Our data suggest that the soluble factors from surrounding native NCs in the cartilage to be fixed can compromise the quality of the engineered cartilage if used in reconstructive surgery.

The predictive value of serum soluble ICAM-1 and CXCL13 in the therapeutic response to TNF inhibitor in rheumatoid arthritis patients who are refractory to csDMARDs

BACKGROUND

Tumor necrosis factor-α (TNFα) inhibitors (TNFi) have greatly improved the prognosis of RA and become the first therapeutic option for patients who failed the conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) therapy, but not all these patients respond well to TNFi. So far, there has been no definite biomarker to predict the response to TNFi yet.

METHODS

Sixty rheumatoid arthritis (RA) patients with disease duration more than 6 months and at least low disease activity defined by DAS28-CRP > 3.2 although after csDMARDs (including MTX and/or leflunomide) treatment for more than 3 months were included. They were further treated with TNFα receptor Fc fusion protein and MTX 10 mg per week for 12 weeks. Soluble ICAM-1 (sICAM-1) and CXCL13 concentrations in sera from 60 RA patients and 20 healthy controls were tested by ELISA right before and at the end of 12 weeks of TNFi therapy. The correlation between sICAM-1 and CXCL13 with disease activity and their predictive values for TNFi response were analyzed.

RESULTS

The mean age of the 60 patients was 54.8 ± 11.6 years. Serum sICAM-1 and CXCL13 concentrations were higher in RA patients than heathy controls, higher in seropositive RA patients than in seronegative ones, and higher in RA patients with higher disease activity. Serum sICAM-1 and CXCL13 levels were decreased after TNFi therapy, especially in good responders. Baseline sICAM-1 concentration was independently associated with the EULAR response (p = 0.033, OR = 1.014, 95% CI = 1.003-1.026). The sICAM-1^high/CXCL13^high patients had the highest response rate, which was significantly higher than the sICAM-1^low/CXCL13^low group (OR = 8.143, 95% CI = 1.040-75.482, p = 0.045).

CONCLUSION

sICAM-1 and CXCL13 are elevated in RA patients and correlated with disease activity. sICAM-1 is an independent predictor of TNFi response in csDMARDs refractory RA patients. Key Points • This study confirmed the predictive value of soluble ICAM-1 (sICAM-1) and CXCL13 on the response to TNFi in RA patient. • Baseline sICAM-1 concentration was independently associated with the EULAR response. • The sICAM-1^high/CXCL13^high patients had significantly higher response rate than the sICAM-1^low/CXCL13^low group.

Role of Chemokines and Chemokine Receptors in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases and a prototypic inflammatory disease, affecting the small joints of the hands and feet. Chemokines and chemokine receptors play a critical role in RA pathogenesis via immune cells recruitment. Several chemokines and chemokine receptors are abundant in the peripheral blood and in the local inflamed joints of RA. Furthermore, synthetic and biologics disease modifying anti rheumatic drugs have been reported to affect chemokines expression. Thus, many studies have focused on targeting chemokines and chemokine receptors, where some have shown positive promising results. However, most of the chemokine blockers in human trials of RA treatment displayed some failures that can be attributed to several reasons in their structures and binding affinities. Nevertheless, targeting chemokines will continue to be under development, in order to improve their therapeutic potentials in RA and other autoimmune diseases. In this review we provide an up-to-date knowledge regarding the role of chemokines and chemokine receptors in RA with an emphasis on their activities on immune cells. We also discussed the effects of drugs targeting those molecules in RA. This knowledge might provide impetus for developing new therapeutic modalities to treat this chronic disease.

Filgotinib, a JAK1 Inhibitor, Modulates Disease-Related Biomarkers in Rheumatoid Arthritis: Results from Two Randomized, Controlled Phase 2b Trials

INTRODUCTION

The Janus kinase (JAK) inhibitor therapeutic class has shown significant clinical benefit in the treatment of rheumatoid arthritis (RA). We sought to gain insight into the mode of action and immunological effects of filgotinib, a JAK1 selective inhibitor, in active RA by analyzing secreted and cell-based biomarkers key to RA pathophysiology in two phase 2b trials of filgotinib in active RA.

METHODS

Immune cell subsets and 34 serum biomarkers were analyzed longitudinally over 12 weeks using blood samples collected from patients with active RA receiving filgotinib (100 or 200 mg once daily) or placebo (PBO) in the two phase 2b trials (DARWIN 1, on a background of methotrexate, and DARWIN 2, as monotherapy).

RESULTS

Consistently across both studies, filgotinib treatment decreased multiple immune response biomarkers that have key roles in RA for immune response, and decreased markers that promote matrix degradation, angiogenesis, leukocyte adhesion, and recruitment. Filgotinib did not significantly modulate T and natural killer (NK) lymphoid subsets, but slightly increased B cell numbers after 12 weeks. Multiple correlations were observed for changes in biomarkers with disease activity score 28-CRP. MIP1β showed modest predictivity at baseline for ACR50 response at 12 weeks in the 100 mg filgotinib dose across both studies (AUROC, 0.65 and 0.67, p < 0.05).

CONCLUSIONS

Filgotinib regulates biomarkers from multiple pathways, indicative of direct and indirect network effects on the immune system and the stromal response. These effects were not associated with reductions of major circulating lymphoid populations.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01888874, NCT01894516.

Changes in expression of serum chemokine CXCL13 and IL-6 after hip replacement, and the relationship with lower limb vein thrombus

Changes in the expression of serum chemokine CXC ligand 13 (CXCL13) and interleukin-6 (IL-6), and the relationship with lower limb vein thrombus were explored. A total of 128 patients undergoing hip replacement in The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine from May 2017 to June 2019 were selected, and the patients suffering from lower limb vein thrombus were enrolled as group A and other patients not suffering from it were enrolled as group B. Enzyme-linked immuno-sorbent assay was employed to determine the levels of serum chemokine CXCL13 and IL-6, and receiver operating characteristic curves of serum chemokine CXCL13 and IL-6 levels in diagnosing restenosis after surgery were drawn. Pearson's correlation coefficient was adopted to analyze the correlation between serum chemokine CXCL13 and IL-6, and the logistic regression analysis to analyze the risk factors affecting hip replacement in patients. The levels of serum CXCL13 and IL-6 in group A were significantly higher than those in group B (both P<0.001). The specificity and sensitivity of serum CXCL13 level in diagnosis of lower limb vein thrombus after hip replacement were 61.76 and 80.00%, respectively, and those of serum IL-6 level in diagnosis were 70.59 and 66.67%, respectively. Serum CXCL13 level was positively correlated with serum IL-6 level (P<0.001), and age, body mass index (BMI), CXCL13 level and IL-6 level of the patients were independent risk factors affecting the efficacy of hip replacement. Serum CXCL13 level and serum IL-6 level can be used as biological indexes for prediction of early lower limb vein thrombus after hip replacement, and logistic regression analysis revealed that the age of the patients, BMI, diabetes history, hyperlipidemia history, hypertension history, CXCL13 level and IL-6 level are independent risk factors affecting the efficacy of hip replacement.

Chemokines: A Potential Therapeutic Target to Suppress Autoimmune Arthritis

BACKGROUND

Chemokines are a family of low molecular weight proteins that induce chemotaxis of inflammatory cells, which mainly depends on the recognition of a chemo-attractant gradient and interaction with the substratum. In Rheumatoid Arthritis (RA), abundant chemokines are expressed in synovial tissue, cause inflammatory cells migration into the inflamed joint that necessitates the formation of new blood vessels i.e. angiogenesis. Over the decades, studies showed that continuous inflammation may lead to the loss of tissue architecture and function, causing severe disability and cartilage destruction. In spite of the advancement of modern drug therapy, thousands of arthritic patients suffer mortality and morbidity globally. Thus, there is an urgent need for the development of novel therapeutic agents for the treatment of RA.

METHODS

This review is carried out throughout a non-systematic search of the accessible literature, will provide an overview of the current information of chemokine in RA and also exploring the future perspective of the vital role of targeting chemokine in RA treatment.

RESULTS

Since, chemokines are associated with inflammatory cells/leucocyte migration at the site of inflammation in chronic inflammatory diseases and hence, blockade or interference with chemokines activity showing a potential approach for the development of new anti-inflammatory agents. Currently, results obtained from both preclinical and clinical studies showed significant improvement in arthritis.

CONCLUSION

This review summarizes the role of chemokines and their receptors in the pathogenesis of RA and also indicates possible interactions of chemokines/receptors with various synthetic and natural compounds that may be used as a potential therapeutic target in the future for the treatment of RA.

Using the Immunophenotype to Predict Response to Biologic Drugs in Rheumatoid Arthritis

Tumour necrosis factor (TNF)-α is a key mediator of inflammation in rheumatoid arthritis, and its discovery led to the development of highly successful anti-TNF therapy. Subsequently, other biologic drugs targeting immune pathways, namely interleukin-6 blockade, B cell depletion, and T cell co-stimulation blockade, have been developed. Not all patients respond to a biologic drug, leading to a knowledge gap between biologic therapies available and the confident prediction of response. So far, genetic studies have failed to uncover clinically informative biomarkers to predict response. Given that the targets of biologics are immune pathways, immunological study has become all the more pertinent. Furthermore, advances in single-cell technology have enabled the characterization of many leucocyte subsets. Studying the blood immunophenotype may therefore, define biomarker profiles relevant to each individual patient's disease and treatment outcome. This review summarises our current understanding of how immune biomarkers might be able to predict treatment response to biologic drugs.

Anti-TNF Therapy in Spondyloarthritis and Related Diseases, Impact on the Immune System and Prediction of Treatment Responses

Immune-mediated inflammatory diseases (IMIDs), such as spondyloarthritis (SpA), psoriasis, Crohn's disease (CD), and rheumatoid arthritis (RA) remain challenging illnesses. They often strike at a young age and cause lifelong morbidity, representing a considerable burden for the affected individuals and society. Pioneering studies have revealed the presence of a TNF-dependent proinflammatory cytokine cascade in several IMIDs, and the introduction of anti-TNF therapy 20 years ago has proven effective to reduce inflammation and clinical symptoms in RA, SpA, and other IMID, providing unprecedented clinical benefits and a valid alternative in case of failure or intolerable adverse effects of conventional disease-modifying antirheumatic drugs (DMARDs, for RA) or non-steroidal anti-inflammatory drugs (NSAIDs, for SpA). However, our understanding of how TNF inhibitors (TNFi) affect the immune system in patients is limited. This question is relevant because anti-TNF therapy has been associated with infectious complications. Furthermore, clinical efficacy of TNFi is limited by a high rate of non-responsiveness (30–40%) in RA, SpA, and other IMID, exposing a substantial fraction of patients to side-effects without clinical benefit. Despite the extensive use of TNFi, it is still not possible to determine which patients will respond to TNFi before treatment initiation. The recent introduction of antibodies blocking IL-17 has expanded the therapeutic options for SpA, as well as psoriasis and psoriatic arthritis. It is therefore essential to develop tools to guide treatment decisions for patients affected by SpA and other IMID, both to optimize clinical care and contain health care costs. After a brief overview of the biology of TNF, its receptors and currently used TNFi in the clinics, we summarize the progress that has been made to increase our understanding of the action of TNFi on the immune system in patients. We then summarize efforts dedicated to identify biomarkers that can predict treatment responses to TNFi and we conclude with a section dedicated to the recently introduced inhibitors of IL-17A and IL-23 in SpA and related diseases. The focus of this review is on SpA, however, we also refer to RA on topics for which only limited information is available on SpA in the literature.

Sex-based differences in association between circulating T cell subsets and disease activity in untreated early rheumatoid arthritis patients

BACKGROUND

It is not known if sex-based disparities in immunological factors contribute to the disease process in rheumatoid arthritis (RA). Hence, we examined whether circulating T cell subset proportions and their association with disease activity differed in male and female patients with untreated early rheumatoid arthritis (ueRA).

METHODS

Proportions of T cell subsets were analyzed in peripheral blood from 72 ueRA DMARD- and corticosteroid-naïve patients (50 females and 22 males) and in 31 healthy age- and sex-matched controls. Broad analysis of helper and regulatory CD4⁺ T cell subsets was done using flow cytometry. Disease activity in patients was assessed using DAS28, CDAI, swollen joint counts, tender joint counts, CRP, and ESR.

RESULTS

Multivariate factor analyses showed that male and female ueRA patients display distinct profiles of association between disease activity and circulating T cell subset proportions. In male, but not female, ueRA patients Th2 cells showed a positive association with disease activity and correlated significantly with DAS28-ESR, CDAI, and swollen and tender joint counts. Likewise, proportions of non-regulatory CTLA-4⁺ T cells associated positively with disease activity in male patients only, and correlated with DAS28-ESR. In contrast, there was a negative relation between Th1Th17 subset proportions and disease activity in males only. The proportions of Th17 cells correlated positively with DAS28-ESR in males only, while proportions of Th1 cells showed no relation to disease activity in either sex. There were no significant differences in proportions of T cell subsets between the sexes in patients with ueRA.

CONCLUSIONS

Our findings show sex-based differences in the association between T cell subsets and disease activity in ueRA patients, and that Th2 helper T cells may have a role in regulating disease activity in male patients.

Systematic review and meta-analysis of the efficacy and safety of Biqi capsule in rheumatoid arthritis patients

Biqi capsule is a Traditional Chinese Medicine preparation for treating rheumatoid arthritis (RA), and clinical studies have indicatedthat its effect may be more beneficial than that of Western medicine. The present study aimed to estimate the efficacy and safety of Biqi capsule alone or combined with methotrexate (MTX) compared with MTX alone for treating RA by performing a meta-analysis of randomized controlled trials and controlled clinical trials. A systematic literature search of studies published until March 2017 was performed. References from relevant studies were screened to obtain additional articles. The results were independently evaluated for relevance, and full-text studies were assessed for eligibility. The risk of bias was assessed using the Cochrane collaboration tool for assessing risk of bias. Out of 558 citations that were initially retrieved, a total of 5 studies comprising 522 patients met the inclusion criteria. The risk of bias of these trials was generally unclear or high. Meta-analysis indicated that Biqi capsule had better effects on C-reactive protein [standardized mean difference (SMD), −7.05; 95% CI -(10.77–3.33)] and tender joint count [SMD, −3.02; 95% CI, -(3.81–2.22)] and fewer adverse effects (AEs) than MTX [relative risk (RR), 0.19; 95% CI, 0.08–0.43]. Biqi capsule plus MTX was superior to MTX in terms of the total effect (RR, 1.17; 95% CI, 1.06–1.28), rheumatoid factor [SMD, −12.54; 95% CI, -(16.87–8.20)], swollen joint count [SMD, −1.50; 95% CI, -(1.99–1.01)], score of joint swelling [SMD −2.07; 95% CI, -(2.76–1.38)], tender joint count [SMD, −2.16; 95% CI, -(2.86–1.47)] and score of joint tenderness [SMD, −4.69; 95% CI, -(5.92–3.47)]. There was no difference in AEs between Biqi capsule plus MTX and MTX (RR, 0.71; 95% CI, 0.34–1.50). In conclusion, the present study indicated that compared with MTX, Biqi capsule plus MTX appeared to have more benefits but that Biqi capsule alone was not better for RA patients than MTX. In the other words, Biqi capsule plus MTX is more effective and has fewer AEs compared to MTX. However, the trials selected in the present meta-analysis have various limitations, including the lack of blinding and the short duration of the treatment; therefore, the conclusions are not sufficiently definitive. More randomized controlled trials are necessary to evaluate the use of Biqi capsule for managing RA.

Identification of sarilumab pharmacodynamic and predictive markers in patients with inadequate response to TNF inhibition: a biomarker substudy of the phase 3 TARGET study

Introduction

Interleukin-6 (IL-6) orchestrates formation of an inflammatory pannus, leading to joint damage in rheumatoid arthritis (RA). Sarilumab is a human monoclonal antibody blocking the IL-6Rα. In TARGET (NCT01709578), a phase 3 study in adults with moderate-to-severe RA and inadequate response or intolerance to tumour necrosis factor inhibitors, subcutaneous sarilumab 200 mg or 150 mg every 2 weeks (q2w) plus conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) significantly reduced disease activity versus placebo plus csDMARDs.

Methods

Circulating levels of biomarkers associated with synovial inflammation (matrix metalloproteinase 3 (MMP-3), collagen type I MMP-cleaved fragment (C1M), collagen type III MMP-cleaved fragment (C3M)), myeloid (soluble intercellular adhesion molecule 1 (sICAM-1), IL-8 and calprotectin) and lymphoid activation (chemokine, CXC motif, ligand 13 (CXCL13), CXCL10, B cell-activating factor) and bone remodelling (receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin and osteocalcin) were evaluated in patients from a TARGET substudy.

Results

Sarilumab significantly decreased C1M, C3M, CXCL13, MMP-3 and total RANKL levels at week 24 versus placebo; some markers were significantly suppressed at week 2 and normalised to levels in healthy controls. Levels of sICAM-1 were predictive of disease activity score by C-reactive protein and clinical disease activity index low disease activity (LDA) response in the sarilumab 200 mg q2w group at week 12. A trend was observed in which patients with lower sICAM-1 levels at baseline had better response compared with patients with higher sICAM-1.

Conclusions

Sarilumab plus csDMARDs decreased circulating biomarkers of synovial inflammation and bone resorption; sICAM-1 was predictive of achieving LDA with sarilumab.

Trial registration number

NCT01709578; Post-results.

Response to Treatment with TNFα Inhibitors in Rheumatoid Arthritis Is Associated with High Levels of GM-CSF and GM-CSF+ T Lymphocytes

Biologic TNFα inhibitors are a mainstay treatment option for patients with rheumatoid arthritis (RA) refractory to other treatment options. However, many patients either do not respond or relapse after initially responding to these agents. This study was carried out to identify biomarkers that can distinguish responder from non-responder patients before the initiation of treatment. The level of cytokines in plasma and those produced by ex vivo T cells, B cells and monocytes in 97 RA patients treated with biologic TNFα inhibitors was measured before treatment and after 1 and 3 months of treatment by multiplex analyses. The frequency of T cell subsets and intracellular cytokines were determined by flow cytometry. The results reveal that pre-treatment, T cells from patients who went on to respond to treatment with biologic anti-TNFα agents produced significantly more GM-CSF than non-responder patients. Furthermore, immune cells from responder patients produced higher levels of IL-1β, TNFα and IL-6. Cytokine profiling in the blood of patients confirmed the association between high levels of GM-CSF and responsiveness to biologic anti-TNFα agents. Thus, high blood levels of GM-CSF pre-treatment had a positive predictive value of 87.5% (61.6 to 98.5% at 95% CI) in treated RA patients. The study also shows that cells from most anti-TNFα responder patients in the current cohort produced higher levels of GM-CSF and TNFα pre-treatment than non-responder patients. Findings from the current study and our previous observations that non-responsiveness to anti-TNFα is associated with high IL-17 levels suggest that the disease in responder and non-responder RA patients is likely to be driven/sustained by different inflammatory pathways. The use of biomarker signatures of distinct pro-inflammatory pathways could lead to evidence-based prescription of the most appropriate biological therapies for different RA patients.

Pathogenic role of endogenous TNF-α in the development of Sjögren's-like sialadenitis and secretory dysfunction in non-obese diabetic mice

Patients with Sjögren's syndrome (SS), an autoimmune disease primarily affecting exocrine glands, exhibit enhanced TNF-α expression in the saliva and salivary glands. However, the precise in vivo role of TNF-α during the initiation and development of SS is not clearly defined. The present study is undertaken to determine the function of endogenously produced TNF-α in the pathogenesis of SS in non-obese diabetic (NOD) mice, a model of this human disease. Administration of a neutralizing anti-TNF-α antibody to female NOD mice during the stage prior to disease onset significantly improved salivary secretion, indicating a remission of clinical symptoms of SS. TNF-α blockade also decreased the number of leukocyte foci and reduced the number of T cells and B cells in the submandibular glands (SMG). Moreover, TNF-α blockade reduced T-bet protein levels in the SMG, suggesting a decrease in T helper 1 and T cytotoxic 1 cells. These cellular changes induced by TNF-α neutralization were associated with a reduction in T- and B-cell chemoattractants CXCL9 and CXC13. In addition, TNF-α blockade markedly increased the expression level of tight junction protein claudin-1 and water channel protein aquaporin-5, two key factors required for normal salivary secretion, in the SMG. Collectively, these findings indicate that endogenous TNF-α has a pathogenic role in the development of SS in the NOD model of this disease.

Blood chemokine profile in untreated early rheumatoid arthritis: CXCL10 as a disease activity marker

Background

We have recently analyzed the profile of T-cell subtypes based on chemokine receptor expression in blood from untreated early rheumatoid arthritis (ueRA) patients compared to healthy controls (HC). Here, we compared the levels of the respective chemokines in blood plasma of ueRA patients with those of HC. We also studied the association of chemokine levels with the proportions of circulating T-cell subsets and the clinical disease activity.

Methods

Peripheral blood was obtained from 43 patients with ueRA satisfying the ACR 2010 criteria and who had not received any disease-modifying anti-rheumatic drugs (DMARD) or prednisolone, and from 14 sex- and age-matched HC. Proportions of T helper cells in blood, including Th0, Th1, Th2, Th17, Th1Th17, TFh, and regulatory T cells, were defined by flow cytometry. Fifteen chemokines, including several CXCL and CCL chemokines related to the T-cell subtypes as well as to other major immune cells, were measured in blood plasma using flow cytometry bead-based immunoassay or ELISA. Clinical disease activity in patients was evaluated by assessing the following parameters: Disease Activity Score in 28 joints (DAS28), Clinical Disease Activity Index (CDAI), swollen joint counts (SJC), tender joint counts (TJC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The data were analyzed using multivariate factor analyses followed by univariate analyses.

Results

Multivariate discriminant analysis showed that patients with ueRA were separated from HC based on the blood plasma chemokine profile. The best discriminators were CXCL9, CXCL10, CXCL13, CCL4, and CCL22, which were significantly higher in ueRA compared to HC in univariate analyses. Among the chemokines analyzed, only CXCL10 correlated with multiple disease activity measures, including DAS28-CRP, DAS28-ESR, CDAI, SJC in 66 joints, CRP, and ESR.

Conclusions

High circulating levels of CXCL10 in the plasma of ueRA patients and the association with the clinical disease activity suggests that CXCL10 may serve as a disease activity marker in early rheumatoid arthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1224-1) contains supplementary material, which is available to authorized users.