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Whereas previous projects attempted to standardize imaging in patients with axial spondyloarthritis (axSpA), few studies have been published about the need for specific details regarding the image acquisition and lesions that may be less familiar to general radiologists. This work reports consensus recommendations developed by the Assessment of SpondyloArthritis International Society (ASAS) that aim to standardize the imaging reports in patients suspected of having or with known axSpA. A task force consisting of radiologists and rheumatologists from ASAS and one patient representative formulated two surveys that were completed by ASAS members. The results of these surveys led to the development of 10 recommendations that were endorsed by 73% (43 of 59) of ASAS members. The recommendations are targeted to the radiologist and include best practices for the inclusion of clinical information, technical details, image quality, and imaging findings in radiology reports. These recommendations also emphasize that imaging findings that indicate differential diagnoses and referral suggestions should be included in the concluding section of the radiology report. With these recommendations, ASAS aims to improve the diagnostic process and care for patients suspected of having or with known axSpA.
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Articulación Sacroiliaca , Humanos , Articulación Sacroiliaca/diagnóstico por imagen , Espondiloartritis Axial/diagnóstico por imagen , Sociedades Médicas , Espondiloartritis/diagnóstico por imagen , Diagnóstico Diferencial , Imagen por Resonancia Magnética/métodosRESUMEN
BACKGROUND: A range of sacroiliac joint (SIJ) MRI protocols are used in clinical practice but not all were specifically designed for diagnostic ascertainment. This can be confusing and no standard diagnostic SIJ MRI protocol is currently accepted worldwide. OBJECTIVE: To develop a standardised MRI image acquisition protocol (IAP) for diagnostic ascertainment of sacroiliitis. METHODS: 13 radiologist members of Assessment of SpondyloArthritis International Society (ASAS) and the SpondyloArthritis Research and Treatment Network (SPARTAN) plus two rheumatologists participated in a consensus exercise. A draft IAP was circulated with background information and online examples. Feedback on all issues was tabulated and recirculated. The remaining points of contention were resolved and the revised IAP was presented to the entire ASAS membership. RESULTS: A minimum four-sequence IAP is recommended for diagnostic ascertainment of sacroiliitis and its differential diagnoses meeting the following requirements. Three semicoronal sequences, parallel to the dorsal cortex of the S2 vertebral body, should include sequences sensitive for detection of (1) changes in fat signal and structural damage with T1-weighting; (2) active inflammation, being T2-weighted with fat suppression; (3) bone erosion optimally depicting the bone-cartilage interface of the articular surface and (4) a semiaxial sequence sensitive for detection of inflammation. The IAP was approved at the 2022 ASAS annual meeting with 91% of the membership in favour. CONCLUSION: A standardised IAP for SIJ MRI for diagnostic ascertainment of sacroiliitis is recommended and should be composed of at least four sequences that include imaging in two planes and optimally visualise inflammation, structural damage and the bone-cartilage interface.
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OBJECTIVES: To a) identify threshold values of presenteeism measurement instruments that reflect unacceptable work state in employed r-axSpA patients; b) determine whether those thresholds accurately predict future adverse work outcomes (AWO) (sick leave or short/long-term disability); c) evaluate the performance of traditional health-outcomes for r-axSpA; d) explore whether thresholds are stable across contextual factors. METHODS: Data from the multinational AS-PROSE study was used. Thresholds to determine whether patients consider themselves in an 'unacceptable work state' were calculated at baseline for four instruments assessing presenteeism and two health-outcomes specific for r-axSpA. Different approaches derived from the receiver operating characteristic methodology were used. Validity of the optimal thresholds was tested across contextual factors and for predicting future AWO over 12 months. RESULTS: Of 366 working patients, 15% reported an unacceptable work state; 6% experienced at least one AWO in 12 months. Optimal thresholds were: WPAI-presenteeism ≥40 (AUC 0.85), QQ-method <97 (0.76), WALS ≥0.75 (AUC 0.87), WLQ-25 ≥ 29 (AUC 0.85). BASDAI and BASFI performed similarly to the presenteeism instruments: ≥4.7 (AUC 0.82) and ≥3.5 (AUC 0.79), respectively. Thresholds for WALS and WLQ-25 were stable across contextual factors, while for all other instruments they overestimated unacceptable work state in lower educated persons. Proposed thresholds could also predict future AWO, although with lower performance, especially for QQ-method, BASDAI and BASFI. CONCLUSIONS: Thresholds of measurement instruments for presenteeism and health status to identify unacceptable work state have been established. These thresholds can help in daily clinical practice to provide work related support to r-axSpA patients at risk for AWO.
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Proper assessment of patients with psoriatic arthritis (PsA) requires assessment of all disease domains, including axial disease. Magnetic resonance imaging (MRI) is the method of choice for evaluating axial involvement in PsA. When assessing patients with PsA for spinal involvement, it is important to assess both vertebral body lesions and posterolateral lesions, such as inflammation in facet joints and costovertebral joints, and enthesitis at spinous and transverse processes. The Canada-Denmark (CanDen) assessment system for spine MRIs is the preferred method for detailed evaluation of inflammation and structural damage at various anatomical locations in the spine, and it is reproducible and sensitive to change. The Assessment of Spondyloarthritis international Society (ASAS) has recently published MRI definitions of inflammatory and structural lesions in the spine, incorporating the CanDen definitions of spinal lesions on MRI. Applying the ASAS definitions and the CanDen assessment system in clinical practice and trials is recommended. Ongoing research/studies, not least the Axial Involvement in Psoriatic Arthritis (AXIS) study, may provide a data-driven definition of axial involvement in PsA. Ongoing research is expected to further improve and validate assessment tools for axial PsA and to provide a much-needed data-driven consensus-based definition of axial involvement in PsA.
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OBJECTIVE: (1) To compare the capacity to detect sacroiliac joint (SIJ) erosions and baseline-to-week 104 change in erosions between magnetic resonance imaging (MRI) and radiographs in recent-onset axial spondyloarthritis (axSpA); and (2) to compare treatment-discriminatory capacities of MRI and radiographic scores for erosion detection in patients receiving etanercept in the Effect of Etanercept on Symptoms and Objective Inflammation in Nonradiographic axSpA (EMBARK) trial vs controls in the DESIR (Devenir des Spondylarthropathies Indifférenciées Récentes) cohort. METHODS: Anonymized SIJ MRI and radiographs were assessed at patient and joint surface levels. Three readers evaluated MRI; 3 different readers evaluated radiographs. Final scores for comparison of radiographs and MRI for detection of erosions were assigned based on agreement of ≥ 2 of 3 readers' assessments. RESULTS: At baseline, discordance in erosion detection between imaging methods was more frequent for MRI erosions in the absence of radiographic erosions (48/224 [21.4%] patients) than for radiographic erosions in the absence of MRI erosions (14/224 [6.3%] patients; P < 0.001). After 104 weeks, a decrease in erosions was observed on MRI but not radiographs in 49/221 (22.2%) patients, and on radiographs but not MRI in 6/221 (2.7%) patients (P < 0.001). In the treatment-discriminant capacity analysis, the largest standardized differences between etanercept and control cohorts at week 104 were changes in Spondyloarthritis Research Consortium of Canada MRI erosion discrete score, changes in erosion average score, and meeting the modified New York criteria on radiographs, with unadjusted/adjusted Hedges G effect sizes of 0.40/0.50, 0.40/0.56, and 0.40/0.43, respectively. CONCLUSION: In recent-onset axSpA, SIJ erosions and erosion change were observed more frequently on MRI than radiography. The significance of interval improvement of MRI erosions warrants further research. [ClinicalTrials.gov: NCT01258738, NCT01648907].
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Espondiloartritis Axial , Etanercept , Imagen por Resonancia Magnética , Radiografía , Articulación Sacroiliaca , Humanos , Articulación Sacroiliaca/diagnóstico por imagen , Articulación Sacroiliaca/patología , Imagen por Resonancia Magnética/métodos , Adulto , Femenino , Masculino , Espondiloartritis Axial/diagnóstico por imagen , Espondiloartritis Axial/tratamiento farmacológico , Etanercept/uso terapéutico , Antirreumáticos/uso terapéutico , Resultado del Tratamiento , Índice de Severidad de la Enfermedad , Persona de Mediana EdadRESUMEN
OBJECTIVE: To begin evaluating deep learning (DL)-automated quantification of knee joint effusion-synovitis via the OMERACT filter. METHODS: A DL algorithm previously trained on Osteoarthritis Initiative (OAI) knee MRI automatically quantified effusion volume in MRI of 53 OAI subjects, which were also scored semi-quantitatively via KIMRISS and MOAKS by 2-6 readers. RESULTS: DL-measured knee effusion correlated significantly with experts' assessments (Kendall's tau 0.34-0.43) CONCLUSION: The close correlation of automated DL knee joint effusion quantification to KIMRISS manual semi-quantitative scoring demonstrated its criterion validity. Further assessments of discrimination and truth vs. clinical outcomes are still needed to fully satisfy OMERACT filter requirements.
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Aprendizaje Profundo , Articulación de la Rodilla , Imagen por Resonancia Magnética , Osteoartritis de la Rodilla , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/patología , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/diagnóstico por imagen , Algoritmos , Masculino , Femenino , Persona de Mediana Edad , Reproducibilidad de los Resultados , AncianoRESUMEN
INTRODUCTION: A previous network meta-analysis established 16-week relative efficacy with bimekizumab, an inhibitor of interleukin (IL)-17F in addition to IL-17A, versus other treatments for patients with radiographic axial spondyloarthritis (r-axSpA; i.e., ankylosing spondylitis), including the IL-17A inhibitors secukinumab and ixekizumab. This matching-adjusted indirect comparison (MAIC) assessed 52-week relative efficacy of bimekizumab versus secukinumab and ixekizumab. METHODS: Individual patient data from BE MOBILE 2 (bimekizumab 160 mg; N = 220) were matched to pooled summary data from MEASURE 1/2/3/4 (secukinumab 150 mg), MEASURE 3 (secukinumab 300 mg; escalated dose for inadequate responders), COAST-V (ixekizumab) and COAST-V/-W (ixekizumab). BE MOBILE 2 patients were reweighted using propensity score weights based on age, sex, ethnicity, tumor necrosis factor inhibitor (TNFi) exposure, weight, baseline ASDAS and BASFI (secukinumab) and baseline BASDAI (ixekizumab), and 52-week efficacy outcomes from the trial recalculated. Odds ratios (OR) or mean difference for unanchored comparisons are reported with 95% confidence intervals (CI). RESULTS: At week 52, MAIC demonstrated that patients may have higher likelihood of improvement in key efficacy outcomes with bimekizumab versus secukinumab 150 mg (e.g., ASAS40: [OR (95% CI): 1.48 (1.05, 2.10); p = 0.026]; effective sample size [ESS] = 177). Differences in 52-week efficacy outcomes between bimekizumab and secukinumab 300 mg dose escalation were non-significant (ESS = 120). Bimekizumab versus ixekizumab 80 mg comparisons (COAST-V only; ESS = 84) also suggested that differences were non-significant for most key efficacy outcomes. Other ixekizumab comparisons (COAST-V/-W; ESS = 45) suggested bimekizumab may have higher comparative efficacy for many of the same efficacy outcomes, however ixekizumab analyses were limited by poor population overlap, likely due to the greater proportion of patients with previous TNFi exposure. CONCLUSIONS: Patients treated with bimekizumab may have a higher likelihood of achieving improved longer-term efficacy versus secukinumab 150 mg, suggesting bimekizumab may be a favorable therapeutic option for r-axSpA. Differences in efficacy outcomes with bimekizumab versus ixekizumab 80 mg were mostly non-significant, depending on the populations considered.
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INTRODUCTION: The objective of this analysis is to evaluate the improvement in spinal pain with ixekizumab, placebo, and adalimumab based on objective measures of inflammation response in patients with ankylosing spondylitis (AS). METHODS: The COAST-V 52-week, double-blind, placebo-controlled, randomized phase III trial examined the efficacy of ixekizumab in patients with active AS; adalimumab was used as an active reference arm. Treatment effects on reduction in pain were assessed by objective measures of controlled and persisting inflammation (defined by magnetic resonance imaging [MRI], C-reactive protein [CRP], or MRI + CRP status). Pathway analysis was used to analyze treatment effect that was not attributable to reduction in inflammation biomarkers. RESULTS: In patients with AS, when inflammation was controlled as assessed by MRI, patients treated with ixekizumab experienced a reduction in spinal pain at night (SP-N, numeric rating scale, ixekizumab mean = - 3.9, p < 0.001, adalimumab mean = - 2.6, p < 0.05) compared to placebo (mean = - 1.6) at week 16. When inflammation was controlled as assessed by MRI + CRP, ixekizumab and adalimumab had numerically greater reductions at week 16 in SP-N versus placebo. All ixekizumab groups had further improvements at week 52. When inflammation was persisting as assessed by MRI + CRP, ixekizumab-treated patients had significant reduction in SP-N (mean = - 3.7, p < 0.001) versus placebo (mean = - 1.7), improvement with adalimumab did not reach significance (mean = - 2.6, p = 0.06). In the pathway analysis at week 16, ixekizumab had a greater effect on pain outcomes compared to adalimumab. CONCLUSION: This post hoc analysis is supportive of the hypothesis that ixekizumab reduces pain in AS by additional mechanisms other than the reduction of measurable inflammation. TRIAL REGISTRATION NUMBER: NCT02696785.
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OBJECTIVE: Upadacitinib improved the signs and symptoms of non-radiographic axial spondyloarthritis (nr-axSpA) versus placebo over 14 weeks in the primary analysis of the SELECT-AXIS 2 nr-axSpA study. Here, we evaluated the efficacy and safety of upadacitinib through 1 year in patients with nr-axSpA in SELECT-AXIS 2. METHODS: Patients aged at least 18 years diagnosed with nr-axSpA who fulfilled the 2009 Assessment of SpondyloArthritis International Society (ASAS) classification criteria and were receiving stable background therapy were randomized to upadacitinib 15 mg once daily or placebo for the 52-week double-blind period. Efficacy was assessed using non-responder imputation incorporating multiple imputation (NRI-MI) and as-observed analyses for binary endpoints, and mixed-effects model repeated measures for continuous endpoints. RESULTS: Of 314 randomized patients, 259 (upadacitinib, n = 129; placebo, n = 130) completed 52 weeks of treatment. More patients receiving upadacitinib versus placebo achieved ≥40% improvement in ASAS at week 52 (63% vs 43%, NRI-MI; nominal P < 0.001). Similar treatment effects were observed for the achievement of axSpA Disease Activity Score inactive disease (33% v 11%, NRI-MI; nominal P < 0.001). Overall, patients receiving upadacitinib versus placebo showed greater improvement in disease activity, inflammation, pain, function, enthesitis, and quality of life through 52 weeks. Adverse events were generally comparable between the treatment groups. No opportunistic infections, malignancies, major adverse cardiovascular events, venous thromboembolic events, inflammatory bowel disease, or deaths were reported in those receiving upadacitinib. CONCLUSION: Treatment with upadacitinib showed sustained efficacy versus placebo with no new safety findings identified through 1 year. These results support the continued favorable benefit-risk profile of upadacitinib treatment for nr-axSpA.
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OBJECTIVE: To develop a reference image atlas for the Outcome Measures in Rheumatology whole-body MRI scoring system for inflammation in peripheral joints and entheses (OMERACT MRI-WIPE) of the knee region. METHODS: Image examples of each pathology, location and grade, were collected and discussed at web-based, interactive meetings within the OMERACT MRI in Arthritis Working Group. Subsequently, reference images were selected by consensus. RESULTS: Reference images for each grade, pathology and location are depicted, along with definitions, reader rules and recommended MRI-sequences. CONCLUSION: The atlas guides scoring whole-body MRIs for inflammation in joints and entheses of the knee region according to MRI-WIPE methodology in clinical trials and cohorts.
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Inflamación , Espondiloartritis , Humanos , Inflamación/diagnóstico por imagen , Espondiloartritis/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Imagen de Cuerpo Entero/métodos , Índice de Severidad de la Enfermedad , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: To develop a reference image atlas for scoring the hip/pelvis region according to the OMERACT whole-body MRI scoring system for inflammation in peripheral joints and entheses (MRI-WIPE). METHODS: We collected image examples of each pathology, location and grade, discussed them at web-based, interactive meetings and, finally, selected reference images by consensus. RESULTS: Reference images for each grade and location of osteitis, synovitis and soft tissue inflammation are provided, as are definitions, reader rules and recommended MRI-sequences. CONCLUSION: A reference image atlas was created to guide scoring whole-body MRIs for arthritis and enthesitis in the hip/pelvis region in spondyloarthritis/psoriatic arthritis clinical trials and cohorts.
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Espondiloartritis , Sinovitis , Humanos , Inflamación/diagnóstico por imagen , Espondiloartritis/diagnóstico por imagen , Sinovitis/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Pelvis/diagnóstico por imagen , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: We aimed to assess: 1. The frequency of axial spondyloarthritis (axSpA) according to extra-articular presentation and HLA-B27 status; 2. Clinical and imaging features that distinguish axSpA from non-axSpA; 3. The impact of MRI on diagnosis and classification of axSpA. METHODS: The Screening in Axial Spondyloarthritis in Psoriasis, Iritis, Colitis, (SASPIC) study enrolled patients in two multicenter cohorts. Consecutive patients with undiagnosed chronic back pain attending dermatology, ophthalmology, and gastroenterology clinics with PsO, AAU, or IBD, were referred to a local rheumatologist with special expertise in axSpA for a structured diagnostic evaluation. The primary outcome was proportion of patients diagnosed with axSpA by final global evaluation. RESULTS: Frequency of axSpA was 46.7%, 61.6%, and 46.8% in SASPIC-1 cases (n=212) and 23.5%, 57.9%, and 23.3% in SASPIC-2 cases (n=151) with PsO, AAU, or IBD, respectively. Among B27 positives, axSpA was diagnosed in 70%, 74.5%, and 66.7% in SASPIC-1, and in 71.4%, 87.8%, and 55.6% in SASPIC-2 in patients with PsO, AAU, or IBD, respectively. All musculoskeletal clinical features were non-discriminatory. MRI was indicative of axSpA in 60-80% of patients and MRI in all patients (SASPIC-2) versus on-demand (SASPIC-1) led to 25% fewer diagnoses of axSpA in HLA B27 negatives with PsO or IBD. Performance of the ASAS classification criteria was greater with routine MRI (SASPIC-2) though sensitivity was lower than previously reported. CONCLUSIONS: Optimal management of patients presenting with PsO, AAU, IBD, and undiagnosed chronic back pain should include referral to a rheumatologist. Conducting MRI in all patients enhances diagnostic accuracy.
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OBJECTIVE: To assess whether using ultrasound (US) in addition to clinical information versus only clinical information in a treat-to-target (T2T) strategy leads to more clinical remission and to less radiographic progression in RA. METHODS: Patients with RA from the 2-year prospective BIODAM cohort were included. Clinical and US data (US7-score) were collected every 3 months and hands and feet radiographs every 6 months. At each visit, it was decided whether patients were treated according to the clinical definition of T2T with DAS44 remission as benchmark (T2T-DAS44). T2T-DAS44 was correctly applied if: (i) DAS44 remission had been achieved or (ii) if not, treatment was intensified. A T2T strategy also considering US data (T2T-DAS44-US) was correctly applied if: (i) both DAS44 and US remission (synovitis-score < 2, Doppler-score = 0) were present; or (ii) if not, treatment was intensified. The effect of T2T-DAS44-US on attaining clinical remission and on change in Sharp-van der Heijde score compared to T2T-DAS44 was analysed. RESULTS: A total of 1016 visits of 128 patients were included. T2T-DAS44 was correctly followed in 24% of visits and T2T-DAS44-US in 41%. DAS44 < 1.6 was achieved in 39% of visits. Compared to T2T-DAS44, using the T2T-DAS44-US strategy resulted in a 41% lower likelihood of DAS44 remission [OR (95% CI): 0.59 (0.40;0.87)] and had no effect on radiographic progression [ß(95% CI): 0.11 (- 0.16;0.39)] assessed at various intervals up to 12 months later. CONCLUSION: Our results do not suggest a benefit of using the US7-score in addition to clinical information as a T2T benchmark compared to clinical information alone. Key Points ⢠Ultrasound has a valuable role in diagnostic evaluation of rheumatoid arthritis, but it is unclear whether adding ultrasound to the clinical assessment in a treat-to-target (T2T) strategy leads to more patients achieving remission and reduction in radiographic progression. ⢠Our data from a real-world study demonstrated that adding information from ultrasound to the clinical assessment in a T2T strategy led to a lower rather than a higher likelihood of obtaining clinical remission as compared to using only clinical assessment. ⢠Our data demonstrated that adding ultrasound data to a T2T strategy based only on clinical assessment did not offer additional protection against radiographic progression in patients with RA. ⢠Adding US to a T2T strategy based on clinical assessment led to far more treatment intensifications (with consequences for costs and exposure to adverse events) without yielding a meaningful clinical benefit.
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Antirreumáticos , Artritis Reumatoide , Progresión de la Enfermedad , Radiografía , Inducción de Remisión , Índice de Severidad de la Enfermedad , Humanos , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/diagnóstico por imagen , Femenino , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Antirreumáticos/uso terapéutico , Anciano , Ultrasonografía , Resultado del Tratamiento , AdultoRESUMEN
OBJECTIVES: To develop and validate classification criteria for axial disease in youth with juvenile spondyloarthritis (SpA; AxJSpA). METHODS: This international initiative consisted of four phases: 1) Item generation; 2) Item reduction; 3) Criteria development; and 4) Validation of the AxJSpA criteria by an independent team of experts in an internationally representative Validation cohort. RESULTS: These criteria are intended to be used on youth with a physician diagnosis of juvenile SpA and for whom axial disease is suspected. Item generation consisted of a systematic literature review and a free-listing exercise using input from international physicians and collectively resulted in 108 items. After the item reduction exercise and expert panel input, 37 items remained for further consideration. The final AxJSpA criteria domains included: imaging: active inflammation, imaging: structural lesions, pain chronicity, pain pattern, pain location, stiffness, and genetics. The most heavily weighted domains were active inflammation and structural lesions on imaging. Imaging typical of sacroiliitis was deemed necessary, but not sufficient, to classify a youth with AxJSpA. The threshold for classification of AxJSpA was a score of ≥55 (out of 100). When tested in the validation data set, the final criteria had a specificity of 97.5% (95% CI: 91.4-99.7), sensitivity of 64.3% (95% CI: 54.9-73.1) and Area Under the Receiver Operating Characteristic (AUROC) curve of 0.81 (95% CI: 0.76-0.86). CONCLUSIONS: The new AxJSpA classification criteria require an entry criterion, physician diagnosis of juvenile SpA, and include seven weighted domains. The AxJSpA classification criteria are validated and designed to identify participants for research studies.
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BACKGROUND: There is limited understanding regarding the inhibition of structural damage in the sacroiliac joint of patients with non-radiographic axial spondyloarthritis. This study evaluated the effect of the interleukin-17A inhibitor ixekizumab versus placebo on structural lesions in the sacroiliac joints as assessed by MRI at week 16 in patients with non-radiographic axial spondyloarthritis from the COAST-X study. METHODS: COAST-X was a 52-week, randomised, double-blind, placebo-controlled, parallel-group study done at 107 sites in 15 countries in Europe, Asia, North America, and South America. Eligible participants were adults (aged ≥18 years) with active axial spondyloarthritis without definite radiographic sacroiliitis (non-radiographic axial spondyloarthritis), objective signs of inflammation (via MRI or C-reactive protein), and an inadequate response or intolerance to non-steroidal anti-inflammatory drugs. Patients were randomly allocated to placebo or double-blind ixekizumab 80 mg every 4 weeks (Q4W) or 2 weeks (Q2W), with an 80 mg or 160 mg starting dose. We report a post-hoc analysis of 266 patients with available MRI scans from baseline and week 16. MRI scans were scored using the Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joint structural score (SSS) method independently by two masked readers. Treatment comparisons used analysis of covariance based on observed cases. Correlations were evaluated among changes in SPARCC SSS for erosion, fat lesions, and backfill, and between changes in SPARCC SSS and sacroiliac joint inflammation scores and clinical measures. COAST-X was registered with ClinicalTrials.gov, NCT02757352. FINDINGS: Between Aug 2, 2016, and Jan 29, 2018, 303 patients were enrolled to the COAST-X study. 290 (96%) of 303 participants completed the week 16 visit (95 in the ixekizumab Q4W group, 98 in the ixekizumab Q2W group, and 97 in the placebo group), and MRI scans were available for 266 patients at baseline and week 16 (85 in the ixekizumab Q4W group, 91 in the ixekizumab Q2W group, and 90 in the placebo group). Changes from baseline to week 16 in mean SPARCC SSS for erosion were -0·39 for ixekizumab Q4W (p=0·003 vs placebo), -0·40 for ixekizumab Q2W (p=0·002), and 0·16 for placebo; for fat lesions: 0·16 for ixekizumab Q4W (p=0·013), 0·10 for ixekizumab Q2W (p=0·067), and -0·04 for placebo; and for backfill: 0·21 for ixekizumab Q4W (p=0·011), 0·22 for ixekizumab Q2W (p=0·006), and -0·10 for placebo. Ankylosis did not change. Effects of ixekizumab versus placebo on structural changes were most pronounced in patients with baseline inflammation in the sacroiliac joints. Changes from baseline at week 16 in erosion, fat lesions, and backfill were correlated. INTERPRETATION: Although the clinical relevance is not yet clear, patients with non-radiographic axial spondyloarthritis receiving ixekizumab had significant reductions in erosions and increases in fat lesions and backfill in the sacroiliac joints versus placebo at week 16, suggesting an early repair process with ixekizumab treatment. FUNDING: Eli Lilly and Company.