Targeting the interleukin-23/17 axis in axial spondyloarthritis

Innovate therapeutic targets for autoimmune diseases: insights from proteome-wide mendelian randomization and Bayesian colocalization

BACKGROUND

Despite growing knowledge regarding the pathogenesis of autoimmune diseases (ADs) onset, the current treatment remains unsatisfactory. This study aimed to identify innovative therapeutic targets for ADs through various analytical approaches.

RESEARCH DESIGN AND METHODS

Utilizing Mendelian randomization, Bayesian co-localization, phenotype scanning, and protein-protein interaction network, we explored potential therapeutic targets for 14 ADs and externally validated our preliminary findings.

RESULTS

This study identified 12 circulating proteins as potential therapeutic targets for six ADs. Specifically, IL12B was judged to be a risk factor for ankylosing spondylitis (p = 1.61E - 07). TYMP (p = 6.28E - 06) was identified as a protective factor for ulcerative colitis. For Crohn's disease, ERAP2 (p = 4.47E - 14), HP (p = 2.08E - 05), and RSPO3 (p = 6.52E - 07), were identified as facilitators, whereas FLRT3 (p = 3.42E - 07) had a protective effect. In rheumatoid arthritis, SWAP70 (p = 3.26E - 10), SIGLEC6 (p = 2.47E - 05), ISG15 (p = 3.69E - 05), and FCRL3 (p = 1.10E - 10) were identified as risk factors. B4GALT1 (p = 6.59E - 05) was associated with a lower risk of Type 1 diabetes (T1D). Interestingly, CTSH was identified as a protective factor for narcolepsy (p = 1.58E - 09) but a risk factor for T1D (p = 7.36E - 11), respectively. External validation supported the associations of eight of these proteins with three ADs.

CONCLUSIONS

Our integrated study identified 12 potential therapeutic targets for ADs and provided novel insights into future drug development for ADs.

Causal relationship between gut microbiota and ankylosing spondylitis and potential mediating role of inflammatory cytokines: A mendelian randomization study

Associations between gut microbiota and ankylosing spondylitis have been discovered in previous studies, but whether these associations reflect a causal relationship remains inconclusive. Aiming to reveal the bidirectional causal associations between gut microbiota and ankylosing spondylitis, we utilized publicly available genome wide association study summary data for 211 gut microbiota (GM) taxa and ankylosing spondylitis (AS) to conduct two sample mendelian randomization analyses. Mediation analysis was performed to explore mediating inflammatory cytokines. We found that genetically predicted higher abundance of Lactobacillaceae family, Rikenellaceae family and Howardella genus had suggestive associations with decreased risk of ankylosing spondylitis while genetic proxied higher abundance of Actinobacteria class and Ruminococcaceae_NK4A214_group genus was associated with increased risk of ankylosing spondylitis. IL23 and IFN-γ were potential mediating cytokines for GM dysbiosis, especially for Actinobacteria class, leading to AS. Our study provided a new exploration direction for the treatment of AS. Lactobacillaceae family, Rikenellaceae family, Howardella genus, Actinobacteria class and Ruminococcaceae_NK4A214_group genus are expected to become new therapeutic targets and monitoring indicators for AS.

Research progress on the clinical application and mechanism of iguratimod in the treatment of autoimmune diseases and rheumatic diseases

Autoimmune diseases are affected by complex pathophysiology involving multiple cell types, cytokines, antibodies and mimicking factors. Different drugs are used to improve these autoimmune responses, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antibodies, and small molecule drugs (DMARDs), which are prevalent clinically in the treatment of rheumatoid arthritis (RA), etc. However, low cost-effectiveness, reduced efficacy, adverse effects, and patient non-response are unattractive factors driving the development of new drugs such as iguratimod. As a new disease-modifying antirheumatic drug, iguratimod has pharmacological activities such as regulating autoimmune disorders, inflammatory cytokines, regulating immune cell activation, differentiation and proliferation, improving bone metabolism, and inhibiting fibrosis. In recent years, clinical studies have found that iguratimod is effective in the treatment of RA, SLE, IGG4-RD, Sjogren 's syndrome, ankylosing spondylitis, interstitial lung disease, and other autoimmune diseases and rheumatic diseases. The amount of basic and clinical research on other autoimmune diseases is also increasing. Therefore, this review systematically reviews the latest relevant literature in recent years, reviews the research results in recent years, and summarizes the research progress of iguratimod in the treatment of related diseases. This review highlights the role of iguratimod in the protection of autoimmune and rheumatic bone and related immune diseases. It is believed that iguratimod's unique mode of action and its favorable patient response compared to other DMARDs make it a suitable antirheumatic and bone protective agent in the future.

Randomized double-blinded controlled trial on the effect of synbiotic supplementation on IL-17/IL-23 pathway and disease activity in patients with axial spondyloarthritis

BACKGROUND

Interleukin 17 (IL17)-expressing CD4⁺ T cells and IL-17/IL-23 pathway play a key role in the pathogenesis of axial spondyloarthritis (axSpA). Synbiotics have been suggested due to their immunomodulatory effects in the treatment of autoimmune diseases. This randomized double-blind, placebo-controlled trial was designed to assess the effects of synbiotic supplement on IL-17/IL-23 pathway and disease activity in patients with axSpA.

METHODS

Forty-eight axSpA patients were randomly allocated to use one synbiotic capsule or placebo daily for 12 weeks. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and ASAS-endorsed disease activity score-C-reactive protein (ASDAS-CRP). The secondary outcome was proportion of IL17-expressing CD4+ T cells, IL-17 and IL-23 gene expression, and supernatant levels of IL-17 and IL-23, which were measured at the baseline and end of the trial.

RESULTS

A total of 48 patients were randomized into the synbiotic and placebo groups. Thirty-eight patients completed the study. Synbiotic supplementation significantly reduced the proportion of IL17-expressing CD4⁺ T cells (4.88 ± 2.47 vs. 2.16 ± 1.25), gene expression of IL-17 (1.03 ± 0.24 vs. 0.65 ± 0.26) and IL-23 (1.01 ± 0.13 vs. 0.68 ± 0.24) and serum IL-17 (38.22 ± 14.40 vs. 24.38 ± 11.68) and IL-23 (51.77 ± 17.40 vs. 32.16 ± 12.46) compared with baseline. Significant differences between groups were noticed only in the proportion of IL17-expressing CD4⁺ T cells, and IL-17 and IL-23 gene expression. Synbiotic supplementation did not significantly alter BASDAI and ASDAS-CRP compared with baseline and placebo group at the end of trial.

CONCLUSION

Present study indicated beneficial effect of synbiotic supplement on IL-17/IL-23 pathway without improving disease activity in axSpApatients.HighlightsSynbiotic supplementation reduced IL17-expressing CD4⁺ T cells proportion in axSpA.Synbiotic supplementation decreased IL-17 and IL-23 gene expression in axSpA.Synbiotic supplementation did not change disease activity score in axSpA.

Current and emerging biologic and small molecule systemic treatment options for psoriasis and psoriatic arthritis

Psoriasis and psoriatic arthritis are chronic inflammatory diseases affecting the skin and joints, respectively. Psoriasis and psoriatic arthritis are associated with a high comorbidity burden as well as negative impact on quality of life. Impact on health-related quality of life is optimized when both skin and joint manifestations are effectively treated. The identification of key cytokines involved in disease pathogenesis has led to the development of several therapeutic options for psoriatic disease. When selecting a therapy, it is important to consider disease severity, psoriasis disease subtypes or domains of psoriatic arthritis, comorbidities, patient preference for treatment, among other factors. This review summarizes current biologic and small molecule treatment options as well as emerging therapies for moderate-to-severe adult plaque psoriasis and psoriatic arthritis.

Effectiveness and safety of secukinumab in axial spondyloarthritis: a 24-month prospective, multicenter real-life study

Objectives:

To evaluate, in a multicentric Italian cohort of axial spondyloarthritis (axSpA) patients on Secukinumab (SEC) followed for 24 months: (1) the long-term effectiveness and safety of SEC; (2) the drug retention rate and low disease activity (LDA) measured as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) < 4/Ankylosing Spondylitis Disease Activity Score (ASDAS) < 2.1 and very low disease activity (VLDA) measured as BASDAI < 2/ASDAS < 1.3; (3) any differences in outcomes according to line of biological treatment (naïve/non-naïve), gender (male/female), subtype of axSpA [radiographic axSpA (r-axSpA)/non-radiographic axSpA (nr-axSpA)].

Methods:

Consecutive axSpA patients treated with SEC were evaluated prospectively. Disease characteristics, previous/ongoing treatments, comorbidities, and follow-up duration were collected. Disease activity/functional/clinimetric scores and biochemical-values were recorded at baseline (T0), 6 (T6), 12 (T12), and 24 (T24) months. Effectiveness was evaluated over-time with descriptive statistics; multivariate Cox and logistic regression models were used to evaluate predictors of drug discontinuation and LDA at T6. Infections and adverse events were recorded.

Results:

A total 249 patients (47.8% male; median age 51) were enrolled; 40.9% had HLA-B27; 53.8% had r-axSpA, and 46.2% nr-axSpA. SEC was prescribed in 28.9% naïve and in 71.1% non-naïve patients. SEC effectiveness was shown as an improvement in several outcomes, such as ASDAS [T0 = 3.5 (2.9–4.4) versus T24 = 1.9 (1.2–2.4); p = 0.02] and BASDAI [T0 = 6.5 (5.0–7.5) versus T24 = 2.8 (1.8–4.0); p = 0.03]. At T24, naïve patients showed better physical functioning and lower disease activity than non-naïve. After 24 months of treatment, 90.7% of naïve and 75.3% of non-naïve patients achieved LDA (BASDAI < 4). Treatment was discontinued in 24.5% patients, mainly due to primary/secondary loss of effectiveness, and in 6.8% due to adverse events. Retention rate at T24 was 75% in the whole population, with some difference depending on gender ( p = 0.002).

Conclusion:

In a real-life clinical setting, SEC proved to be safe and effective in axSpA, mainly in naïve-patients, with a notable drug retention rate. No differences were observed between r-axSpA and nr-axSpA.

Interleukin 27 is a novel cytokine with anti-inflammatory effects against spondyloarthritis through the suppression of Th17 responses

Introduction

Spondylarthritis (SpA) development in HLA-B27/human β2-microglobulin transgenic rat (B27-rat) is correlated with altered conventional dendritic cell (cDC) function that promotes an inflammatory pattern of CD4+T cells, including a biased expansion of pro-inflammatory Th₁₇ population and imbalance of regulatory T cells cytokine profile. Transcriptomic analysis revealed that cDCs from B27-rats under express IL-27, an anti-inflammatory cytokine which induces the differentiation of IL-10⁺ regulatory T cells and inhibits Th₁₇ cells.

Methods

Here, we first investigated whether in vitro addition of exogenous IL-27 could reverse the inflammatory pattern observed in CD4⁺ T cells. Next, we performed preclinical assay using IL-27 to investigate whether in vivo treatment could prevent SpA development in B27-rats.

Results

in vitro addition of IL-27 to cocultures of cDCs and CD4⁺ T cell subsets from B27-rats reduced IL-17 and enhanced IL-10 production by T cells. Likewise, IL-27 inhibited the production of IL-17 by CD4⁺ T cells from SpA patients. Interestingly, in vivo treatment with recombinant IL-27 starting before SpA onset, inhibited SpA development in B27-rats through the suppression of IL-17/TNF producing CD4⁺ T cells.

Discussion

Overall, our results reveal a potent inhibitory effect of IL-27 and highlight this cytokine as a promising new therapeutic target in SpA, especially for SpA patients non responders to currently approved biotherapies.

Update on Axial Spondyloarthritis

Understanding of the spondyloarthritis diseases has changed significantly in the last 15 years. It is now clear that there are patients with and without radiographic changes and the terminology has changed to reflect that: radiographic axial spondyloarthritis and non-radiographic axial spondyloarthritis. In addition, the importance of the presence of inflammatory back pain with spondyloarthritis in making the diagnosis is now well established. It is also clear that women are much more likely to develop axial spondyloarthritis than previously thought. Finally, there are treatments now available to treat axial spondyloarthritis and more hopefully to be approved in the next year.

New developments in ankylosing spondylitis-status in 2021

Axial SpA (axSpA) is a common rheumatic disease characterized by inflammation leading to bone formation and functional impairment. TNF-α and IL-17 represent established targets in axSpA. TNF-α and IL-17 inhibitors have demonstrated efficacy in clinical trials and are currently approved biologic DMARDs for all subsets of the disease. Several lines of evidence implicate a role of an IL-23–IL-17 axis in the disease pathogenesis. In this light, and given the success of IL-17 blockade in axSpA, a similar good response to IL-23 was anticipated. Nevertheless, two clinical trials of anti-IL-23 monoclonal antibodies in axSpA have clearly exhibited negative results. This failure has raised theories for a degree of IL-23 independent pathway. The Janus kinase (JAK) pathway is also a potential therapeutic target, since several cytokines, including those involved in the IL-23–IL-17 axis, signal through the JAK family of tyrosine kinases. Further studies and more extended evaluation of response to cytokine inhibition across different tissues will be required to improve our understanding of SpA pathogenesis and determine its optimal management.

IL-23 and axial disease: do they come together?

IL-23 is a key cytokine in the pathogenesis of spondyloarthritides, including PsA and axial spondyloarthritis, as well as related conditions, such as psoriasis and IBD. Genetic associations, animal models and translational studies in humans demonstrate the key role played by IL-23, especially when coupled with downstream overexpression of IL-17 via stimulation of T helper 17 (Th17) and other cells by IL-23. Whereas IL-23 inhibition has shown clear-cut benefit in psoriasis and peripheral manifestations of PsA, trials of IL-23 inhibitors have failed in the treatment of ankylosing spondylitis. More recently, exploratory data from PsA patients with axial symptoms suggests that improvement may occur, but needs confirmation in dedicated axial spondyloarthritis (axSpA) trials. Hypotheses for these apparently conflicting findings about IL-23 inhibition in various forms of spondylitis are discussed.

Ultrasound-Verified Peripheral Arthritis in Patients with HLA-B*35 Positive Spondyloarthritis

Background: We aimed to investigate possible association between the HLA-B*35 allele and peripheral arthritis, tenosynovitis and enthesitis. Methods: Ultrasound of peripheral joints and tendons was performed in 72 HLA-B*35 positive patients with preliminary diagnosis of undifferentiated axial form of spondyloarthitis and joint and tendon pain. Patients with other known types of axial and peripheral spondyloarthritis were excluded as well as patients with other known types of arthritis. Results: Pathological changes were found in the joints of 33 (46%) patients and on the tendons in 13 (18%) patients. The most common ultrasound findings were joint effusion and synovial proliferation with positive power Doppler signal grade 1. The most common ultrasound finding in patients with painful tendons was tenosynovitis. A higher disease activity and an increased incidence of elevated CRP (≥5 mg/L) were more often observed in the group with positive ultrasound findings. Conclusion: In this study, we showed that the HLA-B*35 allele could be a potential risk factor for developing peripheral arthritis, but not for tenosynovits and enthesitis in patients with the undifferentiated axial form of spondyloarthritis. This result may influence the follow up of these patients, especially since it gives us an opportunity to consider the use of different types of DMARDs in the treatment of these patients.

Efficacy and safety of brodalumab, an anti-IL17RA monoclonal antibody, in patients with axial spondyloarthritis: 16-week results from a randomised, placebo-controlled, phase 3 trial

Objective

To investigate the efficacy and safety of brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, in patients with axial spondyloarthritis (axSpA).

Methods

In a multicentre, placebo-controlled phase 3 study (NCT02985983) conducted at 48 sites across Japan, Korea and Taiwan, patients with axSpA were randomised 1:1 to receive subcutaneous brodalumab 210 mg (n=80) or placebo (n=79) at baseline, weeks 1 and 2 and every 2 weeks thereafter, during the 16-week double-blind period. The primary endpoint was the proportion of patients with Assessment of SpondyloArthritis International Society (ASAS) 40 response at week 16. Secondary endpoints included the proportion of patients with ASAS 20 response and change in Ankylosing Spondylitis Disease Activity Score using C-reactive protein (ASDAS-CRP) at week 16 and safety.

Results

ASAS 40 response rate (n/N; 95% CI) was 43.8% (35/80; 32.7, 55.3) with brodalumab vs 24.1% (19/79; 15.1, 35.0) with placebo (rate difference, 19.7% (5.3, 34.1); p=0.018 by stratified Cochran-Mantel-Haenszel test). ASAS 20 response rate (n/N; 95% CI) was 67.5% (54/80; 56.1, 77.6) vs 41.8% (33/79; 30.8, 53.4) and least squares mean change (95% CI) from baseline (brodalumab, 2.660; placebo, 2.716) in ASDAS-CRP was –1.127 (–1.322, –0.931) with brodalumab vs –0.672 (–0.872, –0.473) with placebo at week 16. Treatment-emergent adverse events were reported in 44 (55%) and 45 (57%) patients in the brodalumab and placebo groups, respectively.

Conclusion

Brodalumab demonstrated a significant improvement at week 16 in patients with active axSpA. Safety of brodalumab was consistent with that reported in previous global/Japanese psoriasis studies.

Interleukin-17 and Interleukin-23: A Narrative Review of Mechanisms of Action in Psoriasis and Associated Comorbidities

Psoriasis is an immune-mediated inflammatory skin disease associated with numerous inflammatory comorbidities, including increased cardiovascular risk. The interleukin (IL)-23/IL-17 axis plays a central role in the immunopathogenesis of psoriasis and related comorbidities by acting to stimulate keratinocyte hyperproliferation and feed-forwarding circuits of perpetual T cell-mediated inflammation. IL-17 plays an important role in the downstream portion of the psoriatic inflammatory cascade. This review discusses the distinct mechanisms of action of IL-17 and IL-23 in the immunopathogenesis of psoriasis and related comorbidities plus the significant therapeutic benefits of selectively inhibiting these cytokines in patients with moderate to severe plaque psoriasis.

Efficacy and safety of interleukin-17 inhibitors in the treatment of chronic rheumatic diseases: A combined and updated meta-analysis

WHAT IS KNOWN AND OBJECTIVE

To assess the efficacy and safety of interleukin-17 inhibitors (ixekizumab, secukinumab, bimekizumab, netakimab and brodalumab) in chronic inflammatory rheumatic diseases, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA).

METHODS

A comprehensive search for randomized controlled trials (RCTs) evaluating efficacy and safety of interleukin-17 inhibitors was performed through PubMed, Embase and Cochrane Library databases. Quality assessment was performed using the Cochrane Collaboration risk of bias tool. Data were pooled using the fixed or random-effects models.

RESULTS AND DISCUSSION

Twenty RCTs were identified: of these 9 studies on patients with AS and 11 studies on patients with PsA. Concerning clinical efficacy, a pooled analysis showed interleukin-17 inhibitors had a higher response rate for the primary endpoint (p < 0.05) and secondary endpoint (p < 0.05) at the treatment endpoint for AS/PsA patients. Moreover, an increased risk of treatment-emergent adverse events and infection was found in AS patients (p < 0.05). In contrast, no increased risk of any adverse events was reported in PsA patients.

WHAT IS NEW AND CONCLUSION

In this meta-analysis, our findings found interleukin-17 inhibitors had a significant clinical benefit in the management of AS/PsA patients.

Identification of Key Modules and Hub Genes of Annulus Fibrosus in Intervertebral Disc Degeneration

Background: Intervertebral disc degeneration impairs the quality of patients lives. Even though there has been development of many therapeutic strategies, most of them remain unsatisfactory due to the limited understanding of the mechanisms that underlie the intervertebral disc degeneration. Questions/purposes: This study is meant to identify the key modules and hub genes related to the annulus fibrosus in intervertebral disc degeneration (IDD) through: (1) constructing a weighted gene co-expression network; (2) identifying key modules and hub genes; (3) verifying the relationships of key modules and hub genes with IDD; and (4) confirming the expression pattern of hub genes in clinical samples. Methods: The Gene Expression Omnibus provided 24 sets of annulus fibrosus microarray data. Differentially expressed genes between the annulus fibrosus of degenerative and non-degenerative intervertebral disc samples have gone through the Gene Ontology (GO) and pathway analysis. The construction of a gene network and classification of genes into different modules were conducted through performing Weighted Gene Co-expression Network Analysis. The identification of modules and hub genes that were most related to intervertebral disc degeneration was proceeded. In order to verify the relationships of the module and hub genes with intervertebral disc degeneration, Ingenuity Pathway Analysis was operated. Clinical samples were adopted to help verify the hub gene expression profile. Results: One thousand one hundred ninety differentially expressed genes were identified. Terms and pathways associated with intervertebral disc degeneration were presented by GO and pathway analysis. The construction of a Weighted Gene Coexpression Network was completed and clustering differentially expressed genes into four modules was also achieved. The module with the lowest P-value and the highest absolute correlation coefficient was selected and its relationship with intervertebral disc degeneration was confirmed by Ingenuity Pathway Analysis. The identification of hub genes and the confirmation of their expression profile were also realized. Conclusions: This study generated a comprehensive overview of the gene networks underlying annulus fibrosus in intervertebral disc degeneration. Clinical Relevance: Modules and hub genes identified in this study are highly associated with intervertebral disc degeneration, and may serve as potential therapeutic targets for intervertebral disc degeneration.

Achievement of Remission Endpoints with Secukinumab Over 3 Years in Active Ankylosing Spondylitis: Pooled Analysis of Two Phase 3 Studies

Introduction

Clinical remission in patients with ankylosing spondylitis (AS) has been determined using composite indices such as the AS Disease Activity Score inactive disease (ASDAS-ID), Assessment of SpondyloArthritis international Society criteria partial remission (ASAS-PR), and low Bath AS Disease Activity Index (BASDAI) scores. The objective of this exploratory analysis was to evaluate the proportion of secukinumab-treated patients with AS achieving remission defined based on the ASDAS-ID (score < 1.3), ASAS-PR or BASDAI score ≤  2.

Methods

The analysis pooled data from the MEASURE 1 and 2 studies over 3 years. The proportion of patients who achieved ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 with secukinumab was compared with placebo at week 16; results for secukinumab-treated patients were summarized through week 156. Sustainability of each criterion was assessed from week 16 to 156 using shift analysis. The association between each of these criteria and specific patient-reported outcomes (PROs), such as health-related quality of life, function, fatigue, and work impairment, was also explored.

Results

At week 16, a higher proportion of secukinumab-treated patients versus placebo achieved ASDAS-ID (17.6 vs. 3.5%), ASAS-PR (15.4 vs. 4.1%), or BASDAI ≤ 2 (22.3 vs. 6.4%) criteria (all P < 0.0001), which were sustained through 156 weeks. Shift analysis showed that the majority of secukinumab-treated patients achieving remission at week 16 maintained their status at week 156 (ASDAS-ID, 57.1%; ASAS-PR, 68.0% and BASDAI ≤ 2, 74.3%). Remission was also associated with improved PROs over 156 weeks.

Conclusions

Secukinumab-treated patients maintained ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 from week 16 up to 3 years. Patients who achieved at least one of the three responses/states, reported improvement in PROs, which suggests an association of clinical remission/ID with PROs in patients with active AS.

Trial registration

ClinicalTrials.gov: NCT01358175, NCT01863732, and NCT01649375

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-020-00269-6.

Janus Kinase inhibitors in the New Treatment Paradigms of Inflammatory Bowel Disease

This review provides guidance in the decision-making process regarding when to choose a janus kinase [JAK] inhibitor as medical treatment strategy. The focus will be on ulcerative colitis, because the only yet available JAK inhibitor, tofacitinib, has approval for use in ulcerative colitis. The guidance path will include consideration of disease activity, previous treatment, comorbidities, family planning, patient preferences, pharmacology as well as concurrent chronic inflammatory diseases or extraintestinal manifestations. The suggested guidance path illustrates our daily difficulties in the decision-making process regarding best choice for the individual patient. However if predictive biomarkers are lacking, the named criteria can be applied to any other strategy and hence provide support in daily practice.

Pharmacotherapy for juvenile spondyloarthritis: an overview of the available therapies

INTRODUCTION

Spondyloarthropathies (SpA) represent a heterogeneous group of inflammatory arthritides with autoimmune pathogenesis that can affect both adults and children with peculiar features such as enthesitis, sacroiliac joint, and axial involvement. Since juvenile onset of SpA (JSpA) is not well codified by the current juvenile idiopathic arthritis classification, studies in this field are restricted to single categories and therefore cannot be exhaustive. This review aims to report recent advances in the treatment of JSpA.

AREAS COVERED

In order to assess the available therapies for JSpA, the authors have analyzed data obtained from retrospective and prospective studies, case reports, and case series, as well as from controlled trials.

EXPERT OPINION

Given the challenging classification of JSpA, research in this field has been restricted to single subcategories. Little is known of which patients are more likely to develop axial involvement leading to severe spinal damage. Whether TNF inhibitors are capable to prevent or stop disease progression, once started, is yet to be ascertained with structural damage still a matter for research. Therefore, trials on the efficacy of TNF inhibitors in JSpA are strongly advocated since they may help to elucidate their place as a treatment option.

Toxicological considerations in the treatment of axial spondylo-arthritis

INTRODUCTION

The first-line treatment of axial spondyloarthritis (SpA) is with non-steroidal anti-inflammatory drugs (NSAIDs) and is followed by tumor necrosis factor (TNF) inhibitors (the main treatment for patients not responding to NSAIDs) or drugs targetting the IL-23/IL-17 pathway. The efficacy of disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate and sulfasalazine (SSZ) has not been demonstrated, although SSZ can be considered in patients with concomitant peripheral arthritis.

AREAS COVERED

This review describes the beneficial and toxicological effects of the drugs used to treat axial SpA.

EXPERT COMMENTARY

Growing concerns about the safety of anti-TNF drugs underline the need to ensure that all clinicians are capable of taking appropriate preventive action and adequately treating affected patients.

Efficacy and safety of IL-17 inhibitors for the treatment of ankylosing spondylitis: a systematic review and meta-analysis

Objectives

To systematically assess the efficacy and safety of IL-17 inhibitors in patients with active ankylosing spondylitis.

Methods

A systematic review of the literature was performed for randomized controlled trials (RCTs) concerning IL-17 inhibitors in patients with ankylosing spondylitis. Meta-analyses were used to determine the efficacy and safety of the IL-17 inhibitors in the treatment of these patients. The primary endpoint was predefined as the proportion of patients with at least 20% improvement in the Assessment of Spondyloarthritis International Society (ASAS20) response criteria at week 16, and the secondary endpoint was defined as ASAS40 at week 16.

Results

Six phase III randomized, double-blind, placebo-controlled trials including 1733 patients (1153 patients received IL-17 inhibitors, including secukinumab or ixekizumab, whereas 580 patients received a placebo as comparators) were included. At week 16, the IL-17 inhibitor regimen produced a significant increase in the ASAS20 response rate (RR = 1.63, 95% CI 1.45 to 1.84, p = 0.00) and the secondary endpoint ASAS40 response rate (RR = 2.12, 95% CI 1.75 to 2.56, p = 0.00) versus those for the placebo. With respect to the safety profile, more treatment-emergent adverse events (RR = 1.11, 95% CI 1.01 to 1.22, p = 0.03) and non-severe infections (RR = 1.82, 95% CI 1.40 to 2.37, p < 0.001) were described after treatment with IL-17 inhibitors than after treatment with placebo, while no increased risk of other adverse events was indicated after IL-17 inhibitor therapy, including death, discontinuation due to adverse events, or serious adverse events.

Conclusions

IL-17 inhibitors produced favorable response rates but an increased risk of non-severe infections in the treatment of active ankylosing spondylitis.

Taiwan Rheumatology Association consensus recommendations for the management of axial spondyloarthritis

Aim

To establish guidelines for the clinical management of axial spondyloarthritis that take into account local issues and clinical practice concerns for Taiwan.

Method

Overarching principles and recommendations were established by consensus among a panel of rheumatology and rehabilitation experts, based on analysis of the most up‐to‐date clinical evidence and the clinical experience of panelists. All Overarching Principles and Recommendations were graded according to the standards developed by the Oxford Centre for Evidence Based Medicine, and further evaluated and modified using the Delphi method.

Results

The guidelines specifically address issues such as local medical considerations, National Health Insurance reimbursement, and management of extra‐articular manifestations.

Conclusion

It is hoped that this will help to optimize clinical management outcomes for axial spondyloarthritis in Taiwan.

A distinct gut microbiota composition in patients with ankylosing spondylitis is associated with increased levels of fecal calprotectin

Background

Ankylosing spondylitis (AS) shares many characteristics with inflammatory bowel disease (IBD). Intestinal microbiota most likely plays an important role in the development of IBDs and may also be involved in the pathogenesis of AS. We aimed to define and compare the fecal microbiota composition in patients with AS, ulcerative colitis (UC), and healthy controls (HC) and to determine relationships between fecal microbiota, fecal calprotectin, and disease-related variables in AS.

Methods

Fecal microbiota composition was assessed with GA-map™ Dysbiosis Test (Genetic Analysis, Oslo, Norway), which also reports the degree of deviation of the microbiota composition compared with a healthy control population, a Dysbiosis Index (DI) score 1–5. The AS patients were assessed with questionnaires, back mobility tests, fecal calprotectin, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).

Results

Totally, 150 patients with AS (55% men, median age 55.5 years, median BASDAI 3.2), 18 patients with UC (56% men, median age 30.5 years), and 17 HC (65% men, median age 22 years) were included. Principal component analysis showed highly separate clustering of fecal microbiota from the patients with AS, UC, and HC. Compared with HC, fecal microbiota in AS was characterized by a higher abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcus species, and Actinobacteria, but lower abundance of Bacteroides and Lachnospiraceae.

Further, fecal microbiota composition differed between patients with normal (≤ 50 mg/kg, n = 57) and increased (≥ 200 mg/kg, n = 36) fecal calprotectin. Patients with increased fecal calprotectin had lower abundance of bacteria with anti-inflammatory properties such as Faecalibacterium prausnitzii and Clostridium and higher abundance of the genus Streptococcus. No association was found between the fecal microbiota composition and HLAB27 status, disease activity, function, or medication. Dysbiosis (defined as DI ≥ 3) was found in 87% of AS patients.

Conclusions

Patients with AS have a distinct fecal microbiota signature, which is linked to fecal calprotectin levels, a marker of intestinal inflammation, but not to other clinical parameters. These findings suggest a local interplay between intestinal microbiota and gut inflammation in AS.

Trial registration

ClinicalTrials.gov, NCT00858819. Registered March 9, 2009.

Intratumoral Adaptive Immunosuppression and Type 17 Immunity in Mismatch Repair Proficient Colorectal Tumors

PURPOSE

Approximately 10% of patients with mismatch repair-proficient (MMRp) colorectal cancer showed clinical benefit to anti-PD-1 monotherapy (NCT01876511). We sought to identify biomarkers that delineate patients with immunoreactive colorectal cancer and to explore new combinatorial immunotherapy strategies that can impact MMRp colorectal cancer.

EXPERIMENTAL DESIGN

We compared the expression of 44 selected immune-related genes in the primary colon tumor of 19 patients with metastatic colorectal cancer (mCRC) who responded (n = 13) versus those who did not (n = 6) to anti-PD-1 therapy (NCT01876511). We define a 10 gene-based immune signature that could distinguish responder from nonresponder. Resected colon specimens (n = 14) were used to validate the association of the predicted status (responder and nonresponder) with the immune-related gene expression, the phenotype, and the function of tumor-infiltrating lymphocytes freshly isolated from the same tumors.

RESULTS

Although both IL17Low and IL17High immunoreactive MMRp colorectal cancers are associated with intratumor correlates of adaptive immunosuppression (CD8/IFNγ and PD-L1/IDO1 colocalization), only IL17Low MMRp tumors (3/14) have a tumor immune microenvironment (TiME) that resembles the TiME in primary colon tumors of patients with mCRC responsive to anti-PD-1 treatment.

CONCLUSIONS

The detection of a preexisting antitumor immune response in MMRp colorectal cancer (immunoreactive MMRp colorectal cancer) is not sufficient to predict a clinical benefit to T-cell checkpoint inhibitors. Intratumoral IL17-mediated signaling may preclude responses to immunotherapy. Drugs targeting the IL17 signaling pathway are available in clinic, and their combination with T-cell checkpoint inhibitors could improve colorectal cancer immunotherapy.See related commentary by Willis et al., p. 5185.

Implication of IL-17 in Bone Loss and Structural Damage in Inflammatory Rheumatic Diseases

Proinflammatory cytokines play an important role in the systemic and focal bone loss associated with chronic inflammatory diseases. Targeting these cytokines with biologics and small molecules has led to a major improvement of the bone health of patients with inflammatory arthritis. Cytokines from the IL-17 family have been shown to be involved in the pathogenesis of several diseases such as spondyloarthritis, psoriatic arthritis, or psoriasis. IL-17A has been the first described and the most studied. The recent development of targeted therapies against IL-17A or its receptor and their efficacy has confirmed the importance of this cytokine in the development of inflammatory diseases. The aim of this review was to describe the effects of the IL-17 family and more particularly of IL-17A on bone and cartilage tissues. At the cellular level, IL-17A is proosteoclastogenic whereas its effects on osteoblasts depend on the stage of differentiation of these cells. In vivo, IL-17A is not required for normal bone homeostasis but plays an important role in bone loss notably in an ovariectomized mouse model of osteoporosis. Preliminary data from clinical trials showed a stabilisation of bone density in patients treated with anti-IL-17A antibodies. IL-17A plays a central role in the cartilage damage through the induction of collagenases and by decreasing the expression of their inhibitors in synergy with the other proinflammatory cytokines. The prevention of structural damage by anti-IL-17A therapies has been demonstrated in several pivotal clinical trials. Overall, blocking the IL-17A pathway seems to have a positive effect on the bone and cartilage damage observed in inflammatory arthritis. Differences and specificity of these effects compared to those already described with other biologics such as anti-TNF therapies remain to be explored.

Ankylosing spondylitis: etiology, pathogenesis, and treatments

Ankylosing spondylitis (AS), a common type of spondyloarthropathy, is a chronic inflammatory autoimmune disease that mainly affects spine joints, causing severe, chronic pain; additionally, in more advanced cases, it can cause spine fusion. Significant progress in its pathophysiology and treatment has been achieved in the last decade. Immune cells and innate cytokines have been suggested to be crucial in the pathogenesis of AS, especially human leukocyte antigen (HLA)‑B27 and the interleukin‑23/17 axis. However, the pathogenesis of AS remains unclear. The current study reviewed the etiology and pathogenesis of AS, including genome-wide association studies and cytokine pathways. This study also summarized the current pharmaceutical and surgical treatment with a discussion of future potential therapies.

The Effect of TNF Inhibition on Bone Density and Fracture Risk and of IL17 Inhibition on Radiographic Progression and Bone Density in Patients with Axial Spondyloarthritis: a Systematic Literature Review

PURPOSE OF REVIEW

Osteoporosis in axial spondyloarthritis may be modified by therapy. The purpose of this systematic review is to describe (i) the effect of TNFi on BMD, (ii) the effect of secukinumab on BMD, and (iii) the effect of secukinumab on radiographic disease progression in axSpA.

RECENT FINDINGS

We searched PubMed, Embase, and Cochrane using the following retrieval languages: spondyloarthritis, ankylosing spondylitis, TNF, IL-17, x-rays, and osteoporosis. Twenty-nine studies were included; 27 re: TNFi and BMD, and 2 re: IL-17 blockers and x-ray progression. TNFi over 2-4 years increased BMD of the lumbar spine (3.2-14.9%) and hip (2.26-4.7%) without reducing vertebral fractures. Secukinumab reduced radiographic progression; none (73%) and minimal (79%) at 4 years. No data on IL-17 blockade and bone were found. TNFi therapy improves bone density but not vertebral fracture rates. Secukinumab improves symptoms and may slow radiographic progression. Data is lacking regarding the effects of secukinumab on BMD and fractures. These are important questions which may impact the choice of therapy.

Association of synovial tissue polyfunctional T-cells with DAPSA in psoriatic arthritis

OBJECTIVE

This study examines polyfunctional T-cells in psoriatic arthritis (PsA) synovial tissue and their associations with clinical disease and implications for therapy.

METHODS

PsA synovial tissue was enzymatically/mechanically digested to generate synovial tissue single cell suspensions. Frequencies of polyfunctional CD4, CD8, T-helper 1 (Th1), Th17 and exTh17 cells, using CD161 as a marker of Th17 plasticity, were determined by flow cytometry in matched PsA synovial tissue and peripheral blood. Synovial T-cell polyfunctionality was assessed in relation to Disease Activity in PSoriatic Arthritis (DAPSA) and in synovial cell suspensions cultured with a current mode of treatment, phosphodiesterase 4 (PDE4) inhibitor.

RESULTS

PsA synovial tissue infiltrating CD4⁺ T-cells expressed higher levels of interleukin (IL)-17A, interferon gamma (IFN-γ), GM-CSF and CD161, with parallel enrichment of Th1, Th17 and exTh17 T-helper subsets (all p<0.05). Interestingly, a significant proportion of synovial T-cell subsets were triple-positive for GM-CSF, tumour necrosis factor (-TNF), -IL-17 or IFN-γ compared with matched blood (all p<0.05). Importantly, frequencies of polyfunctional T-cells correlated with DAPSA: Th1-GM-CSF⁺/TNF⁺/IFN-γ⁺ (r=0.7, p<0.01), Th17-GM-CSF⁺/TNF⁺/IL-17⁺ (r=0.6, p<0.057) and exTh17-GM-CSF⁺/TNF⁺/IFN-γ⁺ (r=0.7, p=0.0096), with no associations observed for single cytokine-producing T-cells. Following ex vivo culture of PsA synovial tissue cell suspensions, polyfunctional GM-CSF⁺TNFα⁺IL-17A⁺ or/IFN-γ⁺-producing T-cells (p<0.05), but not single cytokine-producing T-cells, were inhibited with a PDE4 inhibitor.

CONCLUSION

These data demonstrate enrichment of polyfunctional T-cells in PsA synovial tissue which were strongly associated with DAPSA and ex vivo therapeutic response.

Practical Pearls About Current Rheumatic Medications

New and existing rheumatic disease is frequently encountered in the primary care setting. The number of medications used to treat various rheumatic conditions continues to increase. Some medications have very specific indications, whereas others have increasing off-label uses. Regardless of the indication, the medications used in rheumatology have variable dosing recommendations, significant side effects, recommended monitoring parameters, and potential medication interactions. Clinicians need to be aware of the potential uses as well as possible pitfalls associated with medications used in rheumatology.

Risankizumab, an IL-23 inhibitor, for ankylosing spondylitis: results of a randomised, double-blind, placebo-controlled, proof-of-concept, dose-finding phase 2 study

Objectives

To evaluate the efficacy and safety of risankizumab, a humanised monoclonal antibody targeting the p19 subunit of interleukin-23 (IL-23), in patients with active ankylosing spondylitis (AS).

Methods

A total of 159 patients with biological-naïve AS, with active disease (Bath Ankylosing Spondylitis Disease Activity Index score of ≥4), were randomised (1:1:1:1) to risankizumab (18 mg single dose, 90 mg or 180 mg at day 1 and weeks 8, 16 and 24) or placebo over a 24-week blinded period. The primary outcome was a 40% improvement in Assessment in Spondylo Arthritis International Society (ASAS40) at week 12. Safety was assessed in patients who received at least one dose of study drug.

Results

At week 12, ASAS40 response rates were 25.5%, 20.5% and 15.0% in the 18 mg, 90 mg and 180 mg risankizumab groups, respectively, compared with 17.5% in the placebo group. The estimated difference in proportion between the 180 mg risankizumab and placebo groups (primary endpoint) was –2.5% (95% CI –21.8 to 17.0; p=0.42). Rates of adverse events were similar in all treatment groups.

Conclusions

Treatment with risankizumab did not meet the study primary endpoint and showed no evidence of clinically meaningful improvements compared with placebo in patients with active AS, suggesting that IL-23 may not be a relevant driver of disease pathogenesis and symptoms in AS.

Trial registration number

NCT02047110; Pre-results.

Whodunit? The Contribution of Interleukin (IL)-17/IL-22-Producing γδ T Cells, αβ T Cells, and Innate Lymphoid Cells to the Pathogenesis of Spondyloarthritis

γδ T cells, αβ T cells, and innate lymphoid cells (ILCs) are capable of producing interleukin (IL)-17A, IL-17F, and IL-22. Among these three families of lymphocytes, it is emerging that γδ T cells are, at least in rodents, the main source of these key pro-inflammatory cytokines. γδ T cells were implicated in multiple inflammatory and autoimmune diseases, including psoriasis, experimental autoimmune encephalomyelitis and uveitis, colitis, and rheumatoid arthritis. Recent findings pointed toward a central role of γδ T cells in the pathogenesis of spondyloarthritis (SpA), a group of inflammatory rheumatic diseases affecting the axial skeleton. SpA primarily manifests as inflammation and new bone formation at the entheses, which are connecting tendons or ligaments with bone. In SpA patients, joint inflammation is frequently accompanied by extra-articular manifestations, such as inflammatory bowel disease or psoriasis. In humans, genome-wide association studies could link the IL-23/IL-17 cytokine axis to SpA. Accordingly, antibodies targeting IL-23/IL-17 for SpA treatment already showed promising results in clinical studies. However, the contribution of IL-17-producing γδ T cells to SpA pathogenesis is certainly not an open-and-shut case. Indeed, the cell types that are chiefly involved in local inflammation in human SpA still remain largely unclear. Some studies focusing on blood or synovium from SpA patients reported augmented IL-17-producing and IL-23 receptor-expressing γδ T cells, but other cell types might contribute as well. Here, we summarize the current understanding of how γδ T cells, αβ T cells, and ILCs contribute to the pathogenesis of human and experimental SpA.

IL23R gene variants in relation to IL17A levels and clinical phenotype in patients with ankylosing spondylitis

Background

IL23 receptor (IL23R) binding by IL23 is required for the maturation of CD4⁺ cells into Th17 cells and subsequent generation of IL17A and TNF. As IL23R variations contribute to AS susceptibility, we investigated the effect of IL23R variants on cytokine levels and disease measures in an AS cohort.

Methods

This was a cross-sectional study of AS patients (n = 334, 90% B27⁺, age 45 years). IL23R genotyping for three non-synonymous single-nucleotide polymorphisms (rs11209026, protective allele A; rs10489629, protective allele A; and rs11209032, risk allele A) was done by Taqman RT-PCR. IL23, IL17A, TNF and IL6 concentrations were determined by sandwich ELISA. Genotypic associations were analysed with non-parametric methods.

Results

Twenty-two AS patients (6.6%) carried the protective rs11209026 A allele, whereas 206 (61.7%) carried the rs11209032A risk allele (P = 0.03). Two patients homozygous for rs11209026A had late onset, no co-morbidity and undetectable cytokine levels. IL23R genotypes and five common haplotypes were unrelated with age at onset, BASFI or co-morbidity (all P >0.2). There was no overall difference in the concentration of IL17A (184 vs 233 pg/ml, P > 0.2) or IL23 (276 vs 262 pg/ml, P > 0.4) between AS patients and controls, but a global haplotype association (P = 0.01) was observed for IL23 concentrations.

Conclusion

Homozygosity for rs11209026A is rare in AS patients, but may ameliorate the clinical presentation. IL17A and IL23 levels are similar in controls and AS patients. IL23R variants influence IL23 levels but not IL17A levels in AS patients, suggesting that IL23R impacts more on cell types other than Th17 cells.

Anti-IL17A in Axial Spondyloarthritis-Where Are We At?

Knowledge regarding the mechanisms of the IL17–IL23 pathway and its role in spondyloarthritis (SpA) has been pivotal to the development of IL-17 blockade in patients with axial SpA. Previously, only anti-TNF has proven to be clinically efficacious in patients with active disease, despite non-steroidal anti-inflammatory drugs and physiotherapy. However, up to 50% fail to achieve a clinically significant response. Secukinumab, a fully humanized monoclonal antibody targeting IL-17A, has recently been approved for use in patients with active ankylosing spondylitis. Clinical studies and current issues surrounding the use of secukinumab will be discussed.