Is IL-6 an appropriate target to treat spondyloarthritis patients refractory to anti-TNF therapy? A multicentre retrospective observational study

No Significant Effects of IL-23 on Initiating and Perpetuating the Axial Spondyloarthritis: The Reasons for the Failure of IL-23 Inhibitors

Axial spondyloarthritis (axSpA) is comprised of ankylosing spondylitis (AS) and non-radiographic axSpA. In recent years, the involvement of the interleukin (IL)-23/IL-17 axis in the pathophysiology of axSpA has been widely proposed. Since IL-23 is an upstream activating cytokine of IL-17, theoretically targeting IL-23 should be effective in axSpA, especially after the success of the treatment with IL-17 blockers in the disorder. Unfortunately, IL-23 blockade did not show meaningful efficacy in clinical trials of AS. In this review, we analyzed the possible causes of the failure of IL-23 blockers in AS: 1) the available data from an animal model is not able to support that IL-23 is involved in a preclinical rather than clinical phase of axSpA; 2) Th17 cells are not principal inflammatory cells in the pathogenesis of axSpA; 3) IL-17 may be produced independently of IL-23 in several immune cell types other than Th17 cells in axSpA; 4) no solid evidence supports IL-23 as a pathogenic factor to induce enthesitis and bone formation. Taken together, IL-23 is not a principal proinflammatory cytokine in the pathogenesis of axSpA.

Different risk profiles of biologic agents for new-onset psoriasis in patients with rheumatoid arthritis

OBJECTIVE

To investigate rates and risk factors for incident and recurrent psoriasis in rheumatoid arthritis (RA) patients treated with different biologic (b) and conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs).

METHODS

RA patients enrolled in the German biologics register RABBIT without (n = 14,525) or with a history of psoriasis (n = 375) were analyzed separately. All first events of psoriasis reported until October 2017 were assigned to the treatments prescribed in the previous 3 months. Crude incidence rates (IR) of psoriasis were calculated per 1000 patient-years. To investigate risk factors for psoriasis, cox regressions with and without inverse probability weights were applied to adjust for confounding by indication.

RESULTS

117 incident and 37 recurrent psoriatic events were reported. Patients exposed to TNFi had a significantly higher incidence rate (IR = 3.04/1,000 PY) than those exposed to csDMARDs only (IR = 0.65), whereas IRs for abatacept, rituximab and tocilizumab did not differ significantly from csDMARDs. Adjusted Cox regression confirmed a higher risk for TNFi. Female sex (HR: 1.7) and smoking (HR: 2.1) were significantly associated with incident psoriasis while methotrexate decreased the risk (HR: 0.5). For recurrent psoriasis, IRs for TNFi, abatacept and rituximab were significantly higher than for csDMARDs.

CONCLUSIONS

Our data confirm a previously observed increased risk of incident psoriasis in patients exposed to TNFi compared to csDMARDs. However, the overall risk is low and the event is usually non-serious. Comedication of TNFi with methotrexate seems to lower the risk of incident psoriasis. In patients with a history of psoriasis, recurrence as adverse event is rare.

The effect of anti-IL-6 receptor antibody for the treatment of McH-lpr/lpr-RA1 mice that spontaneously developed destructive arthritis and enthesitis

Background

McH-lpr/lpr-RA1 mice are a new strain of mice which spontaneously develop destructive arthritis and enthesitis in the ankle. There is no published data that drug treatment has been trialed on these mice. This study examined the effect of the mouse anti-IL-6 receptor antibody, MR16–1, for the treatment of arthritis and enthesitis in McH-lpr/lpr-RA1 mice.

Methods

Male McH-lpr/lpr-RA1 mice were randomly divided into control and treatment groups. MR16–1 was administered from 10 weeks of age for the treatment group. Saline was applied for the control group. The drug was administered once a week, at an initial dose of 2 mg, then maintained at 0.5 mg once per week thereafter. The effects were evaluated by the histopathological synovitis score, in vivo imaging using indocyanine green liposomes, and analysis of the gene expression of inflammatory cytokines.

Results

Tissue analyses were carried out at 14, 17 and 20 weeks of age. The synovitis scores of treated groups were significantly lower compared with those of the control group at 14 and 17 weeks of age. The kappa coefficient was 0.77. However, progression of entheseal ossification persisted in the MR16–1 treated group. In vivo imaging using indocyanine green liposomes showed significant decreases in signal intensities of treated groups at week 14, but no significant differences were observed at week 18. Blood serum amyloid A levels in treated groups were significantly lower at 17 weeks of age. The gene expression levels of Tnf and Il17 were also significantly lower in MR16–1 treated groups.

Conclusions

Administration of the anti-IL-6 receptor antibody is effective for the treatment of synovitis and bone destruction of McH-lpr/lpr-RA1 mice. McH-lpr/lpr-RA1 mice may be a suitable experimental model for the development of new treatments for destructive arthritis and enthesitis. IL-6 signal blockade could contribute to the treatment of destructive arthritis, and further studies should be carried out to confirm its potential in the prevention of enthesopathy developed to ossification.

Interleukin-6 in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a chronic childhood arthritis. Its pathogenesis is very complicated, with the involvement of not only immune cells but various types of parenchymal cells, and is affected by both genetic and environmental predispositions. The clinical spectrum from inflammation to related conditions is largely mediated by cytokines including interleukin (IL)-6. Fluctuations in IL-6 and its related molecules can modulate the pathogenesis and the clinical presentation positively or negatively. The recent clinical impact of IL-6 blockade on JIA has begun a therapeutic paradigm shift. This review describes the characteristics of JIA, mainly focused on IL-6 with the current therapeutic perspective.

IL-23R and IL-17A polymorphisms correlate with susceptibility of ankylosing spondylitis in a Southwest Chinese population

The association between the IL-23R and IL-17A polymorphisms and ankylosing spondylitis (AS) in the Southwest Chinese Population is still unclear. The purpose of this study is to detect the association between IL-23R and IL-17A polymorphisms and AS. A case-control study consisting of 486 AS patients and 480 healthy controls was performed. We used the high-resolution melting methods (HRM) to genotype five selected single nucleotide polymorphisms (SNPs), rs6693831, rs7517847, rs1884444, rs10889677 in the IL-23R gene and rs2275913 in the IL-17A gene. Meanwhile, the laboratory indexes were recorded. In this study, patients with genotype CC (p = 8.574E-8) and allele C (p = 3.206E-31) on SNP rs6693831 (IL-23R) showed decreased risk of AS. The genotype TT (p = 4.551E-6) and allele T (p = 0.02) on SNP rs1884444 (IL-23R) showed significant lower risk of AS. Individuals carrying the allele A of rs2275913 showed higher morbidity of AS (p = 0.04). We first detected that rs6693831 and rs1884444 in IL-23R gene and rs2275913 in IL-17A gene have genetic association with AS.

Beyond TNF Inhibitors: New Pathways and Emerging Treatments for Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by psoriasis, synovitis, enthesitis, spondylitis and association with other extra-articular manifestations. Chronic inflammation of involved tissues possibly leads to structural damage and to a reduction in function and quality of life. The treatment of PsA dramatically changed with the introduction of anti-tumor necrosis factor (TNF)-α drugs, which have been shown to reduce the symptoms and signs of the disease, and slow radiographic progression. However, some patients do not respond to anti-TNFα or have a loss of response. Recently, the discovery of new pathogenic mechanisms have made possible the development of new drugs that target pro-inflammatory cytokines, such as interleukin (IL)-12, IL-23 and IL-17, or interfere with cellular pathways involved in skin, joint and entheseal inflammation. New molecules, namely ustekinumab, secukinumab, and apremilast have shown efficacy and safety over the various components of the disease in randomized clinical trials. These drugs have been recently approved for the treatment of PsA and included in new treatment recommendations. Other molecules are currently being tested in phase III clinical trials and are potential new treatment options for PsA. The aim of this review is to update the new pathways involved in the development of the disease and the emerging treatments for PsA beyond TNFα inhibition.

Pharmacological treatment of spondyloarthritis: exploring the effectiveness of nonsteroidal anti-inflammatory drugs, traditional disease-modifying antirheumatic drugs and biological therapies

Spondyloarthritis represents a heterogeneous group of articular inflammatory diseases that share common genetic, clinical and radiological features. The therapy target of spondyloarthritis relies mainly in improving patients' quality of life, controlling articular inflammation, preventing the structural joints damage and preserving the functional abilities, autonomy and social participation of patients. Among these, traditional disease-modifying antirheumatic drugs have been demonstrated to be effective in the management of peripheral arthritis; moreover, in the last decade, biological therapies have improved the approach to spondyloarthritis. In patients with axial spondyloarthritis, tumor necrosis factor α inhibitors are currently the only effective therapy in patients for whom conventional therapy with nonsteroidal anti-inflammatory drugs has failed. The aim of this review is to summarize the current experience and evidence about the pharmacological approach in spondyloarthritis patients.

All-Trans Retinoic Acid Improves the Effects of Bone Marrow-Derived Mesenchymal Stem Cells on the Treatment of Ankylosing Spondylitis: An In Vitro Study

Previous studies have demonstrated the immunosuppressive effects of both all-trans retinoic acid (ATRA) and mesenchymal stem cells (MSCs). The present study aimed to assess the immunoregulatory effects of ATRA on MSCs in the treatment of ankylosing spondylitis (AS). Bone marrow-derived MSCs from healthy donors were pretreated with ATRA and cocultured with CD3/28-activated peripheral blood mononuclear cells (PBMCs) derived from AS patients. Frequencies of Th17 and regulatory T (Treg) cells were analyzed using flow cytometry. The secretion and the mRNA level of key cytokines were measured with cytometric bead array and quantitative real-time PCR, respectively. ATRA pretreatment increased interleukin-6 (IL-6) secretion of MSCs. Th17 and Treg subset populations were increased and reduced by ATRA-pretreated MSCs, respectively. ATRA-pretreated MSCs significantly decreased not only the vital pathogenic cytokine in AS, tumor necrosis factor-α (TNF-α), but also AS-boosting factors interleukin-17 (IL-17A) and interferon-γ (IFN-γ). These results indicated that IL-6 may be a potential protective factor in AS and highlighted the promising role of ATRA in improving the efficacy of MSC-based treatment of AS.

Update on ankylosing spondylitis: current concepts in pathogenesis

Ankylosing spondylitis is an insidiously progressive and debilitating form of arthritis involving the axial skeleton. The long delay in diagnosis and insufficient response to currently available therapeutics both advocate for a greater understanding of disease pathogenesis. Genome-wide association studies of this highly genetic disease have implicated specific immune pathways, including the interleukin (IL)-17/IL-23 pathway, control of nuclear factor kappa B (NF-κB) activation, amino acid trimming for major histocompatibility complex (MHC) antigen presentation, and other genes controlling CD8 and CD4 T cell subsets. The relevance of these pathways has borne out in animal and human subject studies, in particular, the response to novel therapeutic agents. Genetics and the findings of autoantibodies in ankylosing spondylitis revisit the question of autoimmune vs. autoinflammatory etiology. As environmental partners to genetics, recent attention has focused on the roles of microbiota and biomechanical stress in initiating and perpetuating inflammation. Herein, we review these current developments in the investigation of ankylosing spondylitis pathogenesis.

Impact of biological therapy on spondyloarthritis

PURPOSE

In this review, we focus on the clinical and radiological aspects related to the biological therapy of ankylosing spondylitis (AS), axial spondyloarthritis (SpA) and psoriatic arthritis (PsA).

METHODS

A review was carried out in the main medical databases to evaluate the available literature.

RESULTS

Even if there is emerging interest for the role of biological agents other than tumour necrosis factor (TNF)-α inhibitors in spondyloarthritis, anti-TNF-α treatment is currently the only effective therapy for patients in whom conventional therapy with non-steroideal anti-inflammatory drugs (NSAIDs) has failed. Nevertheless, the potential impact of earlier treatment and the best drugs or combinations of drugs for preventing radiographic progression in SpA are yet to be determined.

CONCLUSIONS

Anti-TNF-α treatment is currently used with efficacy in the greater part of patients with SpA. In these patients, availability of biological treatment is limited on the bases of potential toxicity and cost. On the basis of clinical trials, biologics other than TNF-α inhibitors can currently not be recommended for the treatment of SpA.

Biological therapies for spondyloarthritis

Biological therapies and new imaging techniques have changed the therapeutic and diagnostic approach to spondyloarthritis. In patients with axial spondyloarthritis, tumor necrosis factor α (TNFα) inhibitor treatment is currently the only effective therapy in patients for whom conventional therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) has failed. TNFα inhibitor treatment is more effective in preventing articular damage in peripheral joints than in axial ones. It is important to treat patients at an early stage of disease to reduce disease progression; moreover it is necessary to identify causes of therapy inefficacy in preventing joint damage in the axial subset.

Recommendations of the French Society for Rheumatology (SFR) on the everyday management of patients with spondyloarthritis

The management of spondyloarthritis is challenging and has changed with the development of new concepts and treatments.

OBJECTIVE

To develop practice guidelines for the everyday management of patients with spondyloarthritis (including psoriatic arthritis), by updating previous national and international recommendations, based on a review of recently published data.

METHODS

A task force and a multidisciplinary literature review group were established. The task force identified the issues that remained unresolved. Based on existing recommendations and recent publications, the task force developed practice guidelines, which were revised by the literature review group and graded according to AGREE.

RESULTS

Practice guidelines for the management of spondyloarthritis are reported. After a review of the general diagnostic principles, 30 practice guidelines are given: 5 on general principles, 4 on the management strategy, 5 on non-pharmacological treatments, 7 on conventional pharmacological treatments, 6 on biotherapies, and 3 on surgical treatments and follow-up.

CONCLUSION

The updated practice guidelines reported here constitute a global framework that can guide physicians in the everyday management of spondyloarthritis.

Clinical experience of IL-6 blockade in rheumatic diseases - implications on IL-6 biology and disease pathogenesis

Interleukin 6 (IL-6) plays a significant role in many rheumatological diseases and has been described as both a pro- and anti-inflammatory cytokine. IL-6 blockade has been investigated in various rheumatic diseases and a humanised anti-IL-6 receptor antibody has been licensed for use in rheumatoid arthritis, systemic and polyarticular juvenile idiopathic arthritis. The increasing clinical experience of IL-6 blockade in rheumatic diseases adds to the existing knowledge regarding the physiological and pathological roles of IL-6.

IL-17 in the rheumatologist's line of sight

Over the past decades, the identification of several new cytokines, including interleukin (IL)-17 and IL-23, and of new T helper cell subsets, including Th17 cells, has changed the vision of immunological processes. The IL-17/Th17 pathway plays a critical role during the development of inflammation and autoimmunity, and targeting this pathway has become an attractive strategy for a number of diseases. This review aims to describe the effects of IL-17 in the joint and its roles in the development of autoimmune and inflammatory arthritis. Furthermore, biotherapies targeting directly or indirectly IL-17 in inflammatory rheumatisms will be developed.

Emerging drugs for axial spondyloarthritis including ankylosing spondylitis

INTRODUCTION

Only non-steroidal anti-inflammatories (NSAIDs) and TNF inhibitors (TNFi) are effective in ankylosing spondylitis (AS). However, not all patients successfully respond to these drugs and a subset may have contraindications to their use.

AREAS COVERED

In the last decade, an earlier diagnosis of AS has been achieved due to the increasing availability of MRI. This has led to prompt treatment initiation with improved outcomes. NSAIDs and TNFi are the current treatments for AS which lead to sustained clinical responses in the long term. Recent studies have shown other potential biomarkers in AS, such as the IL-17/IL-23 axis. This has translated into the development of new drugs which interfere with these pathways, such as apremilast and secukinumab, which have shown efficacy in early clinical trials.

EXPERT OPINION

AS carries considerable short- and long-term disabilities. Anti-TNF-α therapies reduce pain, improve function and decrease inflammation as seen by MRI. New treatment options are being developed which may prove efficacious on those patients not responding to anti-TNF. The ultimate research goal should focus on treatments to prevent and stop new bone formation.

Pathological role of interleukin-6 in psoriatic arthritis

Psoriatic arthritis (PsA) is a clinical manifestation of psoriatic disease. Although the pathogenesis of PsA remains unknown, PsA can be managed by treatments similar to those used for rheumatoid arthritis (RA). Because interleukin-(IL-) 6 has been suggested to have a pathogenic role in PsA, a humanized anti-IL-6 receptor antibody tocilizumab treatment for PsA was recently tried. However, the efficacy of tocilizumab for PsA was not favorable. This suggests that the pathogenic roles of IL-6 in PsA and RA are different. In RA, tumor necrosis factor (TNF) primarily contributes to the arthritis effector phase and IL-6 contributes to the arthritis priming phase. In PsA, the TNF-related effector phase is similar to that in RA, but the IL-6-related priming phase might not be critical. This paper discusses the role of IL-6 in PsA.