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Ankylosing spondylitis (AS) is the historic term used for decades for the HLA-B27-associated inflammatory disease affecting mainly the sacroiliac joints (SIJ) and spine. Classification criteria for AS have radiographic sacroiliitis as a dominant characteristic. However, with the availability of MRI of SIJ, it could be demonstrated that the disease starts long before definite SIJ changes become visible on radiographs. The Assessment of SpondyloArthritis international Society, representing a worldwide group of experts reached consensus on changes in the nomenclature pertaining to axial spondyloarthritis (axSpA), such as the terminology of diagnosis and of assessment of disease activity tools. These are important changes in the field, as experts in axSpA are now in agreement that the term axSpA is the overall term for the disease. A further differentiation, of which radiographic versus non-radiographic is only one aspect, may be relevant for research purposes. Another important decision was that the terms AS and radiographic axSpA (r-axSpA) can be used interchangeably, but that the preferred term is r-axSpA. Based on the decision that axSpA is the correct terminology, a proposal was made to officially change the meaning of the ASDAS acronym to 'Axial Spondyloarthritis Disease Activity Score'. In addition, for simplification it was proposed that the term ASDAS (instead of ASDAS-CRP) should be preferred and applied to the ASDAS calculated with C reactive protein (CRP). It is hoped that these changes will be used consequently for education, in textbooks, manuscripts and presentations., Competing Interests: Competing interests: DvdH has received consulting fees from AbbVie, Argenx, Bayer, BMS, Galapagos, Gilead, GlaxoSmithKline, Janssen, Lilly, Novartis, Pfizer, Takeda, UCB Pharma. She is Director of Imaging Rheumatology bv, associate editor of ARD, editorial board member of J Rheumatol and RMD Open, advisor of ASAS. AM has received consulting fees from AbbVie, Amgen, BMS, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB Pharma and Viatris. SR has received research grants and/or consulting fees from AbbVie, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, UCB, Sanofi. MD has received consulting fees from Pfizer, AbbVie, UCB, Amgen, BMS, Galapagos, Lilly, Novartis, Merck. FAvG has received consultation fees from Novartis, BMS, AbbVie, MSD, Janssen, Lily, UCB. LG has received research grants and/or consulting fees from AbbVie, Acelyrin, Eli Lilly, Fresenius Kabi, Janssen, Novartis, Pfizer, UCB. RDI has received consulting fees from Abbvie, Janssen, Novartis, UCB. RBML has received consulting fees from AbbVie, BMS, Galapagos, Eli-Lilly, Novartis, Jansen, Pfizer and UCB, is director of Rheumatology Consultancy BV and past-president and executive member of ASAS. HM-O has received grant support from Janssen, Novartis and UCB. Honoraria and/or speaker fees from AbbVie, Biogen, Eli-Lilly, Janssen, Moonlake, Novartis, Pfizer, Takeda and UCB. VN-C has received consultancy/speaker/research grants from Abbvie, BMS, Fresenius Kabi, Galapagos, Janssen, Lilly, Moonlake, MSD, Novartis, Pfizer, Roche, UCB. AP, Patient with AxSpa, Eupati Fellow, Patient Expert, Advocator, President of Cyprus League of People with Rheumatism, President of AGORA Federation, Secretary of Axial Spondylarthritis International Federation (ASIF), EULAR-Advocacy Committee Member-Pare Committee Member. DP has received research support from AbbVie, Eli Lilly, MSD, Novartis, Pfizer, consulting fees from AbbVie, Biocad, Bristol-Myers Squibb, Eli Lilly, Janssen, Moonlake, Novartis, Pfizer and UCB, and speaker fees from AbbVie, Canon, DKSH, Eli Lilly, Janssen, MSD, Medscape, Novartis, Peervoice, Pfizer and UCB. MP has received consulting fees from Novartis as well as support for attending meetings and/or travel from Abbvie, Jannsen, Novartis and UCB. MR has receieved consulting/speaker fees from Abbvie, Chugai, Boehringer, Eli-Lilly, Janssen, Novartis, UCB. PDS-B has received consulting/ speaker's fees from AbbVie, Celltrion, Eli Lilly, GSK, Janssen, Novartis, Pfizer and UCB. AS has received speaking and/or consulting fees from Abbvie, Novartis, UCB and Lilly. JS has received gees for consultancies and for being a member of speakers’ bureau from Abbvie, Merck, Novartis and UCB. FEVdB has received consulting fees from Abbvie, Amgen, Eli Lilly, Galapagos, Janssen, Moonlake, Novartis and UCB. IvdH-B has received consulting/speaker’s fees from UCB, Lilly, AbbVie, MSD, BMS, Novartis. PMM has received consulting/speaker’s fees from Abbvie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB. XB has received consulting/speaker’s fees Abbvie, Amgen, BMS, Chugai, Galapagos, Gilead, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz, UCB, Zuellig Pharma and is Member of the Editorial Board of ARD, ASAS President and EULAR President Elect., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ on behalf of EULAR.)

Background: The association of the human lymphocyte antigen B27 (HLA-B27) with ankylosing spondylitis (AS), also now called axial spondylarthritis (axSpA), was first described 50 years ago., Objective: This article gives an overview of the available knowledge on the topic., Material and Methods: This is a narrative review based on the experience of the authors., Results: The HLA-B27 is a member of the HLA class I family of genes of the major histocompatibility complex (MHC). The prevalence of HLA-B27 in the central European population is approximately 8 %, i.e., the vast majority of carriers of HLA-B27+ remain healthy. The frequency of HLA-B27 shows a decline from north to south. The HLA-B27 explains only 30 % of the genetic burden of axSpA. The prevalence of the disease correlates with the frequency of HLA-B27 in the population, i.e., there are geographic differences. Approximately 60-90 % of patients with axSpA worldwide are HLA-B27+. Some 200 subtypes of HLA-B27 can be differentiated using the polymerase chain reaction (PCR). In Thailand and Sardinia two subtypes were found that are not associated with axSpA. The physiological function of HLA class I molecules is the defence of the organism against microbes. Microbial peptides are presented to the immune system, which can be specifically attacked by CD8+ T‑cells. Genetic polymorphisms of the enzyme endoplasmic reticulum aminopeptidase 1 (ERAP1), which breaks down peptides in the endoplasmic reticulum, are associated only with HLA-B27+ diseases., Discussion: The pathogenesis of axSpA is unclear but a major hypothesis is that of the arthritogenic peptides. In this it is assumed that potentially pathogenic foreign or autologous peptides can be presented by HLA-B27. If nothing else, HLA-B27 plays an important role in the diagnosis, classification and determination of the severity of axSpA., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: Upadacitinib, a Janus kinase inhibitor, has demonstrated efficacy and an acceptable safety profile in patients with ankylosing spondylitis (AS) in the phase III SELECT-AXIS programs. We report the 1-year efficacy and safety in patients with AS and an inadequate response to biologic disease-modifying antirheumatic drugs (bDMARD-IR) from the SELECT-AXIS 2 study., Methods: Patients ≥ 18 years with active AS who met the modified New York criteria for AS and were bDMARD-IR received double-blind upadacitinib 15 mg once daily (QD) or placebo for 14 weeks. Patients who completed 14 weeks could enter an open-label extension and receive upadacitinib 15 mg QD for up to 2 years. Efficacy endpoints included the percentage of patients achieving ≥ 40% improvement in Assessment of SpondyloArthritis international Society response (ASAS40), Ankylosing Spondylitis Disease Activity Score (ASDAS) low disease activity (LDA), and ASDAS inactive disease (ID); and change from baseline in total and nocturnal back pain, and Bath Ankylosing Spondylitis Functional Index (BASFI). Subgroup analyses (bDMARD lack of efficacy versus intolerance, and prior tumor necrosis factor inhibitor [TNFi] versus interleukin-17 inhibitor [IL-17i] exposure) were conducted. Binary and continuous efficacy endpoints were assessed using non-responder imputation with multiple imputation (NRI-MI) and as observed (AO) analyses; and mixed-effects model repeated measures (MMRM) and AO, respectively. Safety was assessed based on adverse events. Data through week 52 are reported., Results: Of 420 randomized patients, 366 (continuous upadacitinib: n = 181; placebo to upadacitinib: n = 185) completed 52 weeks of treatment. At week 52, in the continuous upadacitinib and placebo to upadacitinib groups, ASAS40, ASDAS LDA, and ASDAS ID were achieved by 66% and 65%, 57% and 55%, and 26% and 25% (all NRI-MI); and change from baseline in total back pain, nocturnal back pain, and BASFI was -4.5 and -4.3, -4.6 and -4.4, and -3.6 and -3.5 (all MMRM), respectively. No new safety risks were identified. Subgroup analyses were consistent with the overall study population., Conclusions: Upadacitinib 15 mg QD demonstrated sustained improvement up to 52 weeks in bDMARD-IR patients with AS. Efficacy was generally similar in patients with lack of efficacy versus intolerance to bDMARDs and prior TNFi versus IL-17i exposure., Trial Registration: NCT02049138., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Objectives: To compare MRI and conventional radiography of SI joints for detection of structural lesions typical for axial spondyloarthritis (axSpA)., Methods: Adult patients from the Assessment of SpondyloArthritis international Society (ASAS) cohort with symptoms suggestive of axSpA and both SI joint MRI and radiographs available for central reading were included. Radiographs were evaluated by three readers according to the modified New York (mNY) criteria grading system. The presence of structural damage on radiographs was defined as fulfilment of the radiographic mNY criterion and, additionally, a lower threshold for sacroiliitis of at least grade 2 unilaterally. MRI scans were assessed for the presence of structural changes indicative of axSpA by seven readers. Diagnostic performance [sensitivity, specificity, positive and negative predictive values (PPV and NPV) and positive and negative likelihood ratios (LR+ and LR-)] of MRI and radiographs (vs rheumatologist's diagnosis of axSpA) were calculated., Results: Overall, 183 patients were included and 135 (73.7%) were diagnosed with axSpA. Structural lesions indicative of axSpA on MRI had sensitivity 38.5%, specificity 91.7%, PPV 92.9%, NPV 34.6%, LR+ 4.62 and LR- 0.67. Sacroiliitis according to the mNY criteria had sensitivity 54.8%, specificity 70.8%, PPV 84.1%, NPV 35.8%, LR+ 1.88 and LR- 0.64. Radiographic sacroiliitis of at least grade 2 unilaterally had sensitivity 65.2%, specificity 50.0%, PPV 78.6%, NPV 33.8%, LR+ 1.30 and LR- 0.69., Conclusion: Structural lesions of the SI joint detected by MRI demonstrated better diagnostic performance and better interreader reliability compared with conventional radiography., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: The Assessment of Spondyloarthritis international Society Health Index (ASAS HI) measures global functioning and health in patients with axial spondyloarthritis (axSpA) covering domains of physical, emotional, and social functioning. The main aim of this study was to investigate the sensitivity to change of ASAS HI in comparison with established variables of disease activity, function, and mental health., Methods: Patients with axSpA from the disease register RABBIT-SpA with follow-up time of at least 12 months and available ASAS HI questionnaires were included. Patients received questionnaires addressing disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], Ankylosing Spondylitis Disease Activity Score [ASDAS]), physical function (Bath Ankylosing Spondylitis Functional Index [BASFI]), mental health (5-item World Health Organization Well-Being Index [WHO-5]), and global functioning (ASAS HI). Standardized response means (SRMs) were calculated to compare the sensitivity to change of different variables., Results: Six hundred and sixty-seven patients were included, 552 treated with biologic disease-modifying antirheumatic drugs (bDMARDs) and 115 with conventional synthetic DMARDs and/or nonsteroidal antiinflammatory drugs (control group). Between baseline and month 12, the mean ASAS HI declined from 6.9 to 5.1 in the bDMARD group and from 5.9 to 5.6 in the conventionally treated group. In the bDMARD group, the SRM of ASAS HI was 0.52, compared to 0.59 for BASFI, 0.65 for WHO-5, 0.73 for BASDAI, and 0.90 for ASDAS. The following ASAS HI domains were most frequently affected: pain (78% agreed), maintaining body position (75%), and energy/drive (73%). In the patients receiving bDMARDs, there was an improvement in all items. In the control group, the largest improvement was seen in pain., Conclusion: As expected, ASDAS and BASDAI as disease activity scores showed high sensitivity to change, whereas changes in physical function (BASFI), mental health (WHO-5), and the broader concept of functioning and health (ASAS HI) were moderate., (Copyright © 2023 by the Journal of Rheumatology.)

The possibility of detection of structural damage on magnetic resonance imaging (MRI) of sacroiliac joints raises the question of whether MRI can substitute radiographs for diagnostic evaluation and to a further extent for classification of axial spondyloarthritis (axSpA). In this viewpoint, we will argue that it is time to replace conventional radiographs with MRI for the assessment of structural changes in sacroiliac joints. This message is based on current data on the following questions: (1) How reliable are conventional radiographs in the diagnosis of axSpA overall and radiographic axSpA in particular? (2) How does T1-weighted MRI compare to radiographs in the detection of sacroiliitis? (3) Are there now other (better) MRI sequences than T1-weighted, which might be more suitable for the detection of structural lesions? (4) Which MRI sequences should be performed for the diagnostic evaluation of the sacroiliac joints? (5) Do we have data to define sacroiliitis based on structural changes detected by MRI?, Competing Interests: Competing interests: DP: research support from AbbVie, Eli Lilly, MSD, Novartis and Pfizer; consulting fees from AbbVie, Biocad, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, MSD, Moonlake, Novartis, Pfizer, Samsung Bioepis and UCB; speaker fees from AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, MSD, Medscape, Novartis, Peervoice, Pfizer and UCB. TD: research grants to the institution from Canon MS and the Berlin Institute of Health; consulting and lecture fees from Eli Lilly, Novartis, MSD, Roche and Canon MS. XB: grants from Abbvie, BMS, Eli-Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, Sandoz, Sanofi and UCB; consulting fees from Abbvie, BMS, Eli-Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, Sandoz, Sanofi and UCB; honoraria from Abbvie, BMS, Eli-Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, Sandoz, Sanofi and UCB; meeting attendance support from Abbvie, BMS, Eli-Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, Sandoz, Sanofi and UCB; leadership roles as editorial board member of Annals of Rheumatic Diseases, ASAS president. KGAH: consulting fees from AbbVie and lecture honoraria from Novartis, Pfizer and MSD; cofounder of BerlinFlame GmbH. JS: honoraria for consultancy or being a member of a speaker’s bureau from Abbvie, Novartis, MSD and UCB., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To evaluate the efficacy and safety of upadacitinib, a Janus kinase inhibitor, in patients with active ankylosing spondylitis (AS) with an inadequate response (IR) to biological disease-modifying antirheumatic drugs (bDMARDs)., Methods: Adults with active AS who met modified New York criteria and had an IR to one or two bDMARDs (tumour necrosis factor or interleukin-17 inhibitors) were randomised 1:1 to oral upadacitinib 15 mg once daily or placebo. The primary endpoint was Assessment of SpondyloArthritis international Society 40 (ASAS40) response at week 14. Sequentially tested secondary endpoints included Ankylosing Spondylitis Disease Activity score, Spondyloarthritis Research Consortium of Canada MRI spine inflammation score, total back pain, nocturnal back pain, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index and Maastricht Ankylosing Spondylitis Enthesitis Score. Results are reported from the 14-week double-blind treatment period., Results: A total of 420 patients with active AS were randomised (upadacitinib 15 mg, n=211; placebo, n=209). Significantly more patients achieved the primary endpoint of ASAS40 at week 14 with upadacitinib vs placebo (45% vs 18%; p<0.0001). Statistically significant improvements were observed with upadacitinib vs placebo for all multiplicity-controlled secondary endpoints (p<0.0001). Adverse events were reported for 41% of upadacitinib-treated and 37% of placebo-treated patients through week 14. No events of malignancy, major adverse cardiovascular events, venous thromboembolism or deaths were reported with upadacitinib., Conclusion: Upadacitinib 15 mg was significantly more effective than placebo over 14 weeks of treatment in bDMARD-IR patients with active AS. No new safety risks were identified with upadacitinib., Trial Registration Number: NCT04169373., Competing Interests: Competing interests: DvdH has received consulting fees from AbbVie, Bayer, BMS, Cyxone, Eisai, Galapagos, Gilead, GSK, Janssen, Lilly, Novartis, Pfizer, and UCB Pharma; is the director of Imaging Rheumatology BV; is an Associate Editor of the Annals of Rheumatic Diseases; is an editorial board member of the Journal of Rheumatology; and is an advisor for the Assessment in SpondyloArthritis international Society. XB has received grant/research support from AbbVie and Novartis; consulting fees from AbbVie, BMS, Chugai, MSD, Novartis, Pfizer, and UCB; speakers’ bureau fees from AbbVie, BMS, Celgene, Chugai, Merck, Novartis, Pfizer, and UCB; and is an editorial board member of the Annals of Rheumatic Diseases. JS has received grant/research support from AbbVie, Merck, and UCB; has been a consultant for AbbVie, Merck, Novartis, and UCB; and has served on the speakers’ bureau for AbbVie, Merck, and Novartis. AD has received grant/research support from AbbVie, BMS, Celgene, GSK, Lilly, Novartis, Pfizer, and UCB; and honoraria or consultation fees from AbbVie, Amgen, Aurinia, BMS, Celgene, GSK, Janssen, Lilly, MoonLake, Novartis, Pfizer, and UCB. RDI has received grant/research support from AbbVie, Amgen, Janssen, and Novartis; and has been a consultant for AbbVie, Amgen, Janssen, Lilly, Novartis, Pfizer, and Sandoz. HK has received grant/research support from AbbVie, Asahi-Kasei, Boehringer Ingelheim, Chugai, Eisai, and Mitsubishi-Tanabe; consulting fees from AbbVie, Janssen, Lilly, Novartis, Sanofi, and UCB; and received speakers’ bureau fees from AbbVie, Asahi-Kasei, BMS, Chugai, Eisai, Janssen, Lilly, Mitsubishi-Tanabe, Novartis, and Pfizer. XZ has none declared. YS, XB, PW and I-HS are employees of AbbVie and may own stock or options. ALP is a former employee of AbbVie and may own stock or options., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate the longitudinal association between radiographic sacroiliitis progression and treatment with tumor necrosis factor inhibitors (TNFi) in patients with early axial spondyloarthritis (SpA) in a long-term inception cohort., Methods: We included patients from the German Spondyloarthritis Inception Cohort who underwent radiographic assessment of the sacroiliac joints at baseline and at least once more during the 10-year follow-up. Two central readers scored the radiographs according to the modified New York criteria for ankylosing spondylitis. The sacroiliac sum score was calculated as a mean of the scores determined by both readers. TNFi use was assessed according to exposure in the current and/or previous 2-year radiographic interval. The association between TNFi use and radiographic sacroiliitis progression was examined by longitudinal generalized estimating equation analysis with adjustment for potential confounders., Results: In this long-term inception cohort, 10-year follow-up data on 737 radiographic intervals assessed in 301 patients with axial SpA (166 patients with nonradiographic axial SpA and 135 patients with radiographic axial SpA) were obtained. Having received ≥12 months of treatment with TNFi in the previous 2-year radiographic interval was associated with a significant decrease in the sacroiliitis sum score (β = -0.09 [95% confidence interval (95% CI) -0.18, -0.003]; analyses adjusted for age, sex, symptom duration, HLA-B27 status, Bath Ankylosing Spondylitis Disease Activity Index score, C-reactive protein, and nonsteroidal antiinflammatory drug intake). In contrast, among patients receiving TNFi in the current radiographic interval, there was no significant association with change in the sacroiliitis sum score (β = 0.05 [95% CI -0.05, 0.14]). This effect of having received ≥12 months of treatment with TNFi in the previous 2-year radiographic interval was stronger in patients with nonradiographic axial SpA as compared to patients with radiographic axial SpA (β = -0.16 [95% CI -0.28, -0.03] versus β = -0.04 [95% CI -0.15, 0.07])., Conclusion: Treatment with TNFi was associated with the reduction in radiographic sacroiliitis progression in patients with axial SpA. This effect became evident between 2 and 4 years after treatment was initiated., (© 2022 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Objectives: To compare demographic and clinical characteristics of patients with axial SpA (axSpA) across geographic regions., Methods: Patients With Axial Spondyloarthritis: Multicountry Registry of Clinical Characteristics (PROOF) is an observational study that enrolled recently diagnosed (≤1 year) axSpA patients fulfilling the Assessment of SpondyloArthritis international Society classification criteria from rheumatology clinical practices in 29 countries across six geographic regions. Demographics and disease-related parameters were collected. Here we present baseline data for patients who were classified as radiographic axSpA (r-axSpA) or non-radiographic axSpA (nr-axSpA) confirmed by central reading., Results: Of the 2170 patients enrolled, 1553 were classified based on central evaluation of sacroiliac radiographs [r-axSpA: 1023 (66%); nr-axSpA: 530 (34%)]. Patients with nr-axSpA had a significantly higher occurrence of enthesitis (40% vs 33%), psoriasis (10% vs 5%) and IBD (4% vs 2%) vs r-axSpA patients. Significant differences in axSpA characteristics were observed between geographic regions. The highest occurrence of peripheral arthritis (60%), enthesitis (52%) and dactylitis (12%) was in Latin America, and the lowest was in Canada (9%, 9% and 2%, respectively). The occurrence of uveitis and psoriasis was highest in Canada (18% and 14%, respectively) and lowest in China (6% and <1%, respectively). IBD was highest in Arabia (21%), and no cases were observed in China. In multivariable analysis adjusted for factors potentially affecting peripheral and extramusculoskeletal manifestations, geographic regions still exhibited significant differences in frequencies of uveitis (P < 0.01), psoriasis (P < 0.0001) and peripheral arthritis (P < 0.0001)., Conclusion: The multinational PROOF study of axSpA patients showed significant regional differences in peripheral and extramusculoskeletal manifestations of SpA, which could be considered in management guidelines and clinical trials., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Introduction: Long-term safety and efficacy of upadacitinib in patients with active ankylosing spondylitis (AS) has not been previously reported., Methods: In SELECT-AXIS 1, patients receiving placebo were switched to upadacitinib 15 mg once daily at week 14 while patients initially randomised to upadacitinib continued their regimen through week 104. Efficacy was assessed using as-observed (AO) and non-responder imputation (NRI)., Results: Of 187 patients randomised, 144 patients (77%) completed week 104. Among patients receiving continuous upadacitinib, 85.9% (AO) and 65.6% (NRI) achieved Assessment of SpondyloArthritis international Society 40 response (ASAS40) at week 104. Similar magnitude of ASAS40 responses were observed among patients who switched from placebo to upadacitinib (88.7% and 63.8%, respectively). The mean change from baseline to week 104 in Spondyloarthritis Research Consortium of Canada MRI spine and sacroiliac joint inflammation scores were -7.3 and -5.3, respectively, in the continuous upadacitinib group and -7.9 and -4.9 in the placebo-to-upadacitinib switch group. The mean (95% CI) change from baseline to week 104 in the modified Stoke Ankylosing Spondylitis Spine Score was 0.7 (0.3, 1.1) in the total group. Adverse event rate was 242.7/100 patient-years. No serious infections, adjudicated major adverse cardiovascular events, lymphoma, non-melanoma skin cancer, or gastrointestinal perforations were observed., Conclusions: Upadacitinib 15 mg once daily showed sustained and consistent efficacy over 2 years for ASAS40 and other clinically relevant endpoints. A low rate of radiographic progression was observed and no new safety findings were observed., Competing Interests: Competing interests: DvdH has received consultancy fees from AbbVie, Bayer, BMS, Cyxone, Eisai, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Lilly, Novartis, Pfizer, and UCB Pharma and is a Director of Imaging Rheumatology BV. AD has received research grants, consultancy fees, speaker fees, and other support (medical writing support) from Novartis and Pfizer; research grants, consultancy fees, and other support (medical writing support) from AbbVie, Eli Lilly, and UCB Pharma; research grants and consultancy fees from GlaxoSmithKline; consultancy fees and other support (medical writing support) from Janssen; consultancy fees from Aurinia, Boehringer Ingelheim, Celgene, and MoonLake; and other support (medical writing support) from Amgen. WPM has received research grants and consultancy fees from AbbVie, Novartis, and Pfizer; and consultancy fees from Boehringer Ingelheim, Celgene, Galapagos, Gilead, Janssen, Lilly and UCB Pharma and is Chief Medical Officer of CARE Arthritis. JS has received consultancy and speaker fees from AbbVie, Janssen, Lilly, Merck, Novartis, and UCB. FVdB has received consultancy fees and/or speaker fees from AbbVie, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB Pharma. T-HK has received speaker fees from AbbVie, Celltrion, Kirin, Lilly, and Novartis. MK has received consulting fees and/or speaker fees from AbbVie, Amgen, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, and UCB Pharma. AJO has served as a consultant and/or on advisory boards for AbbVie, BMS, Roche, Janssen, Lilly, Novartis, Pfizer, UCB, Gilead, and Paradigm. BC has received research grants, consultancy and speaker fees from and served as a board member for AbbVie and Lilly; received consultancy fees from and served as a board member for Gilead, Galapagos, and Janssen; received consultancy fees from Celltrion; and received speaker fees from BMS, Celltrion, Merck, Novartis, Pfizer, and Roche-Chugai. YS, YD and PKW are full-time, salaried employees of AbbVie Inc. and own AbbVie stock or stock options. I-HS is a full-time, salaried employee of AbbVie, owns AbbVie stock or stock options, and is an inventor on a patent application., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: A positive family history (PFH) of spondyloarthritis (SpA) consists of five SpA-related entities, of which a PFH of axial spondyloarthritis (axSpA) is most common in European patients with axSpA. Moreover, a PFH of axSpA is associated with human leucocyte antigen B27 (HLA-B27) positivity in these patients. It is unknown if this holds true in patients with axSpA in other parts of the world., Objective: To investigate the geographical prevalence of a PFH of SpA and its association with HLA-B27 positivity in patients with axSpA worldwide., Methods: Cross-sectional analyses included patients from the ASAS peripheral involvement in Spondyloarthritis (PerSpA) study from 24 countries worldwide with an axSpA diagnosis, known HLA-B27 status and family history. Logistic regression models were built to assess the effect of HLA-B27 status on the occurrence of PFH. This was repeated for each of the five SpA entities in a PFH., Results: Among 2048 patients, axSpA was the most common SpA entity in a PFH in all geographical regions (Asia 28%, Europe and North America 27%, Latin America 20%, Middle East and North Africa 41%). A PFH of axSpA was associated with HLA-B27 positivity in Asia (OR 4.19), Europe and North America (OR 2.09) and Latin America (OR 3.95), but not in the Middle East and North Africa (OR 0.98), which has a lower prevalence of HLA-B27 positivity. A PFH of other SpA entities was less prevalent and not consistently associated with HLA-B27 positivity., Conclusion: In patients with axSpA worldwide, axSpA was consistently the most common SpA entity in a family history and was associated with HLA-B27 positivity in all geographical regions but one., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To propose a data-driven definition for structural changes of sacroiliac (SI) joints in the context of axial spondyloarthritis (axSpA) imaging on a large collective of CT datasets., Methods: 546 individuals (102 axSpA, 80 non-axSpA low back pain and 364 controls without back pain) with SI joint CTs were evaluated for erosions, sclerosis and ankylosis using a structured scoring system. Lesion frequencies and spatial distribution were compared between groups. Diagnostic performance (sensitivity (SE), specificity (SP), positive predictive values, negative predictive values and positive and negative likelihood ratios) was calculated for different combinations of imaging findings. Clinical diagnosis served as standard of reference., Results: Ankylosis and/or erosions of the middle and dorsal joint portions yielded the best diagnostic performance with SE 67.6% and SP 96.3%. Inclusion of ventral erosions and sclerosis resulted in lower diagnostic performance with SE 71.2%/SP 92.5% and SE 70.6%/SP 90.0%, respectively., Conclusions: Sclerosis and ventrally located erosions of SI joints have lower specificity on CT of the SI joint in the context of axSpA imaging. Ankylosis and/or erosions of the middle and dorsal joint portions show a strong diagnostic performance and are appropriate markers of a positive SI joint by CT., Competing Interests: Competing interests: KGAH reports lecture fees from AbbVie, MSD and Novartis outside the submitted work. KZ reports funding (research grant) from the Assessment of Spondyloarthritis international Society (ASAS) during the conduct of this study. DP reports grants and personal fees from AbbVie, Eli Lilly, MSD, Novartis, Pfizer and personal fees from Bristol-Myers Squibb, Roche, UCB, Biocad, GlaxoSmithKline, Gilead, Janssen, Samsung Bioepis and UCB outside the submitted work. FP reports grants and personal fees from Novartis, Lilly and UCB, as well as personal fees from AbbVie, AMGEN, BMS, Hexal, MSD, Pfizer and Roche outside the submitted work. JS reports personal fees from AbbVie, Janssen, Merck, Novartis, UCB and Lilly, outside the submitted work. TD reports funding (research grant) from the ASAS and lecture fees from Canon Medical, AbbVie, MSD and Novartis pharma, outside the submitted work. For all other authors, none were reported., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To identify clusters of peripheral involvement according to the specific location of peripheral manifestations (ie, arthritis, enthesitis and dactylitis) in patients with spondyloarthritis (SpA) including psoriatic arthritis (PsA), and to evaluate whether these clusters correspond with the clinical diagnosis of a rheumatologist., Methods: Cross-sectional study with 24 participating countries. Consecutive patients diagnosed by their rheumatologist as PsA, axial SpA or peripheral SpA were enrolled. Four different cluster analyses were conducted: one using information on the specific location from all the peripheral manifestations, and a cluster analysis for each peripheral manifestation, separately. Multiple correspondence analyses and k-means clustering methods were used. Distribution of peripheral manifestations and clinical characteristics were compared across the different clusters., Results: The different cluster analyses performed in the 4465 patients clearly distinguished a predominantly axial phenotype (cluster 1) and a predominantly peripheral phenotype (cluster 2). In the predominantly axial phenotype, hip involvement and lower limb large joint arthritis, heel enthesitis and lack of dactylitis were more prevalent. In the predominantly peripheral phenotype, different subgroups were distinguished based on the type and location of peripheral involvement: a predominantly involvement of upper versus lower limbs joints, a predominantly axial enthesitis versus peripheral enthesitis, and predominantly finger versus toe involvement in dactylitis. A poor agreement between the clusters and the rheumatologist's diagnosis as well as with the classification criteria was found., Conclusion: These results suggest the presence of two main phenotypes (predominantly axial and predominantly peripheral) based on the presence and location of the peripheral manifestations., Competing Interests: Competing interests: None declared., (© 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.)

Objectives: To determine quantitative SI joint MRI lesion cut-offs that optimally define a positive MRI for inflammatory and structural lesions typical of axial SpA (axSpA) and that predict clinical diagnosis., Methods: The Assessment of SpondyloArthritis international Society (ASAS) MRI group assessed MRIs from the ASAS Classification Cohort in two reading exercises where (A) 169 cases and 7 central readers; (B) 107 cases and 8 central readers. We calculated sensitivity/specificity for the number of SI joint quadrants or slices with bone marrow oedema (BME), erosion, fat lesion, where a majority of central readers had high confidence there was a definite active or structural lesion. Cut-offs with ≥95% specificity were analysed for their predictive utility for follow-up rheumatologist diagnosis of axSpA by calculating positive/negative predictive values (PPVs/NPVs) and selecting cut-offs with PPV ≥ 95%., Results: Active or structural lesions typical of axSpA on MRI had PPVs ≥ 95% for clinical diagnosis of axSpA. Cut-offs that best reflected a definite active lesion typical of axSpA were either ≥4 SI joint quadrants with BME at any location or at the same location in ≥3 consecutive slices. For definite structural lesion, the optimal cut-offs were any one of ≥3 SI joint quadrants with erosion or ≥5 with fat lesions, erosion at the same location for ≥2 consecutive slices, fat lesions at the same location for ≥3 consecutive slices, or presence of a deep (i.e. >1 cm depth) fat lesion., Conclusion: We propose cut-offs for definite active and structural lesions typical of axSpA that have high PPVs for a long-term clinical diagnosis of axSpA for application in disease classification and clinical research., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Clinical data collection requires correct and complete data sets in order to perform correct statistical analysis and draw valid conclusions. While in randomized clinical trials much effort concentrates on data monitoring, this is rarely the case in observational studies- due to high numbers of cases and often-restricted resources. We have developed a valid and cost-effective monitoring tool, which can substantially contribute to an increased data quality in observational research., Methods: An automated digital monitoring system for cohort studies developed by the German Rheumatism Research Centre (DRFZ) was tested within the disease register RABBIT-SpA, a longitudinal observational study including patients with axial spondyloarthritis and psoriatic arthritis. Physicians and patients complete electronic case report forms (eCRF) twice a year for up to 10 years. Automatic plausibility checks were implemented to verify all data after entry into the eCRF. To identify conflicts that cannot be found by this approach, all possible conflicts were compiled into a catalog. This "conflict catalog" was used to create queries, which are displayed as part of the eCRF. The proportion of queried eCRFs and responses were analyzed by descriptive methods. For the analysis of responses, the type of conflict was assigned to either a single conflict only (affecting individual items) or a conflict that required the entire eCRF to be queried., Results: Data from 1883 patients was analyzed. A total of n = 3145 eCRFs submitted between baseline (T0) and T3 (12 months) had conflicts (40-64%). Fifty-six to 100% of the queries regarding eCRFs that were completely missing were answered. A mean of 1.4 to 2.4 single conflicts occurred per eCRF, of which 59-69% were answered. The most common missing values were CRP, ESR, Schober's test, data on systemic glucocorticoid therapy, and presence of enthesitis., Conclusion: Providing high data quality in large observational cohort studies is a major challenge, which requires careful monitoring. An automated monitoring process was successfully implemented and well accepted by the study centers. Two thirds of the queries were answered with new data. While conventional manual monitoring is resource-intensive and may itself create new sources of errors, automated processes are a convenient way to augment data quality.

Purpose of Review: To evaluate recent data on diagnostic delay in axial spondyloarthritis (axSpA), factors affecting the delay, potential ways of early diagnosis improvement, and risks associated with early diagnostic approaches., Recent Findings: Although axSpA can be diagnosed nowadays within the first months after symptom onset, the diagnostic delay remains with several years still remarkably high in many parts of the world. Female gender, human leukocyte antigen-B27 negativity, and younger age at disease onset are among factors associated with a delayed referral to a rheumatologist and consequently with a larger diagnostic delay. Early referral algorithms are helpful in the identification of patients with a high probability of axSpA among patients with chronic back pain. A careful diagnostic evaluation with correct imaging interpretation is required to avoid misdiagnosis of axSpA in patients with unspecific back pain., Summary: The diagnostic delay is still considerable in axSpA. The ways to early diagnosis in axSpA are well defined. Imaging findings should always be considered in the clinical context to avoid axSpA misdiagnosis., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: We have now about 20 years of experience with the treatment of axial spondyloarthritis with biologics, which raises the question what we can learn from past experience, and which open questions should be addressed in future investigations., Recent Findings: Many studies have shown that axSpA patients - both patients in their nonradiological and radiological stage - respond similarly well to biologic treatment and these patients should be seen as having the same disease at different stages. AxSpA respond best to TNF-blocker - and probably also to other biologics - if the disease duration is short and if objective parameters of inflammation, such as C-reactive protein or MRI are positive. Primary aim of treatment is to reach and maintain clinical remission. Once remission is achieved, it can be maintained by continuing treatment, and in a proportion of yet not well defined patients the drug dose can be reduced without inducing a flare. The recent demonstration of a good efficacy, in addition to TNF blockers, also of IL-17 inhibitors and JAK-inhibitors in axSpA patients raises the question how to select the best patients for the best treatment. Radiographic progression can best be stopped by effectively suppressing inflammation, whether different drugs have here a different effect has still to be defined. More sensitive measurements of radiographic progression are urgently needed., Summary: Reaching and maintaining clinical remission and preventing structural bony damage is the primary treatment target in patients with axSpA. How to reach this aim best has to be further explored in the future., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Genetic determinants of fibrin clot formation and fibrinolysis have an impact on local and systemic inflammatory response. The aim of the present study was to assess whether coagulation-related genotypes affect the predictive value of C-reactive protein (CRP) in regards of radiographic spinal progression in axial spondyloarthritis (axSpA)., Methods: Two hundred and eight patients with axSpA from the German Spondyloarthritis Inception Cohort were characterised for genotypes of α-fibrinogen, β-fibrinogen (FGB) and γ-fibrinogen, factor XIII A-subunit (F13A) and α 2 -antiplasmin (A2AP). The relation between CRP levels and radiographic spinal progression defined as worsening of the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) by ≥2 points over 2 years was assessed in dependence on the respective genetic background in logistic regression analyses., Results: Overall, CRP was associated with mSASSS progression ≥2 points: time-averaged CRP ≥10 mg/L, OR: 3.32, 95% CI 1.35 to 8.13. After stratification for coagulation-related genotypes, CRP was strongly associated with mSASSS progression in individuals predisposed to form loose, fibrinolysis-susceptible fibrin clots (FGB rs1800790GG, OR: 6.86, 95% CI 2.08 to 22.6; A2AP 6Trp, OR: 5.86, 95% CI 1.63 to 21.0; F13A 34Leu, OR: 8.72, 95% CI 1.69 to 45.1), while in genotypes predisposing to stable fibrin clots, the association was absent or weak (FGB rs1800790A, OR: 0.83, 95% CI 0.14 to 4.84; A2AP 6Arg/Arg, OR: 1.47, 95% CI 0.35 to 6.19; F13A 34Val/Val, OR: 1.72, 95% CI 0.52 to 5.71)., Conclusions: Elevated CRP levels seem to be clearly associated with radiographic spinal progression only if patients are predisposed for loose fibrin clots with high susceptibility to fibrinolysis., Competing Interests: Competing interests: None declared., (© 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.)

Background: Radiographs of the sacroiliac joints are commonly used for the diagnosis and classification of axial spondyloarthritis. The aim of this study was to develop and validate an artificial neural network for the detection of definite radiographic sacroiliitis as a manifestation of axial spondyloarthritis (axSpA)., Methods: Conventional radiographs of the sacroiliac joints obtained in two independent studies of patients with axSpA were used. The first cohort comprised 1553 radiographs and was split into training (n = 1324) and validation (n = 229) sets. The second cohort comprised 458 radiographs and was used as an independent test dataset. All radiographs were assessed in a central reading session, and the final decision on the presence or absence of definite radiographic sacroiliitis was used as a reference. The performance of the neural network was evaluated by calculating areas under the receiver operating characteristic curves (AUCs) as well as sensitivity and specificity. Cohen's kappa and the absolute agreement were used to assess the agreement between the neural network and the human readers., Results: The neural network achieved an excellent performance in the detection of definite radiographic sacroiliitis with an AUC of 0.97 and 0.94 for the validation and test datasets, respectively. Sensitivity and specificity for the cut-off weighting both measurements equally were 88% and 95% for the validation and 92% and 81% for the test set. The Cohen's kappa between the neural network and the reference judgements were 0.79 and 0.72 for the validation and test sets with an absolute agreement of 90% and 88%, respectively., Conclusion: Deep artificial neural networks enable the accurate detection of definite radiographic sacroiliitis relevant for the diagnosis and classification of axSpA.

Objective: The aim was to investigate the reliability and validity of radiographic sacroiliitis assessment in anteroposterior (AP) lumbar radiographs compared with conventional pelvic radiographs in patients with axial spondyloarthritis (axSpA)., Methods: Patients from the German Spondyloarthritis Inception Cohort were selected based on the availability of pelvic and AP lumbar radiographs with visible SI joints at baseline and year 2. Two readers scored the images independently in a random order according to the modified New York criteria. The sacroiliitis sum score was calculated as the mean of both readers. Patients were classified as radiographic (r-)axSpA if radiographic sacroiliitis of grade ≥2 bilaterally or grade ≥3 unilaterally was present in the opinion of both readers and as non-radiographic (nr-)axSpA otherwise. The reliability and validity of sacroiliitis assessment in AP lumbar radiographs was assessed using intraclass correlation coefficients (ICCs), absolute agreement and κ statistics., Results: A total of 226 sets of radiographs were scored from 113 patients included in the study. The ICC for the sacroiliitis sum score was 0.91 at both baseline and year 2. A total of 62 (54.9%) and 55 (48.7%) patients were classified as r-axSpA at baseline and 65 (57.5%) and 60 (53.1%) patients at year 2 based on evaluation of pelvic and AP lumbar radiographs, respectively. The absolute agreement between the methods on the classification was 84.9 and 85.0% at baseline and year 2, respectively, with the κ of 0.70 at both time points., Conclusion: Radiographic sacroiliitis can be assessed in AP lumbar radiographs with a similar reliability to conventional pelvic radiographs., (© 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.)

Objectives: To characterise peripheral musculoskeletal involvement in patients with spondyloarthritis (SpA) including psoriatic arthritis (PsA), across the world., Methods: Cross-sectional study with 24 participating countries. Patients with a diagnosis of axial SpA (axSpA), peripheral SpA (pSpA) or PsA according to their rheumatologist were included. The investigators were asked which diagnosis out of a list of six (axSpA, PsA, pSpA, inflammatory bowel disease-associated SpA, reactive arthritis or juvenile SpA (Juv-SpA)) fitted the patient best. Peripheral manifestations (ie, peripheral joint disease, enthesitis, dactylitis and root joint disease), their localisation and treatments were evaluated., Results: A total of 4465 patients were included (61% men, mean age 44.5 years) from four geographic areas: Latin America (n=538), Europe plus North America (n=1677), Asia (n=975) and the Middle East plus North Africa (n=1275). Of those, 78% had ever suffered from at least one peripheral musculoskeletal manifestation; 57% had peripheral joint disease, 44% had enthesitis and 15% had dactylitis. Latin American had far more often peripheral joint disease (80%) than patients from other areas. Patients with PsA had predominantly upper limb and small joint involvement (52%).Hip and shoulder involvement was found in 34% of patients. The prevalence of enthesitis ranged between 41% in patients with axSpA and 65% in patients with Juv-SpA. Dactylitis was most frequent among patients with PsA (37%)., Conclusion: These results suggest that all peripheral features can be found in all subtypes of SpA, and that differences are quantitative rather than qualitative. In a high proportion of patients, axial and peripheral manifestations coincided. These findings reconfirm SpA clinical subtypes are descendants of the same underlying disease, called SpA., Competing Interests: Competing interests: None declared., (© 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.)

Objectives: Osteitis condensans ilii (OCI) has become an important differential diagnosis for axial spondyloarthritis (axSpA). The objective of this matched case-control study was to investigate demographic, clinical, laboratory and MRI characteristics of OCI as compared with axial spondyloarthritis (axSpA)., Methods: A total of 60 patients diagnosed with OCI were included in the final analysis. From 27 of these patients, MRIs of the sacroiliac joints were available. OCI patients were matched with a 1:1 ratio by back pain duration to patients with definite axSpA in order to compare clinical, laboratory and MRI characteristics., Results: The OCI patients were nearly all females (96.7 vs 46.7%), had a significantly lower prevalence of inflammatory back pain (39.5 vs 88.9%), a significantly lower percentage of HLA-B27 positives (35.2 vs 80.0%) and a lower prevalence of the majority of other SpA features as compared with axSpA patients. Interestingly, there was no difference in the prevalence of osteitis in the sacroiliac joints (92.6 vs 85.2% in OCI and axSpA, respectively, P = 0.44), but there was a difference in the prevalence of erosions (7.4 vs 66.7%, respectively, P = 0.0001). In addition, in OCI nearly all lesions were localized in the anterior part of the sacroiliac joints while in axSpA lesions were localized predominantly in the middle part of the joint (for osteitis: 96 vs 4% in OCI and 28.6 vs 71.4% in axSpA; P = 0.0002 for the inter-group difference)., Conclusion: Clinical and imaging features of OCI compared with axSpA are described that should help in differential diagnosis., (© 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.)

Objectives: To study the association between the presence of antibodies against CD74 and structural damage in the sacroiliac joints and spine in patients with axial spondyloarthritis (axSpA)., Methods: Antibodies against CD74 were measured in the sera of patients with axSpA from 2 cohorts: 1. An observational cohort from Damp in Northern Germany and 2. from a clinical trial (ENRADAS), in which the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) had been evaluated by two readers blinded to the time point at baseline and two years later. The presence of antibodies against CD74 was correlated with the presence and grade of radiographic sacroiliitis in the observational cohort, and with baseline mSASSS in the ENRADAS cohort., Results: The sensitivity of IgA anti-CD74 antibodies for axSpA was 50% in the Damp cohort and 42% in ENRADAS. The presence of IgA antibodies against CD74 was associated with a higher grade of sacroiliitis (observational cohort) and a higher baseline mSASSS in the ENRADAS cohort., Conclusions: IgA antibodies against CD74 are not only markers of AS, but are associated with structural damage development in the sacroiliac joints and in the spine.

Objectives: The diagnostic delay in axial spondyloarthritis (axial SpA) remains unacceptably high, with one of the reasons being a late referral. Structured physician-based referral programs are able to improve early diagnosis, but lack of implementation is still an issue. The objective of this study was to evaluate an online self-referral (OSR) tool for patients with back pain and to compare it to an established physician-based referral tool., Methods: Patients with back pain were included if they either fulfilled the requirements of the OSR tool or were referred by a physician using the Berlin referral tool. Rheumatologists in the specialized center performed a structured assessment in all patients that resulted in the final diagnosis of axial SpA / no axial SpA. Furthermore, we attempted to optimize the OSR tool in terms of maximizing the specificity constrained by a sensitivity of at least 90% of the original strategy., Results: 361 consecutive patients (180 via the OSR and 181 via the Berlin referral tool) were included in the study. A total of 35 patients (19.4%) in the self-referral group and 71 patients (39.2%) in the physician-referral group were finally diagnosed with axial SpA. Axial SpA patients from the OSR group were more often HLA-B27 negative, females, and were more frequently at a non-radiographic stage as compared to axial SpA patients who came via the physician-based tool. Both groups had, however, a similar disease burden. According to the pre-defined selection criterion we identified an optimized combination of ≥2 IBP parameters and ≥1 other SpA parameters (in addition to both stem parameters)., Conclusions: Despite the better performance of the physician-based referral strategy, the proportion of axial SpA among self-referred patients (19.4%) was clearly higher than the assumed 5% prevalence of axial SpA in patients with chronic back pain. Based on our data driven approach the performance of the OSR strategy could be further improved if at least two IBP parameters plus one additional SpA parameter had to be present in addition to the stem parameters. The OSR tool can be used in specialized centers in addition to a physician-based referral strategy to improve early diagnosis and to increase awareness of axial SpA., Competing Interests: Declaration of Competing Interest Authors declare no conflicts of interest in relation to the content of the present work., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: In contrast to other chronic rheumatic musculoskeletal diseases such as rheumatoid arthritis, comorbidities in axial spondyloarthritis (axSpA) and their impact on disease outcomes are less well studied. The aim of this study was to investigate the prevalence of comorbidities and their association with disease activity and functional impairment in a large population-based cohort of patients with axSpA., Methods: A random sample of patients with axSpA, stratified by age and sex, was drawn from health insurance data. Patients in the sample received a survey on demographic, socioeconomic, and disease-related parameters. Comorbidities were defined using the Elixhauser coding algorithms excluding rheumatoid arthritis/collagen vascular diseases and including osteoporosis and fibromyalgia, resulting in a set of 32 comorbidities. The prevalence of comorbidities in the axSpA patients and their pharmacological treatment were examined. Multivariable linear regression models were calculated to determine the association of comorbidities with disease activity and functional status., Results: A total of 1776 axSpA patients were included in the analyses (response, 47%; mean age, 56 years; 46% female). The most prevalent comorbidities were hypertension, depression, and chronic pulmonary disorders. The number of comorbidities was significantly associated with both the BASDAI and BASFI: β (95% CI) = 0.17 (0.09-0.24) and 0.24 (0.15-0.32), respectively. When analysed separately, hypertension, depression, and chronic pulmonary disease were comorbidities with a significant and independent association with BASFI, while for BASDAI, such an association was found for depression and chronic pulmonary disease only., Conclusions: Comorbidities are common in axSpA patients and are associated with higher disease activity and higher levels of functional impairment. Higher disease activity and higher levels of functional impairment might be indicators of severe disease resulting in the development of comorbidities.

Purpose of Review: To provide a summary of the recent and expected developments related to the treatment of axial spondyloarthritis., Recent Findings: An increasing number of interleukin-17 blocking agents show efficacy in axial spondyloarthritis including both non-radiographic and radiographic forms. Janus kinase inhibitors showed promising results in phase II studies in radiographic axial spondyloarthritis and have, therefore, a potential to become a therapeutic option in this indication in the future. Inhibition of structural damage progression in axial spondyloarthritis seems to be possible in the case of effective and early anti-inflammatory treatment, although there are still open questions related to particular drug classes. Despite major advances in the field and growing therapeutic options, there are still many open questions related to the optimized treatment strategies and to the individual choice of a drug in axial spondyloarthritis.

Objectives: The Assessment of SpondyloArthritis international Society (ASAS) MRI working group conducted a multireader exercise on MRI scans from the ASAS classification cohort to assess the spectrum and evolution of lesions in the sacroiliac joint and impact of discrepancies with local readers on numbers of patients classified as axial spondyloarthritis (axSpA)., Methods: Seven readers assessed baseline scans from 278 cases and 8 readers assessed baseline and follow-up scans from 107 cases. Agreement for detection of MRI lesions between central and local readers was assessed descriptively and by the kappa statistic. We calculated the number of patients classified as axSpA by the ASAS criteria after replacing local detection of active lesions by central readers and replacing local reader radiographic sacroiliitis by central reader structural lesions on MRI., Results: Structural lesions, especially erosions, were as frequent as active lesions (≈40%), the majority of patients having both types of lesions. The ASAS definitions for active MRI lesion typical of axSpA and erosion were comparatively discriminatory between axSpA and non-axSpA. Local reader overcall for active MRI lesions was about 30% but this had a minor impact on the number of patients (6.4%) classified as axSpA. Substitution of radiography with MRI structural lesions also had little impact on classification status (1.4%)., Conclusion: Despite substantial discrepancy between central and local readers in interpretation of both types of MRI lesion, this had a minor impact on the numbers of patients classified as axSpA supporting the robustness of the ASAS criteria for differences in assessment of imaging., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To investigate the efficacy and safety of ixekizumab for up to 52 weeks in two phase 3 studies of patients with active radiographic axial spondyloarthritis (r-axSpA) who were biological disease-modifying antirheumatic drug (bDMARD)-naive (COAST-V) or tumour necrosis factor inhibitor (TNFi)-experienced (COAST-W)., Methods: Adults with active r-axSpA were randomised 1:1:1:1 (n=341) to 80 mg ixekizumab every 2 (IXE Q2W) or 4 weeks (IXE Q4W), placebo (PBO) or 40 mg adalimumab Q2W (ADA) in COAST-V and 1:1:1 (n=316) to IXE Q2W, IXE Q4W or PBO in COAST-W. At week 16, patients receiving ixekizumab continued their assigned treatment; patients receiving PBO or ADA were rerandomised 1:1 to IXE Q2W or IXE Q4W (PBO/IXE, ADA/IXE) through week 52., Results: In COAST-V, Assessment of SpondyloArthritis international Society 40 (ASAS40) responses rates (intent-to-treat population, non-responder imputation) at weeks 16 and 52 were 48% and 53% (IXE Q4W); 52% and 51% (IXE Q2W); 36% and 51% (ADA/IXE); 19% and 47% (PBO/IXE). Corresponding ASAS40 response rates in COAST-W were 25% and 34% (IXE Q4W); 31% and 31% (IXE Q2W); 14% and 39% (PBO/IXE). Both ixekizumab regimens sustained improvements in disease activity, physical function, objective markers of inflammation, QoL, health status and overall function up to 52 weeks. Safety through 52 weeks of ixekizumab was consistent with safety through 16 weeks., Conclusion: The significant efficacy demonstrated with ixekizumab at week 16 was sustained for up to 52 weeks in bDMARD-naive and TNFi-experienced patients. bDMARD-naive patients initially treated with ADA demonstrated further numerical improvements after switching to ixekizumab. Safety findings were consistent with the known safety profile of ixekizumab., Trial Registration Number: NCT02696785/NCT02696798., Competing Interests: Competing interests: MD has served as a consultant and received research grants from AbbVie, Eli Lilly and Company, Pfizer and UCB Pharma. JC-CW has served as a consultant and/or speaker and/or has received research grants from Abbott, Bristol-Myers Squibb, Celgene, Chugai, Eisai, Eli Lilly and Company, Janssen, Novartis, Pfizer, Sanofi-Aventis, TSH Taiwan and UCB Pharma. RL has served as a consultant and/or advisor and/or has received research grants from AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly and Company, Janssen, Galapagos, Merck, Novartis, Pfizer and UCB Pharma. RL is the director of Rheumatology Consultancy BV, a company that was indirectly contracted by Eli Lilly and Company to perform read services for the COAST program. JS has served as a consultant and/or speaker for AbbVie, Boehringer Ingelheim, Eli Lilly and Company, Janssen, Merck, Novartis, Pfizer, Roche and UCB Pharma. XB has served as a consultant and/or has received research grants from AbbVie, Bristol-Myers Squibb, Celgene, Janssen, MSD, Novartis, Pfizer, Roche and UCB Pharma. FVdB has served as a consultant and/or speaker and/or has received research grants from AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly and Company, Janssen, Merck, Novartis, Pfizer, Sanofi and UCB Pharma. WPM has served as a consultant and/or received honoraria and/or 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. JE has served as a consultant and/or received research grants from AbbVie, Boehringer Ingelheim, Eli Lilly and Company, Janssen, Novartis, Pfizer, Takeda and UCB Pharma. JAW has been a consultant and/or received research grants from AbbVie, Amgen, Celgene, Eli Lilly and Company, Novartis, Pfizer and UCB Pharma. AD has been a consultant and/or received research support from AbbVie, Bristol-Myers Squibb, Eli Lilly and Company, Glaxo Smith & Klein, Janssen, Novartis, Pfizer and UCB Pharma. DvdH has been a consultant for AbbVie, Amgen, Astellas, AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Daiichi, Eli Lilly and Company, Galapagos, Gilead, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda and UCB Pharma and is a Director of Imaging Rheumatology BV. TT has been a consultant and speaker for AbbVie, Astellas, Bristol-Myers Squibb, Eisai, Eli Lilly and Company, Janssen, Mitsubishi Tanabe, Novartis, Pfizer and Takeda. XL, FZ, CCB, GG and HC are current employees and shareholders of Eli Lilly and Company. LSG has been a consultant and/or received research grants/support from AbbVie, Amgen, Eli Lilly and Company, Galapagos, Janssen, Novartis, Pfizer and UCB Pharma., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To evaluate the performance of the Ankylosing Spondylitis Disease Activity Score based on a validated quick quantitative C-reactive protein assay (ASDAS-qCRP) as compared to ASDAS based on a routine lab CRP assay (ASDAS-CRP) and ASDAS based on erythrocyte sedimentation rate (ASDAS-ESR)., Methods: Disease activity assessment was performed in 50 patients with axial spondyloarthritis (axSpA). Routine lab CRP was measured in the central lab while the quantitative quick-CRP assay and ESR measurements were performed locally. ASDAS-CRP, ASDAS-qCRP and ASDAS-ESR were subsequently calculated., Results: The mean (±SD) serum level of the routine lab CRP (6.2±8.3mg/l) was lower than of the quick-CRP (7.4±8.4mg/l) (P<0.05). Whereat, there was no significant difference in the mean values of ASDAS-CRP and ASDAS-qCRP in axSpA patients (2.70±0.94 and 2.74±0.96, respectively, P=0.069), while the ASDAS-ESR (2.85±1.0) was significantly higher than ASDAS-CRP (P=0.036) and numerically higher than ASDAS-qCRP (P=0.125). In 47 of the 50 cases of axSpA (94%), patients were assigned to the same disease activity category according to ASDAS-CRP and ASDAS-qCRP., Conclusions: ASDAS-qCRP performed similarly well compared to ASDAS-CRP with the absolute agreement on the disease activity category according to the ASDAS of 94%. ASDAS-qCRP is, therefore, feasible for an immediate decision-making in clinical practice and trials aimed at treating to target., (Copyright © 2019 Société française de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.)

The cytokines IL-23 and IL-17 have an important role in the pathogenesis of, and as a therapeutic target in, both animal models of chronic inflammation and some human chronic inflammatory diseases. The traditional view is that a main source of IL-17 is T cells and that IL-17 production is under the control of IL-23. IL-17 inhibition has shown good efficacy in clinical trials for ankylosing spondylitis (AS), a subtype of axial spondyloarthritis (axSpA) characterized by radiographic evidence of sacroiliitis. On the basis of data from animal models, genetic studies and the investigation of tissue and blood samples from patients with AS, IL-23 had also been predicted to be important in the pathogenesis of this disease and was therefore considered a potential therapeutic target for axSpA. However, two placebo-controlled, double-blind clinical trials in axSpA of monoclonal antibodies directed against either the p40 protein or the p19 protein of the IL-23 molecule had clear negative results. These findings indicate that IL-23 and IL-17 are at least partly uncoupled in axSpA. Reasons as to why, when and how such an uncoupling might occur are discussed in this Review, with special reference to the unique microenvironment of the subchondral bone marrow in axSpA.

Objectives: To compare the clinical characteristics, burden of disease (eg, disease activity, function, quality of life), treatment modalities and treatment effect in patients with radiographic and non-radiographic axial Spondyloarthritis (r-axSpA and nr-axSpA)., Methods: A systematic literature review (2009-2018) was performed using the participants, intervention, comparator and outcomes methodology. Studies reporting outcomes (clinical presentation, burden of disease, treatment modalities and treatment effect) of both r-axSpA and nr-axSpA were included. A pooled analysis was performed (standardised means difference and relative risk for continuous and binary variables, respectively) and random or fixed effects methods were used depending on the heterogeneity of the studies., Results: 60 studies out of 787 references were included. Pooled analysis showed that, compared with patients with nr-axSpA, patients with r-axSpA were more frequently men (69.6% vs 53.6%), smokers (37.7% vs 31.1%) and had higher mean disease duration (8.6 vs 5.0 years) and longer time to diagnosis (6.1 vs 4.2 years). Peripheral manifestations were more prevalent in nr-axSpA, while uveitis and structural damage on MRI of the sacroiliac joints were more prevalent in r-axSpA. C-reactive protein and the Bath Ankylosing Spondylitis Mobility Index were higher in r-axSpA, while Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index and Ankylosing Spondylitis Quality of Life were similar in both groups. No significant differences were found with regard to treatment effect., Conclusions: Patients with r-axSpA and nr-axSpA share a similar clinical presentation except for peripheral involvement, which is more prevalent among nr-axSpA. Except for a more impaired mobility in r-axSpA, both groups showed a comparable burden of disease, treatment modalities and treatment effect., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: The Assessment of SpondyloArthritis international Society (ASAS) MRI working group (WG) was convened to generate a consensus update on standardised definitions for MRI lesions in the sacroiliac joint (SIJ) of patients with spondyloarthritis (SpA), and to conduct preliminary validation., Methods: The literature pertaining to these MRI lesion definitions was discussed at three meetings of the group. 25 investigators (20 rheumatologists, 5 radiologists) determined which definitions should be retained or required revision, and which required a new definition. Lesion definitions were assessed in a multi-reader validation exercise using 278 MRI scans from the ASAS classification cohort by global assessment (lesion present/absent) and detailed scoring (inflammation and structural). Reliability of detection of lesions was analysed using kappa statistics and the intraclass correlation coefficient (ICC)., Results: No revisions were made to the current ASAS definition of a positive SIJ MRI or definitions for subchondral inflammation and sclerosis. The following definitions were revised: capsulitis, enthesitis, fat lesion and erosion. New definitions were developed for joint space enhancement, joint space fluid, fat metaplasia in an erosion cavity, ankylosis and bone bud. The most frequently detected structural lesion, erosion, was detected almost as reliably as subchondral inflammation (κappa/ICC:0.61/0.54 and 0.60/0.83) . Fat metaplasia in an erosion cavity and ankylosis were also reliably detected despite their low frequency (κappa/ICC:0.50/0.37 and 0.58/0.97)., Conclusion: The ASAS-MRI WG concluded that several definitions required revision and some new definitions were necessary. Multi-reader validation demonstrated substantial reliability for the most frequently detected lesions and comparable reliability between active and structural lesions., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: The objective of this study was to assess the current diagnostic delay in axial SpA (axSpA) and to analyse factors associated with it., Methods: A stratified sample of subjects with a diagnosis of axSpA (International Classification of Diseases, 10th Revision code M45) was drawn from health insurance data in Germany and was questioned on disease-related, lifestyle and socio-economic characteristics. The diagnostic delay was calculated as the time from back pain onset until a diagnosis of axSpA. A multivariable linear regression analysis was performed to explore factors associated with the diagnostic delay., Results: Among 1677 patients with axSpA included in the analysis, the mean diagnostic delay was 5.7 years (median 2.3). Of those, 407 patients were diagnosed in 1996-2005 and 484 patients in 2006-2015. The mean diagnostic delay was not substantially different in both periods: 6.3 years (median 2.6) and 7.4 (2.7), respectively. Multivariable linear regression revealed that female sex [β = 1.85 (95% CI 1.06, 2.65)], negative HLA-B27 status [β = 3.61 (95% CI 2.07, 5.14)], presence of psoriasis [β = 1.40 (95% CI 0.08, 2.73)] and younger age at symptom onset [β = 1.91 (95% CI 1.53, 2.29)] were factors associated with a longer diagnostic delay., Conclusion: The diagnostic delay in axSpA is still unacceptably long. Patients who are female, young at symptom onset, HLA-B27 negative or have psoriasis have a longer diagnostic delay. Specific referral strategies might be necessary in order to decrease the diagnostic delay in patients presenting with these characteristics., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: This analysis assessed baseline predictors of remission in patients with non-radiographic axial spondyloarthritis (nr-axSpA) who received open-label adalimumab therapy., Methods: ABILITY-3 enrolled 673 adult patients with nr-axSpA who had objective evidence of inflammation by MRI or elevated high-sensitivity C reactive protein at screening, active disease and an inadequate response to two or more non-steroidal anti-inflammatory drugs. Patients received adalimumab 40 mg every other week during a 28-week open-label lead-in period. Clinical remission was defined as Ankylosing Spondylitis Disease Activity Score inactive disease (ASDAS ID; score <1.3) and Assessment of SpondyloArthritis international Society partial remission (ASAS PR; score <2/10 in each of the four ASAS domains). Stepwise logistic regression was used to identify baseline predictors of remission at week 12 and at final visit (last postbaseline visit up to week 28). Only patients without missing data were included., Results: Overall, 593 patients were included in the ASDAS ID and 596 in the ASAS PR analysis at week 12. Younger age (≤45 years), male sex, positive human leucocyte antigen (HLA)-B27 and higher Spondyloarthritis Research Consortium of Canada (SPARCC) MRI sacroiliac joint score were consistent predictors of remission by both ASAS ID and ASDAS PR at week 12. Results were generally similar in the final visit analysis. Other variables did not consistently predict remission., Conclusions: In ABILITY-3, consistent and strong baseline predictors of remission included younger age, male sex, HLA-B27 positivity and higher SPARCC MRI sacroiliac joint score among patients with active nr-axSpA receiving adalimumab therapy, similar to previous findings in ankylosing spondylitis., Competing Interests: Competing interests: JS has received consulting fees from AbbVie, Boehringer Ingelheim, Janssen, Lilly, Merck, Novartis, Pfizer, Sun Pharma, and UCB; and speaker fees from AbbVie, Janssen, Lilly, Merck, Novartis, Pfizer and UCB. RL has received consulting or advisory board fees from Abbott/AbbVie, Ablynx, Amgen, AstraZeneca, Bristol Myers Squibb, Celgene, Janssen, Galapagos, GlaxoSmithKline, Novartis, Novo Nordisk, Merck, Pfizer, Roche, Schering-Plough, TiGenix, UCB and Wyeth; research grants from Abbott, Amgen, Centocor, Novartis, Pfizer, Roche, Schering-Plough, UCB and Wyeth; speaker fees from Abbott/AbbVie, Amgen, Bristol Myers Squibb, Janssen, Merck, Pfizer, Roche, Schering-Plough, UCB and Wyeth; and is director of Rheumatology Consultancy BV, a registered Dutch company. MM has received research grants from Amgen, AbbVie and UCB Pharma and consulting fees from Novartis and Eli Lilly. SZ, XW, AL and JKA are full-time employees of AbbVie and may own AbbVie stock and/or stock options.

Objective: To compare proton density-weighted short-tau inversion recovery (PD-STIR) and T2-weighted fat-suppressed turbo spin echo (T2-FS) sequences for detecting osteitis lesions of the sacroiliac joints (SIJ) in patients with chronic low back pain (CLBP)., Methods: This prospective study included 110 patients with CLBP and suspected spondyloarthritis and 18 healthy controls. All 128 participants (age range: 19-57 yrs) underwent 3.0 Tesla magnetic resonance imaging (MRI) of the SIJ including PD-STIR and T2-FS. Two readers independently scored PD-STIR and T2-FS images for osteitis in separate sessions. Sum scores and signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Images were further analyzed as to whether they fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criterion of a positive MRI (MRI+). Interreader agreement was calculated using intraclass correlation coefficients., Results: Average osteitis sum scores were higher for T2-FS images (mean sum score of 4.10 in T2-FS vs 2.55 in PD-STIR, p = 0.017). Mean SNR was 16.54 for PD-STIR and 37.30 for T2-FS (p = 0.0289). Mean CNR was 4.14 for PD-STIR and 20.20 for T2-FS (p = 0.0212). For both readers, the ASAS MRI+ definition was more often fulfilled by T2-FS than by PD-STIR images, resulting in more patients being classified as having axial spondyloarthritis (axSpA): 68 patients using T2-FS versus 58 patients using PD-STIR. Interreader intraclass correlation coefficients were very good for both PD-STIR (0.91) and T2-FS (0.86)., Conclusion: T2-FS sequences improve image quality and hence the detection of osteitis compared to the PD-STIR sequence. More patients were classified as axSpA based on a positive MRI by T2-FS.

Objective: To compare the performance of a new three-dimensional MRI sequence (volumetric interpolated breath-hold examination; MR-VIBE) with a conventional T1-weighted sequence (MR-T1) for the detection of erosions in the sacroiliac joints (SIJs) using low-dose CT (ldCT) as reference., Methods: ldCT and T1-MRI and MR-VIBE of 110 prospectively included patients with low back pain and suspected axial spondyloarthritis (axSpA) were scored for erosions by two readers. The presence of erosions on the patients' level, the erosion sum score, sensitivity and specificity of both MRI sequences using ldCT as a reference as well as agreement between the readers were assessed., Results: MR-VIBE had a higher sensitivity than MR-T1 (95% vs 79%, respectively) without a decrease in specificity (93% each). MR-VIBE compared with MR-T1 identified 16% more patients with erosions (36 vs 30 of 38 patients with positive ldCT findings). The erosion sum score was also higher for MR-VIBE (8.1±9.3) than MR-T1 (6.7±8.4), p=0.003. The agreement on erosion detection was also higher for MR-VIBE (κ=0.71) compared with MRI-T1 (κ=0.56)., Conclusion: VIBE detected erosions in the SIJs with higher sensitivity without a loss of specificity and superior reliability compared with a standard T1-weighted sequence. Its value for the diagnosis of axSpA has still to be determined., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To determine the prevalence of fat metaplasia and other structural lesions of the sacroiliac joints associated with axial spondyloarthritis in a nonrheumatological patient population., Methods: Magnetic resonance imaging examinations that included the pelvis and were performed in patients without known rheumatological disease were used for this retrospective cross-sectional study. These images were evaluated for sacroiliac fat metaplasia, sclerosis, osteophytes, and joint space alterations such as erosions or ankylosis. Patients were divided into 7 age groups (15-24 to ≥ 75 yrs). Prevalence of lesions across age groups was calculated. Possible clinical confounders (e.g., status post radiation, suspected inflammatory bowel disease) were investigated regarding their effect on lesion prevalence and extent, to exclude bias., Results: A total of 485 patients were enrolled. Fat metaplasia was very common and increased with age, from a prevalence of 50.6% in the age groups < 45, to 94.4% in patients ≥ 75 years. Erosions were uncommon: 0.6% of patients < 45, and 2.6% of the entire study population exhibited this feature, with no detectable age-dependent increase. Sclerosis and osteophytes were detected in 13.7% and 37.0% of patients, respectively. None of the investigated clinical confounders had a significant effect on lesion prevalence., Conclusion: Our study shows a very high prevalence of fat metaplasia adjacent to the sacroiliac joint in asymptomatic patients, while erosions are extremely uncommon.

Objectives: The aim of this study was to assess the psychological well-being and to analyse factors associated with depressive symptoms in axial spondyloarthritis (axSpA)., Methods: A stratified random sample of subjects with a diagnosis of axSpA (International Classification of Diseases, Tenth Revision, German Modification M45) was drawn from health insurance data in Germany. These persons received a postal questionnaire on disease-related, psychological and lifestyle factors as well as socioeconomic status. Additional information to verify the axSpA diagnosis was also collected. The psychological well-being was assessed by means of the 5-item WHO Well-Being Index (WHO-5), which is considered a screening tool for depression. The following established cut-offs on the WHO-5 were applied: >50: good well-being, no depressive symptoms; 29-50: mild depressive symptoms; ≤28: moderate-to-severe depressive symptoms. Information on comorbidities, drug prescriptions and non-pharmacological treatment was retrieved from claims data and linked to the questionnaire data., Results: A total of 1736 persons with a confirmed axSpA diagnosis were included. Using the cut-offs on the WHO-5, 533 persons (31%) were found to have moderate-to-severe depressive symptoms, 479 (28%) had mild depressive symptoms and 724 (42%) had a good well-being. Multivariable logistic regression revealed that higher disease activity, higher level of functional impairment, lower income, self-reported stress and lack of exercise, and younger age represent factors associated with moderate-to-severe depressive symptoms., Conclusions: The prevalence of depressive symptoms in axSpA subjects is high and associated with disease-related parameters, socioeconomic status and lifestyle factors. These findings highlight the need for the careful evaluation of depressive symptoms as a part of the management strategy for axSpA., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Peripheral spondyloarthritis refers to spondyloarthritis with predominant peripheral (arthritis, enthesitis or dactylitis) involvement. Diagnosis can be challenging, particularly in the absence of SpA extra-articular manifestations such as uveitis, psoriasis or inflammatory bowel disease. Evaluation of disease activity should always include assessment of objective signs of inflammation, particularly in the presence of enthesitis as the sole peripheral manifestation, mainly due to the potential misdiagnosis with fibromyalgia tender points. Several recommendations for management/treatment of psoriatic arthritis have been published by EULAR and GRAPPA but none for peripheral SpA in general. NSAIDs and glucocorticoids are recommended as the first step of treatment in all peripheral manifestations, while conventional synthetic (cs) DMARDs seem only efficacious in arthritis. Several biologics and targeted synthetic (ts) DMARDs (TNFi, anti-IL17 and JAK-inhibitors) have been proven to be efficacious in peripheral involvement in PsA (arthritis and enthesitis), but studies on peripheral SpA are lacking., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: The aim of the study was to investigate the functional relevance of the development of structural damage in the spine in patients with early axial spondyloarthritis (axSpA)., Methods: Altogether, 210 patients with early axSpA (symptom duration ⩽10 years) who completed a 2-year clinical and radiographic follow-up in the GErman SPondyloarthritis Inception Cohort were included. An association between structural damage in the spine [modified Stoke AS Spine Score (mSASSS)] and functional status (the BASFI) or spinal mobility (the BASMI) was assessed in a longitudinal linear mixed model analysis; both unstandardized (β) and standardized (βstand) regression coefficients were calculated., Results: There was an association between mSASSS and BASFI: β = 0.05 (95% CI: 0.03, 0.08) and βstand = 0.20 (95% CI: 0.11, 0.59) adjusted for disease activity parameters (the BASDAI and CRP), the presence of definite radiographic sacroiliitis and sex. An association between mSASSS and BASMI was stronger: β = 0.08 (95% CI: 0.05, 0.11) and βstand = 0.41 (95% CI: 0.25, 0.57) adjusted for the same parameters. These data indicate that, over time, an increase of 20 or 12 mSASSS points would be responsible for an increase of one BASFI or one BASMI point, respectively. Disease activity (BASDAI) also showed a significant association with BASFI [β = 0.79 (95% CI: 0.71, 0.86) and βstand = 0.71 (95% CI: 0.63, 0.77)] and BASMI [β = 0.22 (95% CI: 0.15, 0.30) and βstand = 0.28 (95% CI: 0.18, 0.37)]., Conclusion: Structural damage in the spine and disease activity are both determinants of the functional status and spinal mobility in early axSpA.

Background: Adalimumab was effective in treating patients with nonradiographic axial spondyloarthritis (nr-axSpA) in the 12-week ABILITY-1 trial. We present long-term efficacy and safety results of adalimumab from the open-label ABILITY-1 extension, including the relationship between clinical and magnetic resonance imaging (MRI) remission and impact of sustained clinical remission on physical function., Methods: Patients received adalimumab 40 mg every other week or placebo for 12 weeks, then open-label adalimumab for up to 144 weeks. Clinical and safety data were collected through 3 years, and MRI data were collected until 2 years. Analyses were performed in the total population and subpopulation with positive MRI and/or elevated C-reactive protein (MRI/CRP-positive) at baseline. Clinical and MRI remission definitions included Ankylosing Spondylitis Disease Activity Score inactive disease (ASDAS ID; score < 1.3) and Spondyloarthritis Research Consortium of Canada (SPARCC) MRI score < 2 for sacroiliac joints (SIJs), spine, or both. Physical function was assessed using the Bath Ankylosing Spondylitis Functional Index., Results: Overall, 185 patients were included in the total population and 142 in the MRI/CRP-positive subpopulation; 65% and 68%, respectively, completed 3 years. Clinical, functional, and MRI improvements were similar and equally sustainable in both populations. At year 3, the percentages of patients in ASDAS ID in the MRI/CRP-positive subpopulation were 30%/33% (nonresponder imputation) and 46%/49% (observed) for those initially receiving adalimumab/placebo. At years 1 and 2, patients in ASDAS ID vs not had significantly greater improvements in SPARCC SIJ scores from baseline (P < 0.001). Among patients with baseline MRI scores ≥ 2 who achieved ASDAS ID at year 2, 44-68% also had MRI remission. Significantly more patients with sustained ASDAS ID through year 2 or 3 vs without achieved normal physical function (100% vs 48%; 100% vs 44%; both P < 0.001). No new safety concerns were observed., Conclusions: In the ABILITY-1 study of nr-axSpA, adalimumab therapy provided sustained clinical and functional improvements through 3 years, as well as suppression of MRI axial inflammation, which was greater in patients who achieved clinical remission. Sustained clinical remission was associated with increased attainment of normal physical function. The safety profile of adalimumab was consistent with prior studies., Trial Registration: ClinicalTrials.gov , NCT00939003 ; registered on July 10, 2009.

Background: Functional status and spinal mobility in patients with axial spondyloarthritis (axSpA) are known to be determined both by disease activity and by structural damage in the spine. The impact of structural damage in the sacroiliac joints (SIJ) on physical function and spinal mobility in axSpA has not been studied so far. The objective of the study was to analyze the impact of radiographic sacroiliitis on functional status and spinal mobility in patients with axSpA., Methods: In total, 210 patients with axSpA were included in the analysis. Radiographs of SIJ obtained at baseline and after 2 years of follow up were scored by two trained readers according to the modified New York criteria grading system (grade 0-4). The mean of two readers' scores for each joint and a sum score for both SIJ were calculated for each patient giving a sacroiliitis sum score between 0 and 8. The Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) at baseline and after 2 years were used as outcome measures., Results: Longitudinal mixed model analysis adjusted for structural damage in the spine (modified Stoke Ankylosing Spondylitis Spine Score - mSASSS), disease activity (Bath Ankylosing Spondylitis Disease Activity Index - BASDAI and C-reactive protein level) and gender, revealed an independent association of the sacroiliitis sum score with the BASFI: b = 0.10 (95% CI 0.01-0.19) and the BASMI: b = 0.12 (95% CI 0.03-0.21), respectively, indicating that change by one radiographic sacroiliitis grade in one joint is associated with BASFI/BASMI worsening by 0.10/0.12 points, respectively, independently of disease activity and structural damage in the spine., Conclusion: Structural damage in the SIJ might have an impact on functional status and spinal mobility in axSpA independently of spinal structural damage and disease activity., Trial Registration: ClinicalTrials.gov, NCT01277419 . Registered on 14 January 2011.

Objective: To evaluate the long-term clinical and imaging efficacy of etanercept in patients with early, active nonradiographic axial spondyloarthritis (SpA)., Methods: Adult patients who satisfied the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial SpA (but not the modified New York radiographic criteria), with symptom duration >3 months to <5 years, and who were unresponsive to ≥2 nonsteroidal antirheumatic drugs (NSAIDs) received double-blind etanercept 50 mg/week or placebo for 12 weeks, followed by open-label etanercept 50 mg/week to week 104. Clinical, magnetic resonance imaging (MRI; Spondyloarthritis Research Consortium of Canada [SPARCC] scores), and safety outcomes at 104 weeks were analyzed., Results: Of 215 randomized patients (etanercept: n = 106; placebo: n = 109), 205 entered the study (etanercept/etanercept: n = 100; placebo/etanercept: n = 105) and 169 completed the open-label period (etanercept/etanercept: n = 83; placebo/etanercept: n = 86). At week 104, 61 of 81 (75%), 49 of 81 (61%), 48 of 80 (60%), and 57 of 81 (70%) patients who received etanercept throughout the trial achieved ASAS20, ASAS40, Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease, and Bath Ankylosing Spondylitis Disease Activity Index criteria for 50% improvement (BASDAI 50) scores, respectively (observed). From baseline to week 104, continued improvements in clinical outcomes (ASDAS-C-reactive protein: -1.5 and -1.7; BASDAI: -3.3 and -3.8 [last observation carried forward]), and SPARCC MRI scores (sacroiliac joint: -6.0 and -3.4; spinal: -2.1 and -0.8 [observed]) were seen in patients receiving etanercept/etanercept and placebo/etanercept. During the study, 8% in the etanercept/etanercept group and 7% in the placebo/etanercept group had serious adverse events; no new safety signals were seen., Conclusion: Patients with early, active nonradiographic axial SpA and an inadequate response to at least 2 NSAIDs demonstrated improvement in clinical and imaging outcomes that were sustained through 104 weeks of etanercept treatment., (© 2017, American College of Rheumatology.)

Objective: The aim was to assess the long-term safety and efficacy of certolizumab pegol over 4 years of continuous treatment in patients with axial spondyloarthritis (axSpA), including both AS and non-radiographic (nr-) axSpA., Methods: RAPID-axSpA was a phase 3 randomized trial, double blind and placebo controlled to week 24, dose blind to week 48 and open label to week 204. Patients had a clinical diagnosis of axSpA, meeting Assessment of SpondyloArthritis international Society (ASAS) criteria, and had active disease. The assessed outcomes included ASAS20, ASAS40, AS DAS (ASDAS), BASDAI, BASFI and BASMI scores, along with selected measures of remission. Further patient-reported outcomes, peripheral arthritis, enthesitis, uveitis and quality-of-life measures are also reported., Results: Two hundred and eighteen of 325 patients randomized (AS: 121; nr-axSpA: 97) received certolizumab pegol from week 0. Of these, 65% remained in the study at week 204 (AS: 67%; nr-axSpA: 63%). Across all outcomes, for AS and nr-axSpA, sustained improvements were observed to week 204 [week 204 overall axSpA: ASAS20: 54.1% (non-responder imputation); 83.7% (observed case, OC); ASAS40: 44.0% (non-responder imputation); 68.1% (OC); ASDAS inactive disease: 32.1% (last observation carried forward); 31.4% (OC)]. In the safety set (n = 315), there were 292.8 adverse events and 10.4 serious adverse events per 100 patient-years. No deaths were reported., Conclusion: In the first study to evaluate the efficacy of an anti-TNF across both axSpA subpopulations, improvements in clinical and patient-reported outcomes at 24 and 96 weeks were sustained through 4 years of treatment, with no new safety signals., Trial Registration: ClinicalTrials.gov, http://clinicaltrials.gov, NCT01087762., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Purpose of the Review: The purpose of this review is to discuss new evidence explaining the progress from bony inflammation over repair tissue to new bone formation in axial spondyloartrhitis and its correlations in imaging and histology of the bone., Recent Findings: Data from imaging, histology and treatment interventions indicates that the disease starts with inflammation, followed by replacement of subchondral bone marrow by repair tissue which presence is crucial for the stimulation of new bone formation. The magnetic resonance imaging (MRI) sequences of STIR and T1 are currently the most commonly used imaging techniques to follow this process; explanations are offered for the limited sensitivity to detect these bony changes on MRI in their different phases. Early and effective anti-inflammatory treatment is crucial for the prevention of long-term ankylosis. Whether there are currently also treatment options targeting new bone formation in these patients directly is less clear.