Secukinumab after anti-tumour necrosis factor-α therapy: a phase III study in active rheumatoid arthritis

Do cytokines play a role in the transition from acute to chronic musculoskeletal pain?

Musculoskeletal pain has a high prevalence of transition to chronic pain and/or persistence as chronic pain for years or even a lifetime. Possible mechanisms for the development of such pain states are often reflected in inflammatory or neuropathic processes involving, among others, cytokines and other molecules. Since biologics such as blockers of TNF or IL-6 can attenuate inflammation and pain in a subset of patients with rheumatoid arthritis, the question arises to what extent cytokines are involved in the generation of pain in human musculoskeletal diseases. In numerous experimental non-human studies, cytokines have been shown to alter neuronal sensitivity in the peripheral and central nociceptive systems. In this review, we addressed the involvement of cytokines in postoperative pain, complex regional pain syndrome, rheumatoid arthritis, osteoarthritis, temporomandibular joint disease, low back pain and fibromyalgia using PubMed searches including meta-analyses of data. There is evidence that certain pro- and anti-inflammatory cytokines are regulated in all of these diseases, often in both acute and chronic disease states. However, within these data, we found a great deal of heterogeneity in the association between cytokine levels and pain. Neutralization of cytokines showed antinociceptive effects in subgroups of patients with chronic pain (e.g., in a proportion of patients with rheumatoid arthritis), but failed to reduce chronic pain in other diseases (e.g., osteoarthritis). More systematic studies are needed to unravel the pathogenic role of cytokines in human musculoskeletal pain, taking into account the disease process and the mechanisms of pain initiation and maintenance.

Exploring microRNA signatures in pediatric non-infectious uveitis: meta-analysis and molecular profiling of patient samples

To find a distinct non-coding RNA characteristic for idiopathic uveitis in the pediatric population. To explore the autoimmune-related miRNA expression profile in pediatric patients with idiopathic uveitis (IU) and juvenile idiopathic arthritis-associated uveitis (JIA-AU) and find a common molecular background for idiopathic uveitis and other autoimmune diseases. The expression levels of miRNAs were analyzed by quantitative real-time PCR using serum samples from patients with idiopathic uveitis (n = 8), juvenile idiopathic arthritis-associated uveitis (n = 7), and healthy controls. We selected the most promising miRNAs from the original research papers: miR-16-5p, miR-26a-5p, miR-145-5p, and miR-451a as markers for juvenile idiopathic arthritis; miR-23a-3p, miR-29a-3p, miR-140-5p, miR-193a-5p, and miR-491-5p for uveitis in the adult population; and miR-125a-5p, miR-146a-5p, miR-155-5p, miR-223-5p, and miR-223-3p characteristic for both diseases and confirm their expression changes in serum from children with idiopathic uveitis. We comprehensively reviewed the literature enrolling the papers that met the inclusion criteria (miRNA and non-infectious uveitis/juvenile idiopathic arthritis) and performed target prediction analysis of appoint miRNAs. It additionally confirmed that altered miRNAs target the immunologically involved genes. Immunological-involved miRNAs such as miR-146a-5p and miR-155-5p show diverse expression levels in different patients as they interact with multiple targets. miR-204-5p is downregulated in both patient groups compared to healthy controls. miR-204-5p and miR-155-5p are candidates for molecular markers of autoimmune uveitis. We did not identify the miRNAs specific only to idiopathic uveitis, but for the first time in the pediatric population, we confirmed that this disease entity shares a molecular basis with other autoimmune diseases. Further studies are required to elucidate the molecular interactions among miRNAs, cytokines, and transcription factors within the intricate immune response, particularly in the eye.

Type 17 immunity: novel insights into intestinal homeostasis and autoimmune pathogenesis driven by gut-primed T cells

The IL-23 signaling pathway in both innate and adaptive immune cells is vital for orchestrating type 17 immunity, which is marked by the secretion of signature cytokines such as IL-17, IL-22, and GM-CSF. These proinflammatory mediators play indispensable roles in maintaining intestinal immune equilibrium and mucosal host defense; however, their involvement has also been implicated in the pathogenesis of chronic inflammatory disorders, such as inflammatory bowel diseases and autoimmunity. However, the implications of type 17 immunity across diverse inflammation models are complex. This review provides a comprehensive overview of the multifaceted roles of these cytokines in maintaining gut homeostasis and in perturbing gut barrier integrity, leading to acute and chronic inflammation in various models of gut infection and colitis. Additionally, this review focuses on type 17 immunity interconnecting multiple organs in autoimmune conditions, with a particular emphasis on the pathogenesis of autoimmune arthritis and neuroinflammation driven by T cells primed within the gut microenvironment.

From bench to bedside - is there a role of IL-17 drugs in rheumatoid arthritis?

INTRODUCTION

IL-17 has been described as a pro-inflammatory cytokine that is relevant in the seronegative spondylarthritides with IL-17 targeted therapies being licensed for their treatment.There is evidence to demonstrate that IL-17 is found in RA joints and contributes to the pro-inflammatory cascade. This results in synovial hyperplasia and osteoclastogenesis thus causing joint destruction and bony erosions.

AREAS COVERED

This review article summarizes trials that have studied the use of IL-17 targeted therapies in RA patients who have failed conventional synthetic disease-modifying therapy (C-DMARDS) and biologic DMARDS.

EXPERT OPINION

The trials that have studied IL-17 inhibitors in RA patients have only shown a modest improvement in disease activity. In several trials, the primary endpoint was not achieved whilst in others, when comparing with existing licensed biologics for RA, did not demonstrate any superiority.Tissue Necrosis Factor-alpha (TNF-α) likely plays more of a pivotal role in the pathogenesis of RA with IL-17 having a synergistic effect. Therefore, in our opinion, IL-17 inhibitors as an independent therapy for RA are less likely to provide a cost-effective benefit. There may be scope to potentially combine it with TNF-α-inhibitors (TNF-i), but this requires further research especially with the potential concerns related to increased immunosuppression.

Cytokines, Vascular Endothelial Growth Factors, and PlGF in Autoimmunity: Insights From Rheumatoid Arthritis to Multiple Sclerosis

In this review, we will explore the intricate roles of cytokines and vascular endothelial growth factors in autoimmune diseases (ADs), with a particular focus on rheumatoid arthritis (RA) and multiple sclerosis (MS). AD is characterized by self-destructive immune responses due to auto-reactive T lymphocytes and Abs. Among various types of ADs, RA and MS possess inflammation as a central role but in different sites of the patients. Other common aspects among these two ADs are their chronicity and relapsing-remitting symptoms requiring continuous management. First factor inducing these ADs are cytokines, such as IL-6, TNF-α, and IL-17, which play significant roles in the pathogenesis by contributing to inflammation, immune cell activation, and tissue damage. Secondly, vascular endothelial growth factors, including VEGF and angiopoietins, are crucial in promoting angiogenesis and inflammation in these two ADs. Finally, placental growth factor (PlGF), an emerging factor with bi-directional roles in angiogenesis and T cell differentiation, as we introduce as an "angio-lymphokine" is another key factor in ADs. Thus, while angiogenesis recruits more inflammatory cells into the peripheral sites, cytokines secreted by effector cells play critical roles in the pathogenesis of ADs. Various therapeutic interventions targeting these soluble molecules have shown promise in managing autoimmune pathogenic conditions. However, delicate interplay between cytokines, angiogenic factors, and PlGF has more to be studied when considering their complementary role in actual pathogenic conditions. Understanding the complex interactions among these factors provides valuable insights for the development of innovative therapies for RA and MS, offering hope for improved patient outcomes.

HDAC2 exacerbates rheumatoid arthritis progression via the IL-17-CCL7 signaling pathway

Histone deacetylases (HDACs) have been reported to regulate the immune response in rheumatoid arthritis (RA). The current study aimed to explore key HDACs and their molecular mechanism in RA. First, the expression of HDAC1, HDAC2, HDAC3 and HDAC8 in RA synovial tissue was determined by qRT-PCR. The effects of HDAC2 on the proliferation, migration, invasion, and apoptosis of fibroblast-like synoviocytes (FLS) in vitro were studied. Furthermore, collagen-induced arthritis (CIA) rat models were established to evaluate the severity of arthritis in joints, and the levels of inflammatory factors were examined by immunohistochemistry staining, ELISA, and qRT-PCR. Transcriptome sequencing was used to screen differentially expressed genes (DEGs) with HDAC2 silencing in the synovial tissue of CIA rat, and downstream signaling pathways were predicted by enrichment analysis. The results showed that HDAC2 was highly expressed in the synovial tissue of RA patients and CIA rats. Overexpressed HDAC2 promoted FLS proliferation, migration, and invasion and inhibited FLS apoptosis in vitro, resulting in secretion of inflammatory factors and RA exacerbation in vivo. There were 176 DEGs, including 57 downregulated and 119 upregulated genes, after silencing HDAC2 in CIA rats. DEGs were primarily enriched in Platinum drug resistance, IL-17 as well as the PI3K-Akt signaling pathways. CCL7, which was implicated in the IL-17 signaling pathway, was downregulated after HDAC2 silencing. Furthermore, CCL7 overexpression aggravated the development of RA, which was demonstrated to be effectively attenuated by HDAC2 suppression. In conclusion, this study demonstrated that HDAC2 exacerbated the progression of RA by regulating the IL-17-CCL7 signaling pathway, suggesting that HDAC2 may be a promising therapeutic target for RA treatment.

The forgotten key players in rheumatoid arthritis: IL-8 and IL-17 - Unmet needs and therapeutic perspectives

Despite the relevant advances in our understanding of the pathogenetic mechanisms regulating inflammation in rheumatoid arthritis (RA) and the development of effective therapeutics, to date, there is still a proportion of patients with RA who do not respond to treatment and end up progressing toward the development of joint damage, extra-articular complications, and disability. This is mainly due to the inter-individual heterogeneity of the molecular and cellular taxonomy of the synovial membrane, which represents the target tissue of RA inflammation. Tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) are crucial key players in RA pathogenesis fueling the inflammatory cascade, as supported by experimental evidence derived from in vivo animal models and the effectiveness of biologic-Disease Modifying Anti-Rheumatic Drugs (b-DMARDs) in patients with RA. However, additional inflammatory soluble mediators such as IL-8 and IL-17 exert their pathogenetic actions promoting the detrimental activation of immune and stromal cells in RA synovial membrane, tendons, and extra-articular sites, as well as blood vessels and lungs, causing extra-articular complications, which might be excluded by the action of anti-TNFα and anti-IL6R targeted therapies. In this narrative review, we will discuss the role of IL-8 and IL-17 in promoting inflammation in multiple biological compartments (i.e., synovial membrane, blood vessels, and lung, respectively) in animal models of arthritis and patients with RA and how their selective targeting could improve the management of treatment resistance in patients.

Positive Effects of Biologics on Osteoporosis in Rheumatoid Arthritis

Osteoporosis is a systemic skeletal disorder that causes vulnerability of bones to fracture owing to reduction in bone density and deterioration of the bone tissue microstructure. The prevalence of osteoporosis is higher in patients with autoimmune inflammatory rheumatic diseases, including rheumatoid arthritis (RA), than in those of the general population. In this autoimmune inflammatory rheumatic disease, in addition to known risk factors for osteoporosis, various factors such as chronic inflammation, autoantibodies, metabolic disorders, drugs, and decreased physical activity contribute to additional risk. In RA, disease-related inflammation plays an important role in local or systemic bone loss, and active treatment for inflammation can help prevent osteoporosis. In addition to conventional synthetic disease-modifying anti-rheumatic drugs that have been traditionally used for treatment of RA, biologic DMARDs and targeted synthetic DMARDs have been widely used. These agents can be employed more selectively and precisely based on disease pathogenesis. It has been reported that these drugs can inhibit bone loss by not only reducing inflammation in RA, but also by inhibiting bone resorption and promoting bone formation. In this review, the pathogenesis and research results of the increase in osteoporosis in RA are reviewed, and the effects of biological agents on osteoporosis are discussed.

Gastroenterological safety of IL-17 inhibitors: a systematic literature review

INTRODUCTION

Interleukin 17 is a proinflammatory cytokine considered to play a significant role in the immunopathogenesis of many chronic immune-mediated disorders. Interleukin 17 inhibitors provide an excellent treatment option for patients with psoriasis, psoriatic arthritis, or ankylosing spondylitis. However, Interleukin 17 inhibitors have been suspected of worsening or triggering new-onset inflammatory bowel disease.

AREAS COVERED

A literature search was conducted until March 2021 to investigate reporting prevalence, and characteristics of all gastroenterological adverse events in patients treated with Interleukin 17 inhibitors. One hundred and six clinical randomized trials were included, involving 40,053 patients. Inflammatory bowel disease cases were reported in 0.4% of patients exposed to Interleukin 17 inhibitors. The most frequent other gastrointestinal adverse events were diarrhea (2.5%), nausea or vomiting (0.7%), and gastroenteritis (0.2%). Sixty-one uncontrolled or retrospective studies were included, involving 16,791 patients. Sixty (0.36%) inflammatory bowel disease cases were reported, 0.6% of patients reported other gastrointestinal adverse events.

EXPERT OPINION

Interleukin 17 inhibitors are safe and effective in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. Low incidence rate of developing new-onset inflammatory bowel disease or exacerbating preexisting inflammatory bowel disease with anti-IL-17 agents has been reported. Clinicians should be aware of the possibility of these concerns when considering this therapy.

The heterogeneous human memory CCR6+ T helper-17 populations differ in T-bet and cytokine expression but all activate synovial fibroblasts in an IFNγ-independent manner

BACKGROUND

Chronic synovial inflammation is an important hallmark of inflammatory arthritis, but the cells and mechanisms involved are incompletely understood. Previously, we have shown that CCR6+ memory T-helper (memTh) cells and synovial fibroblasts (SF) activate each other in a pro-inflammatory feedforward loop, which potentially drives persistent synovial inflammation in inflammatory arthritis. However, the CCR6+ memTh cells are a heterogeneous population, containing Th17/Th22 and Th17.1 cells. Currently, it is unclear which of these subpopulations drive SF activation and how they should be targeted. In this study, we examined the individual contribution of these CCR6+ memTh subpopulations to SF activation and examined ways to regulate their function.

METHODS

Th17/Th22 (CXCR3-CCR4+), Th17.1 (CXCR3+CCR4-), DP (CXCR3+CCR4+), and DN (CXCR3-CCR4-) CCR6+ memTh, cells sorted from PBMC of healthy donors or treatment-naïve early rheumatoid arthritis (RA) patients, were cocultured with SF from RA patients with or without anti-IL17A, anti-IFNγ, or 1,25(OH)2D3. Cultures were analyzed by RT-PCR, ELISA, or flow cytometry.

RESULTS

Th17/Th22, Th17.1, DP, and DN cells equally express RORC but differ in production of TBX21 and cytokines like IL-17A and IFNγ. Despite these differences, all the individual CCR6+ memTh subpopulations, both from healthy individuals and RA patients, were more potent in activating SF than the classical Th1 cells. SF activation was partially inhibited by blocking IL-17A, but not by inhibiting IFNγ or TBX21. However, active vitamin D inhibited the pathogenicity of all subpopulations leading to suppression of SF activation.

CONCLUSIONS

Human CCR6+ memTh cells contain several subpopulations that equally express RORC but differ in TBX21, IFNγ, and IL-17A expression. All individual Th17 subpopulations are more potent in activating SF than classical Th1 cells in an IFNγ-independent manner. Furthermore, our data suggest that IL-17A is not dominant in this T cell-SF activation loop but that a multiple T cell cytokine inhibitor, such as 1,25(OH)2D3, is able to suppress CCR6+ memTh subpopulation-driven SF activation.

Identifying RNA Biomarkers and Molecular Pathways Involved in Multiple Subtypes of Uveitis

PURPOSE

Uveitis is a heterogeneous collection of diseases. We tested the hypothesis that despite the diversity of uveitides, there could be common mechanisms shared by multiple subtypes, and that evidence of these common mechanisms may be detected as gene expression profiles in whole blood.

DESIGN

Cohort study.

METHODS

Ninety subjects with uveitis including axial spondyloarthritis (n = 17), sarcoidosis (n = 13), inflammatory bowel disease (n = 12), tubulointerstitial nephritis with uveitis (n = 10), or idiopathic uveitis (n = 38) as well as 18 healthy controls were enrolled, predominantly at Oregon Health & Science University. RNA-Seq data generated from peripheral, whole blood identified 19,859 unique transcripts. We analyzed gene expression pathways via Kyoto Encyclopedia of Genes and Genomes and Gene Ontology (GO). We validated our list of upregulated genes by comparison to a previously published study on peripheral blood gene expression among 50 subjects with diverse forms of uveitis.

RESULTS

Both the Kyoto Encyclopedia of Genes and Genomes and GO analysis identified multiple shared pathways or GO terms with a P value of <.0001. Almost all pathways related to the immune response and/or response to an infection. A total of 119 individual transcripts were upregulated by at least 1.5-fold and false discovery rate <.05, and 61 were downregulated by similar criteria. Comparing mRNA from our study with a false discovery rate <.05 and the prior report, we identified 10 common gene transcripts: ICAM1, IL15RA, IL15, IRF1, IL10RB, GSK3A, TYK2, MEF2A, MEF2B, and MEF2D.

CONCLUSIONS

Many forms of uveitis share overlapping mechanisms. These data support the concept that a single therapeutic approach could benefit diverse forms of this disease.

Local Sustained Delivery of Anti-IL-17A Antibodies Limits Inflammatory Bone Loss in Murine Experimental Periodontitis

Periodontal disease (PD) is a chronic destructive inflammatory disease of the tooth-supporting structures that leads to tooth loss at its advanced stages. Although the disease is initiated by a complex organization of oral microorganisms in the form of a plaque biofilm, it is the uncontrolled immune response to periodontal pathogens that fuels periodontal tissue destruction. IL-17A has been identified as a key cytokine in the pathogenesis of PD. Despite its well documented role in host defense against invading pathogens at oral barrier sites, IL-17A-mediated signaling can also lead to a detrimental inflammatory response, causing periodontal bone destruction. In this study, we developed a local sustained delivery system that restrains IL-17A hyperactivity in periodontal tissues by incorporating neutralizing anti-IL-17A Abs in poly(lactic-coglycolic) acid microparticles (MP). This formulation allowed for controlled release of anti-IL-17A in the periodontium of mice with ligature-induced PD. Local delivery of anti-IL-17A MP after murine PD induction inhibited alveolar bone loss and osteoclastic activity. The anti-IL-17A MP formulation also decreased expression of IL-6, an IL-17A target gene known to induce bone resorption in periodontal tissues. This study demonstrates proof of concept that local and sustained release of IL-17A Abs constitutes a promising therapeutic strategy for PD and may be applicable to other osteolytic bone diseases mediated by IL-17A-driven inflammation.

Biologic Drugs for Rheumatoid Arthritis in the Context of Biosimilars, Genetics, Epigenetics and COVID-19 Treatment

Rheumatoid arthritis (RA) affects around 1.2% of the adult population. RA is one of the main reasons for work disability and premature retirement, thus substantially increasing social and economic burden. Biological disease-modifying antirheumatic drugs (bDMARDs) were shown to be an effective therapy especially in those rheumatoid arthritis (RA) patients, who did not adequately respond to conventional synthetic DMARD therapy. However, despite the proven efficacy, the high cost of the therapy resulted in limitation of the widespread use and unequal access to the care. The introduction of biosimilars, which are much cheaper relative to original drugs, may facilitate the achievement of the therapy by a much broader spectrum of patients. In this review we present the properties of original biologic agents based on cytokine-targeted (blockers of TNF, IL-6, IL-1, GM-CSF) and cell-targeted therapies (aimed to inhibit T cells and B cells properties) as well as biosimilars used in rheumatology. We also analyze the latest update of bDMARDs' possible influence on DNA methylation, miRNA expression and histone modification in RA patients, what might be the important factors toward precise and personalized RA treatment. In addition, during the COVID-19 outbreak, we discuss the usage of biologicals in context of effective and safe COVID-19 treatment. Therefore, early diagnosing along with therapeutic intervention based on personalized drugs targeting disease-specific genes is still needed to relieve symptoms and to improve the quality of life of RA patients.

Interleukin-17A Interweaves the Skeletal and Immune Systems

The complex crosstalk between the immune and the skeletal systems plays an indispensable role in the maintenance of skeletal homeostasis. Various cytokines are involved, including interleukin (IL)-17A. A variety of immune and inflammatory cells produces IL-17A, especially Th17 cells, a subtype of CD4⁺ T cells. IL-17A orchestrates diverse inflammatory and immune processes. IL-17A induces direct and indirect effects on osteoclasts. The dual role of IL-17A on osteoclasts partly depends on its concentrations and interactions with other factors. Interestingly, IL-17A exerts a dual role in osteoblasts in vitro. IL-17A is a bone-destroying cytokine in numerous immune-mediated bone diseases including postmenopausal osteoporosis (PMOP), rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondylarthritis (axSpA). This review will summarize and discuss the pathophysiological roles of IL-17A on the skeletal system and its potential strategies for application in immune-mediated bone diseases.

Genetics and the axial spondyloarthritis spectrum

The axial SpAs (axSpAs) are clearly clinically a heterogeneous set of diseases with markedly varying extra-articular features. These diseases are all highly heritable and have overlapping but differing genetic origins. Shared features include association with HLA class I alleles and genes of the IL-23 pathway, among other things. Significant differences do exist however, both in the genetic loci involved and at specific loci in the individual genetic variants associated with each disease. These similarities and differences are of great interest in regards to disease pathogenesis and treatment development, although individually they are too small in effect to be of prognostic or diagnostic value. Polygenic risk scores, which capture a high proportion of the genetic variation between disorders, have been shown to have clinically useful discriminatory capacity in axSpA. This suggests they have the potential to enable improved disease classification, incorporating basic pathogenic features such as genomics, and ultimately benefitting clinical care. The aim of this article is to review the genetic characteristics of the spectrum of axSpAs and to discuss how this influences our understanding of the disease pathogenesis and the clinical implications of this understanding.

Efficacy and safety of secukinumab in patients with psoriatic arthritis: A meta-analysis of different dosing regimens

The appropriate dosing regimens of secukinumab for psoriatic arthritis (PsA) are not well defined. We performed a meta-analysis to evaluate the efficacy and safety of different dosing regimens of secukinumab in the treatment of PsA. A systematic search was conducted using major electronic databases to identify relevant randomized controlled trials (RCTs) comparing secukinumab 300 mg versus secukinumab 150 mg in patients with PsA. Meta-analysis was performed using Review Manager software (version 5.3). Six studies with a total of 1141 patients were included. At week 24, secukinumab 300 mg was associated with a higher American College of Rheumatology 20% response (ACR 20), ACR 50, PASI 75 response rate, and dactylitis resolution rate than secukinumab 150 mg, especially in the anti-TNF-IR subgroup. At week 52, secukinumab 300 mg was associated with a higher psoriasis area and severity index (PASI) 75 and PASI 90 response rate than secukinumab 150 mg. There was no significant difference between secukinumab 300 mg and secukinumab 150 mg in the risk of any adverse events (AEs) and serious AEs at either week 24 or week 52. Secukinumab 300 mg was significantly more effective than 150 mg, especially for patients with PsA who have failed TNF therapy, and it was well tolerated.

Understanding Refractory Rheumatoid Arthritis: Implications for a Therapeutic Approach

Refractory rheumatoid arthritis (RA) has emerged as an area of unmet need in a landscape of generally well-controlled disease. Whilst most patients are adequately treated on methotrexate and other first-line disease-modifying anti-rheumatic drugs (DMARDs), a proportion requires biologic (b) and targeted synthetic (ts) DMARDs, with a further subsection failing multiple agents. Recent observational studies have adopted working definitions of refractory RA based on number of failed DMARDs, with prevalence estimates of 6-21% depending on threshold and study population. Risk factors include treatment delay, baseline disease activity and function, female gender, smoking, obesity and lower socioeconomic status. Practical and conceptual challenges in defining refractory RA arise from limitations of disease activity scores used to assess response, with attendant misclassification risk of co-existent non-inflammatory pathology, and failure to capture additional outcomes, such as fatigue, that have variable treatment response. Time is an important factor in defining refractory disease; registry studies show that growing treatment options have resulted in rapid b/tsDMARD cycling and earlier refractory status, and refractory RA is itself a dynamic concept, evolving with each new therapeutic class. Whilst the biology underpinning refractory RA remains largely unknown, a general overview of biomarker studies and clinical trials old and new offers insights into prediction of response and treatment failure. Whilst the future holds promise, current data are insufficient to personalise or meaningfully sequence b/tsDMARDs. Therefore, avoidance of a refractory course is best achieved by following proven management paradigms (e.g. early diagnosis and treat-to-target), addressing modifiable risk factors, and considering enrolment in novel trials.

Osteoporosis in Rheumatoid Arthritis: Dangerous Liaisons

Osteoporosis has been classically considered a comorbidity of rheumatoid arthritis (RA). However, recent advances in the pathogenesis of osteoporosis in RA have shown a close interplay between cells of the immune system and those involved in bone remodeling, introducing new actors into the classic route in which osteoclast activation is related to the RANK/RANKL/OPG pathway. In fact, the inflammatory state in early stages of RA, mediated by interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α has the ability to activate and differentiate osteoclasts not only through their relationship with RANKL, but also through the Wnt/DKK1/sclerostin pathway, leading to bone loss. The role of synovial fibroblasts and activated T lymphocytes in the expression of the RANKL system and its connection to bone destruction is also depicted. In addition, autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies are other pathogenic mechanisms for the development of bone erosions and systemic osteoporosis in RA, even before the onset of arthritis. The aim of this review is to unravel the relationship between different factors involved in the development of osteoporosis in RA patients, both the classic factors and the most novel, based on the relationship of autoantibodies with bone remodeling. Furthermore, we propose that bone mineral density measured by different techniques may be helpful as a biomarker of severity in early arthritis patients.

Interleukin-17 in rheumatoid arthritis: Trials and tribulations

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine with well-characterized biological effects on stromal cell activation, angiogenesis, and osteoclastogenesis. The presence of this cytokine in the inflamed joints of patients with rheumatoid arthritis (RA), together with compelling data from in vitro and experimental arthritis models demonstrating its pro-inflammatory effects, made this cytokine a strong candidate for therapeutic targeting. Clinical trials, however, have shown relatively modest success in RA as compared with other indications. Guided by recent insights in IL-17 biology, this review aims to explore possible reasons for the limited clinical efficacy of IL-17A blockade in RA, and what we can learn from these results going forward.

Efficacy and Safety of Anti-Interleukin-17A Monoclonal Antibody Secukinumab in Treatment of Ankylosing Spondylitis: A Meta-Analysis

Different signaling pathways have been studied in ankylosing spondylitis. New treatment options such as secukinumab could have an important role inhibiting the release of proinflammatory cytokine IL-17. The aim of this study was to compare the efficacy and safety of secukinumab in ankylosing spondylitis. A systematic review was conducted using MEDLINE and EMBASE databases to identify randomized clinical trials (RCTs) that assess the role of secukinumab in ankylosing spondylitis. The variables were safety (total adverse events, serious adverse events, headache, nasopharyngitis, cough, deaths, discontinuation due to adverse events, candida, neutropenia, and diarrhea) and efficacy based on quality-of-life scores (ASAS 20, ASAS 40, ASAS 5/6, ASASPR). Three RCTs (770 patients) that compare secukinumab with placebo were included in the study. There were significant differences in the quality-of-life scores in favor of the secukinumab group (p < 0.05). Regarding the adverse events, there were higher rates of any adverse events in the secukinumab group (p < 0.05). Also, the secukinumab group showed a higher rate of nasopharyngitis and diarrhea (p < 0.05). The use of secukinumab in ankylosing spondylitis increased the quality of life and had more adverse events rate compared with placebo.

Synergistic Interaction Between High Bioactive IL-17A and Joint Destruction for the Occurrence of Cardiovascular Events in Rheumatoid Arthritis

Rheumatoid arthritis (RA) remains a cause of morbidity and mortality in many patients while new treatments have changed the face of the disease. Despite the emergence of these new drugs, cardiovascular (CV) diseases remain more frequent in RA patients compared with the general population. However, predictive biomarkers of RA severity and precise guidelines to manage the CV risk in these patients are still lacking. Pro-inflammatory cytokines contribute both to RA and CV pathogenesis. Focusing on IL-17A, high levels of bioactive IL-17A were associated with destruction in RA but also during myocardial infarction. The study aimed to assess the relationship between bioactive IL-17A, destruction and the occurrence of CV events (CVE) in RA patients with a very long follow-up. Thirty-six RA patients were followed between 1970 and 2012 in Lyon, France. They were tested for bioactive IL-17A and clinical and biological characteristics were recorded at baseline. Then, the occurrence of CVE was registered during the follow-up. To study the bioactive fraction of IL-17A, the bioassay used the ability of human umbilical vein endothelial cells to produce IL-8 in presence of RA plasma samples with or without an anti-IL-17A antibody. Bioactive IL-17A level at baseline was higher in RA patients who later experienced a CVE compared to those without (0.77 vs 0.21 ng/ml, p-value = 0.0095, Mann-Whitney test) and synergized with joint destruction (p-value = 0.020, Kruskal-Wallis test). Through its effects on vessels and thrombosis, high levels of bioactive IL-17A could represent a long-term marker of CV risk.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Efficacy of pharmacological treatment in rheumatoid arthritis: a systematic literature research informing the 2019 update of the EULAR recommendations for management of rheumatoid arthritis

OBJECTIVES

To inform the 2019 update of the European League against Rheumatism (EULAR) recommendations for the management of rheumatoid arthritis (RA).

METHODS

A systematic literature research (SLR) to investigate the efficacy of any disease-modifying antirheumatic drug (DMARD) (conventional synthetic (cs)DMARD, biological (b) and biosimilar DMARD, targeted synthetic (ts)DMARD) or glucocorticoid (GC) therapy in patients with RA was done by searching MEDLINE, Embase and the Cochrane Library for articles published between 2016 and 8 March 2019.

RESULTS

234 abstracts were selected for detailed assessment, with 136 finally included. They comprised the efficacy of bDMARDs versus placebo or other bDMARDs, efficacy of Janus kinase (JAK) inhibitors (JAKi) across different patient populations and head-to-head of different bDMARDs versus JAKi or other bDMARDs. Switching of bDMARDs to other bDMARDs or tsDMARDs, strategic trials and tapering studies of bDMARDs, csDMARDs and JAKi were assessed. The drugs evaluated included abatacept, adalimumab, ABT-122, baricitinib, certolizumab pegol, SBI-087, CNTO6785, decernotinib, etanercept, filgotinib, golimumab, GCs, GS-9876, guselkumab, hydroxychloroquine, infliximab, leflunomide, mavrilimumab, methotrexate, olokizumab, otilimab, peficitinib, rituximab, sarilumab, salazopyrine, secukinumab, sirukumab, tacrolimus, tocilizumab, tofacitinib, tregalizumab, upadacitinib, ustekinumab and vobarilizumab. The efficacy of many bDMARDs and tsDMARDs was shown. Switching to another tumour necrosis factor inhibitor (TNFi) or non-TNFi bDMARDs after TNFi treatment failure is efficacious. Tapering of DMARDs is possible in patients achieving long-standing stringent clinical remission; in patients with residual disease activity (including patients in LDA) the risk of flares is increased during the tapering. Biosimilars are non-inferior to their reference products.

CONCLUSION

This SLR informed the task force regarding the evidence base of various therapeutic regimen for the development of the update of EULAR's RA management recommendation.

Risk for development of inflammatory bowel disease under inhibition of interleukin 17: A systematic review and meta-analysis

Objective

Cases of inflammatory bowel disease (IBD) during treatment with interleukin (IL)-17 antagonists have been reported from trials in psoriasis, psoriatic arthritis, and ankylosing spondylitis. The aim of this study was to assess the overall risk for development of IBD due to IL-17 inhibition.

Design

Systematic review and meta-analysis of studies conducted 2010–2018 of treatment with IL-17 antagonists in patients with psoriasis, psoriatic arthritis, ankylosing spondylitis, and rheumatoid arthritis. We compared risk of IBD development in anti-IL-17 treated patients compared to placebo treatments. We also computed incident rates of IBD overall. A ‘worst case scenario’ defining subjects ambiguous for prevalent versus incident cases for the latter was also applied.

Results

Sixty-six studies of 14,390 patients exposed to induction and 19,380 patients exposed to induction and/or maintenance treatment were included. During induction, 11 incident cases of IBD were reported, whereas 33 cases were diagnosed during the entire treatment period. There was no difference in the pooled risk of new-onset IBD during induction studies for both the best-case [risk difference (RD) 0.0001 (95% CI: -0.0011, 0.0013)] and worst-case scenario [RD 0.0008 (95% CI: -0.0005, 0.0022)]. The risk of IBD was not different from placebo when including data from maintenance and long-term extension studies [RD 0.0007 (95% CI: -0.0023, 0.0036) and RD 0.0022 (95% CI: -0.0010, 0.0055), respectively].

Conclusions

The risk for development of IBD in patients treated with IL-17 antagonists is not elevated. Prospective surveillance of patients treated with IL-17 antagonists with symptom and biomarker assessments is warranted to assess for onset of IBD in these patients.

Interleukin 17A and IL-17F Expression and Functional Responses in Rheumatoid Arthritis and Peripheral Spondyloarthritis

OBJECTIVE

Targeting the interleukin 17 (IL-17) axis is efficacious in psoriasis and spondyloarthritis (SpA), but not in rheumatoid arthritis (RA). We investigated potential differences in tissue expression and function of IL-17A and IL-17F in these conditions.

METHODS

mRNA expression of cytokines and their receptors was assessed by quantitative PCR in psoriasis skin samples, in SpA and RA synovial tissue (ST) samples and in fibroblast-like synoviocytes (FLS). Cytokines were measured in synovial fluid (SF) and FLS supernatants by ELISA. FLS were stimulated with IL-17A or IL-17F cytokines supplemented with tumor necrosis factor (TNF), or with pooled SF from patients with SpA or RA.

RESULTS

Levels of IL-17A (P = 0.031) and IL-17F (P = 0.017) mRNA were lower in psoriatic arthritis ST compared to paired psoriasis skin samples. The level of IL-17A mRNA was 2.7-fold lower than that of IL-17F in skin (P = 0.0078), but 17.3-fold higher in ST (P < 0.0001). In SF, the level of IL-17A protein was 37.4-fold higher than that of IL-17F [median 292.4 (IQR 81.4-464.2) vs median 7.8 (IQR 7.7-8.7) pg/mL; P < 0.0001]. IL-17A and IL-17F mRNA and protein levels did not differ in SpA compared to RA synovitis samples, and neither were the IL-17 receptors IL-17RA and IL-17RC, or the TNF receptors TNFR1 and TNR2, differentially expressed between SpA and RA ST, nor between SpA and RA FLS. SpA and RA FLS produced similar amounts of IL-6 and IL-8 protein upon stimulation with IL-17A or IL-17F cytokines, supplemented with 1 ng/ml TNF. Pooled SpA or RA SF samples similarly enhanced the inflammatory response to IL-17A and IL-17F simulation in FLS.

CONCLUSION

The IL-17A/IL-17F expression ratio is higher in SpA synovitis compared to psoriasis skin. Expression of IL-17A and IL-17F, and the functional response to these cytokines, appear to be similar in SpA and RA synovitis.

Synovial Tissue Inflammation Mediated by Autoimmune T Cells

In rheumatoid arthritis (RA), various hematopoietic and non-hematopoietic cells present in the synovial tissue secrete numerous inflammatory mediators including pro-inflammatory cytokines critical for the induction of chronic joint inflammation and bone destruction. Fibroblast-like synoviocytes (FLSs) in the non-hematopoietic cell compartment are key inflammatory cells activated in inflamed joints and driving the disease; yet how synovial tissue inflammation is modulated by autoimmune T cells is not fully understood. In this review, mainly based on recent findings with a mouse model of spontaneous autoimmune arthritis, we discuss the mechanism of Th17-mediated synovial tissue inflammation; that is, what environmental stimuli and arthritogenic self-antigens trigger arthritis, how arthritogenic T cells initiate joint inflammation by stimulating FLSs, and how the cellular sources of GM-CSF from lymphoid and tissue stromal cells in the synovium contribute to the development of arthritis. We also highlight possible plasticity of Th17 cells toward pathogenic GM-CSF producers, and the functional instability of regulatory T cells under inflammatory conditions in RA joints.

Systematic review with meta-analysis: risk of new onset IBD with the use of anti-interleukin-17 agents

BACKGROUND

New onset IBD has been reported with the use of anti-IL-17 agents, but it remains unclear to what extent this is attributed to treatment or to underlying disease.

AIM

To evaluate the risk of new onset IBD with the use of anti-IL-17 agents METHODS: Electronic databases were searched for randomised controlled trials (RCT) of anti-IL-17 agents (brodalumab, ixekizumab and secukinumab). Risk of new onset IBD was compared to placebo by Mantel-Haenszel (MH) risk difference (RD). Sensitivity analyses including meta-analysis using fixed-effect model, MH and Peto odds ratio and MH risk ratio were performed due to incidence of rare adverse events. The risk of diarrhoea was also assessed due to the possibility of underdiagnosis of IBD.

RESULTS

Thirty-eight RCTs including 16 690 patients treated with anti-IL-17 agents were included. Twelve cases of new onset IBD were reported with anti-IL-17 agents in five studies, whereas no cases were reported with placebo. There was no difference in the risk of developing new onset IBD with anti-IL-17 agents compared to placebo (MH RD 0.00062, 95% CI -0.00072-0.0021, P = 0.35). Sensitivity analyses demonstrated no consistent risk with any method. There was no difference in the risk of diarrhoea (MH RD 0.0013, 95% CI -0.0014-0.0041, P = 0.34).

CONCLUSIONS

New onset IBD with the use of anti-IL-17 agents was rare. Interpretation of the results needs caution due to the presence of many zero-event studies.

Efficacy and safety of bimekizumab as add-on therapy for rheumatoid arthritis in patients with inadequate response to certolizumab pegol: a proof-of-concept study

OBJECTIVE

Evaluate the efficacy and safety of dual neutralisation of interleukin (IL)-17A and IL-17F with bimekizumab, a monoclonal IgG1 antibody, in addition to certolizumab pegol (CZP) in patients with rheumatoid arthritis (RA) and inadequate response (IR) to certolizumab pegol.

METHODS

During this phase 2a, double-blind, proof-of-concept (PoC) study (NCT02430909), patients with moderate-to-severe RA received open-label CZP 400 mg at Weeks 0, 2 and 4, and 200 mg at Week 6. Patients with IR at Week 8 (Disease Activity Score 28-joint count C-reactive protein (DAS28(CRP))>3.2) were randomised 2:1 to CZP (200 mg every 2 weeks (Q2W)) plus bimekizumab (240 mg loading dose then 120 mg Q2W) or CZP plus placebo. The primary efficacy and safety variables were change in DAS28(CRP) between Weeks 8 and 20 and incidence of treatment-emergent adverse events (TEAEs).

RESULTS

Of 159 patients enrolled, 79 had IR at Week 8 and were randomised to CZP plus bimekizumab (n=52) or CZP plus placebo (n=27). At Week 20, there was a greater reduction in DAS28(CRP) in the CZP-IR plus bimekizumab group compared with the CZP-IR plus placebo group (99.4% posterior probability). The most frequent TEAEs were infections and infestations (CZP plus bimekizumab, 50.0% (26/52); CZP plus placebo, 22.2% (6/27)).

CONCLUSIONS

PoC was confirmed based on the rapid decrease in disease activity achieved with 12 weeks of CZP plus bimekizumab. No unexpected or new safety signals were identified when neutralising IL-17A and IL-17F in patients with RA concomitantly treated with CZP, but the rate of TEAEs was higher with dual inhibition.

Meta-analysis of IL-17 inhibitors in two populations of rheumatoid arthritis patients: biologic-naïve or tumor necrosis factor inhibitor inadequate responders

OBJECTIVES

To evaluate the efficacy and safety of interleukin 17 (IL-17) inhibitors in two rheumatoid arthritis (RA) populations: biologic-naïve or tumor necrosis factor inhibitor inadequate responders (TNF-IR).

METHOD

A systematic search was performed in major electronic databases to identify relevant randomized controlled trials (RCTs) reporting the American College of Rheumatology 20% (ACR20), ACR50, ACR70 responses and adverse events (AEs) of IL-17 inhibitors versus placebo in patients with RA. We divided these patients into two subgroups: biologic-naïve or TNF-IR. The meta-analysis was performed using Review Manager 5.3 software. Results were expressed as risk ratio (RR) with pertinent 95% confidence interval (95% CI).

RESULTS

Ten studies with a total of 2499 patients were included. For biologic-naïve patients, ACR50 and ACR70 responses were significantly better with IL-17 inhibitors than placebo (RR = 1.71, 95% CI 1.23-2.38, P = 0.001 and RR = 2.63, 95% CI 1.10-6.25, P = 0.03, respectively), but ACR20 responses for IL-17 inhibitors were not statistically superior to placebo (RR = 1.34, 95% CI 0.94-1.91, P = 0.11). For TNF-IR, IL-17 inhibitors were effective in achieving ACR20 (RR = 1.67, 95% CI 1.40-2.00, P < 0.00001), ACR50 (RR = 1.94, 95% CI 1.43-2.63, P < 0.0001), and ACR70 (RR = 2.11, 95% CI 1.26-3.55, P = 0.005) compared to placebo. In the safety analysis, IL-17 inhibitors did not show increased risk of any AEs by comparing to placebo in both biologic-naïve patients and TNF-IR.

CONCLUSION

IL-17 inhibitors were effective in the treatment of RA without increased risk of AEs, whether for biologic-naïve patients or TNF-IR. Key Points • In this meta-analysis comparing IL-17 inhibitors with placebo in 2499 rheumatoid arthritis patients, IL-17 inhibitors improved ACR50 and ACR70, but not ACR20, responses in biologic-naïve patients. • IL-17 inhibitors improved ACR20, ACR50, and ACR70 responses in tumor necrosis factor inhibitor inadequate responders.

Efficacy and safety of secukinumab in active rheumatoid arthritis with an inadequate response to tumor necrosis factor inhibitors: a meta-analysis of phase III randomized controlled trials

OBJECTIVES

To address the efficacy and safety of secukinumab in comparison with placebo in active rheumatoid arthritis (RA) patients who had an inadequate response to tumor necrosis factor (TNF) inhibitors.

METHODS

Databases of PubMed, Embase, and Web of Science were searched to identify the relevant randomized controlled trials (RCTs). Risk ratio (RR) and 95% confidence interval (95% CI) were calculated with the Mantel-Haenszel random effects method. Statistical heterogeneity was assessed using the Cochran Q and I² tests.

RESULTS

A total of 1292 patients from three phase III RCT studies were included. Compared with placebo, secukinumab 150 mg was superior at 24 weeks in terms of ACR20 with RR (1.66, 95% CI 1.33, 2.08; P < 0.0001; I² = 0%), ACR50 (1.88, 95% CI 1.29, 2.72; P = 0.0009; I² = 0%), and ACR70 (2.15, 95% CI 1.15, 4.02; P = 0.02; I² = 0%). Consistent effects were also observed in pooled group of 150 mg and 75 mg secukinumab. For secukinumab 75 mg alone, ACR20 response rate was significantly higher compared with placebo (RR 1.62, 95% CI 1.29, 2.03; P < 0.00001; I² = 0%). Although ACR50 and ACR70 response rates showed a favorable trend to be higher, no statistical difference was observed (RR 1.68, 95% CI 0.99, 2.85, P = 0.05, I² = 47%; RR 1.81, 95% CI 0.78, 4.21, P = 0.17, I² = 34%, respectively). Compared with the placebo group, there was no increased risk of adverse effects (AEs) and serious AEs at 16 weeks in the pooled secukinumab group.

CONCLUSIONS

In active RA patients with an inadequate response to TNF inhibitors, secukinumab may be a therapeutic option. Secukinumab 150 mg showed significantly better clinical efficacy with no increased risk of AEs and serious AEs compared with placebo.

TRIAL REGISTRATION

Clinical Trials.gov identifier: NCT01770379, NCT01350804, NCT01377012 Key Points • Secukinumab 150 mg showed significantly better clinical efficacy in active RA patients with an inadequate response to TNF inhibitors. • No increased risk of AEs and serious AEs in secukinumab group compared with placebo.

Incidence rates of inflammatory bowel disease in patients with psoriasis, psoriatic arthritis and ankylosing spondylitis treated with secukinumab: a retrospective analysis of pooled data from 21 clinical trials

OBJECTIVES

Here, we present the reported incidence rates of inflammatory bowel disease (IBD) in patients receiving treatment with secukinumab for psoriasis (PsO), psoriatic arthritis (PsA) or ankylosing spondylitis (AS), in a pooled analysis of 21 clinical trials.

METHODS

Data from all patients who had received at least one dose of secukinumab were included. Safety analyses were conducted to evaluate cumulative IBD rates as well as per-year rates, by indication. Crohn's disease (CD), ulcerative colitis (UC) and IBD unclassified (IBDU) events were analysed using exposure-adjusted incidence rates (patient incidence rates per 100 patient-years (PY)).

RESULTS

A total of 7355 patients with a cumulative exposure of 16 226.9 PY were included in the pooled analysis. Among 5181 patients with PsO, there were 14 cases of UC, 5 cases of CD and 1 case of IBDU, with exposure adjusted incidence rates (EAIRs) of 0.13, 0.05 and 0.01, respectively. Of these 20 cases, 14 were new-onset. In 1380 patients with PsA, there were 3 cases of UC, 3 cases of CD and 2 cases of IBDU (EAIRs 0.08, 0.08 and 0.05); 7 of these represented new-onset cases. Among 794 patients with AS, there were 4 cases of UC, 8 cases of CD and 1 case of IBDU (EAIRs 0.2, 0.4 and 0.1); 9 were new-onset cases. In the per year analysis, the EAIRs for each indication did not increase over time with secukinumab treatment.

CONCLUSIONS

In this pooled secukinumab safety analysis of 7355 patients across 21 clinical trials, cases of IBD events (including CD, UC and IBDU) were uncommon.

The pathogenicity of Th17 cells in autoimmune diseases

IL-17-producing T helper (Th17) cells have been implicated in the pathogenesis of many inflammatory and autoimmune diseases. Targeting the effector cytokines IL-17 and GM-CSF secreted by autoimmune Th17 cells has been shown to be effective for the treatment of the diseases. Understanding a molecular basis of Th17 differentiation and effector functions is therefore critical for the regulation of the pathogenicity of tissue Th17 cells in chronic inflammation. Here, we discuss the roles of proinflammatory cytokines and environmental stimuli in the control of Th17 differentiation and chronic tissue inflammation by pathogenic Th17 cells in humans and in mouse models of autoimmune diseases. We also highlight recent advances in the regulation of pathogenic Th17 cells by gut microbiota and immunometabolism in autoimmune arthritis.