Clinical Trials Supporting the Role of the IL-17/IL-23 Axis in Axial Spondyloarthritis

Targeted therapies for uveitis in spondyloarthritis: A narrative review

Spondyloarthritis (SpA) encompasses a group of chronic inflammatory disorders of the joints frequently associated with uveitis in almost a quarter of cases. SpA-related uveitis typically affects the eye anterior chamber with sudden onset, causing pain, redness, photophobia, and blurred vision. Ophthalmologists will describe an acute anterior unilateral uveitis. Most patients present with episodic acute anterior non-granulomatous uveitis and retain excellent visual acuity. However, systemic treatments are recommended in the event of frequent relapses (2-3/year) or in rare cases of sight-threatening with ocular complications. The improved understanding of the pathogenesis of SpA has led to the management of this disease by biologics. Here, we review the main data regarding the opportunity to target specific components in inflammatory pathways for the treatment of SpA-related uveitis. These therapies are recommended for long-term control when uveitis relapses occur too frequently despite conventional systemic treatments. Significant benefits have been obtained with the tumor necrosis factor-α inhibitors (TNFis), particularly infliximab and adalimumab. Paradoxically, a high number of uveitis occurrences have been shown on etanercept. Mixed results have been demonstrated with interleukin-17 antagonists (secukinumab) and interleukin-12/interleukin-23 antagonists (ustekinumab) in cases of failure of TNFis. JAK inhibitors seem to be a valuable class of medications for these patients in the future. Although SpA-related uveitis is typically managed with conventional local and/or systemic treatments, these biological/targeted therapies may provide avenues to control both the underlying SpA and uveitis manifestations. Thus, a close collaboration between patients, rheumatologists, internists, and ophthalmologists is needed to optimally manage ocular inflammation in SpA.

Association between serum interleukin-17 levels and ectopic bone formation in OPLL patients with DISH

OBJECTIVE

To investigate the relationship between the severity and morphology of heterotopic ossification in the spinal ligaments including sacroiliac (SI) joints, and serum interleukin-17 (IL-17) levels in patients with ossification of the posterior longitudinal ligament (OPLL) with or without diffuse idiopathic skeletal hyperostosis (DISH), as well as a non-OPLL group.

METHODS

A total of 103 patients with OPLL [DISH (-), n = 50; DISH (+), n = 53] and 53 age- and gender-matched controls were included. The serum levels of IL-17 were analysed, and the severity of ectopic ossification and the morphology of ectopic bone formation were evaluated. The SI joint morphological variations were categorized into four types.

RESULTS

No significant differences were found in serum IL-17 levels between the OPLL and control groups. However, the DISH (+) group showed higher IL-17 levels than the DISH (-) group, especially in female patients (P = 0.003). Additionally, IL-17 levels were positively correlated with the number of flat vertebral units, this being one of the characteristic DISH ossification types (R2 = 0.199, P = 0.012). IL-17 levels in the type showing bridging osteophyte and bone fusion were significantly higher in the DISH (+) group than in the DISH (-) group.

CONCLUSION

The morphological characteristics of paravertebral bone formation in the entire spine, including the SI joint, are likely associated with serum IL-17 levels in OPLL. These findings provide pathological and serological evidence of local inflammation contributing to paravertebral ossification of OPLL patients.

IL-17 Control of Cutaneous Immune Homeostasis

IL-17 is widely recognized for its roles in host defense and inflammatory disorders. However, it has become clear that IL-17 is also an essential regulator of barrier tissue physiology. Steady-state microbe sensing at the skin surface induces low-level IL-17 expression that enhances epithelial integrity and resists pathogens without causing overt inflammation. Recent reports describe novel protective roles for IL-17 in wound healing and counteracting physiologic stress; however, chronic amplification of these beneficial responses contributes to skin pathologies as diverse as fibrosis, cancer, and autoinflammation. In this paper, we discuss the context-specific roles of IL-17 in skin health and disease and therapeutic opportunities.

Mendelian randomization analysis reveals causal associations of inflammatory bowel disease with Spondylarthritis

OBJECTIVE

Inflammatory bowel disease (IBD) is strongly associated with Spondylarthritis (SpA), but the causal relationship remains unclear. This study explores the causal associations between IBD (Crohn's disease [CD] and ulcerative colitis [UC]) and several common subtypes of SpA (Ankylosing Spondylitis [AS], Psoriatic Arthritis [PsA], and Reactive Arthritis [ReA]), using bidirectional two-sample Mendelian randomization (TSMR).

METHODS

The causal effects of genetically predicted IBD on AS, PsA, and ReA were firstly investigated in this forward study. The causal effects from AS, PsA, and ReA on IBD were analyzed in the reverse MR. Inverse variance weighted, weighted median, and MR-Egger were applied in the MR analyses. The pleiotropic effects, heterogeneity, and leave-one-out sensitivity analysis were also evaluated.

RESULTS

The forward MR analysis demonstrated that IBD increased risk for AS (OR:1.278; P = 1.273 × 10-5), PsA (OR:1.192; P = 1.690 × 10-5), and ReA (OR:1.106; P = 1.524 × 10-3). Among them, CD increased risk of AS (OR:1.196; P = 3.424 × 10-4), PsA (OR:1.101; P = 1.537 × 10-3), ReA (OR:1.079; P = 6.321 × 10-3) whereas UC increased risk of AS (OR:1.166; P = 2.727 × 10-2), PsA (OR:1.110; P = 1.944 × 10-2), and ReA (OR:1.091; P = 1.768 × 10-2). The reverse-direction MR disclosed no notable association; neither was any evidence of pleiotropy detected.

CONCLUSION

Our study verifies a causal effect of IBD to AS, PsA as well as ReA, but not vice versa. This might bring new insights for the management of IBD and SpA in clinical practice.

The role of ixekizumab in the treatment of nonradiographic axial spondyloarthritis

Nonradiographic axial spondyloarthritis (nr-axSpA) is a subtype of SpA with undeveloped definite radiographic sacroiliitis. Tumor necrosis factor inhibitors have demonstrated effectiveness in nr-axSpA patients who do not respond to first-line therapy. More recently, accumulated data from genetic, experimental, and clinical studies revealed that IL-17 is a key player in the pathogenesis of SpA, leading to development of new biologics directly inhibiting IL-17. Among them, ixekizumab is a high-affinity monoclonal antibody that selectively targets IL-17A and has exhibited significant efficacy and acceptable safety profiles in the treatment of nr-axSpA. The aim of this paper is to narratively review the recent insights of IL-17 in the pathogenesis of axSpA and discuss the effectiveness and safety of ixekizumab in treatment of nr-axSpA.

Myeloid and lymphoid expression of C9orf72 regulates IL-17A signaling in mice

A mutation in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Patients with ALS or FTD often develop autoimmunity and inflammation that precedes or coincides with the onset of neurological symptoms, but the underlying mechanisms are poorly understood. Here, we knocked out murine C9orf72 in seven hematopoietic progenitor compartments by conditional mutagenesis and found that myeloid lineage C9orf72 prevents splenomegaly, loss of tolerance, and premature mortality. Furthermore, we demonstrated that C9orf72 plays a role in lymphoid cells to prevent interleukin-17A (IL-17A) production and neutrophilia. Mass cytometry identified early and sustained elevation of the costimulatory molecule CD80 expressed on C9orf72-deficient mouse macrophages, monocytes, and microglia. Enrichment of CD80 was similarly observed in human spinal cord microglia from patients with C9ORF72-mediated ALS compared with non-ALS controls. Single-cell RNA sequencing of murine spinal cord, brain cortex, and spleen demonstrated coordinated induction of gene modules related to antigen processing and presentation and antiviral immunity in C9orf72-deficient endothelial cells, microglia, and macrophages. Mechanistically, C9ORF72 repressed the trafficking of CD80 to the cell surface in response to Toll-like receptor agonists, interferon-γ, and IL-17A. Deletion of Il17a in C9orf72-deficient mice prevented CD80 enrichment in the spinal cord, reduced neutrophilia, and reduced gut T helper type 17 cells. Last, systemic delivery of an IL-17A neutralizing antibody augmented motor performance and suppressed neuroinflammation in C9orf72-deficient mice. Altogether, we show that C9orf72 orchestrates myeloid costimulatory potency and provide support for IL-17A as a therapeutic target for neuroinflammation associated with ALS or FTD.

Uric acid promotes interleukin-17 expression to cause kidney injury

Uric acid, an oxidation end-product of purine metabolism, is reportedly to be a risk factor for kidney injury. However, its underlying mechanism is still a mystery. This study aimed to reveal the detailed roles of uric acid in inducing kidney injury and the possible mechanisms. Injection of rats with uric acid significantly increased tubular injury score, and levels of blood urea nitrogen, serum creatinine, and urine kidney injury molecule-1. Uric acid increased the expression of collagen I, alpha-smooth muscle actin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. Kyoto Encyclopedia of Genes and Genomes analysis result showed the IL-17 signaling pathway as the most significantly enriched pathway involved in hyperuricemia-related kidney injury. Long-term injection of uric acid induced significant production of IL-17 and recruitment of Th17 cells. Treating rats with the anti-IL-17 mAb attenuated uric acid-induced kidney injury, accompanied by the inactivation of nuclear factor-κB (NF-κB). In conclusion, uric acid was confirmed to be a risk factor for kidney injury via inducing IL-17 expression. Neutralization of IL-17 using the specific mAb relieved uric acid-induced kidney injury via inhibition of NF-κB signaling.

Impact of sex and gender on axSpA diagnosis and outcomes

Axial spondyloarthritis (axSpA) was historically considered a disease of men, largely due to the recognition of a more severe, progressive phenotype, ankylosing spondylitis (AS; or radiographic axSpA, r-axSpA) aiding the clinical diagnosis [1,2]. Data demonstrating the near equal prevalence of axSpA in women only started to emerge in the last decades, highlighting intrinsic differences in disease phenotype, and clinical and imaging characteristics between sexes, which partly explain the issue of underdiagnosis in women. Similar to the evolving understanding of spondyloarthritis and the diseases that term describes, the concepts of gender and sex also warrant further clarification to accurately assess their potential role in disease pathophysiology and phenotypic expression. This narrative review delves into the most recent evidence from the literature on the true prevalence of sex differences in axSpA, and the impact of sex and gender on diagnosis, disease characteristics and treatment response in this, still underserved, chronic disease.

Identification of the key mechanisms of action of Si-Ni-San in uveitis using bioinformatics and network pharmacology

BACKGROUND

Uveitis is an eye disease with a high rate of blindness, whose pathogenesis is not completely understood. Si-Ni-San (SNS) has been used as a traditional medicine to treat uveitis in China. However, its mechanism of action remains unclear. This study explored the potential mechanisms of SNS in the treatment of uveitis through network pharmacology and bioinformatics.

METHODS

Using R language and Perl software, the active components and predicted targets of SNS, as well as the related gene targets of uveitis, were mined through the Traditional Chinese Medicine Systems Pharmacology, Therapeutic Target, Gene Expression Omnibus, GeneCards, and DrugBank databases. The network diagram of active components and intersection targets was constructed using Cytoscape software and the String database. The CytoNCA plug-in was used to conduct topological analysis on the network diagram and screen out the core compounds and key targets. The genes were analyzed for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment. Chemoffice, Pymol, AutoDock, and Vina were used to analyze the molecular docking of key targets and core compounds of diseases through the PubChem database.

RESULTS

JUN, RELA, and MAPK may play important roles in the treatment of uveitis by SNS. Kyoto encyclopedia of genes and genomes pathway enrichment analysis showed that core genes were mainly concentrated in MAPK, toll-like receptor, tumor necrosis factor, and nucleotide oligomerization domain-like receptor signaling pathways. In addition, molecular docking results showed that the bioactive compounds (kaempferol, luteolin, naringin, and quercetin) exhibited good binding ability to JUN, RELA, and MAPK.

CONCLUSION

Based on these findings, SNS exhibits multi-component and multi-target synergistic action in the treatment of uveitis, and its mechanism may be related to anti-inflammatory and immune regulation.

The Interleukine-17 Cytokine Family: Role in Development and Progression of Spondyloarthritis, Current and Potential Therapeutic Inhibitors

Spondyloarthritis (SpA) encompasses a group of chronic inflammatory rheumatic diseases with a predilection for the spinal and sacroiliac joints, which include axial spondyloarthritis, psoriatic arthritis, reactive arthritis, arthritis associated with chronic inflammatory bowel disease, and undifferentiated spondyloarthritis. The prevalence of SpA in the population varies from 0.5 to 2%, most commonly affecting young people. Spondyloarthritis pathogenesis is related to the hyperproduction of proinflammatory cytokines (TNFα, IL-17A, IL-23, etc.). IL-17A plays a key role in the pathogenesis of spondyloarthritis (inflammation maintenance, syndesmophites formation and radiographic progression, enthesites and anterior uveitis development, etc.). Targeted anti-IL17 therapies have established themselves as the most efficient therapies in SpA treatment. The present review summarizes literature data on the role of the IL-17 family in the pathogenesis of SpA and analyzes existing therapeutic strategies for IL-17 suppression with monoclonal antibodies and Janus kinase inhibitors. We also consider alternative targeted strategies, such as the use of other small-molecule inhibitors, therapeutic nucleic acids, or affibodies. We discuss advantages and pitfalls of these approaches and the future prospects of each method.

Peptide-based vaccine targeting IL17A attenuates experimental spondyloarthritis in HLA-B27 transgenic rats

OBJECTIVES

Spondyloarthritis (SpA) is known as series of immune-mediated inflammatory disease of the axial and peripheral joints. Human leucocyte antigen (HLA)-B27 is a genetic risk factor for SpA. Recent evidence suggests that the interleukin -17 (IL17) axis strongly contributes to SpA. This study aimed to assess the efficacy of an IL17A peptide-based vaccine on SpA manifestations in model rats.

METHODS

HLA-B27/human β₂-microglobulin (hβ₂M) transgenic rats were immunised with heat-inactivated Mycobacterium tuberculosis (MT) to develop spondylitis and arthritis as an experimental SpA model after immunisation with a keyhole limpet hemocyanin-conjugated IL17A peptide-based vaccine with an alum adjuvant three times. The IL17A antibody titre was assessed using ELISA, and arthritis score and joint thickness were monitored two times a week. Enzyme-linked immunospot (ELISpot) assays for IL4- and interferon-γ-secreting splenocytes were conducted to evaluate IL17A-specific T cell activation. We also evaluated the effect of IL17A vaccine in SpA therapeutic model.

RESULTS

The IL17A peptide-based vaccine with alum adjuvant successfully induced antibody production and suppressed the arthritis score and joint thickness. X-ray and histological analyses showed that enthesitis, bone destruction and new bone formation were inhibited by the IL17A vaccine. The ELISpot assay showed that the IL17A peptide-based vaccine did not elicit any IL17A-reactive T cell responses. IL17A vaccine tends to mitigate, but not significant, in SpA treatment model. These data showed that the peptide-based vaccine targeting IL17A alleviated the SpA phenotype in a heat-inactivated MT-induced SpA model in HLA-B27/hβ₂M transgenic rats.

CONCLUSIONS

IL17A peptide-based vaccine may be a therapeutic option for SpA treatment.

Safety and efficacy of probiotic supplementation in 8 types of inflammatory arthritis: A systematic review and meta-analysis of 34 randomized controlled trials

Objective

To evaluate Safety and efficacy of probiotic supplementation in inflammatory arthritis.

Methods

The literature on the treatment of inflammatory arthritis with probiotics has been collected in databases such as CNKI, Pubmed, Cochrane library, Embase, etc. The search time is for them to build the database until May 2022. The included literatures are randomized controlled trials (RCTs) of probiotics in the treatment of hyperuricemia and gout. The Cochrane risk assessment tool was used for quality evaluation, and the Rev Man5.3 software was used for meta-analysis.

Results

A total of 37 records were finally included, involving 34 RCTs and 8 types of autoimmune disease (Hyperuricemia and gout, Inflammatory bowel disease arthritis, juvenile idiopathic arthritis [JIA], Osteoarthritis [OA], Osteoporosis and Osteopenia, Psoriasis, rheumatoid arthritis (RA), Spondyloarthritis). RA involved 10 RCTs (632 participants) whose results showed that probiotic intervention reduced CRP. Psoriasis involved 4 RCTs (214 participants) whose results showed that probiotic intervention could reduce PASI scores. Spondyloarthritis involved 2 RCTs (197 participants) whose results showed that probiotic intervention improved symptoms in patients. Osteoporosis and Ostepenia involving 10 RCTs (1156 participants) showed that probiotic intervention improved bone mineral density in patients. Hyperuricemia and gout involving 4 RCTs (294 participants) showed that probiotic intervention improved serum uric acid in patients. OA involving 1 RCTs (433 participants) showed that probiotic intervention improved symptoms in patients. JIA involving 2 RCTs (72 participants) showed that probiotic intervention improved symptoms in patients. Inflammatory bowel disease arthritis involving 1 RCTs (120 participants) showed that probiotic intervention improved symptoms in patients. All of the above RCTs showed that probiotics did not increase the incidence of adverse events.

Conclusion

Probiotic supplements may improve Hyperuricemia and gout, Inflammatory bowel disease arthritis, JIA, OA, Osteoporosis and Osteopenia, Psoriasis, RA, Spondyloarthritis. However, more randomized controlled trials are needed in the future to determine the efficacy and optimal dosing design of probiotics.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021286425, identifier CRD42021286425.

IL-23 in axial spondyloarthritis and psoriatic arthritis: a good fit for biological treatment?

INTRODUCTION

Interleukin 23 (IL-23) is a pro-inflammatory cytokine that plays a protective role against bacterial and fungal infections. However, the dysregulation of the IL-23/IL-17 axis provides a solid substrate for the development of various inflammatory diseases, such as psoriatic arthritis (PsA) and ankylosing spondylitis (AS).

AREAS COVERED

In different clinical trials, several drugs against IL-23 have shown efficacy and safety towards PsA, with excellent results on skin and joint scores. However, the same drugs did not show the same efficacy in AS, suggesting that IL-23 may not be a relevant driver of the pathobiology and clinical symptoms of active axial spondyloarthritis (axSpA).

EXPERT OPINION

These drugs have shown an excellent efficacy and a good safety profile towards PsA, while in AS the efficacy of the IL-23 blockade is lacking for reasons not yet known. Several hypotheses have been reported, but further studies will be needed for a greater understanding. This suggests the involvement of pathways or mechanisms for the development of SpA that remain unknown. In order to allow a wide use of IL-23 inhibitors, further clinical trials and long-term prospective studies are necessary.

Therapeutic Targets for Ankylosing Spondylitis - Recent Insights and Future Prospects

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease belonging to the axial spondyloarthritis (axSpA), a group of diseases that affects the axial skeleton and causes severe pain and disability. An early diagnosis and appropriate treatment can reduce the severity of the disease and the risk of progression. TNF-α inhibitors demonstrated efficacy and effectiveness in axSpA patients by reducing disease activity, minimizing inflammation and improving the quality of life. More recently, new insights in pathogenesis of axSpA, including the discovery of the role of IL-23/IL-17 axis and intracellular pathways, led to the development of new biologics and small molecules that improve our therapeutic armamentarium. New alternatives are also being soon available. The aim of this paper is to narratively review the recent insights and future prospects in the treatment of AS and, more in general, axSpA.

Th17 cells: from gut homeostasis to CNS pathogenesis

Th17 cells play crucial roles in host-microbe interactions, but can also promote chronic inflammation and tissue pathology. Factors influencing Th17 cell heterogeneity and effector functions in different inflammatory contexts remain unclear. Schnell et al. demonstrate that intestinal Th17 cells form a reservoir from which pathogenic Th17 cells can be elicited during severe tissue inflammation.

Evidence for the Use of Secukinumab in Patients with Radiographic and Non-radiographic Axial Spondyloarthritis in the Last 5 Years

Axial spondyloarthritis (axSpA) is an inflammatory rheumatic disorder that causes chronic pain, primarily in the spine and sacroiliac joints. It is characterized by the presence of type 1 major histocompatibility complex HLA-B27 genetic marker, arthritis in peripheral joints, enthesitis and/or dactylitis and extra-articular manifestations. Current guidelines recommend biological therapy when first-line therapy is not sufficiently effective. The finding that the interleukin (IL)-17 axis is vital for the pathogenesis of axSpA propelled the development of secukinumab, a fully human monoclonal antibody directed against IL-17A. The present review provides evidence on the efficacy and safety of secukinumab in the treatment of radiographic and non-radiographic axSpA from nine randomized controlled phase III trials, as well as evidence from real-world observational analyses. The primary endpoint in six clinical trials was the proportion of patients meeting the Assessment of SpondyloArthritis international Society criteria for either 20% or 40% improvement (ASAS20, ASAS40) at week 16. Significantly more patients achieved the primary endpoint with secukinumab compared with placebo in all the studies except MEASURE 4. Both clinical trials and real-world studies showed significant improvements in the secondary endpoints of disease activity, quality of life, and pain and fatigue relative to placebo. The benefits of secukinumab were generally sustained during longer-term (up to 5 years) treatment. Overall, secukinumab was well tolerated with a low frequency of adverse events and treatment persistence was high in the real-world setting. Although indirect comparisons suggest that secukinumab and adalimumab have comparable efficacy and safety, they are being directly compared in the ongoing SURPASS study. During the current coronavirus disease 2019 (COVID-19) pandemic, it is advisable to continue biological therapy in patients who do not have severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection, but interrupt treatment during an infection, reinitiating once the patient has recovered from the infection. In conclusion, secukinumab is a largely safe and effective treatment for radiographic and non-radiographic axSpA.

[New possibilities in therapy of ocular inflammation in rheumatic diseases]

This review is devoted to the potential application of genetically engineered biological drugs of different classes in the treatment of main forms of uveitis and other types of non-infectious ocular inflammation in immunoinflammatory rheumatic diseases. The article presents the results of studies demonstrating the influence of interleukin-17 inhibitor secukinumab on the course of uveitis in spondylarthritis, shows the possibilities of treating uveitis in juvenile idiopathic arthritis with inhibitors of interleukin-6, co-stimulation of T-lymphocytes. Inhibition of interleukin-1 is considered an effective method of influencing the ocular inflammation in monogenic autoinflammatory syndromes and Behcet's disease. Rituximab is considered as an option for immunosuppressive therapy of non-infectious uveitis and scleritis.

The gut-enthesis axis and the pathogenesis of Spondyloarthritis

Subclinical inflammation is associated with Spondylarthritis (SpA). SpA patients show features of dysbiosis, altered gut barrier function, and local expansion of innate and innate-like cells involved in type 3 immune response. The recirculation of intestinal primed immune cells into the bloodstream and, in some cases, in the joints and the inflamed bone marrow of SpA patients gave the basis of the gut-joint axis theory. In the light of the critical role of enthesis in the pathogenesis of SpA and the identification of mucosal-derived immune cells residing into the normal human enthesis, a gut-enthesis axis is also likely to exist. This work reviews the current knowledge on enthesis-associated innate immune cells' primary involvement in enthesitis development, questions their origin, and critically discusses the clues supporting the existence of a gut-enthesis axis contributing to SpA development.

Immunopathophysiology of Juvenile Spondyloarthritis (jSpA): The "Out of the Box" View on Epigenetics, Neuroendocrine Pathways and Role of the Macrophage Migration Inhibitory Factor (MIF)

Juvenile spondyloarthritis (jSpA) is a an umbrella term for heterogeneous group of related seronegative inflammatory disorders sharing common symptoms. Although it mainly affects children and adolescents, it often remains active during adulthood. Genetic and environmental factors are involved in its occurrence, although the exact underlying immunopathophysiology remains incompletely elucidated. Accumulated evidence suggests that, in affected patients, subclinical gut inflammation caused by intestinal dysbiosis, is pivotal to the future development of synovial-entheseal complex inflammation. While the predominant role of IL17/23 axis, TNF-α, and IL-7 in the pathophysiology of SpA, including jSpA, is firmly established, the role of the cytokine macrophage migration inhibitory factor (MIF) is generally overlooked. The purpose of this review is to discuss and emphasize the role of epigenetics, neuroendocrine pathways and the hypothalamic-pituitary (HPA) axis, and to propose a novel hypothesis of the role of decreased NLRP3 gene expression and possibly MIF in the early phases of jSpA development. The decreased NLRP3 gene expression in the latter, due to hypomethylation of promotor site, is (one of) the cause for inflammasome malfunction leading to gut dysbiosis observed in patients with early jSpA. In addition, we highlight the role of MIF in the complex innate, adaptive cellular and main effector cytokine network, Finally, since treatment of advanced bone pathology in SpA remains an unmet clinical need, I suggest possible new drug targets with the aim to ultimately improve treatment efficacy and long-term outcome of jSpA patients.