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Objective: To describe the radiographic phenotype of axial spondyloarthritis (SpA) according to the presence of HLA-B27., Methods: An international collaboration compared the radiographic phenotype of axial SpA according to HLA-B27 status. Patients with ankylosing spondylitis (AS) and axial psoriatic arthritis (PsA) were collected. Radiographs were read centrally, blinded to clinical details. The symmetry of the sacroiliac joints and lumbar syndesmophytes and the morphology of syndesmophytes (typical marginal versus atypical chunky), together with the modified Stoke Ankylosing Spondylitis Spine Score and the Psoriatic Arthritis Spondylitis Radiographic Index, were recorded., Results: A total of 244 patients with PsA and 198 patients with AS were included. In PsA, 60 patients (25%) were HLA-B27 positive while in AS, 148 patients (75%) were HLA-B27 positive. Patients with HLA-B27 were younger and more often male and had a longer duration of disease. In multivariable logistic regression, HLA-B27 was significantly associated with syndesmophyte symmetry (odds ratio [OR] 3.02 [95% confidence interval (95% CI) 1.38, 6.61]) and marginal syndesmophytes (OR 1.97 [95% CI 1.16, 3.36]) but not with sacroiliac symmetry. Mean radiographic scores were higher for patients with HLA-B27., Conclusion: Patients with axial SpA who are positive for HLA-B27 have more severe radiographic damage, more marginal syndesmophytes, and more frequent syndesmophyte symmetry compared to patients who are negative for HLA-B27., (© 2020, American College of Rheumatology.)

Objective: The present study was undertaken to investigate the effectiveness and safety of dose reduction of tumor necrosis factor inhibitor (TNFi) therapy in the treatment of axial spondyloarthritis (SpA) compared to usual care., Methods: We searched the Cochrane Central Register of Controlled Trials, Embase, Medline, and trial registries. We screened, extracted data, and assessed risk of bias in duplicate. Data were pooled using random-effects models; subgroup analyses were performed for type of TNFi, prior TNFi exposure, and follow-up duration. Outcomes of interest were Assessment of SpondyloArthritis international Society (ASAS) response and remission criteria, disease activity, relapse, and safety., Results: We included 6 randomized trials with 747 participants (442 with ankylosing spondylitis and 305 with nonradiographic axial SpA). Compared to the standard dose, there were fewer events with the reduced dose for the ASAS criteria for 40% improvement (risk ratio [RR] 0.62 [95% confidence interval (95% CI) 0.49, 0.78]) and for ASAS partial remission (RR 0.17 [95% CI 0.06, 0.46]). There was a mean increase in the Bath Ankylosing Spondylitis Disease Activity Index score (mean difference [MD] 0.35 [95% CI 0.10, 0.60]) and no difference in C-reactive protein levels (MD 0.16 [95% CI -0.76, 1.07]) with the reduced dose. There were more disease flares/relapses (RR 1.73 [95% CI 1.32, 2.27]) with the reduced dose. There were no differences in infection rates (incidence rate ratio [IRR] 0.98 [95% CI 0.76, 1.25]) or injection/infusion reactions (IRR 0.71 [95% CI 0.42, 1.19])., Conclusion: Patients with axial SpA may experience little to no clinical benefit from reduction of TNFi therapy. Maintaining the standard dose probably improves the sustained effect on disease activity and helps to prevent disease flare., (© 2020, American College of Rheumatology.)

Circulating miRNAs appear promising therapeutic and prognostic biomarkers. We aimed to investigate the predictive value of circulating miRNAs on the disease outcome following anti-TNF therapy in patients with ankylosing spondylitis (AS). Our study included 19 AS patients assessed at baseline (M0), after three (M3) and twelve months (M12) of therapy. Total RNA was isolated from plasma. A comprehensive analysis of 380 miRNAs using TaqMan Low Density Array (TLDA) was followed by a single assay validation of selected miRNAs. All AS patients had high baseline disease activity and an excellent response to anti-TNF therapy at M3 and M12. TLDA analysis revealed the dysregulation of 17 circulating miRNAs, including miR-145. Single assay validation confirmed that miR-145 is significantly downregulated at M3 compared to baseline. The decrease in the levels of miR-145 from M0 to M3 negatively correlated with the change in BASDAI from M0 to M3; and positively correlated with disease activity improvement from M3 to M12 as per BASDAI and ASDAS. The predictive value of the early change in miR-145 and levels of miR-145 at M3 were further validated by Receiver operating curves analysis. We show thatthe early change in circulating miR-145 may be a predictor for the future outcome ofAS patients treated with TNF inhibitors. Patients with a more significant decrease in miR-145 levels may show further significant improvement of disease activity after 12 months. Monitoring the expression of miR-145 in plasma in AS patients may, therefore, influence our therapeutic decision-making.

Background: Genetic polymorphisms in the endoplasmic reticulum aminopeptidase gene ERAP2 has been attributed with the etiopathogenesis of ankylosing spondylitis (AS). Here we assessed the association of ERAP2 gene single nucleotide polymorphisms (SNPs) with AS predisposition in Iranian patients and determined their effect on the inflammatory state of the patients., Methods: For genotyping of rs2548538, rs2287988, and rs17408150 SNPs using a real-time allelic discrimination approach, DNA was extracted from the whole blood of 250 AS patients and 250 healthy individuals. RNA of the peripheral blood mononuclear cells was separated, cDNA was synthesized, and transcriptional levels of cytokines, including interleukin (IL)-17A, IL-23, IL-10, and transforming growth factor-β, were measured. Enzyme-linked immunosorbent assay was used to measure the serum concentration on the cytokines., Results: Three ERAP2 gene SNPs were not associated significantly with AS risk. Nonetheless, rs2287988 and rs17408150 SNPs showed statistically significant association with susceptibility to the disease in those AS patients who were positive for human leukocyte antigen (HLA)-B27. Transcriptional level and serum concentration of IL-17A and IL-23 were higher, but those of IL-10 were lower in both AS patients and the HLA-B27-positive patient group relative to the control group. Nevertheless, ERAP2 gene SNPs in the HLA-B27-positive AS patients did not affect the transcription level and serum concentration of cytokines., Conclusions: ERAP2 gene rs2287988 and rs17408150 SNPs are associated with susceptibility to AS, but they are probably not determining the levels of IL-17A, IL-23, and IL-10 in this disease., (© 2021 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease which mainly affects the spine, sacroiliac joint and peripheral joints. To date, the exact causes and pathogenesis of AS still remain unknown. It is considered that the pathogenesis of AS is associated with genetic, infection, environment, immunity and other factors. Among them, the role of genetic factors in the pathogenesis of AS has been studied most deeply. However, over the past few years, the function of environmental predisposition and epigenetic modification in the pathogenesis of AS has received extensive attention. This paper summarizes the recent progress in the epigenetics of AS, including abnormal epigenetic modifications at AS-associated genomic loci, such as DNA methylation, histone modification, microRNA, and so on. In summary, the findings of this review attempt to explain the role of epigenetic modification in the occurrence and development of AS. Nevertheless, there are still unknown and complicated aspects worth exploring to deepen our understanding of the pathogenesis of AS., (© 2021 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Background and Objective: Stroke is a major contributor to the global burden of disease. Although numerous modifiable risk factors (RF) for stroke have been identified, some remain unexplained. Increasing studies have investigated stroke risk in arthritis, but their results are inconsistent. We aimed to synthesize, quantify, and compare the risk of stroke for the major types of arthritis in cohort studies by using a systematic review and meta-analysis approach., Methods: We searched Chinese and English databases to identify relevant studies from inception to April 30, 2020. Only studies adjusting at least for age and sex were included. We calculated pooled effect estimates for relative risk (RR) and 95% confidence interval (CI) and identified potential sources of heterogeneity and publication bias., Results: A total of 1,348 articles were retrieved, and after an preliminary screening of titles and abstracts, 69 were reviewed for full text, and finally, 32 met the criteria for meta-analysis. Stroke risk in arthritis was significantly increased in studies adjusting for age and sex (RR = 1.36, 95% CI: 1.27-1.46) and for at least one traditional risk factor (RR = 1.40, 95% CI: 1.28-1.54). The results of studies stratified by stroke subtype were consistent with the main finding (ischemic stroke: RR = 1.53, 95% CI: 1.32-1.78; hemorrhagic stroke: RR = 1.45, 95% CI: 1.15-1.84). In subgroup analysis by arthritis type, stroke risk was significantly increased in rheumatoid arthritis (RR = 1.38, 95% CI: 1.29-1.48), ankylosing spondylitis (RR = 1.49, 95% CI: 1.25-1.77), psoriatic arthritis (RR = 1.33, 95% CI: 1.22-1.45), and gout (RR = 1.40, 95% CI: 1.13-1.73) but not osteoarthritis (RR = 1.03, 95% CI: 0.91-1.16). Age and sex subgroup analyses indicated that stroke risk was similar by sex (women: RR = 1.47, 95% CI: 1.31-1.66; men: RR = 1.44, 95% CI: 1.28-1.61); risk was higher with younger age (<45 years) (RR = 1.46, 95% CI: 1.17-1.82) than older age (≥65 years) (RR = 1.17, 95% CI: 1.08-1.26)., Conclusions: Stroke risk was increased in multiple arthritis and similar between ischemic and hemorrhagic stroke. Young patients with arthritis had the highest risk., Competing Interests: The authors have declared that no competing interests exist.

Heritability of Spondyloarthritis (SpA) is highlighted by several familial studies and a high association with the presence of human leukocyte antigen (HLA)-B * 27. Though it has been over four decades since the association of HLA-B * 27 with SpA was first determined, the pathophysiological roles played by specific HLA-B * 27 allotypes are not fully understood. Popular hypotheses include the presentation of arthritogenic peptides, triggering of endoplasmic reticulum (ER) stress by misfolded HLA-B * 27, and the interaction between free heavy chains or heavy chain homodimers of HLA-B * 27 and immune receptors to drive IL-17 responses. Several non-HLA susceptibility loci have also been identified for SpA, including endoplasmic reticulum aminopeptidases (ERAP) and those related to the IL-23/IL-17 axes. In this review, we summarize clinical aspects of SpA including known characteristics of gut inflammation, enthesitis and new bone formation and the existing models for understanding the association of HLA-B * 27 with disease pathogenesis. We also examine newer insights into the biology of HLA class I (HLA-I) proteins and their implications for expanding our understanding of HLA-B * 27 contributions to SpA pathogenesis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kavadichanda, Geng, Bulusu, Negi and Raghavan.)

Ankylosing spondylitis (AS) is a common form of inflammatory spinal arthritis with a complex polygenic aetiology. Genome-wide association studies have identified more than 100 loci, including some involved in antigen presentation ( HLA-B27 , ERAP1 , and ERAP2 ), some in Th17 responses ( IL6R, IL23R, TYK2 , and STAT3 ), and others in macrophages and T-cells ( IL7R, CSF2 , RUNX3 , and GPR65 ). Such observations have already helped identify potential new therapies targeting IL-17 and GM-CSF. Most AS genetic associations are not in protein-coding sequences but lie in intergenic regions where their direct relationship to particular genes is difficult to assess. They most likely reflect functional polymorphisms concerned with cell type-specific regulation of gene expression. Clarifying the nature of these associations should help to understand the pathogenic pathways involved in AS better and suggest potential cellular and molecular targets for drug therapy. However, even identifying the precise mechanisms behind the extremely strong HLA-B27 association with AS has so far proved elusive. Polygenic risk scores (using all the known genetic associations with AS) can be effective for the diagnosis of AS, particularly where there is a relatively high pre-test probability of AS. Genetic prediction of disease outcomes and response to biologics is not currently practicable., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wordsworth, Cohen, Davidson and Vecellio.)

Aim: Ankylosing spondylitis (AS) pathogenesis has focused on the adaptive immune response; however, innate immune responses may also play a role in the inflammatory response of AS. Dysregulated neutrophil activation can induce tissue damage and contribute to the pathogenesis of immune-related diseases. Hence, the aim of this study was to assess the effect of immune complexes formed with the p30 of Salmonella typhimurium and anti-p30 antibodies present in the sera of AS patients and controls in inducing the release of neutrophil extracellular traps (NETs) and the secretion of pro-inflammatory cytokines., Methods: We collected polymorphonuclear leukocytes (PMNs) from healthy donors. The PMNs isolated were stimulated with p30 alone or in immunocomplexes formed with antibodies presents in sera of AS patients or control subjects. Then, the NETs were analyzed by fluorescence microscopy. Concentrations of interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, IL-8 and IL-10, were determined using the Cytometric Bead Array kit., Results: Significant difference was observed in the release of NETs between the neutrophils stimulated with p30 + AS (70.52 ± 16.24) those unstimulated neutrophils (9.94 ± 12.12; P = .0095), stimulated with phorbol 12-myristate 13-acetate (39.78 ± 14.50; P = .0190), stimulated with control serum (CS) (10.85 ± 5.33; P = .0082) and serum of AS patient (10.28 ± 6.15; P = .0087). The stimulation of neutrophils with p30 alone induced a relatively low production of IL-6 (64.5 pg/mL), IL-8 (2658.3 pg/mL), IL-1β (31.11 pg/mL), and TNF-α (3.8 pg/mL), compared to p30 + AS and p30 + CS groups., Conclusion: Our results show that neutrophils release NETs and pro-inflammatory cytokines in response to p30 in immunocomplexes. These findings could improve our understanding of the role of innate immunity in the initiation and/or maintenance of inflammatory responses, and in the progression of AS., (© 2021 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

The aims of this study was to investigate the influences of hsa&#95;circ&#95;0056558/miR-1290/CDK6 axis in ankylosing spondylitis (AS). The differentially expressed has&#95;circ&#95;0056558 and miR-1290 in AS tissue were analysed based on RNA-seq data and microarray data, respectively. qRT-PCR was performed for detection of relative expression levels of hsa&#95;circ&#95;0056558, miR-1290, CDK6, osteogenic differentiation markers (Runx2 and Osterix) and other inflammatory factors (TNF-α, IL-1β, and IL-6). Western blotting analysis was conducted to test the protein levels of CDK6, osteogenic differentiation markers (Runx2 and Osterix), and PI3K/AKT/NF-κB pathway-associated proteins. CCK8 assay and flow cytometry were conducted to determine cell proliferation and cell apoptotic ability, respectively. Targeted relationships were predicted by bioinformatic analysis and verified by dual-luciferase reporter assay. The differentiation of fibroblast cells was analysed by alkaline phosphatase (ALP) activity assay. Our findings revealed that the expression levels of both circ&#95;0056558 and CDK6 in AS tissue were significantly higher than that in normal samples. Besides, hsa&#95;circ&#95;0056558 could suppress cell proliferation and differentiation by facilitating CDK6 expression and suppressing miR-1290 expression in AS. Over-expression of miR-1290 negatively regulated CDK6 expression to enhance cell proliferation. The protein levels of p-AKT, p-NF-κB p65, and p-IκBα were promoted by hsa&#95;circ&#95;0056558 or CDK6 over-expression while suppressed by miR-1290 up-regulation. In conclusion, our study demonstrated that hsa&#95;circ&#95;0056558 and CDK6 suppressed cell proliferation and differentiation while enhanced cell apoptosis by competitive binding to miR-1290 in AS, which might be possibly achieved by PI3K/AKT/NF-κB pathway, providing us novel therapeutic strategy for AS.

Axial spondyloarthritis is a prevalent form of chronic arthritis which is related to psoriatic arthritis and skin psoriasis. TNF and IL-17A as well as IL-17F are key cytokines contributing to the pathobiology of this disease, as evidence by the therapeutic efficacy of inhibition of these factors. Despite the evidence that IL-23 acts as an upstream driver of Th17 cells, the T lymphocytes producing IL-17, and that IL-23 inhibition shows profound efficacy in psoriasis, blocking IL-23 failed to show any evidence of clinical efficacy in axial spondyloarthritis. In this viewpoint article, we revisit the reasons-to-believe in a role of IL-23 in the pathobiology of axial spondyloarthritis, discuss what we have learned on the pathobiology of this disease in general and on the function of the IL-23/IL-17 axis in particular, and share a handful of lessons learned that are of relevance for the translation of emerging biological insights into clinical therapeutics., Competing Interests: DB is currently an employee of UCB Pharma. IA received research grants from Pfizer, Tanabe Research Labs, Merck, and Novartis., (Copyright © 2021 Baeten and Adamopoulos.)

Genome-wide association studies (GWAS) have identified 113 single nucleotide polymorphisms (SNPs) affecting the risk of developing ankylosing spondylitis (AS), and an on-going GWAS study will likely identify 100+ new risk loci. The translation of genetic findings to novel disease biology and treatments has been difficult due to the following challenges: (1) difficulties in determining the causal genes regulated by disease-associated SNPs, (2) difficulties in determining the relevant cell-type(s) that causal genes exhibit their function(s), (3) difficulties in determining appropriate cellular contexts to interrogate the functional role of causal genes in disease biology. This review will discuss recent progress and unanswered questions with a focus on these challenges. Additionally, we will review the investigation of biology and the development of drugs related to the IL-23/IL-17 pathway, which has been partially driven by the AS genetics, and discuss what can be learned from these studies for the future functional and translational study of AS-associated genes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Nancy, Yan, Hui, Paul and Liye.)

Objectives: This study was designed to evaluate the role of anti-CD74 antibodies in diagnosis of axial spondyloarthritis (axSpA) and their relationship to disease duration and disease activity., Methods: Fifty patients with axSpA, 15 patients with RA and 15 healthy subjects were included in the study. Clinical examination and laboratory tests were done. The ESR, CRP level and ASDAS were measured as markers of the disease activity. Quantitative determination of human CD74 IgG antibodies was done., Results: The mean age of the patients was 38.22 (S.D.12.20) years. The level of CD74 autoantibodies was significantly higher in axSpA in comparison to control groups. Most patients with positive articular and extra-articular manifestations were positive for CD74 autoantibodies. In patients with inactive disease, 33.3% were positive for CD74 autoantibodies, as were 83% with active disease. High percentages of patients with early and late axSPA were CD74 autoantibody positive. The majority of patients with positive disease activity in early and late axSpA were CD74 autoantibody positive. CD74 autoantibodies had 80% sensitivity vs both control groups with 87% specificity vs the healthy control group and 80% vs the RA control group in the diagnosis of axSpA., Conclusions: The frequency of positive anti-CD74 IgG antibodies was as high in patients with early axSpA as in those with late axSpA, with no significant differences. There was a significant difference in the frequency of positive anti-CD74 IgG antibodies between patients with positive and negative disease activity. Based on the sensitivity and specificity of anti-CD74 IgG, this is a promising diagnostic tool to support the clinical diagnosis of axSpA., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Importance: Approximately one-quarter of the global population have latent tuberculosis infection (LTBI), and tuberculosis (TB) is accountable for more than 1.5 million deaths annually. Methotrexate, cyclosporine, and tumor necrosis factor inhibitors may be associated with increased risk of TB and LTBI reactivation, although data are limited on the risks of TB with use of newer biologics., Objective: To assess the association of secukinumab with reporting of active TB development, TB reactivation, and LTBI activation as an adverse event (AE) in patients with psoriasis, psoriatic arthritis, or ankylosing spondylitis., Design, Setting, and Participants: This pooled cohort study pooled data from 28 clinical trials of secukinumab used in psoriasis (17 phase 3 or 3b and 2 phase 4 trials), psoriatic arthritis (5 phase 3 trials), and ankylosing spondylitis (4 phase 3 trials). A search of the Novartis Secukinumab Compound Pool Database was conducted for the 28 trials. All trial participants who had received at least 1 approved subcutaneous dose of secukinumab (150 mg or 300 mg) were included. Before randomization in these trials, patients underwent screening for TB. Patients with active TB were excluded, and patients with LTBI were treated according to local guidelines. Data were analyzed from the start of treatment in the individual studies through December 25, 2018., Main Outcomes and Measures: Reporting of active TB or LTBI as an AE over a 5-year period using exposure-adjusted incidence rates (EAIR; incidence rates per 100 patient-years)., Results: A total of 12 319 patients were included, of whom 8819 patients had psoriasis (71.6%; 5930 men [67.2%]; mean [SD] age, of 44.9 [13.5] years), 2523 had psoriatic arthritis (20.5%; 1323 women [52.4%]; mean [SD] age, 48.8 [12.1] years), and 977 had ankylosing spondylitis (7.3%; 658 men [67.3%]; mean [SD] age, 42.3 [11.9] years). In the total population, 684 patients (5.6%) had tested positive for LTBI at screening. Over 5 years, LTBI as an AE during secukinumab treatment was reported in 13 patients (0.1% of 12 319). Of these 13 patients, 6 had a prior positive LTBI test result, and 7 were newly diagnosed as having LTBI. Four of the 7 patients had psoriasis (EAIR, 0.03; 95% CI, 0.01-0.07), 1 had psoriatic arthritis (EAIR, 0.02; 95% CI, 0.00-0.11), and 2 had ankylosing spondylitis (EAIR, 0.08; 95% CI, 0.01-0.28). No cases of active TB were reported., Conclusions and Relevance: This study found that LTBI reported as an AE after secukinumab treatment was uncommon and appeared to support the use of secukinumab in chronic systemic inflammatory conditions.

Objectives: Janus kinase inhibitors (JAKi) have been approved for use in various immune-mediated inflammatory diseases. With five agents licensed, it was timely to summarise the current understanding of JAKi use based on a systematic literature review (SLR) on efficacy and safety., Methods: Existing data were evaluated by a steering committee and subsequently reviewed by a 29 person expert committee leading to the formulation of a consensus statement that may assist the clinicians, patients and other stakeholders once the decision is made to commence a JAKi. The committee included patients, rheumatologists, a gastroenterologist, a haematologist, a dermatologist, an infectious disease specialist and a health professional. The SLR informed the Task Force on controlled and open clinical trials, registry data, phase 4 trials and meta-analyses. In addition, approval of new compounds by, and warnings from regulators that were issued after the end of the SLR search date were taken into consideration., Results: The Task Force agreed on and developed four general principles and a total of 26 points for consideration which were grouped into six areas addressing indications, treatment dose and comedication, contraindications, pretreatment screening and risks, laboratory and clinical follow-up examinations, and adverse events. Levels of evidence and strengths of recommendations were determined based on the SLR and levels of agreement were voted on for every point, reaching a range between 8.8 and 9.9 on a 10-point scale., Conclusion: The consensus provides an assessment of evidence for efficacy and safety of an important therapeutic class with guidance on issues of practical management., Competing Interests: Competing interests: DA has received grants from AbbVie, Novartis and Roche, consulting and lecture fees from Abbvie, Amgen, Celgene, Lilly, Medac, Merck Sharpe & Dohme, Novartis, Pfizer, Roche, Sandoz and Sanofi/Genzyme. W-HB has received a research grant from Pfizer and honoraria for advice from Abbvie, Alimirall, BMS, Celgene, Janssen, Leo, Lilly, Novartis and UCB. TD received study support and/or consulting fees by AbbVie, Celgene, Eli-Lilly, EMD/Merck, Janssen, Novartis, Pfizer, Roche, Sanofi, UCB Pharma. MD: grants from Pfizer, Abbvie, UCB, Janssen, Novartis and honoraria from Pfizer, Abbvie, UCB, Janssen, MSD, Novartis, BMS, Celgene, Biogen, Sandoz. PE: grants from AbbVie, Novartis, Samsung, Lilly and honoraria from AbbVie, Novartis, BMS, Gilead, Samsung, Lilly. XB, KG received consultancy and lecture fees from Novartis, Pfizer and Roche and investigational grants from Roche. EBL reports grants from Green pharma, Seoul, grants from Handoc, Seoul, and personal fees from Pfizer. PTN has received research grants and funding for clinical trials and honoraria for advice and lectures on behalf of Abbvie, BMS, Boehringer Ingelheim, Celgene, Eli-Lilly, Gilead, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, UCB Pharma. JEP has consulted for Amgen, AbbVie, BMS, Celltrion, Gilead, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, Samsung, Sandoz, Sanofi, Teva, UCB. RMF has received research grants and funding for clinical trials and honoraria for adbice from Abbvie, Amgen, Astra-Zeneca, BMS, Celltrion, Lilly, Gilead, GSK, Janssen, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi, Tahio and UCB. DvdH received consulting fees AbbVie, Amgen, Astellas, AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma and is Director of Imaging Rheumatology bv. JDI has received research funding or honoraria from Abbvie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche. AK has received lecture fees from Bristol-Myers Squibb, Celgene, Merck Sharp and Dohme and Pfizer. JK received grant support for clinical research from Abbvie, BMS, Lilly, Novartis, Pfizer and consulted with Abbvie, BMS, Lilly, Novartis, Pfizer and Regeneron/Sanofi. IBM has received research funding or honoraria from Abbvie, Astra Zeneca, Celgene, GSK, Lilly, Boehringer, Pfizer, Janssen, Novartis, UCB, BMS, Sanofi. WPM has served as a consultant, and/or received honoraria and/or has received research/educational grants from AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly and Company, Galapagos, Janssen, Novartis, Pfizer and UCB Pharma, and is Chief Medical Officer of CARE Arthritis Limited. MV: no conflict of interest. JSS has received research Grants for his institution from AbbVie, BMS, Lilly, MSD, Pfizer, Roche and honoraria for consultancies and/or speaking engagements: Abbvie, Amgen, Astra-Zeneca, Astro-Celltrion, BMS, Celgene, ILTOO, Janssen, Lilly, MSD, Novartis-Sandoz, Pfizer, Roche, Samsung, Sanofi, UCB. MS-M has no conflicts of interest. LST received grant support from Janssen, GSK and Pfizer and honoraria for consultations and/or speaking engagements from Janssen, Pfizer, Sanofi, Abbvie and Lilly. TT received grants from Astellas, AbbVie GK, Eisai; speaking fee from: AbbVie GK, Eli Lilly Japan, Astellas, Eisai, Gilead, Pfizer Japan; and consultancy fees from: Astellas, AbbVie GK, Gilead. YT has received speaking fees and/or honoraria from Daiichi-Sankyo, Eli Lilly, Novartis, YL Biologics, Bristol-Myers, Eisai, Chugai, Abbvie, Astellas, Pfizer, Sanofi, Asahi-kasei, GSK, Mitsubishi-Tanabe, Gilead, Janssen and has received research grants from Mitsubishi-Tanabe, Chugai, Abbvie, Takeda, UCB, Daiichi-Sankyo, Eisai. MT: Speaker for BMS, Falk Foundation, Gilead and MSD; advisory boards for Albireo, BiomX, Boehringer Ingelheim, Falk Pharma GmbH, Genfit, Gilead, Intercept, MSD, Novartis, Phenex and Regulus. He further received unrestricted research grants from Albireo, Cymabay, Falk, Gilead, Intercept, MSD and Takeda. He is also co-inventor of patents on the medical use of norUDCA (filed by the medical University of Graz as previous employer). FvdB received consultancy and/or speaker fees from Abbvie, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Merck, Novartis, Pfizer and UCB. MdW has received honoraria for consultancies and speaking through Stichting Tools from AbbVie, BMS, Celgene, Janssen, Lilly, Novartis, Pfizer, Roche. RW: honoraria for speaking engagements and advice from Galapagos, Gilead and Celltrion. KLW received grant support from BMS and Pfizer and honoraria for consultations and /or speaking engagements from Pfizer, BMS, Abbvie, Gilead, Galapagos, Lilly, GSK, UCB. RX received consultancy and/or speaker fees from Abbvie, Lilly, Pfizer, UCB, Janssen., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The strong association with the Major Histocompatibility Complex (MHC) class I genes represents a shared trait for a group of autoimmune/autoinflammatory disorders having in common immunopathogenetic basis as well as clinical features. Accordingly, the main risk factors for Ankylosing Spondylitis (AS), prototype of the Spondyloarthropathies (SpA), the Behçet's disease (BD), the Psoriasis (Ps) and the Birdshot Chorioretinopathy (BSCR) are HLA-B*27, HLA-B*51, HLA-C*06:02 and HLA-A*29:02, respectively. Despite the strength of the association, the HLA pathogenetic role in these diseases is far from being thoroughly understood. Furthermore, Genome-Wide Association Studies (GWAS) have highlighted other important susceptibility factors such as Endoplasmic Reticulum Aminopeptidase (ERAP) 1 and, less frequently, ERAP2 that refine the peptidome presented by HLA class I molecules to CD8 + T cells. Mass spectrometry analysis provided considerable knowledge of HLA-B*27, HLA-B*51, HLA-C*06:02 and HLA-A*29:02 immunopeptidome. However, the combined effect of several ERAP1 and ERAP2 allelic variants could generate an altered pool of peptides accounting for the "mis-immunopeptidome" that ranges from suboptimal to pathogenetic/harmful peptides able to induce non-canonical or autoreactive CD8 + T responses, activation of NK cells and/or garbling the classical functions of the HLA class I molecules. This review will focus on this class of epitopes as possible elicitors of atypical/harmful immune responses which can contribute to the pathogenesis of chronic inflammatory diseases.

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Background: Tumor necrosis factor-α (TNF-α) inhibitor (TNFI)-induced psoriasis remains poorly understood despite having been described 15 years ago. As TNFIs often provide life-changing patient benefits, understanding effective treatments for TNFI-induced psoriasis is important., Objective: We characterized a cohort of patients with TNFI-induced psoriasis whose psoriasis was specifically diagnosed and managed or comanaged by dermatologists at a single tertiary care institution over a 10-year period., Methods: Retrospective review of patients in whom TNFI-induced psoriasis was diagnosed between 2003 and 2013., Results: A total of 102 patients with TNFI-induced psoriasis were identified. The mean age of onset was 40 years, and there was a female predominance (73.5%). Crohn's disease (in 48% of cases) and rheumatoid arthritis (in 24.5% of cases) were the most common primary conditions. Infliximab (in 52% of cases) was the most common inciting agent. The most common TNFI-induced psoriasis subtypes were plaque-type psoriasis (49.5%), scalp psoriasis (47.5%), and palmoplantar pustulosis (41%). Topical medications alone improved or resolved TNFI-induced psoriasis in 63.5% of patients, and cyclosporine and methotrexate (>10 mg weekly) were often effective if topicals failed. Discontinuation of the inciting TNFI with or without other interventions improved or resolved TNFI-induced psoriasis in 67% of refractory cases, whereas switching TNFIs resulted in persistence or recurrence in 64%., Limitations: Retrospective nature of the study and the fact that some patients may have developed typical psoriasis unresponsive to TNFIs., Conclusion: Our study cohort represents the largest single-institution cohort of patients with TNFI-induced psoriasis diagnosed and managed or comanaged by dermatologists to date. On the basis of our findings, we propose a treatment algorithm for TNFI-induced psoriasis., (Copyright © 2018 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Spondyloarthritis comprises a group of inflammatory diseases of the joints and spine, with various clinical manifestations. The group includes ankylosing spondylitis, reactive arthritis, psoriatic arthritis, arthritis associated with inflammatory bowel disease, and undifferentiated spondyloarthritis. The exact etiology and pathogenesis of spondyloarthritis are still unknown, but five hypotheses explaining the pathogenesis exist. These hypotheses suggest that spondyloarthritis is caused by arthritogenic peptides, an unfolded protein response, HLA-B*27 homodimer formation, malfunctioning endoplasmic reticulum aminopeptidases, and, last but not least, gut inflammation and dysbiosis. Here we discuss the five hypotheses and the evidence supporting each. In all of these hypotheses, HLA-B*27 plays a central role. It is likely that a combination of these hypotheses, with HLA-B*27 taking center stage, will eventually explain the development of spondyloarthritis in predisposed individuals.

Ankylosing spondylitis (AS) is a common immune-mediated inflammatory arthritis with a strong genetic predisposition. We review recent data from genetic and animal studies highlighting the importance of Type 17 immune responses. Furthermore, the efficacy (or lack thereof) of different anti-cytokine monoclonal antibodies has highlighted the diversity of Type 17 immune cells and cytokines critical to AS and related spondyloarthritis pathogenesis. Recent studies have strongly implicated the gut microbiome in AS. Finally, we propose that the local metabolic environment of the joint may have a key role in driving AS, and present a novel model of AS pathogenesis., (© 2020 The Authors. Immunology published by John Wiley & Sons Ltd.)

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.

Objectives: Semaphorin 4D (Sema4D) is constitutively expressed on T cells and osteoclasts, and regulates T cell proliferation and bone remodeling. In addition, several studies have shown that Sema4D is involved in the pathogenesis of autoimmunity. We undertook this study to investigate the mechanism by which Sema4D affects the pathogenic progress of ankylosing spondylitis (AS)., Methods: Soluble Sema4D (sSema4D) levels in serum were analyzed by enzyme-linked immunosorbent assay. The cell surface levels and transcripts of Sema4D were evaluated in CD4 + and CD19 + cells from the AS patients and healthy individuals. The mRNA expression levels were assessed by quantitative polymerase chain reaction (qPCR). The proportions of Treg cells and IL-17-producing T-cells (Th17 cells) differentiated from CD4 + T cells were analyzed by flow cytometric analysis. The aryl hydrocarbon receptor (AhR) agonistic effect of Sema4D was detected by analyzing the activation of downstream signaling pathways and target genes using Luciferase and EROD assay., Results: Levels of sSema4D were elevated in both serum from AS patients, and clinical features markers were correlated with serum sSema4D levels. Sema4D facilitated CD4 + T cells proliferation and Th17 cells differentiation and inhibited Treg cells differentiation by enhancing RORγt expression and reducing Foxp3 expression, with increasing expression and secretion of IL-17 and IL-22. It induced the expression and activity of AhR target gene CYP1A1 and XRE reporter activity via interaction with CD72., Conclusion: These findings indicate that Sema4D as a potent activator of T cells in the immune response contributes to the inflammation of AS by inducing imbalance in Th17 and Treg cell populations in an AhR-dependent manner, suggesting it is a crucial participant in AS pathogenesis., (Copyright © 2020 Xie, Wang and Wang.)

Objective: To assess the incidence rate and risk of ankylosing spondylitis (AS) in patients with previous human papillomavirus (HPV) infection compared with those without HPV infection., Methods: All patients with HPV infection (n = 66,314) in the NHIRD (2003-2013) were individually matched with up to four control subjects without HPV infection by age and sex (n = 265,256). All of the patients were tracked until an AS event was noted. Chi-square test was used to analyze the distribution of sociodemographic characteristics in the HPV cohort and non-HPV cohort. Cox proportional hazards regression was used to calculate the HRs for the development of AS, adjusting for age, sex, urbanization, length of hospital stay, medications, and comorbidities adjustment. The Kaplan-Meier method was used to plot the cumulative incidence curves., Results: The HPV cohort had a 1.329 (95% C.I. = 1.138-1.552) times higher risk of AS than that of the non-HPV cohort after adjusting for sex, age, urbanization, length of hospital stay, comorbidities, and medications. Additionally, we applied propensity score weighting to reconfirm the accuracy of our analysis, and the results showed a 1.348 (95% C.I. = 1.153-1.575) times greater risk of AS in the HPV cohort compared with the non-HPV cohort. The cumulative incidence curves plotted by the Kaplan-Meier method revealed that after 120 follow-up months, the HPV cohort displayed a higher cumulative incidence of AS than that of the non-HPV cohort. (Log-rank test p < 0.0001)., Conclusions: Patients with HPV infection had a higher risk of developing AS compared with non-HPV patients., (Copyright © 2020. Published by Elsevier Ltd.)

Interleukin (IL)-17A is a key driver of inflammation and the principal target of anti-IL-17 therapeutic monoclonal antibodies. IL-17A, and its structurally similar family member IL-17F, have been shown to be functionally dysregulated in certain human immune-mediated inflammatory diseases such as psoriasis, psoriatic arthritis, and axial spondyloarthritis. Given the overlapping biology of these two cytokines, we postulated that dual neutralization of IL-17A and IL-17F may provide a greater depth of clinical response in IL-17-mediated diseases than IL-17A inhibition alone. We identified 496.g1, a humanized antibody with strong affinity for IL-17A but poor affinity for IL-17F. Affinity maturation of 496.g1 to 496.g3 greatly enhanced the affinity of the Fab fragment for IL-17F while retaining strong binding to IL-17A. As an IgG1, the affinity for IL-17A and IL-17F was 3.2 pM and 23 pM, respectively. Comparison of 496.g3 IgG1 with the commercially available anti-IL-17A monoclonal antibodies ixekizumab and secukinumab, by surface plasmon resonance and in a human in vitro IL-17A functional assay, showed that 496.g3 and ixekizumab display equivalent affinity for IL-17A, and that both antibodies are markedly more potent than secukinumab. In contrast to ixekizumab and secukinumab, 496.g3 exhibited the unique feature of also being able to neutralize the biological activity of IL-17F. Therefore, antibody 496.g3 was selected for clinical development for its ability to neutralize the biologic function of both IL-17A and IL-17F and was renamed bimekizumab (formerly UCB4940). Early clinical data in patients with psoriasis, in those with psoriatic arthritis, and from the Phase 2 studies in psoriasis, psoriatic arthritis, and ankylosing spondylitis, are encouraging and support the targeted approach of dual neutralization of IL-17A and IL-17F. Taken together, these findings provide the rationale for the continued clinical evaluation of bimekizumab in patients with immune-mediated inflammatory diseases., (Copyright © 2020 Adams, Maroof, Baker, Lawson, Oliver, Paveley, Rapecki, Shaw, Vajjah, West and Griffiths.)

Objective: Ankylosing spondylitis (AS) is a common spondyloarthropathy primarily affecting the axial skeleton and strongly associated with HLA-B*27 carriage. Genetic evidence implicates both autoinflammatory processes and autoimmunity against an HLA-B*27-restricted autoantigen in immunopathology. In addition to articular symptoms, up to 70% of AS patients present with concurrent bowel inflammation, suggesting that adverse interactions between a genetically primed host immune system and the gut microbiome contribute to the disease. Accordingly, this study aimed to characterize adaptive immune responses to antigenic stimuli in AS., Methods: The peripheral CD4 and CD8 T cell receptor (TCR) repertoire was profiled in AS patients (n = 47) and HLA-B*27-matched healthy controls (n = 38). Repertoire diversity was estimated using the Normalized Shannon Diversity Entropy (NSDE) index, and univariate and multivariate statistical analyses were performed to characterize AS-associated clonal signatures. Furthermore, T cell proliferation and cytokine production in response to immunogenic antigen exposure were investigated in vitro in peripheral blood mononuclear cells from AS patients (n = 19) and HLA-B*27-matched healthy controls (n = 14)., Results: Based on the NSDE measure of sample diversity across CD4 and CD8 T cell repertoires, AS patients showed increased TCR diversity compared to healthy controls (for CD4 T cells, P = 7.8 × 10 -6 ; for CD8 T cells, P = 9.3 × 10 -4 ), which was attributed to a significant reduction in the magnitude of peripheral T cell expansions globally. Upon in vitro stimulation, fewer T cells from AS patients than from healthy controls expressed interferon-γ (for CD8 T cells, P = 0.03) and tumor necrosis factor (for CD4 T cells, P = 0.01; for CD8 T cells, P = 0.002). In addition, the CD8 TCR signature was altered in HLA-B*27+ AS patients compared to healthy controls, with significantly expanded Epstein-Barr virus-specific clonotypes (P = 0.03) and cytomegalovirus-specific clonotypes (P = 0.02). HLA-B*27+ AS patients also showed an increased incidence of "public" CD8 TCRs, representing identical clonotypes emerging in response to common antigen encounters, including homologous clonotypes matching those previously isolated from individuals with bacterial-induced reactive arthritis., Conclusion: The dynamics of peripheral T cell responses in AS patients are altered, suggesting that differential antigen exposure and disrupted adaptive immunity are underlying features of the disease., (© 2020 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Ankylosing spondylitis (AS) is associated with autoantibody production to class II MHC-associated invariant chain peptide, CD74/CLIP. In this study, we considered that anti-CD74/CLIP autoantibodies present in sera from AS might recognize CD74 degradation products that accumulate upon deficiency of the enzyme signal peptide peptidase-like 2A (SPPL2a). We analyzed monocytes from healthy controls (n = 42), psoriatic arthritis (n = 25), rheumatoid arthritis (n = 16), and AS patients (n = 15) for SPPL2a enzyme activity and complemented the experiments using SPPL2a-sufficient and -deficient THP-1 cells. We found defects in SPPL2a function and CD74 processing in a subset of AS patients, which culminated in CD74 and HLA class II display at the cell surface. These findings were verified in SPPL2a-deficient THP-1 cells, which showed expedited expression of MHC class II, total CD74 and CD74 N-terminal degradation products at the plasma membrane upon receipt of an inflammatory trigger. Furthermore, we observed that IgG anti-CD74/CLIP autoantibodies recognize CD74 N-terminal degradation products that accumulate upon SPPL2a defect. In conclusion, reduced activity of SPPL2a protease in monocytes from AS predisposes to endosomal accumulation of CD74 and CD74 N-terminal fragments, which, upon IFN-γ-exposure, is deposited at the plasma membrane and can be recognized by anti-CD74/CLIP autoantibodies., (© 2020 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

HLA associations have been linked to many diseases and are important for risk assessment of drug hypersensitivity reactions. The increasing number of HLA alleles discovered generated a list of ambiguities that cannot be resolved with the current clinical assays, which commonly include sequence-specific oligonucleotide probe (SSOP) genotyping, and real-time PCR with melting curve analysis. HLA typing by next-generation sequencing (NGS) has recently been adopted by clinical laboratories for transplantation testing, as it provides unambiguous and cost-effective HLA typing. The goal of this study was to evaluate the feasibility of using NGS-based HLA-B and DQ genotyping for clinical HLA disease association testing, and provide direct comparison with the currently used clinical tests, including SSOP genotyping, and real-time PCR with melting curve analysis. While the real-time PCR method is easy and inexpensive to perform, ambiguities are rapidly increasing as more and more HLA alleles are discovered. SSOP genotyping identifies the alleles present but limitations include ambiguities and underreporting less common alleles. Our data show that HLA typing by NGS is superior to the existing clinical methods for identifying HLA alleles associated with disease or drug hypersensitivity, and offers a viable approach for high volume clinical diagnostic laboratories., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

The delta isoform of phosphoinositide 3-kinase (PI3Kδ) regulates various lymphocyte functions. Considering the key pro-inflammatory role of IL-17A and IL-17F cytokines in psoriasis and spondyloarthritis (SpA), we investigated the potential of PI3Kδ blockade to suppress IL-17A, IL-17F and associated pro-inflammatory cytokines that could synergize with IL-17A and IL-17F. Using in vitro studies with primary human cells and ex vivo studies with inflamed target tissues, we assessed if seletalisib, a selective PI3Kδ inhibitor, suppresses cytokine production by T cells and innate-like lymphocytes, and if seletalisib modulates the inflammatory responses in stromal cell populations in psoriasis (human dermal fibroblasts (HDF)) and SpA (fibroblast-like synoviocytes (FLS)). In vitro, seletalisib inhibited the production of pro-inflammatory cytokines, including IL-17A and IL-17F, from peripheral blood mononuclear cells (PBMCs), T helper 17 (Th17) cells as well as γδ-T cells and mucosal-associated invariant T cells. This inhibition resulted in decreased inflammatory activation of HDF in co-culture systems. Seletalisib was also efficacious in inhibiting SpA PBMCs and synovial fluid mononuclear cells (SFMCs) from producing pro-inflammatory cytokines. Furthermore, supernatant derived from cultured seletalisib-treated Th17 cells showed reduced potency for activating inflammatory responses from cultured SpA FLS and decreased their osteogenic differentiation capacity. Finally, analysis of inflamed SpA synovial tissue biopsies revealed activation of the PI3K-Akt-mTOR pathway. We observed that ex vivo seletalisib treatment of inflamed synovial tissue reduced IL-17A and IL-17F expression. Collectively, inhibition of PI3Kδ reduces the production of pro-inflammatory cytokines from IL-17-producing adaptive and innate-like lymphocytes and thereby inhibits downstream inflammatory and tissue remodeling responses. PI3Kδ-targeting may therefore represent a novel therapeutic avenue for the treatment of IL-17-mediated chronic inflammatory diseases such as psoriasis and SpA., Competing Interests: Declaration of competing interest Dr. Chen, Mr. Sritharan and Dr. Yeremenko have no conflicts of interest to disclose. Drs. Paveley and Payne were employees of UCB Pharma at the time this work was conducted and held stock options for UCB Pharma at that time. Drs. Dedi, Shock, Shaw, Juarez and Baeten are employees of UCB Pharma and holders of shares/stock options. Dr. Kraal is an employee of UWV. Dr. Stevens is an employee of UCB Pharma., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Although human leucocyte antigen (HLA)-B27 is strongly associated with ankylosing spondylitis (AS), the association of unfolded protein response (UPR) induced by HLA-B27 misfolding in AS remains controversial. Since dendritic cells (DCs) are crucial in induction of AS in HLA-B27-transgenic rats, and plasmacytoid DCs (pDCs) belong to one type of DCs, we here aim to study the relevance of pDCs and UPR in AS. Peripheral pDCs were isolated from 27 HLA-B27(+) AS patients and 37 controls. The bone marrow (BM) and synovium of inflamed hips from AS patients and controls were obtained. We found a significantly higher frequency of pDCs in the peripheral blood, BM, or inflamed synovium of hips, which is associated with the enhanced expression of pDC trafficking molecules, CCR6 and CCL20 in the synovium of AS patients. Functional analysis further revealed that several inflammatory cytokines, including TNFα, IL-6, and IL-23, secreted by pDCs were significantly increased in AS patients as compared with those in controls. Remarkably, protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathway in UPR was up-regulated in pDCs of AS patients. Notably, PERK inhibitor treatment significantly inhibited the enhanced cytokine production by pDCs of AS patients. Further, the extent of PERK activation was significantly associated with the increased disease severity of AS patients. Our data uncover the aberrant distribution and function of pDCs in AS patients. The up-regulated PERK pathway in UPR of pDCs not only contributes to enhanced cytokine production of pDCs, but also is associated with increased disease activity of AS patients., (© 2020 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia on behalf of Kaohsiung Medical University.)

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., Competing Interests: The authors have declared that no competing interests exist.

Background: The inadequate storage of biopharmaceuticals may result in an ineffective therapeutic response since poor conservation can lead to the emergence of protein aggregates and cause immunogenicity in patients, which can increase the risk of adverse events by inducing the production of anti-drug antibodies. This can also lead to significant economic losses for public health, given the high cost of these medicines. The aim of this study was to verify whether the home storage of biopharmaceuticals dispensed by the Unified Public System was in accordance with the manufacturers' specified standards and whether external variables interfered with the correct home storage., Methods: This was a prospective observational study. Patients with a confirmed diagnosis of rheumatoid arthritis, ankylosing spondylitis or psoriatic arthritis who were using a biologic exclusively dispensed by Unified Public System were included. Storage temperature was measured by digital thermometer inserted into the refrigerator of the participant's home. Fisher's exact test was performed to cross-reference the temperature data and the qualitative variables obtained using an epidemiologic questionnaire. Mean, minimum, maximum values and standard deviation were described in the quantitative data. Mann-Whitney non-parametric test was performed to the association between temperature excursion and the number of people in the house., Results: A total of 81 participants were included and 67 (82.71%) did not maintain home storage correctly. The maximum temperature observed among all patients was 15.5 °C, the minimum was - 4.4 °C and the average was 5.6 °C (standard deviation 2.8); 10 (12.3%) had at least one negative temperature measured. The average time for participants who had an inadequate temperature record was 8 h and 31 min. Nine participants (90%) who stored the medication into the shelf/drawer below the freezer had a temperature excursion (p = 0.011). Most of the participants (88.5%) who stored their biopharmaceutical near the back side, close to the wall of the refrigerator had a negative temperature record (p < 0.001)., Conclusion: Most of the study participants (82.71%) did not maintain adequate home storage conditions for their biopharmaceutical. Intrinsic factors of household refrigerators may be involved in temperature deviations.

Background & Aims: Inhibitors of Janus kinases (JAKs) are being developed for treatment of inflammatory bowel diseases and other immune-mediated diseases. Tofacitinib is effective in treatment of ulcerative colitis, but there are safety concerns. We performed a systematic review and meta-analysis to investigate the safety profile of tofacitinib, upadacitinib, filgotinib, and baricitinib in patients with rheumatoid arthritis, inflammatory bowel diseases, psoriasis, or ankylosing spondylitis., Methods: We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from January 1, 1990, through July 1, 2019. We performed a manual review of conference databases from 2012 through 2018. The primary outcome was incidence rates of adverse events (AEs) and serious AEs. We also estimated incidence rates of serious infections, herpes zoster infection, non-melanoma skin cancer, other malignancies, major cardiovascular events, venous thromboembolism, and mortality. We performed a meta-analysis, which included controlled studies, to assess the relative risk of these events., Results: We identified 973 studies; of these, 82 were included in the final analysis, comprising 66,159 patients with immune-mediated diseases who were exposed to a JAK inhibitor. Two-thirds of the included studies were randomized controlled trials. The incidence rate of AEs was 42.65 per 100 person-years and of serious AEs was 9.88 per 100 person-years. Incidence rates of serious infections, herpes zoster infection, malignancy, and major cardiovascular events were 2.81 per 100 person-years, 2.67 per 100 person-years, 0.89 per 100 person-years, and 0.48 per 100 person-years, respectively. Mortality was not increased in patients treated with JAK inhibitors compared with patients given placebo or active comparator (relative risk 0.72; 95% confidence interval 0.40-1.28). The meta-analysis showed a significant increase in risk of herpes zoster infection among patients who received JAK inhibitors (relative risk 1.57; 95% confidence interval 1.04-2.37)., Conclusions: In a systematic review and meta-analysis, we found an increased risk of herpes zoster infection among patients with immune-mediated diseases treated with JAK inhibitors. All other AEs were not increased among patients treated with JAK inhibitors., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Pityriasis lichenoides chronica, a papulosquamous disorder often considered a subtype of pityriasis lichenoides. It is considered a clonal T-cell disorder, which may be associated with cutaneous T-cell lymphoma that may develops in response to foreign antigens., Case Presentation: We present a 38-year-old male patient with ankylosing spondylitis who was on treatment with etanercept. After 8 weeks of treatment, the patient presented with scaly erythematous papules, on the back and arms. He was diagnosed clinically with pityriasis lichenoides chronica., Conclusion: Pityriasis lichenoides chronica should be included among the broad clinical spectrum of chronic inflammatory skin diseases which may occur during treatment with TNF-alpha antagonists. J Drugs Dermatol. 2020;19(5): doi:10.36849/JDD.2020.2191.

Ankylosing Spondylitis (AS) is a chronic inflammatory disorder of the spine and sacroiliac joints with unidentified etiology closely associated with metabolic syndrome (MetS). Recent studies have reported that immunological and oxidative stress factors are implicated in AS pathogenesis. The aim of this study was to investigate the oxidative and immunological factors in AS patients with or without MetS compare to control group. Real-Time PCR measured expression level of cytokines, transcription factors and related miRNAs. In addition, Th17 and Treg frequencies and cytokines secretion were evaluated by flowcytometry and ELISA methods, respectively. The oxidative stress biomarkers were also assessed with biochemical methods. In AS patients with MetS, higher Th17 and lower Treg frequency were observed. Increased levels of NF-kB and AP-1 mRNA expression were seen in AS patients with MetS (p = 0.0263 and p = 0.0104, respectively). MiR-146a and miR-223 were significantly decreased (p = 0.0005, p = 0.0161, respectively) and increase in miR-21 (p = 0.0002) was observed in AS patients with MetS compared to AS patients without MetS. Additionally, the secretion of TNF-α (p = 0.0167), IL-1β (p = 0.303), CCL2 (p = 0.0254), CCL3 (p = 0.0119), CXCL8 (p = 0.0364), adiponectin (p = 0.0183) and the levels of SOD (p = 0.0421), NO (p = 0.0451) and CAT (p = 0.0128) were increased in AS patients with MetS. We were not observed significant differences in TOS and GPX levels between studied groups. The higher levels of oxidative stress and immunological inflammatory markers in AS patients with MetS provide further evidences on the oxidative stress and immunological relationship in these patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: There is a need for postmarketing evidence generation for novel biologics and biosimilars., Objective: To assess the feasibility, strengths, and limitations of the Biologics and Biosimilars Collective Intelligence Consortium (BBCIC) Distributed Research Network (DRN) to examine the utilization and comparative safety of immune-modulating agents among patients with autoimmune diseases., Methods: We conducted a retrospective cohort study among patients enrolled in health insurance plans participating in the BBCIC DRN between January 1, 2006, and September 30, 2015. Eligible patients were adult (≥18 years) new users of a disease-modifying nonbiologic and/or biologic agent with a prior diagnosis of rheumatoid arthritis (RA), other inflammatory conditions (psoriasis, psoriatic arthritis, ankylosing spondylitis), or inflammatory bowel disease (IBD). Follow-up started at treatment initiation and ended at the earliest of outcome occurrence (serious infection); treatment discontinuation; or switching, death, disenrollment, or end of study period. The study leveraged the FDA Sentinel System infrastructure for data management and analysis; descriptive statistics of patient characteristics and unadjusted incidence rates of study outcomes during follow-up were calculated., Results: Eligible patient drug episodes included 111,611 with RA (75% female), 61,050 with other inflammatory conditions (51% female), and 30,628 with IBD (52% female). Across all 3 cohorts, approximately half of the patient drug episodes initiated a biologic (50% in RA; 60% in psoriasis, psoriatic arthritis, ankylosing spondylitis; and 55% in IBD). The crude incidence rate of serious infection was 9.8 (9.5-10.0) cases per 100 person-years in RA, 7.1 (6.8-7.5) in other inflammatory conditions, and 14.2 (13.6-14.8) in IBD patients., Conclusions: This study successfully identified large numbers of new users of biologics and produced results that were consistent with those from earlier published studies. The BBCIC DRN is a potential resource for surveillance of biologics., Disclosures: This study was funded by the Biologics and Biosimilars Collective Intelligence Consortium (BBCIC). HealthCore conducted this study in collaboration with Harvard Pilgrim Health Care. Zhang and Sridhar were employed by HealthCore at the time of this study. Haynes is employed by HealthCore funded by PCORI, the NIH, and the FDA. Barr and Eichelberger were employed by AMCP at the time of this study. Lockhart is employed by the BBCIC. Holmes and Clewell are employed by AbbVie. Accrott is an employee of and shareholder in Amgen. Marshall and Brown are employed by Harvard Pilgrim Health Care. Barr is a shareholder in Roche/Genentech. Curtis has received research grants from and consults with the following: Amgen, AbbVie, BMS, CORRONA, Lilly, Janssen, Myriad, Pfizer, Roche, Regeneron, and UCB. Brown has received research grants from GSK and Pfizer and consulting fees from Bayer, Roche, and Jazz Pharmaceuticals, along with funding from the Reagan-Udall Foundation for the FDA to conduct studies for medical product manufacturers, including Eli Lilly, Novartis, Abbvie, and Merck. Brown is also funded by PCORI, the NIH, and the FDA. McMahill-Walraven subcontracts with Harvard Pilgrim Health Care Institute for public health and safety surveillance distributed data network activtities and with the FDA, GSK, and Pfizer. She also reports fees from Reagan Udall Foundation for the FDA and the Patient Centered Outcomes Research Institute.

T helper (Th) cells are CD4 + effector T cells that play a critical role in immunity by shaping the inflammatory cytokine environment in a variety of physiological and pathological situations. Using a combined chemico-genetic approach, we identify histone H3K27 demethylases KDM6A and KDM6B as central regulators of human Th subsets. The prototypic KDM6 inhibitor GSK-J4 increases genome-wide levels of the repressive H3K27me3 chromatin mark and leads to suppression of the key transcription factor RORγt during Th17 differentiation. In mature Th17 cells, GSK-J4 induces an altered transcriptional program with a profound metabolic reprogramming and concomitant suppression of IL-17 cytokine levels and reduced proliferation. Single-cell analysis reveals a specific shift from highly inflammatory cell subsets toward a resting state upon demethylase inhibition. The root cause of the observed antiinflammatory phenotype in stimulated Th17 cells is reduced expression of key metabolic transcription factors, such as PPRC1. Overall, this leads to reduced mitochondrial biogenesis, resulting in a metabolic switch with concomitant antiinflammatory effects. These data are consistent with an effect of GSK-J4 on Th17 T cell differentiation pathways directly related to proliferation and include regulation of effector cytokine profiles. This suggests that inhibiting KDM6 demethylases may be an effective, even in the short term, therapeutic target for autoimmune diseases, including ankylosing spondylitis., Competing Interests: Competing interest statement: B.S. was an employee of Metabolon. P.K.M. and R.K.P. are employees of GlaxoSmithKline. M.L., S.O., and H.O. were at Roche. U.O. and S.G. are coauthors on a 2016 meeting report., (Copyright © 2020 the Author(s). Published by PNAS.)

Objectives: To evaluate the long-term drug retention, efficacy, and safety of the infliximab biosimilar CT-P13 in Korean patients with ankylosing spondylitis (AS) in clinical practice. The primary outcome was drug retention (i.e. time to treatment discontinuation or changing to another biologic) in Korean patients with AS. Additional outcomes included efficacy and safety., Methods: Data were collected through the Korean College of Rheumatology Biologics (KOBIO) registry (ClinicalTrials.gov identifier: NCT01965132). CT-P13 efficacy was assessed using standard disease activity parameters, and safety was evaluated by adverse events (AEs)., Results: Between December 2012 and December 2017, 244 patients with AS treated with CT-P13 were enrolled. Of those, 203 (83.2%) received CT-P13 as first-line therapy. The median duration of treatment was 2.05 years. After 4 years' follow-up, the retention rate of CT-P13 in the overall patient population was 66%. Treatment changes or discontinuations occurred in 38 (15.6%) and 32 (13.1%) patients, respectively. Lack of efficacy was the most common reason for treatment changes, whereas AEs were the most common single cause of discontinuation. Disease activity decreased markedly from baseline following initiation of CT-P13 treatment, and thereafter remained stable. A total of 313 AEs occurred in 118 patients (48.4%); the majority (94.6%) were mild or moderate in severity. The most common treatment-related AEs were infusion or injection-site reactions (4.1% of patients), uveitis (3.7%), and skin rash (3.7%)., Conclusions: In this real-world study, CT-P13 demonstrated encouraging drug retention rates and times, together with reasonable long-term efficacy and safety, in Korean patients with AS.

Objective: Inflammatory bowel disease (IBD) is a well-known extraarticular feature of spondyloarthritis (SpA). The aims of this study were to evaluate factors associated with IBD and incidence over 5 years of followup in the DESIR cohort., Methods: DESIR is a prospective observational cohort of patients with recent-onset inflammatory back pain suggestive of axial SpA. All available variables in the database were compared between patients with and without IBD at baseline and 5 years, and occurrence over 5 years of followup, with uni- and then multivariable analysis., Results: At baseline, of 708 patients, 35 had IBD (prevalence 4.94%, CI 95% 3.3-6.5). IBD was associated (multivariable) with history of uveitis, levels of Dickkopf-1, and tumor necrosis factor, but not with phenotypic presentation (peripheral arthritis, enthesitis, dactylitis, uveitis) or baseline serum levels of other cytokines. At 5 years, 480 patients were analyzed, 58 with IBD. IBD was associated (multivariable) with fulfillment of modified New York criteria, sick leave, Bath Ankylosing Spondylitis Disease Activity Index, and smoking. There was no association with magnetic resonance imaging scores, enthesitis, psoriasis, and bone mineral density. Twenty-three incident cases of IBD were recorded: estimated occurrence rate of 0.95/100 (95% CI 0.57-1.35) patient-years (PY). Incidence of IBD is associated (multivariable) with HLA-B27 (OR 0.36, 95% CI 0.22-0.59), fulfillment of modified New York criteria (OR 3.35, 95% CI 1.85-6.08), and familial history of IBD (OR 3.31, 95% CI 1.62-6.77)., Conclusion: In early SpA, IBD occurs with an incidence of 1/100 PY, and is associated with poor outcome, familial history of IBD, absence of HLA-B27, and fulfillment of modified New York criteria.

Objective: Ankylosing spondylitis (AS) is an inflammatory arthritis in which men have a higher risk of developing progressive axial disease than women. Transcriptomic studies have shown reduced expression of cytotoxic cell genes in the blood of AS patients. HLA-B27 contributes the greatest risk for AS, suggesting a role for CD8+ T cells. This study was undertaken to profile AS patient cytotoxic cells with the hypothesis that an alteration in CD8+ T cells might explain the aberrant cytotoxic profile observed in patients., Methods: Whole blood was examined for GZM and PRF1 gene expression by quantitative polymerase chain reaction. Serum and synovial fluid (SF) were examined for granzyme and perforin 1 expression by bead array, and blood and SF mononuclear cells were examined for granzyme and perforin 1 expression by fluorescence-activated cell sorting (FACS)., Results: GZM and PRF1 gene expression were both reduced in AS patients compared to healthy controls, especially in men. Perforin 1, but not granzyme, protein levels were reduced in AS patient serum. Granzymes were elevated in AS SF, but not in rheumatoid arthritis or osteoarthritis SF. FACS revealed a reduction in granzyme-positive and perforin 1-positive lymphocytes, but not an intrinsic defect in CD8+ T cell granzyme or perforin 1 production. CD8+ T cell frequency was reduced in the blood and increased in the SF of AS patients., Conclusion: Our findings indicate that AS patients have an altered cytotoxic T cell profile. These data suggest that CD8+ T cells with a cytotoxic phenotype are recruited to the joints, where they exhibit an activated phenotype. Thus, a central role for CD8+ T cells in AS may have been overlooked and deserves further study., (© 2019, American College of Rheumatology.)

Objectives: To investigate the associations of miR-451 and macrophage migration inhibitory factor (MIF) with disease activity, radiographic progression, and cytokine levels of ankylosing spondylitis (AS)., Methods: Peripheral blood mononuclear cells (PBMCs) were isolated and cultured from 43 AS patients, 11 peripheral spondyloarthritis (pSpA) patients, and 31 healthy controls. ASDAS-CRP and mSASSS were assessed at the time of blood sampling. Expression levels of miR-451 and MIF were determined using quantitative real-time PCR, and the supernatant concentrations of MIF and cytokines were measured using ELISA. After transfection of miR-451 synthetic mimic or FAM-labelled negative control mimic to AS PBMCs, MIF and cytokine levels were determined using quantitative real-time PCR or ELISA., Results: Level of miR-451 expression was lower in AS PBMCs than in pSpA and control PBMCs, while MIF expression was significantly increased in AS PBMCs compared with those in pSpA and control PBMCs. MIF, TNF-α, and IL-6 concentrations in cell supernatants of AS PBMCs were significantly higher than those of pSpA and control PBMCs. miR-451 expression level did not show significant correlation with clinical parameters, but MIF expression level was elevated in PBMCs from AS patients with high mSASSS (12 or more). Treatment of AS PBMCs with the miR-451 synthetic miRNA mimic significantly reduced mRNA expression levels and cell supernatant concentrations of MIF, TNF-α, and IL-6., Conclusions: The MIF level was elevated in AS patients with greater radiographic damage and overexpression of miR-451 suppressed the MIF and inflammatory cytokine levels. These findings suggest miR-451/MIF may be a novel therapeutic target in the treatment of AS.

Autoimmune rheumatic diseases (ARDs), affecting ~1-1.5% of all humans, are associated with considerable life long morbidity and early mortality. Early studies in the 1990s showed numerical changes of the recently discovered γδ T cells in the peripheral blood and in affected tissues of patients with a variety of ARDs, kindling interest in their role in the immuno-pathogenesis of these chronic inflammatory conditions. Indeed, later studies applied rapid developments in the understanding of γδ T cell biology, including antigens recognized by γδ T cells, their developmental programs, states of activation, and cytokine production profiles, to analyze their contribution to the pathological immune response in these disorders. Here we review the published studies addressing the role of γδ T in the major autoimmune rheumatic diseases, including rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, systemic lupus erythematosus and scleroderma, and animal models thereof. Due to their unique properties spanning adaptive and innate immune functions, the ever deeper understanding of this unique T cell population is shedding new light on the pathogenesis of, while potentially enabling new therapeutic approaches to, these diseases.

The development of autoimmune disorders is incompletely understood. Inefficient thymic T cell selection against self-peptides presented by major histocompatibility antigens (HLA in humans) may contribute to the emergence of auto-reactive effector cells, and molecular mimicry between foreign and self-peptides could promote T cell cross-reactivity. A pair of class I subtypes, HLA-B2705 and HLA-B2709, have previously been intensely studied, because they are distinguished from each other only by a single amino acid exchange at the floor of the peptide-binding groove, yet are differentially associated with the autoinflammatory disorder ankylosing spondylitis. Using X-ray crystallography in combination with ensemble refinement, we find that the non-disease-associated subtype HLA-B2709, when presenting the self-peptide pGR (RRRWHRWRL), exhibits elevated conformational dynamics, and the complex can also be recognized by T cells. Both features are not observed in case of the sequence-related self-peptide pVIPR (RRKWRRWHL) in complex with this subtype, and T cell cross-reactivity between pGR, pVIPR, and the viral peptide pLMP2 (RRRWRRLTV) is only rarely observed. The disease-associated subtype HLA-B2705, however, exhibits extensive conformational flexibility in case of the three complexes, all of which are also recognized by frequently occurring cross-reactive T cells. A comparison of the structural and dynamic properties of the six HLA-B27 complexes, together with their individual ability to interact with T cells, permits us to correlate the flexibility of HLA-B27 complexes with effector cell reactivity. The results suggest the existence of an inverse relationship between conformational plasticity of peptide-HLA-B27 complexes and the efficiency of negative selection of self-reactive cells within the thymus., (Copyright © 2020 Loll, Rückert, Uchanska-Ziegler and Ziegler.)

Lymphotoxin-a (LTA) may be associated with the pathogenesis of inflammatory diseases. To assess the association of the LTA rs909253 A/G polymorphism with plasma level and risk of ankylosing spondylitis (AS) in a Chinese Han population. Genotyping and LTA plasma were tested by mass spectroscopy and enzyme-linked immunosorbent assay (ELISA), respectively. The results showed that the average plasma level of LTA in AS was significantly lower than in the controls (P = 0.000). Our results also indicated that LTA rs909253 A/G was associated with a decreased risk of AS (G vs. A: P = 0.014). Significant differences were also found between the rs909253 A/G genotype and down-regulated plasma level in AS patients, compared with controls. After stratification analysis, a decreased risk of AS was associated with the LTA rs909253 G allele (G vs. A) among female patients, younger patients (Yr. < 30), HLA-B27-positive patients. In addition, In conclusion, LTA rs909253 A/G genotype has a significant relationship with decreased susceptibility to AS.

Background: Axial SpA and Enthesitis related arthritis (ERA) patients show strong HLA-B27 association, gut dysbiosis, high toll like receptor (TLR)2 and 4 expression on monocytes, pro-inflammatory cytokine production and elevated levels of TLR4 endogenous ligands [tenascin-c (TNC) and myeloid related protein (MRP)8/14] in serum. Hence, we aimed to understand if these diseases have similar or different monocyte response., Methods: Fifty adult axial SpA, 52 ERA patients and 25 healthy controls (HC) were enrolled. Cytokine-producing monocyte frequency before and after stimulation with lipopolysaccharide (LPS), peptidoglycan (PG), TNC or MRP8 were measured in whole blood (WB) and synovial fluid mononuclear cells (SFMC) by flow cytometry. Also, IL-6, TNF, MMP3, TNC and MRP8/14 levels were measured in unstimulated and TLR ligand stimulated WB cultures supernatant by ELISA. Finally, the mRNA expression levels of TNF and IL-6 were measured post stimulation with LPS, TNC and MRP8., Results: At baseline, ERA and axial SpA patients showed similar TNF-α producing monocyte frequency which was higher than HC. MRP8 simulation led to increased TNF-α producing monocyte frequency in ERA than axial SpA. TNC and MRP8 stimulation led to similar IL-6 producing monocyte frequency in axial SpA and ERA patients. Baseline TNF and IL-6 producing monocyte frequency also modestly correlated with disease activity scores. TNF and IL-6 producing monocyte frequency increased in response to TLR stimulation in SFMC from both patients. In culture supernatants, axial SpA and ERA patients showed similar TNF production at baseline. MRP8 and TNC stimulation led to higher TNF production from ERA. Baseline IL-6 and MMP3 production was higher in ERA while TLR stimulation led to similar IL-6 and MMP3 production from axial SpA and ERA. TNC stimulation led to higher MMP3 production in ERA. mRNA expression in response to TLR stimulation was observed to be similar in axial SpA and ERA. TNC production was higher in ERA at baseline, while MRP8/14 production was higher in axial SpA than ERA post stimulation., Conclusion: ERA patients have similar monocyte response to exogenous and endogenous TLR ligands as patients with axial SpA. This suggests that differences between pediatric and adult-onset SpA are minimal and they may have a common pathogenesis.