The DESIR cohort: a 10-year follow-up of early inflammatory back pain in France: study design and baseline characteristics of the 708 recruited patients

Performance analysis of a deep-learning algorithm to detect the presence of inflammation in MRI of sacroiliac joints in patients with axial spondyloarthritis

OBJECTIVES

To assess the ability of a previously trained deep-learning algorithm to identify the presence of inflammation on MRI of sacroiliac joints (SIJ) in a large external validation set of patients with axial spondyloarthritis (axSpA).

METHODS

Baseline SIJ MRI scans were collected from two prospective randomised controlled trials in patients with non-radiographic (nr-) and radiographic (r-) axSpA (RAPID-axSpA: NCT01087762 and C-OPTIMISE: NCT02505542) and were centrally evaluated by two expert readers (and adjudicator in case of disagreement) for the presence of inflammation by the 2009 Assessment of SpondyloArthritis International Society (ASAS) definition. Scans were processed by the deep-learning algorithm, blinded to clinical information and central expert readings.

RESULTS

Pooling the patients from RAPID-axSpA (n=152) and C-OPTIMISE (n=579) yielded a validation set of 731 patients (mean age: 34.2 years, SD: 8.6; 505/731 (69.1%) male), of which 326/731 (44.6%) had nr-axSpA and 436/731 (59.6%) had inflammation on MRI per central readings. Scans were obtained from over 30 scanners from 5 manufacturers across over 100 clinical sites. Comparing the trained algorithm with the human central readings yielded a sensitivity of 70% (95% CI 66% to 73%), specificity of 81% (95% CI 78% to 84%), positive predictive value of 84% (95% CI 82% to 87%), negative predictive value of 64% (95% CI 61% to 68%), Cohen's kappa of 0.49 (95% CI 0.43 to 0.55) and absolute agreement of 74% (95% CI 72% to 77%).

CONCLUSION

The algorithm enabled acceptable detection of inflammation according to the 2009 ASAS MRI definition in a large external validation cohort.

Change in different classes of chronic back pain suspicious of axial spondyloarthritis: a latent transition analysis of the SPACE cohort

OBJECTIVES

To follow up four previously identified classes 'pure axial spondyloarthritis' (axSpA) ('axial'), 'axSpA with peripheral signs' ('inflammatory back pain+peripheral'), 'axSpA at risk' and 'no spondyloarthritis' ('no SpA'). They reflect the expert-opinion-free construct or 'Gestalt' of chronic back pain suspicious of axSpA. The aim was to assess participants' transitions between these classes over time.

METHODS

Participants with chronic back pain of ≤2 years duration, suspicious of axSpA from the SPondyloArthritis Caught Early cohort were analysed. Latent class (LCA) and latent transition analysis (LTA) using clinical, laboratory and imaging data at baseline and 2 years were calculated. Conditional and marginal probabilities were obtained, reflecting the probability of a spondyloarthritis feature in a class and the probability of the participant's class membership, respectively. Transitional probabilities were extracted revealing potential switches across classes. The analyses were performed in all participants using imputations for missing data and in participants with full data at baseline and 2 years.

RESULTS

Baseline and 2 years LCA models were constructed for 702 participants, resulting in the same four-class model as previously described. LTA revealed only a 3% transition from the 'no SpA' to the 'at-risk' class from baseline to 2 years with all other participants remaining in their initially assigned class. Sensitivity analysis on 384 participants with complete data at both baseline and 2 years showed similar results, underlining the model's robustness.

CONCLUSIONS

Transitions between the four classes over 2 years were basically inexistent, highlighting the unlikelihood of developing new class-defining features of axSpA after an initial clinical workup.

Artificial intelligence and machine learning in axial spondyloarthritis

PURPOSE OF REVIEW

To evaluate the current applications and prospects of artificial intelligence and machine learning in diagnosing and managing axial spondyloarthritis (axSpA), focusing on their role in medical imaging, predictive modelling, and patient monitoring.

RECENT FINDINGS

Artificial intelligence, particularly deep learning, is showing promise in diagnosing axSpA assisting with X-ray, computed tomography (CT) and MRI analyses, with some models matching or outperforming radiologists in detecting sacroiliitis and markers. Moreover, it is increasingly being used in predictive modelling of disease progression and personalized treatment, and could aid risk assessment, treatment response and clinical subtype identification. Variable study designs, sample sizes and the predominance of retrospective, single-centre studies still limit the generalizability of results.

SUMMARY

Artificial intelligence technologies have significant potential to advance the diagnosis and treatment of axSpA, providing more accurate, efficient and personalized healthcare solutions. However, their integration into clinical practice requires rigorous validation, ethical and legal considerations, and comprehensive training for healthcare professionals. Future advances in artificial intelligence could complement clinical expertise and improve patient care through improved diagnostic accuracy and tailored therapeutic strategies, but the challenge remains to ensure that these technologies are validated in prospective multicentre trials and ethically integrated into patient care.

Clinical and imaging outcomes of different phenotypes of axial spondyloarthritis: 5-year analysis of the DESIR cohort

OBJECTIVES

To compare the long-term outcomes of three phenotypes of axial SpA (axSpA).

METHODS

Patients with a clinical diagnosis of axSpA from the DESIR cohort were grouped into three phenotypes at baseline: 'Pure axSpA' ('Axial'), 'axSpA with peripheral signs' ('IBP+Peripheral') and 'axSpA at risk' ('At risk') by latent class analysis. Clinical and imaging data were collected up to 5 years. Clinical outcomes, measured in each visit, included disability (BASFI) and quality of life (QoL; SF36). Imaging outcomes included inflammatory and structural lesions on MRI and radiographs of spine and SIJ. The association between phenotype membership at baseline and each outcome was tested in multivariable GEE models.

RESULTS

In total, 576 patients with axSpA were included. 'At risk' patients had worse disability and QoL than 'Axial' patients over time. For instance, 'At risk' patients had on average 0.4 more points in BASFI over time than 'Axial' patients [β (95 % CI): 0.4 (0.2; 0.7)]. This difference was mostly noted in female patients who were HLA-B27 positive. In addition, the difference between the 'At risk' and 'Axial' phenotypes was higher in patients receiving bDMARDs than in those not (β=0.6 vs 0.5), since BASFI improved more in 'Axial' (∆BASFI: -1.3) than in 'At risk' (∆BASFI: -0.9) treated patients. There were no differences in disability and QoL between 'Axial' and 'IBP+Peripheral' patients. Imaging outcomes were worse in the 'Axial' phenotype than in the others over time.

CONCLUSION

Patients with 'axSpA at risk' show worse self-reported outcomes over time and are less likely to benefit from anti-inflammatory treatment than those with a classical axSpA phenotype.

Inflammatory activity evaluation in patients with axial spondyloarthritis using MRI relaxometry and mucosal-associated invariant T cells

Background

Currently, there is a lack of an objective quantitative measure to comprehensively evaluate the inflammatory activity of axSpA, which poses certain challenges in accurately assessing the disease activity.

Objective

To explore the value of combined-parameter models of sacroiliac joints (SIJs) MRI relaxometry and peripheral blood Mucosal-associated invariant T (MAIT) cells in evaluating the inflammatory activity of axial spondyloarthritis (axSpA).

Methods

This retrospective clinical study included 88 axSpA patients (median age 31.0 (22.0, 41.8) years, 21.6% females) and 20 controls (median age 28.0 (20.5, 49.5) years, 40.0% females). The axSpA group was classified into active subgroup (n=50) and inactive subgroup (n=38) based on ASDAS-CRP. All participants underwent SIJs MRI examination including T1 and T2* mapping, and peripheral blood flow cytometry analysis of MAIT cells (defined as CD3+Vα7.2+CD161+) and their activation markers (CD69). The T1 and T2* values, as were the percentages of MAIT cells and CD69+MAIT cells were compared between different groups. Combined-parameter models were established using logistic regression, and ROC curves were employed to evaluate the diagnostic efficacy.

Results

The T1 values of SIJs and %CD69+MAIT cells in the axSpA group and its subgroup were higher than the control group (p<0.05), while %MAIT cells were lower than the control group (p<0.05). The T1 values and %CD69+MAIT cells correlated positively, while %MAIT cells correlated negatively, with the ASDAS-CRP (r=0.555, 0.524, -0.357, p<0.001). Between the control and axSpA groups, and between the inactive and active subgroups, the combined-parameter model T1 mapping+%CD69+MAIT cells has the best efficacy (AUC=0.959, 0.879, sensibility=88.6, 70%, specificity=95.0, 94.7%, respectively).

Conclusion

The combined-parameter model T1 mapping+%CD69+MAIT cells allows a more accurate evaluation of the level of inflammatory activity.

Can rheumatologists unequivocally diagnose axial spondyloarthritis in patients with chronic back pain of less than 2 years duration? Primary outcome of the 2-year SPondyloArthritis Caught Early (SPACE) cohort

OBJECTIVES

To investigate the prevalence of axial spondyloarthritis (axSpA) in patients with chronic back pain (CBP) of less than 2 years (2y) duration referred to the rheumatologist, the development of diagnosis over time, and patient characteristics of those developing definite (d-)axSpA over 2y.

METHODS

We analysed the 2y data from SPondyloArthritis Caught Early, a European cohort of patients (<45 years) with CBP (≥3 months, ≤2y) of unknown origin. The diagnostic workup comprised evaluation of clinical SpA features, acute phase reactants, HLA-B27, radiographs and MRI (sacroiliac joints and spine), with repeated assessments. At each visit (baseline, 3 months, 1y and 2y), rheumatologists reported a diagnosis of axSpA or non-axSpA with level of confidence (LoC; 0-not confident at all to 10-very confident).

MAIN OUTCOME

axSpA diagnosis with LoC≥7 (d-axSpA) at 2y.

RESULTS

In 552 patients with CBP, d-axSpA was diagnosed in 175 (32%) at baseline and 165 (30%) at 2y. Baseline diagnosis remained rather stable: at 2y, baseline d-axSpA was revised in 5% of patients, while 8% 'gained' d-axSpA. Diagnostic uncertainty persisted in 30%. HLA-B27+ and baseline sacroiliitis imaging discriminated best 2y-d-axSpA versus 2y-d-non-axSpA patients. Good response to non-steroidal anti-inflammatory drugs and MRI-sacroiliitis most frequently developed over follow-up in patients with a new d-axSpA diagnosis. Of the patients who developed MRI-sacroiliitis, 7/8 were HLA-B27+ and 5/8 male.

CONCLUSION

A diagnosis of d-axSpA can be reliably made in nearly one-third of patients with CBP referred to the rheumatologist, but diagnostic uncertainty may persist in 5%-30% after 2y. Repeated assessments yield is modest, but repeating MRI may be worthwhile in male HLA-B27+ patients.

Impact of disease outcomes on the Assessment of SpondyloArthritis International Society Health Index (ASAS HI): a Bayesian network analysis of the DESIR cohort

OBJECTIVE

The objective of this study is to build a structural model visualising and quantifying the interrelationships of different disease outcomes with the Assessment of SpondyloArthritis International Society Health Index (ASAS HI) in patients with axial spondyloarthritis (axSpA).

METHODS

Cross-sectional data collected at month 72 of the Devenir des Spondylarthropathies Indifferénciées Récentes cohort was analysed. Combining prior knowledge and observed data, probabilistic Bayesian network modelling was used to study how the interplay of different disease outcomes affects the ASAS HI, which measures disease-specific overall functioning and health. Disease outcomes comprised, among others, the Ankylosing Spondylitis (AS) Disease Activity Score (ASDAS) and the Bath AS Functional Index (BASFI).

RESULTS

Data of 384 patients were analysed. The obtained structure suggests that ASAS HI is determined by both patient-reported physical function (BASFI) and disease activity (ASDAS). The parameters of the structural model show that an increase of ASDAS or BASFI by 1 unit corresponds to an increase of ASAS HI by 0.70 or 1.25 units, respectively. Moreover, the model suggests that disease activity has an indirect impact on ASAS HI via BASFI. No relationship between spinal mobility or structural damage and ASAS HI was found.

CONCLUSIONS

This is the first structural model developed to better understand the construct and the interplay between clinically relevant outcomes related to ASAS HI in axSpA patients. It shows that disease activity and physical function have a strong impact on ASAS HI, confirming it to be a valid construct of overall functioning and health in axSpA patients.

Early axial spondyloarthritis according to the ASAS consensus definition: characterisation of patients and effectiveness of a first TNF inhibitor in a large observational registry

OBJECTIVE

To characterise the population fulfilling the Assessment of SpondyloArthritis international Society (ASAS) consensus definition of early axial spondyloarthritis (axSpA) and to determine the effectiveness of a first tumour necrosis factor inhibitor (TNFi) in early versus established axSpA in a large observational registry.

METHODS

A total of 3064 patients with axSpA in the Swiss Clinical Quality Management registry with data on duration of axial symptoms were included (≤2 years=early axSpA, N=658; >2 years=established axSpA, N=2406). Drug retention was analysed in patients starting a first TNFi in early axSpA (N=250) versus established axSpA (N=874) with multiple-adjusted Cox proportional hazards models. Adjusted logistic regression analyses were used to determine the achievement of the ASAS criteria for 40% improvement (ASAS40) at 1 year.

RESULTS

Sex distribution, disease activity, impairments of function and health-related quality of life were comparable between patients with early and established axSpA. Patients with established disease were older, had more prevalent axial radiographical damage and had a higher impairment of mobility. A comparable TNFi retention was found in early versus established disease after adjustment for age, sex, human leucocyte antigen-B27 status, education, body mass index, smoking, elevated C reactive protein and sacroiliac inflammation on MRI (HR 1.05, 95% CI 0.78 to 1.42). The adjusted ASAS40 response was similar in the two groups (OR 1.09, 95% CI 0.67 to 1.78). Results were confirmed in the population fulfilling the ASAS classification criteria.

CONCLUSION

Considering the recent ASAS definition of early axSpA, TNFi effectiveness seems comparable in early versus established disease.

Influence of Sex on Early Axial Spondyloarthritis: A Six-Year Longitudinal Analysis From a Large National Cohort

OBJECTIVE

The objective was to determine sex differences in disease outcomes in recent axial spondyloarthritis (SpA) over time.

METHODS

We analyzed the first 6 years of follow-up of the prospective French multicenter DESIR cohort. Patients analyzed had <3 years of disease, were naive to disease-modifying antirheumatic drugs, and fulfilled the Assessment of SpondyloArthritis international Society classification criteria for axial SpA. Disease activity (Ankylosing Spondylitis Disease Activity Score [ASDAS] using the C-reactive protein [CRP] level), patient global assessment (PtGA), CRP level, and radiographic sacroiliitis were compared between men and women (self-reported sex) by linear and logistic mixed-effects models. Models were created for trajectories of disease activity over 6 years in men and women, using k-means.

RESULTS

Of 494 patients analyzed (mean ± SD age 31.9 ± 7.5 years, symptoms duration 20.7 ± 11.7 months), 50.4% were men. Over 6 years of follow-up, both men and women showed clear improvements in ASDAS-CRP, PtGA, and CRP level. Women had higher ASDAS-CRP and PtGA over time compared to men (both P < 0.0001) with overall similar CRP levels (P = 0.089), whereas structural damage increased more in men (P < 0.0001). One-third of both men (33%) and women (34%) belonged to persistent high/very high disease activity trajectories, but ASDAS-CRP was globally higher in women in these trajectories.

CONCLUSION

In early axial SpA, clinical outcomes (disease activity and symptoms) were worse in women than men over 6 years of follow-up, whereas CRP was similar and structural damage was more frequent in men. Although similarly distributed, disease activity scores were higher in women in high/very high disease activity trajectories. Sex appears to be an important contextual factor in axial SpA.

SpA plus IBD or IBD plus SpA: Does commutative property apply?

The term spondyloarthritis (SpA) encompasses a group of interrelated disorders characterised by the involvement of the musculoskeletal system as well as extra-articular manifestations like acute anterior uveitis, psoriasis and inflammatory bowel diseases (IBD). Likewise, IBD may present with various extra-intestinal manifestations among which those involving the musculoskeletal system, namely peripheral and axial SpA are the most common. The identification of patients with both SpA and IBD is of paramount importance in clinical practice since the coexistence of these two entities has been associated with great disability and decreased quality of life. In order to achieve an early diagnosis of IBD-SpA it is instrumental that rheumatologists seek for gastrointestinal symptoms in SpA patients and likewise that gastroenterologists seek for inflammatory musculoskeletal symptoms in patients with IBD. This narrative review aims at critically appraising the available evidence about SpA occurring in IBD patients versus IBD occurring in patients with SpA and at highlighting similarities and differences between the two scenarios.

A deep learning model for the diagnosis of sacroiliitis according to Assessment of SpondyloArthritis International Society classification criteria with magnetic resonance imaging

PURPOSE

The purpose of this study was to develop and evaluate a deep learning model to detect bone marrow edema (BME) in sacroiliac joints and predict the MRI Assessment of SpondyloArthritis International Society (ASAS) definition of active sacroiliitis in patients with chronic inflammatory back pain.

MATERIALS AND METHODS

MRI examinations of patients from the French prospective multicenter DESIR cohort (DEvenir des Spondyloarthropathies Indifférenciées Récentes) were used for training, validation and testing. Patients with inflammatory back pain lasting three months to three years were recruited. Test datasets were from MRI follow-ups at five years and ten years. The model was evaluated using an external test dataset from the ASAS cohort. A neuronal network classifier (mask-RCNN) was trained and evaluated for sacroiliac joints detection and BME classification. Diagnostic capabilities of the model to predict ASAS MRI active sacroiliitis (BME in at least two half-slices) were assessed using Matthews correlation coefficient (MCC), sensitivity, specificity, accuracy and AUC. The gold standard was experts' majority decision.

RESULTS

A total of 256 patients with 362 MRI examinations from the DESIR cohort were included, with 27% meeting the ASAS definition for experts. A total of 178 MRI examinations were used for the training set, 25 for the validation set and 159 for the evaluation set. MCCs for DESIR baseline, 5-years, and 10-years follow-up were 0.90 (n = 53), 0.64 (n = 70), and 0.61 (n = 36), respectively. AUCs for predicting ASAS MRI were 0.98 (95% CI: 0.93-1), 0.90 (95% CI: 0.79-1), and 0.80 (95% CI: 0.62-1), respectively. The ASAS external validation cohort included 47 patients (mean age 36 ± 10 [SD] years; women, 51%) with 19% meeting the ASAS definition. MCC was 0.62, sensitivity 56% (95% CI: 42-70), specificity 100% (95% CI: 100-100) and AUC 0.76 (95% CI: 0.57-0.95).

CONCLUSION

The deep learning model achieves performance close to those of experts for BME detection in sacroiliac joints and determination of active sacroiliitis according to the ASAS definition.

Peripheral manifestations are major determinants of disease phenotype and outcome in new onset spondyloarthritis

OBJECTIVES

To delineate the impact of peripheral musculoskeletal manifestations on stratification of disease phenotype and outcome in new-onset spondyloarthritis (SpA), using a prospective observational nationwide inception cohort, the BelGian Inflammatory Arthritis and spoNdylitis cohorT (Be-Giant).

METHODS

Newly diagnosed adult SpA patients, fulfilling the Assessment of SpondyloArthritis International Society (ASAS) criteria for axial or peripheral SpA, were included in Be-Giant and prospectively followed every six months. Peripheral involvement (defined as arthritis, enthesitis and/or dactylitis) was determined in relation to clinically similar patient subsets at baseline and disease activity patterns during two-year follow-up, identified through K-means cluster analysis and latent class growth analysis.

RESULTS

From November 2010 to March 2020, 367 patients were enrolled in Be-Giant, of whom 162 (44%) had peripheral manifestations. Two patient clusters [A, axial predominant (n = 248) and B, peripheral predominant (n = 119)] were identified at diagnosis. Longitudinal analysis (n = 115) revealed two trajectories of disease activity in each cluster: one with persistently high disease activity over time ('High'), the other rapidly evolving to low disease activity ('Low'). In cluster A patients, peripheral manifestations predisposed to the 'High' trajectory [odds ratio (OR) = 2.0, 95% CI: 1.3, 3.1, P = 0.001], despite more rapid initiation of biologics compared with patients without peripheral manifestations (hazard ratio (HR)  = 2.1, 95% CI: 1.0, 4.4, P = 0.04 - Cox proportional-hazards model).

CONCLUSION

Peripheral musculoskeletal manifestations are major determinants of phenotypical diversity in new-onset SpA. Intriguingly, stratification of axial SpA according to concomitant peripheral involvement identified an endotype with an unfavorable outcome despite more prompt therapeutic intensification with biologics. These observations justify an endotype-tailored approach beyond current ASAS/EULAR management recommendations.

Hip Pain Associated with Acetabular Dysplasia in Patients with Suspected Axial Spondyloarthritis: DESIR Cohort Data

Objectives

To determine whether acetabular dysplasia is associated with hip pain at physical examination among adults with recent-onset inflammatory back pain (IBP) suggesting axial spondyloarthritis (axSpA).

Methods

This cross-sectional ancillary study was conducted on the prospective DESIR cohort, which enrolled patients aged 18–50 years who had recent-onset IBP. Two readers used antero-posterior pelvic radiographs to assess the Tönnis angle, acetabular angle (AA), lateral centre-edge angle (LCEA), and femoral head extrusion index (FHEI). Abnormality of one or more of these four variables defined acetabular dysplasia. Hip pain upon physical examination was assessed based on Ritchie’s articular index.

Results

The overall prevalence of acetabular dysplasia was 22% (139/636). The proportion of females was higher in the group with acetabular dysplasia. Hip pain was found in 21% (29/139) of patients with versus 12% (59/497) without acetabular dysplasia (OR, 1.96; 95% CI, 1.20 to 3.20); the association was significant in males (OR, 3.14; 95% CI, 1.44 to 6.86) but not females (OR, 1.39; 95% CI, 0.74 to 2.62). Results were similar when acetabular dysplasia was defined on the basis of LCEA alone (OR, 2.15; 95% CI, 1.18 to 2.62).

Conclusion

Among patients with recent-onset IBP suggesting axSpA, acetabular dysplasia was significantly associated with hip pain in males. Hip pain related to acetabular dysplasia might result in overdiagnosis of hip involvement by axSpA.

Geographical prevalence of family history in patients with axial spondyloarthritis and its association with HLA-B27 in the ASAS-PerSpA study

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.

Similarities and differences between non-radiographic and radiographic axial spondyloarthritis: The patient perspective from the Spanish atlas

AIM

Although non-radiographic axial spondyloarthritis (EspAax-nr) is well understood within health institutions, being considered along with radiographic EspAax (EspAax-r) as part of the same disease spectrum, patient understanding is unknown. The aim is to describe the patient's knowledge of the EspAax-nr entity.

METHODS

Atlas 2017, promoted by the Spanish Federation of Spondylarthritis Associations (CEADE), aims to comprehensively understand the reality of EspAax patients from a holistic approach. A cross-sectional on-line survey of unselected patients with self-reported EspAax diagnosis from Spain was conducted. Participants were asked to report their diagnosis. Socio-demographic, disease characteristics and patient-reported outcomes (PROs) were compared between those patients self-reporting as EspAax-nr and EspAax-r.

RESULTS

634 EspAax patients participated. Mean age 45.7±10.9 years, 50.9% female and 36.1% university-educated. 35 (5.2%) self-reported as EspAax-nr. Compared to EspAax-r patients, those with EspAax-nr were more frequently women (48.6% vs 91.4%, p<0.001), had longer diagnostic delay (10.1±8.9 vs 8.5±7.6 years), higher psychological distress (GHQ-12: 7.5±4.9 vs 5.6±4.4) and similar degree of disease activity (BASDAI: 5.7±2.1 vs 5.7±2.0), and unemployment rates (20.0% vs 21.6%). 20.0% of EspAax-nr received biologics vs 36.9% of EspAax-r, p=0.043. Visits to the rheumatologist in the past year were similar in both groups (3.8±4.5 vs 3.2±3.8), while GP visits were much higher within EspAax-nr (8.0±10.7 vs 4.9±13.3 p=0.003).

CONCLUSION

For the first time, EspAax-nr characteristics and PROs have been analyzed from the patient's perspective. Both groups reported similar trends with the exception of EspAax-nr being more frequently women, younger, having longer diagnostic delay and lower use of biologic therapy.

Cluster analysis in early axial spondyloarthritis predicts poor outcome in the presence of peripheral articular manifestations

OBJECTIVES

To assess whether two cluster analysis-based axial SpA (axSpA) endotypes (A for purely axial; B for both axial and peripheral) are stable over time and are associated with different long-term disease outcomes.

METHODS

K-means cluster analysis was performed at each visit (until 5 years) on 584 patients from the DESIR cohort, who completed all planned visits, and validated in 232 consecutive axSpA patients from the BeGiant cohort. Cluster stability overtime was assessed by kappa statistics. A generalized linear mixed-effect analysis was applied to compare outcomes between clusters. Classification and regression tree (CART) analysis was performed to determine a decision rule able to assign a given patient to a definite cluster at onset.

RESULTS

Both endotypes remained remarkably stable over time. In the DESIR cohort, patients in cluster B showed higher disease activity, worse functional outcome and higher need for anti-rheumatic drugs than patients in cluster A. CART analysis yielded three main clinical features (arthritis, enthesitis, and dactylitis) that accurately determined cluster assignment. These results could be replicated in the Be-GIANT cohort.

CONCLUSION

Cluster-based axSpA endotypes were reproducible in two different cohorts, stable over time and associated with different long-term outcome. The axSpA endotype with additional peripheral disease manifestations is associated with more severe disease and requires more intensive drug therapy.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov, https://clinicaltrials.gov, NCT01648907.

Clinical Manifestations and Diagnosis of Axial Spondyloarthritis

BACKGROUND

Axial spondyloarthritis (axSpA) is a chronic, rheumatic disease characterized by inflammation of the sacroiliac joint, spine, and entheses. Axial spondyloarthritis affects up to 1.4% of adults in the United States and is associated with decreased quality of life, increased mortality, and substantial health care-related costs, imposing a high burden on patients, their caregivers, and society.

SUMMARY OF WORK

Diagnosing axSpA can be difficult. In this review, we seek to help rheumatologists in recognizing and diagnosing axSpA.

MAJOR CONCLUSIONS

A discussion of challenges associated with diagnosis is presented, including use and interpretation of imaging, reasons for diagnostic delays, differences in disease presentation by sex, and differential diagnoses of axSpA.

FUTURE RESEARCH DIRECTIONS

The early diagnosis of axSpA and advances in available therapeutic options have improved patient care and disease management, but delays in diagnosis and treatment remain common. Additional research and education are critical for recognizing diverse axSpA presentations and optimizing management early in the course of disease.

Inflammatory bowel disease manifestations in spondyloarthritis: considerations for the clinician

INTRODUCTION

Spondyloarthropathies (SpA) are a group of inflammatory arthritis that can involve the spine and/or peripheral joints. Extra-articular manifestations, such as inflammatory bowel disease (IBD), are frequently observed within the clinical manifestations of SpA and are part of the SpA classification criteria. Evidence of IBD is observed in about 6-7% of SpA patients, and a silent, microscopic gut inflammation, could be present in up to 50% of patients. From a pathogenetic point of view, dysregulated microbiome and migration of T lymphocytes and other cells from gut to the joint ('gut-joint' axis) has been recognized, in the context of a common genetic background.

AREAS COVERED

The aim of this paper is to narratively review the recent evidences on the epidemiology, classification, clinical findings, pathogenesis, diagnosis, and treatment of IBD in patients with SpA and to provide advices for both rheumatologist and gastroenterologist in the management of IBD in SpA.

EXPERT OPINION

IBD manifestations in SpA frequently increase the burden of the disease and represent a clinical challenge, especially for the diagnosis, assessment, and treatment of patients affected by those conditions. New treatment strategies targeting both articular and intestinal manifestations are now available and may lead to a better outcome.

Classification Criteria in Axial Spondyloarthritis: What Have We Learned; Where Are We Going?

Spondyloarthritis (SpA) is a chronic inflammatory condition that can have a predominately peripheral or axial presentation. Axial SpA (axSpA) affects the axial skeleton with either radiographic (r-axSpA) or nonradiographic (nr-axSpA) changes. Radiographic changes are a late disease feature and earlier disease stages can be identified by incorporating other imaging methods. The diagnosis of axSpA is a clinical diagnosis and classification criteria are not aimed to be diagnostic tools. The split between r-axSpA and nr-axSpA is artificial and we should move toward the unifying concept of axSpA. Our understanding of genetics, biomarkers, and immunopathophenotypes will drive further refinement of classification criteria.

Inflammatory Foot Involvement in Spondyloarthritis: From Tarsitis to Ankylosing Tarsitis

Spondyloarthritis (SpA) is a group that includes a wide spectrum of clinically similar diseases manifested by oligoarticular arthritis and axial or peripheral ankylosis. Although axial SpA is predominant in Caucasians and adult-onset patients, juvenile-onset and Latin American patients are characterized by severe peripheral arthritis and particularly foot involvement. The peripheral involvement of SpA can vary from tarsal arthritis to the most severe form named ankylosing tarsitis (AT). Although the cause and etiopathogenesis of axSpA are often studied, the specific characteristics of pSpA are unknown. Several animal models of SpA develop initial tarsitis and foot ankylosis as the main signs, emphasizing the role of foot inflammation in the overall SpA spectrum. In this review, we attempt to highlight the clinical characteristics of foot involvement in SpA and update the knowledge regarding its pathogenesis, focusing on animal models and the role of mechanical forces in inflammation.

Sick leave in early axial spondyloarthritis: the role of clinical and socioeconomic factors. Five-year data from the DESIR cohort

OBJECTIVES

To investigate the occurrence of sick leave (SL) and the impact of clinical and socioeconomic factors on SL in early axial spondyloarthritis (axSpA).

METHODS

Patients with a clinical diagnosis of axSpA from the DEvenir des Spondyloarthrites Indifférenciées Récentes (DESIR) cohort with work-related data and up to 5-year follow-up were studied. Incidence, time to first SL and potential role of baseline and time-varying clinical and socioeconomic factors (age, gender, ethnicity, education, job type, marital and parental status) were analysed. Univariable analyses, followed by collinearity and interaction tests, guided subsequent multivariable time-varying Cox survival model building.

RESULTS

In total, 704 axSpA patients were included (mean (SD) age 33.8 (8.6); 46% men). At baseline, 80% of patients were employed; of these, 5.7% reported being on SL. The incidence of SL among those at risk during the study period (n=620, 88%) was 0.05 (95% CI 0.03 to 0.06) per 1000 days of follow-up. Mean (SD) time to first SL was 806 (595) days (range: 175-2021 days). In multivariable models, male gender (HR 0.41 (95% CI 0.20 to 0.86)) and higher education (HR 0.48 (95% CI 0.24 to 0.95)) were associated with lower hazard of SL, while higher disease activity (HR 1.49 (95% CI 1.04 to 2.13)), older age, smoking and use of tumour necrosis factor inhibitors were associated with higher hazard of SL.

CONCLUSIONS

In this early axSpA cohort of young, working-age individuals, male gender and higher education were independently associated with a lower hazard of SL, whereas older age and higher disease activity were associated with higher hazard of SL. The findings suggest a role of socioeconomic factors in adverse work outcomes, alongside active disease.

How do clinical and socioeconomic factors impact on work disability in early axial spondyloarthritis? Five-year data from the DESIR cohort

Objectives

To investigate the impact of clinical and socioeconomic factors on work disability (WD) in early axial spondyloarthritis (axSpA).

Methods

Patients from the DESIR cohort with a clinical diagnosis of axSpA were studied over 5 years. Time to WD and potential baseline and time-varying predictors were explored, with a focus on socioeconomic (including ethnicity, education, job-type, marital/parental status) and clinical (including disease activity, function, mobility) factors. Univariable analyses, collinearity and interaction tests guided subsequent multivariable time-varying Cox survival analyses.

Results

From 704 patients eligible for this study, the estimated incidence of WD among those identified as at risk (n = 663, 94%), and across the five years of DESIR, was 0.05 (95% CI 0.03, 0.06) per 1000 person-days. Significant differences in baseline socioeconomic factors, including lower educational status and clinical measures, including worse disease activity, were seen in patients developing WD over follow-up, compared with those who never did. In the main multivariable model, educational status was no longer predictive of WD, whereas the AS disease activity score (ASDAS) and the BASFI were significantly and independently associated with a higher hazard of WD [HR (95%CI) 1.79 (1.27, 2.54) and 1.42 (1.22, 1.65), respectively].

Conclusion

WD was an infrequent event in this early axSpA cohort. Nevertheless, clinical factors were among the strongest predictors of WD, over socioeconomic factors, with worse disease activity and function independently associated with a higher hazard of WD. Disease severity remains a strong predictor of adverse work outcome even in early disease, despite substantial advances in therapeutic strategies in axSpA.

Factors associated with remission at 5-year follow-up in recent onset axial spondyloarthritis: results from the DESIR cohort

Objective

The factors contributing to long-term remission in axial SpA (axSpA) are unclear. We aimed to characterize individuals with axSpA at the 5-year follow-up to identify baseline factors associated with remission.

Methods

We included all patients from the DESIR cohort (with recent-onset axSpA) with an available Ankylosing Spondylitis Disease Activity Score–CRP (ASDAS-CRP) at 5-year follow-up. Patients in remission (ASDAS-CRP < 1.3) were compared with those with active disease by demographic, clinical, biological and imaging characteristics. A logistic model stratified on TNF inhibitor (TNFi) exposure was used.

Results

Overall, 111/449 patients (25%) were in remission after 5 years. Among those never exposed to TNFi, 31% (77/247) were in remission compared with 17% (34/202) of those exposed to TNFi. Patients in remission after 5 years were more likely to be male, HLA-B27+, have a lower BMI, and a higher education level. Baseline factors associated with 5-year remission in patients never exposed to TNFi included lower BASDAI [adjusted odds ratio (OR_a) 0.9, 95% CI: 0.8, 0.9) and history of peripheral arthritis (OR_a 2.1, 95% CI: 1.2, 5.3). In those exposed to TNFi, remission was associated with higher education level (OR_a 2.9, 95% CI: 1.6, 5.1), lower enthesitis index (OR_a 0.8, 95% CI: 0.7, 0.9), lower BASDAI (OR_a 0.9, 95% CI: 0.9, 0.9) and lower BMI (OR_a 0.8, 95% CI: 0.7, 0.9).

Conclusion

This study highlights the difficulty in achieving 5-year remission in those with recent-onset axSpA, especially for the more active cases, despite the use of TNFi. Socio-economic factors and BMI are implicated in the outcome at 5 years.

A Benchmarking Study Evaluating Axial Spondyloarthritis Burden in Spain and Other European Countries. Results from the Spanish Atlas and the European Map of Axial Spondyloarthritis (EMAS) Studies

AIM

To compare the burden of disease in Spanish patients with axial spondyloarthritis (axSpA) vs other European countries (OEC).

METHODS

Data from 2846 unselected patients from the European Map of Axial Spondyloarthritis (EMAS) and the Atlas of Axial Spondyloarthritis in Spain (Atlas) were collected through online surveys. Comparative analysis was carried out between Spanish patients (2016) and patients from 12 OEC ( 2017-2018). Socio-demographic characteristics, life habits, and patient-reported outcomes (Bath Ankylosing Spondylitis Disease Activity Index 0-10, spinal stiffness 3-12, functional limitation 0-54, the 12-Item General Health Questionnaire [GHQ-12] for psychological distress 0-12) were compared. Chi-square and Mann-Whitney tests were used for qualitative and quantitative variables respectively.

RESULTS

680 (23.9%) Spanish axSpA patients were compared to 2166 axSpA patients (76.1%) from OEC. Compared to Spain, the OEC group had a higher percentage of females (64.1% vs 52.5%; P < .001) and university-educated participants (51.7% vs 36.9%; P < .001). Spanish patients showed a greater diagnostic delay (8.5 ± 7.7 vs 7.2 ± 8.6 years; P < .001), visits to orthopedic specialists before diagnosis (56.9% vs 25.3%; P < .001), human leukocyte antigen-B27 carriership (77.1% vs 70.1%; P = .003), disease activity (5.7 ± 2.0 vs 5.4 ± 2.0; P = .024), and higher unemployment rates (21.7% vs 9.2%; P < .001). Despite lower rates of diagnosed anxiety and depression, Spanish patients were at higher risk of psychological distress according to the GHQ-12 (5.7 ± 4.5 vs 4.8 ± 4.0; P < .001).

CONCLUSION

Compared to European axSpA patients, Spanish patients experience a longer diagnostic delay and greater psychological distress. Being wrongly referred to orthopedic specialists and facing a more precarious labor scenario appear as possible causal factors, highlighting the need to increase the number of rheumatologists, the training of healthcare professionals, and improving axSpA patients' working conditions.

Physical therapy in axial spondyloarthritis: guidelines, evidence and clinical practice

PURPOSE OF REVIEW

Physical therapy is recommended for the management of axial spondyloarthritis (axSpA) with the focus of promoting physical activity and prescribing exercise within four domains, outlined recently by the European League against Rheumatism (EULAR): aerobic, resistance, flexibility and neuro-motor exercise. There is an increasing evidence base to support physical therapy interventions in axSpA.

RECENT FINDINGS

We present evidence supporting the use of exercise as treatment for patients with axSpA, recent updates among different exercise modalities, and make clear its critical place in the management of this condition. Recent large, multicentre data have shown that high-intensity exercise can improve disease activity and also positively impact cardiovascular risk factors in these patients. Although international treatment guidelines advocate the inclusion of physical activity and exercise for the optimal management of axSpA, specific guidance about the amount of exercise required to produce a beneficial effect is lacking.

SUMMARY

Exercise must be used in the management of axSpA, and whilst hydrotherapy and flexibility exercises are traditionally the main focus, other applications, such as strength training, may be underutilized domains. Further studies are needed to determine the dose-response relationship between exercise and axSpA patient subsets.

Determinants of the patient global assessment of well-being in early axial spondyloarthritis: 5-year longitudinal data from the DESIR cohort

Objectives

To investigate the determinants of patient well-being over time, and the influence of age, gender and education in patients with early axial spondyloarthritis (axSpA).

Methods

Five-year data from DESIR, a cohort of early axSpA, were analysed. The outcome was the BAS-G over 5 years. Generalized estimating equations (GEE) were used to test the relationship between potential explanatory variables from five outcome domains (disease activity, physical function, spinal mobility, structural damage and axial inflammation) and BAS-G over time. Longitudinal relationships were analysed using an autoregressive GEE model. Age, gender and educational level were tested as effect modifiers or confounders.

Results

A total of 708 patients were included. Higher BASDAI questions on fatigue [β (95% CI): 0.17 (0.13, 0.22)], back pain [0.51 (0.46, 0.56)], peripheral joint pain [0.08 (0.04, 0.12)] and severity of morning stiffness [0.08 (0.03–0.13)], and higher BASFI [0.14 (0.08, 0.19)] were associated with a higher BAS-G. In the autoregressive model, the same variables except for morning stiffness were associated with a worsening in BAS-G. Age, gender and educational level were neither effect modifiers nor confounders.

Conclusion

A higher level of back pain is associated with a worsening of patient well-being, as are, though to a lesser extent, higher levels of fatigue, peripheral joint pain and physical disability. Age, gender and educational level do not have an impact on these relationships.

Diagnostic performance of plain radiography for sacroiliitis in patients with suspected axial spondyloarthritis: a systematic review and meta-analysis

BACKGROUND

Plain radiography serves a pivotal role in diagnosing axial spondyloarthritis. However, a broad range of diagnostic performance of plain radiography has been reported.

PURPOSE

To perform a systematic review and meta-analysis to measure the diagnostic performance of plain radiography for sacroiliitis in patients suspected of having axial spondyloarthritis using magnetic resonance imaging (MRI) findings as the reference standard.

MATERIAL AND METHODS

Studies comparing radiography and MRI in the diagnosis of sacroiliitis in patients suspected of having axial spondyloarthritis were searched in PubMed and EMBASE. Additionally, studies analyzed SPondyloaArthritis Caught Early (SPACE), DEvenir des Spondylarthropathies Indifferenciées Récentes (DESIR), GErman Spondyloarthritis Inception Cohort (GESPIC), and South Swedish Arthritis Treatment Group (SSATG) cohorts were manually searched. Pooled sensitivity and specificity of radiography were calculated by using a bivariate random-effects model. Meta-regression analyses were performed to identify the sources of heterogeneity.

RESULTS

Eight eligible studies with 1579 patients were included. The pooled sensitivity and specificity of radiography were 0.55 (95% confidence interval [CI] = 0.40-0.69) and 0.87 (95% CI = 0.72-0.95). The meta-regression analyses showed prospective study design and criteria for MRI positivity considering only active bone marrow edema were associated with lower sensitivity.

CONCLUSION

The plain radiography showed low sensitivity and reasonable specificity in diagnosis of sacroiliitis in patients suspected of having axial spondyloarthritis.

Characteristics Associated with the Occurrence and Development of Acute Anterior Uveitis, Inflammatory Bowel Disease, and Psoriasis in Patients with Ankylosing Spondylitis: Data from the Chinese Ankylosing Spondylitis Prospective Imaging Cohort

Introduction

This study aimed to determine the association between extra-articular manifestations (EAMs) and baseline characteristics of patients with ankylosing spondylitis (AS) and identify their potential risk factors in an observational cohort.

Methods

We analyzed the data of consecutive patients with AS obtained between April 2016 and May 2019 from the ongoing Chinese Ankylosing Spondylitis Prospective Imaging Cohort.

Results

Among the 1414 patients with AS, 23.1% had experienced EAMs at baseline. The prevalence rates of acute anterior uveitis (AAU), inflammatory bowel disease, and psoriasis among patients with AS were 16.7, 6.9, and 2.6%, respectively, and the prevalence of AAU increased significantly with the disease duration. Patients with comorbidity of AAU and psoriasis had Ankylosing Spondylitis Disease Activity Score (ASDAS) than patients without EAMs (2.16 ± 0.984 vs. 1.99 ± 0.956 [p = 0.025] and 2.36 ± 1.01 vs. 1.99 ± 0.96 [p = 0.025]). Among the 1087 patients with AS without EAMs at baseline, 98 developed EAMs during follow-up. Long disease duration (> 10 years) and high disease activity at baseline (ASDAS > 2.1) were associated with the risk of new-onset EAMs (hazard ratio [HR] [95% confidence interval, CI], 2.150 [1.229–3.762] and 2.896 [1.509–5.561], respectively) and new-onset AAU (HR [95% CI], 2.197 [1.325–3.642] and 3.717 [1.611–8.574], respectively).

Conclusions

In Chinese patients with AS, patients with comorbidity of AAU and psoriasis had higher disease activity scores than patients without EAMs. Furthermore, the risk of AAU or combined EAMs increases with the duration of AS and appears to be associated with higher cumulative exposure to inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00293-0.

The Increased Levels of Fecal Calprotectin in Children With Active Enthesitis Related Arthritis and MRI Signs of Sacroiliitis: The Results of a Single Center Cross-Sectional Exploratory Study in Juvenile Idiopathic Arthritis Patients

Enthesitis related arthritis (ERA) is a specific subtype of juvenile idiopathic arthritis (JIA), often regarded as an undifferentiated form of juvenile spondyloarthritis (jSpA). While gut is increasingly recognized as origin and/or target of inflammation in adult onset spondyloarthritis (SpA), the incidence of gut involvement in ERA patients is largely unknown. The aim of this study was to measure the concentration of fecal calprotectin (fCAL), a surrogate marker of gut inflammation, in patients with different subtypes of JIA, as well as to correlate the results with various demographic, clinical, laboratory, imaging, and treatment characteristics. The cross-sectional exploratory study involving 71 patients with ERA, other forms of JIA and children complaining musculoskeletal symptoms was therefore conducted. Along with fCAL assessment, a detailed clinical and laboratory examination was performed, including the calculation of a composite disease activity scores. Moreover, MRI of the sacroiliac joints was performed in all ERA and other patients complaining of low back pain. The median concentration of fCAL was highest in ERA patients (33.2 mg/kg, p = 0.02), with a significant difference between those with inactive and active disease (20.0 vs. 57.4, p = 0.01), as well as those with and without MRI signs of sacroiliitis (22.6 vs. 54.3, p = 0.04). The fCAL did not differ depending on the NSAID use (23 vs. 20, p = 0.18), although weak correlation was observed with the treatment duration (r = 0.25, p = 0.03). In conclusion, our findings indicate that a parallel inflammation in musculoskeletal system and gut can occur not just in adults with SpA, but in children with ERA as well.

Evaluation of the early cervical structural change in patients with non-radiographic axial spondyloarthropathy

In this double-blind, controlled, cross-sectional study, we compared structural changes in the cervical vertebrae of patients with nonradiographic axial spondyloarthropathy (nr-axSpA), patients with ankylosing spondylitis (AS), and a control group. We used the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) to determine whether the involvement of the cervical spine occurs earlier and is more severe than that of the lumbar spine in axial spondyloarthropathy (axSpA). A statistically significant difference was found in the total mSASSS between the AS and nr-axSpA groups (p = 0.038), but not in the cervical and lumbar mSASSS. Although the duration of the symptoms was shorter in the nr-axSpA group than in the AS group, no statistically significant difference was found in the cervical mSASSS between the AS and nr-axSpA groups. In both the AS and nr-axSpA groups, the cervical mSASSS values were found to be higher than the lumbar mSASSS values for the majority of the patients (82.8 and 89.5%, respectively). This may indicate that structural changes in the cervical spine occur during an early period of axSpA.

Development and validation of an alternative ankylosing spondylitis disease activity score when patient global assessment is unavailable

Objective

To develop an alternative Ankylosing Spondylitis Disease Activity Score (ASDAS) to be used in research settings in axial SpA (axSpA) when Patient Global Assessment (PGA) is unavailable in databases.

Methods

Longitudinal data from four axSpA cohorts and two randomized controlled trials were combined. Observations were randomly split in a development (N = 1026) and a validation cohort (N = 1059). Substitutes of PGA by BASDAI total score, single or combined individual BASDAI questions, and a constant value, were established in the development cohort. Conversion factors for each substitute were defined by Generalized Estimating Equations, obtaining seven ‘alternative’ formulae. Validation was performed in the validation cohort according to the OMERACT filter, taking into consideration: (i) truth (agreement with original-ASDAS in the continuous score, by intraclass correlation coefficient and in disease activity states, by weighted kappa); (ii) discrimination [standardized mean difference of ASDAS scores between high/low disease activity states defined by external anchors, e.g. Patient Acceptable Symptom State; agreement (kappa) in the percentage of patients reaching ASDAS improvement criteria according to alternative vs original formulae]; and (iii) feasibility.

Results

Comparing various options, alternative-ASDAS using BASDAI total as PGA replacement proved to be: truthful (intraclass correlation coefficient = 0.98, kappa = 0.90), discriminative [ASDAS scores between Patient Acceptable Symptom State no/yes: standardized mean difference = 1.37 (original-ASDAS standardized mean difference = 1.43); agreement with original-ASDAS in major improvement/clinically important improvement criteria: kappa = 0.93/0.88] and feasible (BASDAI total often available, as questions required for the ASDAS; conversion coefficient ≈ 1).

Conclusion

Alternative-ASDAS using BASDAI total score as PGA replacement is the most truthful, discriminative and feasible instrument.

Similarities and differences between non-radiographic and radiographic axial spondyloarthritis: The patient perspective from the Spanish atlas

AIM

Although non-radiographic axial spondyloarthritis (EspAax-nr) is well understood within health institutions, being considered along with radiographic EspAax (EspAax-r) as part of the same disease spectrum, patient understanding is unknown. The aim is to describe the patient's knowledge of the EspAax-nr entity.

METHODS

Atlas 2017, promoted by the Spanish Federation of Spondylarthritis Associations (CEADE), aims to comprehensively understand the reality of EspAax patients from a holistic approach. A cross-sectional on-line survey of unselected patients with self-reported EspAax diagnosis from Spain was conducted. Participants were asked to report their diagnosis. Socio-demographic, disease characteristics and patient-reported outcomes (PROs) were compared between those patients self-reporting as EspAax-nr and EspAax-r.

RESULTS

634 EspAax patients participated. Mean age 45.7±10.9 years, 50.9% female and 36.1% university-educated. 35 (5.2%) self-reported as EspAax-nr. Compared to EspAax-r patients, those with EspAax-nr were more frequently women (48.6% vs 91.4%, p<0.001), had longer diagnostic delay (10.1±8.9 vs 8.5±7.6 years), higher psychological distress (GHQ-12: 7.5±4.9 vs 5.6±4.4) and similar degree of disease activity (BASDAI: 5.7±2.1 vs 5.7±2.0), and unemployment rates (20.0% vs 21.6%). 20.0% of EspAax-nr received biologics vs 36.9% of EspAax-r, p=0.043. Visits to the rheumatologist in the past year were similar in both groups (3.8±4.5 vs 3.2±3.8), while GP visits were much higher within EspAax-nr (8.0±10.7 vs 4.9±13.3 p=0.003).

CONCLUSION

For the first time, EspAax-nr characteristics and PROs have been analyzed from the patient's perspective. Both groups reported similar trends with the exception of EspAax-nr being more frequently women, younger, having longer diagnostic delay and lower use of biologic therapy.

Diagnostic performance of sacroiliac and spinal MRI for the diagnosis of non-radiographic axial spondyloarthritis in patients with inflammatory back pain

OBJECTIVE

The lack of specificity of the ASAS MRI criteria for non-radiographic axial spondylarthritis (NR-axSpA) justifies the evaluation of the discriminatory capacity of other MRI abnormalities in the sacroiliac joints and dorsolumbar spine.

METHODS

In patients hospitalized for inflammatory lumbar back pain, the diagnostic performance (sensitivity, specificity, positive likelihood ratio (PLR)) of MRI abnormalities was calculated using the rheumatologist expert opinion as a reference: (i) sacroiliac joints: Bone marrow edema (BME) (number and location), extended edema>1cm (deep lesion), fatty metaplasia (number), erosion (number and location), backfill. (ii) Dorsolumbar spine: BME (number and location), fatty metaplasia (number), posterior segment involvement.

RESULTS

In this prospective cohort, 40 NR-axSpA cases and 79 other diagnoses were included. The presence of at least 3 inflammatory signals in the sacroiliac joints (PLR: 25.67 [95% CI: 3.48-48.9]), the presence of at least one sacroiliac erosion (PLR: 12.80 [3.04-54]), the combination of an inflammatory signal and sacroiliac erosion (PLR: 11.85 [2.79-50]), the combination of deep lesion and fatty metaplasia (PLR: 15.80 [2.05-121.9]) or erosion (PLR: 11.86 [1.47-95.01]) had the best diagnostic performance. The combination of spinal and sacroiliac MRI criteria significantly increased diagnostic performance for the diagnosis of NR-axSpA.

CONCLUSION

When NR-axSpA is suspected, in addition to the presence and number of inflammatory lesions, MRI interpretation should include the location and the extent of the sacroiliac lesions, the presence of erosion or fatty metaplasia, and anterior involvement of the lumbar spine.

Comparison of Clinical and Demographic Features of FMF with Sacroiliitis Patients with FMF and Axial Spondyloarthritis Patients

Objectives Familial Mediterranean fever (FMF) is the most common autoinflammatory disease, characterised by recurrent fever and serositis attacks lasting 1–3 days. Musculoskeletal involvement is the second most common manifestation in FMF patients. Sacroiliitis is another musculoskeletal involvement; as there is no spinal involvement, this is called FMF with sacroiliitis. This study was designed to investigate the clinical, demographic and genetic features of FMF in sacroiliitis patients and to compare them with axial SpA and FMF patients.

Materials and Methods Forty-two FMF with sacroiliitis patients, 100 axial SpA patients and 100 FMF patients were recruited, and their demographic characteristics were recorded. Evidence of sacroiliitis was confirmed by sacroiliac joint MRI, and patients were examined for arthritis and enthesitis. MEFV gene mutations, HLA B27 positivity and ESR and CRP results were compared.

Results In the FMF with sacroiliitis group, the M694V mutation was detected in 59.5% of patients. FMF with sacroiliitis patients were largely (83.3%) negative for HLA B27. The frequency of enthesitis was similar between FMF with sacroiliitis and axial SpA, and the frequency of arthritis was higher in axial SpA patients. Inflammatory markers (ESR and CRP) were statistically higher in FMF with sacroiliitis patients compared with axial SpA and FMF patients.

Conclusion When all three groups were compared, the M694V mutation was more common, HLA B27 was largely negative and inflammatory markers were higher in the FMF with sacroiliitis group. FMF should be included in the differential diagnosis of sacroiliitis for managing treatment correctly and preventing complications.

Determinants of the physician global assessment of disease activity and influence of contextual factors in early axial spondyloarthritis

Objective

To investigate determinants of the physician global assessment (PhGA) of disease activity and the influence of the contextual factors on this relationship in patients with early axial spondyloarthritis (SpA).

Methods

Five‐year data of DESIR, a cohort of early axial SpA, were analyzed. Univariable generalized estimating equations (GEEs) were used to investigate contributory explanatory effects of various potential determinants of PhGA. Effect modification by contextual factors (age, sex, and educational level) was tested, and if significant, models were stratified. Autoregressive GEE models (i.e., models adjusted for PhGA at the previous time point) were used to confirm a longitudinal relationship.

Results

A total of 708 patients were included. Higher Bath Ankylosing Spondylitis Disease Activity Index individual questions, swollen joint count in 28 joints (SJC28), tender joint count in 53 joints, Maastricht Ankylosing Spondylitis Enthesitis Score, C‐reactive protein (CRP) level, and Bath Ankylosing Spondylitis Metrology Index score were associated with a higher PhGA. Sex and age were effect modifiers of SJC28; the contributory effect of SJC28 was largest in the younger male stratum (β = 1.07 [95% confidence interval (95% CI) 0.71, 1.43]), and the smallest in the older female stratum (β = 0.13 [95% CI 0.04, 0.22]). Autoregressive GEE models revealed the same determinants as having a longitudinal association with PhGA and the same pattern of effect modification.

Conclusion

Patients’ subjective symptoms, peripheral arthritis and enthesitis, higher CRP level, and impaired spinal mobility contribute to explaining PhGA in patients with early axial SpA, irrespective of sex and age. Intriguingly, physicians consider the presence of swollen joints as more important in males than in females.

Do Smoking and Socioeconomic Factors Influence Imaging Outcomes in Axial Spondyloarthritis? Five-Year Data From the DESIR Cohort

Objective

To investigate the relationship between smoking and imaging outcomes over 5 years in axial spondyloarthritis (SpA) and to assess whether socioeconomic factors influence these relationships.

Methods

Axial SpA patients from the Devenir des Spondylarthropathies Indifferérenciées Récentes cohort were included. The following 4 imaging outcomes were assessed by 3 central readers at baseline, 2 years, and 5 years: spine radiographs (using the modified Stoke Ankylosing Spondylitis Spine Score [mSASSS]), sacroiliac (SI) joint radiographs (using the modified New York criteria), magnetic resonance imaging (MRI) of the spine (using the Spondyloarthritis Research Consortium of Canada [SPARCC] score), and MRI of the SI joint (using the SPARCC score). The explanatory variable of interest was smoking status at baseline. Interactions between smoking and socioeconomic factors (i.e., job type [blue‐collar or manual work versus white‐collar or nonmanual work] and education [low versus high]) were first tested, and if significant, analyses were run using separate strata. Generalized estimating equations models were used, with adjustments for confounders.

Results

In total, 406 axial SpA patients were included (52% male, 40% smokers, and 18% blue collar). Smoking was independently associated with more MRI‐detected SI joint inflammation at each visit over the 5 years, an effect that was seen only in patients with blue‐collar professions (β = 5.41 [95% confidence interval (95% CI) 1.35, 9.48]) and in patients with low education levels (β = 2.65 [95% CI 0.42,4.88]), using separate models. Smoking was also significantly associated with spinal inflammation (β = 1.69 [95% CI 0.45, 2.93]) and SI joint damage (β = 0.57 [95% CI 0.18, 0.96]) across all patients, irrespective of socioeconomic factors and other potential confounders.

Conclusion

Strong associations were found between smoking at baseline and MRI‐detected SI joint inflammation at each visit over a time period of 5 years in axial SpA patients with a blue‐collar job or low education level. These findings suggest a possible role for mechanical stress amplifying the effect of smoking on axial inflammation in axial SpA.

Which imaging outcomes for axSpA are most sensitive to change? A 5-Year analysis of The DESIR Cohort

Objective

To compare the sensitivity to change of different imaging scoring methods in patients with early axial spondyloarthritis (SpA).

Methods

Patients from the Devenir des Spondylarthropathies Indifferérenciées Récentes (DESIR) cohort fulfilling the Assessment of SpondyloArthritis international Society criteria for axial SpA were included. Radiographs and magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and spine were obtained at baseline, 1, 2, and 5 years. Each image was scored by 2 or 3 readers in 3 separate reading waves. The rate of change of outcomes measuring inflammation of the spine and SI joints (e.g., Spondyloarthritis Research Consortium of Canada [SPARCC] score) and structural damage on MRI (e.g., ≥3 fatty lesions) and radiographs (e.g., modified New York grading) was assessed using multilevel generalized estimating equation models (taking all readers and waves into account). To allow comparisons across outcomes, rates were standardized (difference between the individual's value and the population mean divided by the SD).

Results

In total, 345 patients were included. Inflammation detected on MRI of the SI joints (MRI‐SI joints) (standardized rate range –0.278, –0.441) was more sensitive to change compared to spinal inflammation (range –0.030, –0.055). Structural damage in the SI joints showed a higher standardized rate of change on MRI‐SI joints (range 0.015, 0.274) compared to radiography of the SI joints (range 0.043, 0.126). MRI‐SI joints damage defined by ≥3 fatty lesions showed the highest sensitivity to change (0.274). Spinal structural damage slowly progressed over time with no meaningful difference between radiographic (range 0.037, 0.043) and MRI structural outcomes (range 0.008, 0.027).

Conclusion

Structural damage assessed in pelvic radiographs has low sensitivity to change, while fatty lesions detected on MRI‐SI joints are a promising alternative. In contrast, MRI of the spine is not better than radiography of the spine in detecting structural changes in patients with early axial SpA.

Uveitis in spondyloarthritis

Uveitis is the most frequent extra-articular manifestation of axial spondyloarthritis (SpA), occurring in up to one-third of the patients. In the majority of patients, uveitis is acute, anterior and unilateral and presents with photosensitivity, sudden onset of pain and blurred vision. Topical steroids are an effective treatment; however, recurrent or refractory cases may need conventional disease-modifying antirheumatic drugs or biological treatment with monoclonal tumor necrosis factor (TNF) inhibitors, thus also influencing treatment strategy of the underlying SpA. Though the exact pathogenesis of SpA and uveitis remains unknown, both seem to result from the interaction of a specific, mostly shared genetical background (among other HLA-B27 positivity), external influences such as microbiome, bacterial infection or mechanical stress and activation of the immune system resulting in inflammation. Up to 40% of patients presenting with acute anterior uveitis (AAU) have an undiagnosed SpA. Therefore, an effective referral strategy for AAU patients is needed to shorten the diagnostic delay of SpA and enable an early effective treatment. Further, the risk for ophthalmological manifestations increases with the disease duration in SpA; and patients presenting with ocular symptoms should be referred to an ophthalmologist. Thus, a close collaboration between patient, rheumatologist and ophthalmologist is needed to optimally manage ocular inflammation in SpA.

Is Axial Spondyloarthritis More Common Than Rheumatoid Arthritis?

PURPOSE OF REVIEW

To discuss the disease incidence and prevalence rates of axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS) relative to those of rheumatoid arthritis (RA).

RECENT FINDINGS

According to the most recently published systematic reviews, pooled prevalence estimates for RA are 0.38% in North America, and 0.21 to 0.25% in European subregions, while that of AS is 0.20% in North America and 0.25% in Europe. The estimated prevalence of axSpA has been reported to be approximately twice as common as AS in a study from the USA. This finding has also been supported by studies from northern Norway, central Italy, western Turkey, northern and southern regions of China, and rural Taiwan. These data suggest that axSpA, that encompasses AS, may be more prevalent than RA, at least in some countries. In general, higher occurrences of RA relative to AS have been noted worldwide, both in terms of incidence and prevalence. But axSpA, that encompasses AS, may be more prevalent than RA, at least in some countries. There is a need for concurrently run studies in the same population for a reliable comparison to establish occurrence of RA, AS, and axSpA. It is hoped that the implementation of the ICD-11 codes for axSpA will be helpful in determining a more accurate estimate of its incidence and prevalence.

The changing profile of ankylosing spondylitis in the biologic era

OBJECTIVE

To compare disease characteristics, comorbidities, and medication utilization of 1141 patients with ankylosing spondylitis (AS) with short (< 20 years) and long (≥ 20 years) disease duration enrolled in the Prospective Study of Outcomes in AS (PSOAS) study over three different periods of time and followed longitudinally.

METHODS

Study visits were carried out every 6 months examining disease activity (Bath AS Disease Activity Index (BASDAI), C-reactive protein, erythrocyte sedimentation rate), functional impairment, depression, and medication utilization as well as radiographic severity. Groups were compared with regression models using generalized estimating equation, linear, and Poisson regressions after adjusting for sites and for patients withdrawing from the study at less than 2 years follow-up.

RESULTS

Overall, AS patients with long disease duration were more likely to be married, white, receiving disability, and to be with higher functional impairment and radiographic severity, more uveitis, diabetes, hypertension, cardiovascular disease, and osteoporosis, and with less nonsteroidal anti-inflammatory drug (NSAID) and more opioid use than those with short disease duration. Current smoking decreased between 2002 and 2019 regardless of disease duration. Lower baseline NSAID and methotrexate/sulfasalazine use and higher TNF inhibitor usage were seen only in those with shorter disease duration, though NSAID use and functional impairment decreased over time in both groups. Disease activity, depression scores, and NSAID use decreased and anti-TNF use increased in those followed > 8 years.

CONCLUSIONS

Patients with AS enrolling in this multicenter longitudinal cohort have different disease profiles and medication utilization over time, perhaps reflecting innovations in treatment and increasing disease awareness. Key Points • The use of NSAIDs, nonbiologic DMARDs, and prednisone has decreased over the past 16 years in patients with AS. • The use of anti-TNF agents has dramatically increased. • In treated patients, disease activity, depression scores, and functional impairment have decreased over time.

Obesity Increases Disease Activity of Norwegian Patients with Axial Spondyloarthritis: Results from the European Map of Axial Spondyloarthritis Survey

OBJECTIVE

To investigate the prevalence of overweight and obesity, as well as the association between body mass index (BMI) and disease activity in patients with axial spondyloarthritis (axSpA).

METHODS

Norwegian axSpA patients from the European Map of Axial Spondyloarthritis (EMAS) survey were included in this analysis. Sociodemographic, anthropomorphic, and disease-related variables (HLA-B27, comorbidities, BASDAI, and self-reported spinal stiffness) were reported. Patients were categorized into under/normal weight (BMI < 25 kg/m²), overweight (BMI ≥ 25 to < 30 kg/m²), and obese (≥ 30 kg/m²).

RESULTS

Of the 509 participants in the EMAS survey, 35% were categorized as under/normal weight, 39% overweight, and 26% obese. Compared to under/normal-weight patients, overweight patients had significantly higher degree of spinal stiffness (mean (SD) 7.91 ± 2.02 vs 7.48 (2.15) and number of comorbidities (2.45 ± 2.11, vs 1.94), both p < 0.001. Obese patients had significantly higher disease activity (BASDAI mean (SD) 5.87 ± 1.78 vs 4.99 ± 2.08, p < 0.001), degree of spinal stiffness (8.18 ± 2.03 vs 7.48 ± 2.15, p = 0.006), and number of comorbidities (3.43 ± 2.43 vs 1.94. ± .38, p < 0.001) than under/normal weight patients. After adjusting for gender and age, obesity proved to be independently associated with disease activity.

CONCLUSION

Obesity was associated with higher reported BASDAI score, and being overweight or obese was associated with a higher degree of spinal stiffness and number of comorbidities compared to under/normal weight respondents. The results highlight the serious impact of obesity on health status, and obesity should therefore be considered as a modifiable risk factor for disease activity within the disease management of axSpA.

Central reader evaluation of MRI scans of the sacroiliac joints from the ASAS classification cohort: discrepancies with local readers and impact on the performance of the ASAS criteria

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.

Integrated longitudinal analysis does not compromise precision and reduces bias in the study of imaging outcomes: A comparative 5-year analysis in the DESIR cohort

OBJECTIVE

To assess if an integrated longitudinal analysis using all available imaging data affects the precision of estimates of change in patients with axial spondyloarthritis (axSpA), with completers analysis as reference standard.

METHODS

Patients from the DESIR cohort fulfilling the ASAS axSpA criteria were included. Radiographs and MRIs of the sacroiliac joints and spine were obtained at baseline, 1, 2 and 5 years. Each image was scored by 2 or 3 readers in 3 'reading-waves' (or campaigns). Each outcome was analyzed: i. According to a 'combination algorithm' (e.g. '2 out of 3' for binary scores); and ii. Per reader. Change over time was analyzed with generalized estimating equations by 3 approaches: (a)'integrated-analysis' (all patients with ≥1 score from ≥1 reader from all waves); (b1)Completers-only analysis (patients with 5-year follow-up, using scores from individual readers); (b2)Completers analysis using a 'combination algorithm' (as (b1) but with combined scores). Approaches (b1) and (b2) were considered the 'reference'.

RESULTS

In total, 413 patients were included. The 'integrated analysis' was more inclusive with similar levels of precision of the change estimates as compared to both completers analyses. In fact, for low-incident outcomes (e.g.% mNY-positive over 5-years), an increased incidence was 'captured', with more precision, by the 'integrated analysis' compared to the completers analysis with combined scores (% change/year (95%CI): 1.1 (0.7; 1.5) vs 1.2 (0.5; 1.8), respectively).

CONCLUSION

An efficient and entirely assumption-free 'integrated analysis' does not jeopardize precision of the estimates of change in imaging parameters and may yield increased statistical power for detecting changes with low incidence.

Measuring spinal mobility in early axial spondyloarthritis: does it matter?

OBJECTIVES

To investigate the frequency and order of impairment of spinal mobility measures (SMMs) and their cross-sectional and longitudinal usefulness in early axial spondyloarthritis.

METHODS

SMMs measurements of patients from the DESIR (5-year data) and SPACE (2.6 (1.9) years of follow-up) cohorts were analysed. Cross-sectional (group level) and longitudinal (individual level) analyses were performed comparing SMMs to pre-defined cut-offs derived from healthy individuals. Subgroup analyses were used to study patient and disease characteristics potentially influencing spinal mobility. Reliability was analysed using intraclass correlation coefficients and the smallest detectable change.

RESULTS

In 328 DESIR and 148 SPACE patients, lateral spinal flexion (LSF) and mSchober were the most impaired SMMs. If both (LSF and mSchober) were measured, 84% (DESIR) and 74% (SPACE) of the patients with impairment in ≥1 SMM would be captured. LSF and Bath AS Metrology Index best discriminated between subgroups of patients (higher impairment in patients ever treated with biologics, with higher disease activity and presence of baseline syndesmophytes): e.g. 31% of LSF impairment in patients with Ankylosing Spondylitis Disease Activity Score (ASDAS) < 2.1 in ≥2/3 visits vs 49% in those with ASDS ≥ 2.1. A high variability in SMMs within the same patient over time was observed, even when restricting the analysis to patients with low disease activity. Reliability of SMMs was 'fair' to 'good' (inter-reader intraclass correlation coefficients (2, 1): 0.55-0.84; intrareader intraclass correlation coefficients (2, 1): 0.49-0.72). Smallest detectable changes were in general high, e.g. 5.1 cm for LSF.

CONCLUSION

Cross-sectional use of SMMs, at the group level, is informative in patients with early axial spondyloarthritis. However, the high variation of SMMs over time impairs their use, at the individual patient level.

Is a positive family history of spondyloarthritis relevant for diagnosing axial spondyloarthritis once HLA-B27 status is known?

Objectives

A positive family history (PFH) of spondyloarthritis, in particular a PFH of AS or acute anterior uveitis, is associated with HLA-B27 carriership in chronic back pain patients. As it is unknown, the study aimed to investigate if a PFH contributes to diagnosing axial spondyloarthritis (axSpA) once HLA-B27 status is known.

Methods

In axSpA-suspected patients from the Assessment of SpondyloArthritis international Society (ASAS), DEvenir des Spondyloarthropathies Indifférenciéés Récentes (DESIR) and SPondyloArthritis Caught Early (SPACE) cohorts, logistic regression analyses were performed with HLA-B27 status and PFH according to the ASAS definition (ASAS-PFH) as determinants and clinical axSpA diagnosis as outcome at baseline. Analyses were repeated with a PFH of AS or acute anterior uveitis.

Results

In total, 1818 patients suspected of axSpA were analysed (ASAS n = 594, DESIR n = 647, and SPACE n = 577). In patients from the ASAS, DESIR and SPACE cohorts, respectively 23%, 39% and 38% had an ASAS-PFH, 52%, 58% and 43% were HLA-B27 positive, and 62%, 47% and 54% were diagnosed with axSpA. HLA-B27 was independently associated with an axSpA diagnosis in each cohort but an ASAS-PFH was not [ASAS cohort: HLA-B27 odds ratio (OR): 6.9 (95% CI: 4.7, 10.2), ASAS-PFH OR: 0.9 (95% CI: 0.6, 1.4); DESIR: HLA-B27 OR: 2.1 (95% CI: 1.5, 2.9), ASAS-PFH OR: 1.0 (95% CI 0.7, 1.3); SPACE: HLA-B27 OR: 10.4 (95% CI: 6.9, 15.7), ASAS-PFH OR: 1.0 (95% CI: 0.7, 1.5)]. Similar negative results were found for PFH of AS and acute anterior uveitis.

Conclusion

In three independent cohorts with different ethnical backgrounds, ASAS, DESIR and SPACE, a PFH was not associated independently of HLA-B27 with a diagnosis of axSpA. This indicates that in the vast majority of patients presenting with back pain, a PFH does not contribute to the likelihood of an axSpA diagnosis if HLA-B27 status is known.