Sacroiliac radiographic progression over 10 years in axSpA: data from the DESIR inception cohort.

OBJECTIVES: To evaluate sacroiliac radiographic progression over a 10-year follow-up and determine the baseline factors associated with such progression in patients with recent-onset axial spondyloarthritis (axSpA, <3 years). METHODS: This analysis was performed in the DESIR cohort (NCT01648907). The radiographic status of the patients (radiographic axSpA (r-axSpA) vs non-radiographic axSpA (nr-axSpA)) was based on the modified New York (mNY) criteria. Information on mNY criteria on the pelvic radiographs was obtained in four reading waves over a 10-year period. Images were blinded and centrally read by 3 trained readers. The % of mNY net progressors (ie, number of 'progressors' minus number of 'regressors' divided by the total number of patients) was assessed in completers (ie, pelvic radiographs at baseline and 10 years). The yearly likelihood of mNY+ was estimated using an integrated analysis (ie, including all patients with at least one available mNY score ('intention-to-follow' population) using a generalised estimating equations model and time-varying tumour necrosis factor (TNF) use as a confounder. Baseline predictors of mNY+ during 10 years were evaluated. RESULTS: Completers included 294 patients, while intention-to-follow included 659 participants. In the completers, the net % progression (from nr-axSpA to r-axSpA) was 5.8%. In the intention-to-follow population, the probability of being mNY+ was estimated to increase 0.87% (95% CI 0.56 to 1.19) per year (ie, 8.7% after 10 years) while when introducing TNF inhibitors (TNFi) as a time-varying covariate, the probability was 0.45% (95% CI 0.09 to 0.81) (ie, 4.5% after 10 years). Baseline bone marrow oedema (BME) on MRI of the sacroiliac joints (SIJ) was associated with being mNY+ over time OR 6.2 (95% CI 5.3 to 7.2) and OR 3.1 (95% CI 2.4 to 3.9) in HLA-B27+ and HLA-B27-, respectively). Male sex, symptom duration >1.5 years, Axial Spondyloarthritis Disease Activity Score ≥2.1 and smoking (only in HLA-B27 positives) were also associated with being mNY+ over 10 years. BME was not found to be a mediator of the HLA-B27 effect on mNY+ at 10 years. CONCLUSIONS: The yearly likelihood of switching from nr-axSpA to r-axSpA in patients after 10 years of follow-up was low, and even lower when considering TNFi use.

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.

Bone marrow edema in the sacroiliac joints is associated with the development of structural lesions at the same anatomical location over time in patients with axial spondyloarthritis.

OBJECTIVE: To assess whether the presence of bone marrow edema (BME) leads to the development of structural lesions at the same anatomical location of the sacroiliac joints (SIJ), and to investigate the association between BME patterns over time and structural lesions in patients with early axial spondyloarthritis (axSpA). METHODS: Patients with axSpA from the DESIR cohort with ≥2 consecutive magnetic resonance imaging (MRI)-SIJ were assessed at baseline, 2 and 5 years. MRI-SIJ images were divided into 8 quadrants. The association between BME and subsequent structural lesions (sclerosis, erosions, fatty lesions, and ankylosis) on MRI in the same quadrant was tested longitudinally. Additionally, patients were grouped according to the pattern of BME evolution across quadrants over time (no BME, sporadic, fluctuating, and persistent). The association between these patterns and 5-year imaging outcomes (eg: ≥5 erosions and/or fatty lesions on MRI-SIJ) was tested. RESULTS: In total, 196 patients were included. BME in each quadrant was associated with sclerosis (OR:1.9 (95%CI: 1.1;3.4)), erosions (1.9 (1.5;2.5)) and fatty lesions (1.9 (1.4;2.6)). Ankylosis was uncommon. There was a gradient between increased level of inflammation and subsequent damage: compared to the 'no BME' pattern, the sporadic (OR (95% CI): 2.1 (1.0;4.5)), fluctuating (OR:5.6(2.2;14.4)) and persistent (OR:7.5(2.8;19.6)) patterns were associated with higher structural damage on MRI-SIJ at 5-years. CONCLUSIONS: In early axSpA, inflammation on MRI-SIJ leads to damage at the quadrant level. The higher the exposure to inflammation across quadrants in the SIJs over time the higher the likelihood of subsequent structural damage, suggesting a cumulative effect.

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.

Do Illness Perceptions and Coping Strategies Change Over Time in Patients Recently Diagnosed With Axial Spondyloarthritis?

OBJECTIVE: It is unknown if in axial spondyloarthritis (axSpA) patients' illness perceptions and coping strategies change when disease activity changes. METHODS: Patients diagnosed with axSpA and with 1 or more follow-up visits (1 and/or 2 yrs in the SPACE cohort) were included. Mixed linear models were used for illness perceptions (range 1-5), coping (range 1-4), back pain (numeric rating scale range 0-10), health-related quality of life (range 0-100), physical and mental component summary (PCS and MCS; range 0-100), work productivity loss (WPL; range 0-100), and activity impairment (AI; range 0-100%), separately, to test if they changed over time. RESULTS: At baseline, 150 axSpA patients (mean age 30.4 yrs, 51% female, 65% HLA-B27+) had a mean (SD) numeric rating scale back pain of 4.0 (2.5), PCS of 28.8 (14.0), MCS of 47.8 (12.4), WPL of 34.1% (29.8), and AI of 38.7% (27.9). Over 2 years, clinically and statistically significant improvements were seen in the proportion of patients with an Ankylosing Spondylitis Disease Activity Score (ASDAS) of low disease activity (from 39% at baseline to 68% at 2 years), back pain (-1.5, SD 2.2), AI (-14.4%, SD 27.2), PCS (11.1, SD 13.3), and WPL (-15.3%, SD 28.7), but MCS did not change (0.7, SD 13.9; P = 0.201). In contrast, illness perceptions and coping strategies did not change over a period of 2 years. For example, at 2 years patients believed that their illness had severe "consequences" (2.8, SD 0.9) and they had negative emotions (e.g., feeling upset or fear) towards their illness ["emotional representation", 2.5 (0.8)]. Patients most often coped with their pain by putting pain into perspective ["comforting cognitions", 2.8 (0.6)] and tended to cope with limitations by being optimistic ["optimism", 2.9 (0.7)]. CONCLUSION: While back pain, disease activity, and health outcomes clearly improved over 2 years, illness perceptions and coping strategies remained remarkably stable.

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.

Spinal Radiographic Progression in Early Axial Spondyloarthritis: Five-Year Results From the DESIR Cohort.

OBJECTIVE: To analyze the progression of spinal radiographic damage in patients with early axial spondyloarthritis (SpA). METHODS: Axial SpA patients from the DESIR (Devenir des Spondylarthropathies Indifférenciées Récentes) cohort with 5-year spinal (cervical and lumbar) radiographs available (n = 549) were included. Two- and 5-year modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) progression and development of new syndesmophytes (net change: the number of patients with positive change minus the number of patients with negative change divided by the total number of patients) were assessed in subgroups defined at baseline according to the Assessment of SpondyloArthritis international Society axial SpA criteria and its arms, modified New York criteria (mNYC) and the presence of syndesmophytes. RESULTS: Mean ± SD mSASSS progression was 0.2 ± 0.9 at 2 years and 0.4 ± 1.8 at 5 years. Five-year progression was higher in the imaging arm (mean ± SD 0.6 ± 2.3), magnetic resonance imaging (MRI)+/mNYC+ (mean ± SD 1.3 ± 4.0), than in the clinical arm only (mean ± SD 0.1 ± 0.7), and highest in patients with syndesmophytes (mean ± SD 2.7 ± 5.0). At 5 years, 7% of all patients had a net change of any new syndesmophyte; this value was 10% for the imaging arm (mNYC+/MRI+ with 18%), 17% for mNYC+ patients, and 42% for patients with syndesmophytes. CONCLUSION: Spinal radiographic progression, although limited in early axial SpA, can be captured after 2 years. Inflammation and damage in the sacroiliac joint are associated with higher radiographic progression. The presence of baseline syndesmophytes already strongly predicts the development of further structural damage early in the disease.

Are gender-specific approaches needed in diagnosing early axial spondyloarthritis? Data from the SPondyloArthritis Caught Early cohort.

BACKGROUND: Although gender differences have been observed in the severity of axial spondyloarthritis (axSpA), gender differences in disease presentation of early axSpA have not been thoroughly investigated. In particular, their impact on the diagnostic process is unknown. METHODS: Baseline data from the SPondyloArthritis Caught Early cohort, which includes patients with chronic back pain (CBP; duration ≥ 3 months and ≤ 2 years, age of onset < 45 years), were analysed. Patients underwent a full diagnostic work-up, including MRI and radiograph of the sacroiliac joints (MRI-SIJ and X-SIJ), to establish a diagnosis of axSpA. Characteristics of male and female patients with a certain diagnosis of axSpA (confidence level by the physician ≥ 7 on a 0-10 rating scale) were compared. Regression models were built for: the whole CBP cohort stratified by gender, to study which SpA features were associated most with diagnosis in each gender; and for axSpA patients, to test whether gender was associated with imaging positivity (MRI-SIJ+ and/or X-SIJ+). RESULTS: Of the 719 CBP patients, 275 were male. With 146/275 males and 155/444 females diagnosed as axSpA, males were more likely to be diagnosed with axSpA (OR 2.1, 95% CI 1.5-2.9). Despite similar symptom duration, male axSpA patients were younger at diagnosis (27.4 ± 7.5 vs 29.5 ± 7.8 years; p = 0.02). Presence of SpA features was similar in male and female axSpA patients, except for HLA-B27 and imaging positivity that were more common in male axSpA patients (80% vs 60%; p < 0.01 and 78% vs 64%; p = 0.01). Nevertheless, these SpA features were still more prevalent in female axSpA patients than in no-axSpA patients, both females (HLA-B27+ 23%, positive imaging 7%) and males (HLAB27+ 34%, positive imaging 11%) (all p < 0.01). Moreover, in multivariable models with diagnosis of axSpA as outcome, HLA-B27 and imaging positivity were associated with the diagnosis in both sexes. In models with imaging positivity as outcome, male gender and HLA-B27 were both independently associated with MRI+ and/or X-SI+. CONCLUSIONS: While our data show clear gender differences in early axSpA, they highlight that HLA-B27 and imaging are still key elements for diagnosis in both genders. Our study does not suggest that separate diagnostic strategies for men and women are required.

Do ethnicity, degree of family relationship, and the spondyloarthritis subtype in affected relatives influence the association between a positive family history for spondyloarthritis and HLA-B27 carriership? Results from the worldwide ASAS cohort.

BACKGROUND: The Assessment of SpondyloArthritis international Society (ASAS) defines a positive family history (PFH) of spondyloarthritis (SpA) as the presence of ankylosing spondylitis (AS), acute anterior uveitis (AAU), reactive arthritis (ReA), inflammatory bowel disease (IBD), and/or psoriasis in first-degree relatives (FDR) or second-degree relatives (SDR). In two European cohorts, a PFH of AS and AAU, but not other subtypes, was associated with human leukocyte antigen B27 (HLA-B27) carriership in patients suspected of axial SpA (axSpA). Because the importance of ethnicity or degree of family relationship is unknown, we investigated the influence of ethnicity, FDR, or SDR on the association between a PFH and HLA-B27 carriership in patients suspected of axSpA. METHODS: Baseline data from the ASAS cohort of patients suspected of axSpA were analyzed. Univariable analyses were performed. Each disease (AS, AAU, psoriasis, IBD, ReA) in a PFH according to the ASAS definition was a determinant in separate models with HLA-B27 carriership as outcome. Analyses were stratified for self-reported ethnicity, FDR, and SDR. Analyses were repeated in multivariable models to investigate independent associations. RESULTS: A total of 594 patients were analyzed (mean [SD] age 33.7 [11.7] years; 46% male; 52% HLA-B27+; 59% white, 36% Asian, 5% other). A PFH was associated with HLA-B27 carriership in patients with a white (OR, 2.3, 95% CI, 1.4-3.9) or Asian ethnicity (OR, 3.1, 95% CI, 1.6-5.8) and with a PFH in FDR (OR, 2.9, 95% CI, 1.8-4.5), but not with a PFH in SDR (OR, 1.7, 95% CI, 0.7-3.8) or in other ethnicities. A PFH of AS was positively associated with HLA-B27 carriership in all subgroups (white OR, 7.1; 95% CI, 2.9-17.1; Asian OR, 5.7; 95% CI, 2.5-13.2; FDR OR, 7.8; 95% CI, 3.8-16.0; SDR OR, 3.7; 95% CI, 1.2-11.6). A PFH of AAU, ReA, IBD, or psoriasis was never positively associated with HLA-B27 carriership. In the multivariate analysis, similar results were found. CONCLUSIONS: In the ASAS cohort, a PFH of AS, but not of AAU, ReA, IBD, or psoriasis, was associated with HLA-B27 carriership regardless of white or Asian ethnicity or degree of family relationship. This cohort and two European cohorts show that a PFH of AS and possibly a PFH of AAU can be used to identify patients who are more likely to be HLA-B27-positive and therefore may have an increased risk of axSpA.

Which scoring method depicts spinal radiographic damage in early axial spondyloarthritis best? Five-year results from the DESIR cohort.

Objective: To compare the performance of different spinal radiographic damage scoring methods in patients with early axial spondyloarthritis (axSpA). Methods: Five-year spinal radiographs from the DESIR cohort were scored by three readers (averaged) for the calculation of the Stoke AS Spine Score (SASSS), modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), Radiographic AS Spinal Score (RASSS), BASRI-spine and BASRI-total, and following the OMERACT filter, scores were compared according to truth, discrimination (reliability and sensitivity to change) and feasibility. The proportion of patients with a net change > smallest detectable change and >1 was calculated. The proportion of total variance explained by the patient (true variance) was calculated for the change scores as a measure of reliability, using analysis of variance. Results: In total 699 patients were included. Five-year net changes > smallest detectable change (>1) were: RASSS 17% (17%), mSASSS 12% (12%), BASRI-spine and BASRI-total 12% (9%), SASSS 11% (11%). The mSASSS and the RASSS performed the best in terms of capturing the signal (positive change) related to noise (negative change). The proportion of variance explained by the patient was highest for the mSASSS and RASSS (85% for both 5-year progression scores vs 50-55% for other methods). The proportion of patient variance in the thoracic segment of the RASSS was unsatisfactory (46% for progression). Conclusion: The existing scoring methods to assess spinal radiographic damage performed well in early phases of axSpA. The mSASSS and RASSS captured most change. There was no clear gain in additionally scoring the thoracic spine for the RASSS. The mSASSS remains the most sensitive and valid scoring method in axSpA, including early phases of the disease.

The Impact of Illness Perceptions and Coping on the Association Between Back Pain and Health Outcomes in Patients Suspected of Having Axial Spondyloarthritis: Data From the SPondyloArthritis Caught Early Cohort.

OBJECTIVE: To investigate whether illness perceptions and coping influence the relationship between back pain and health outcomes in patients suspected of having axial spondyloarthritis (SpA). METHODS: In the SPondyloArthritis Caught Early cohort, regression models were computed at baseline, with back pain intensity (range 0-10) as the determinant and health-related quality of life, the physical component summary score (PCS) and mental component summary (MCS) of the Short Form 36 (SF-36) health survey, or work productivity loss as outcomes. Subsequently, using Leventhal's Common-Sense Model of Self-Regulation, illness perceptions and, thereafter, coping were added to the models. Analyses were repeated for patients diagnosed and classified as having axial SpA according to the Assessment of SpondyloArthritis international Society axial SpA criteria (ASAS axial SpA), patients only diagnosed with axial SpA (axial SpA-diagnosed only), and those with chronic back pain. RESULTS: A total of 424 patients (145 with ASAS axial SpA, 81 with only a diagnosis of axial SpA, and 198 with chronic back pain); 64% of the total group were female, the mean ± SD age was 30.9 ± 8.1 years, and the mean ± SD symptom duration was 13.3 ± 7.1 months) were studied. In all patients, the strength of the associations between back pain and the PCS, back pain and the MCS score, and back pain and loss of work productivity were decreased by adding illness perceptions to the model, but explained variance improved. Adding coping to these models did not change the results. Comparable results were observed in all subgroups. CONCLUSION: Illness perception, but not coping, is important in the relationship between back pain and HRQoL and work productivity loss in patients suspected of having axial SpA, irrespective of subgroup. This finding suggests that targeting illness perceptions could improve health outcomes in patients suspected of having axial SpA.

Impact of replacing radiographic sacroiliitis by magnetic resonance imaging structural lesions on the classification of patients with axial spondyloarthritis.

OBJECTIVES: To investigate in patients with chronic back pain of a short duration, the utility of adding structural MRI lesions of the SI joints to the imaging criterion of the Assessment of SpondyloArthritis International Society (ASAS) axial SpA (axSpA) criteria and the utility of replacement of radiographic sacroiliitis by structural MRI lesions. METHODS: MRI STIR (inflammation, MRI-SI), MRI T1-weighted images (structural lesions, MRI-SI-s) and radiographs of the SI joints of patients in the SPondyloArthritis Caught Early-cohort (chronic back pain: ⩾3 months, ⩽2 years; onset <45 years) were scored by two well-calibrated readers. Previously proposed cut-offs for a positive MRI-SI-s were used (based on <5% prevalence in no-SpA patients): erosions ⩾3, fatty lesions ⩾3, fatty lesions and/or erosions (erosions/fatty lesions) ⩾5. Using the definitions of MRI-SI-s, patients were classified according to the ASAS axSpA criteria. RESULTS: Twenty-nine of 294 patients were modified New York (mNY) positive and 32 were MRI-SI-s positive (erosions/fatty lesions ⩾5). Agreement between mNY and MRI-SI-s (erosions/fatty lesions ⩾5) was moderate (κ: 0.58). Using the erosions/fatty lesions ⩾5 cut-off, 3/294 additional patients were classified as axSpA (adding MRI). Using this cut-off instead of mNY (replacing mNY), classification did not change in 286 patients (97.3%), but 5 patients (1.7%) would not be classified as axSpA and 3 previously unclassified patients (1.0%) would be classified as axSpA. Similar results were seen for the other cut-offs (erosions ⩾3 and fatty lesions ⩾3). CONCLUSION: Assessment of structural lesions (fatty lesions and erosions) on MRI-SI instead of or in addition to conventional radiographs does not lead to a different ASAS axSpA classification in most of the patients with early disease onset. This suggests that structural lesions (fatty lesions and erosions) can be reliably used in the ASAS axSpA classification of patients, as both addition and replacement of radiographs of the SI joints.

Imaging of the sacroiliac joints is important for diagnosing early axial spondyloarthritis but not all-decisive.

OBJECTIVES: To evaluate the contribution of the results of sacroiliac imaging to diagnosis and to the level of confidence in diagnosis in patients presenting with chronic back pain (CBP) and suspected of having axial spondyloarthritis (axSpA). METHODS: Data from 513 patients from the SPondyloArthritisCaughtEarly cohort with CBP (⩾3 months, ⩽2 years, onset <45 years) were analysed after full diagnostic work-up. Rheumatologists were asked not only to provide a diagnosis before and after the imaging results had been provided to them, but also to provide the level of confidence of this diagnosis on an 11-point numerical scale. RESULTS: Before imaging, 317/513 patients were diagnosed with axSpA. Of these patients, 178/317 (56%) did not have signs of sacroiliitis on either MRI or radiography, which led to the rheumatologist refuting the initial diagnosis of axSpA in 81/178 (46%) patients. Of the 196/513 patients without axSpA before imaging, 35/196 (18%) had signs of sacroiliitis on imaging. Subsequently, 28/35 (80%) patients were diagnosed with axSpA. Overall, imaging was incongruent with the diagnosis before imaging in 213 patients. This led to a change in diagnosis in 109/213 (51%), which corresponds to 21% (109/513) of all patients in the cohort. In general, diagnostic confidence increased by having imaging results available (from 6.2 to 7.4, P < 0.001). CONCLUSION: In patients with CBP suspected of having axSpA, sacroiliac imaging adds to the confidence in the final diagnosis. However, the number of changes in diagnosis suggests that imaging is important but not all-decisive in early axSpA diagnosis.

In Early Axial Spondyloarthritis, Increasing Disease Activity Is Associated with Worsening of Health-related Quality of Life over Time.

OBJECTIVE: In early axial spondyloarthritis (axSpA), data are lacking about the relationship between disease activity and health-related quality of life (HRQOL). We assessed and quantified the association between change in Ankylosing Spondylitis Disease Activity Score (ASDAS) and HRQOL over time in early axSpA. METHODS: Baseline and 1-year data of patients with axSpA fulfilling the Assessment of Spondyloarthritis international Society (ASAS) classification criteria from the SPondyloArthritis Caught Early (SPACE) cohort were analyzed. Associations between change in ASDAS and in physical (PCS) or mental component summary (MCS) of the Medical Outcomes Study Short Form-36 were tested by linear regression models. Age, sex, ASAS criteria arm, and blue- versus white-collar work were tested for effect modification. Subsequently, these factors and medication were tested for confounding. RESULTS: There were 161 patients with axSpA [53% male, mean (± SD) age 29.7 (± 7.5) yrs, symptom duration 13.6 (± 7.2) months, HLA-B27-positive 91%, radiographic sacroiliitis 22%] who had ASDAS of 2.5 (± 1.0) and 2.0 (± 0.8), PCS of 28.4 (± 14.3) and 36.9 (± 13.1), and MCS of 48.2 (± 13.8) and 49.3 (± 12.0) at baseline and 1 year, respectively. Per unit increase in ASDAS between baseline and 1 year, PCS worsened by 9.5 points. The same level of disease activity had fewer adverse effects on physical HRQOL in women and white-collar workers. CONCLUSION: To our knowledge, our data are the first to show that in a broad group of patients with early axSpA, increasing ASDAS is associated with worsening of physical HRQOL, but not mental HRQOL, over time.

Disease activity decrease is associated with improvement in work productivity over 1 year in early axial spondyloarthritis (SPondyloArthritis Caught Early cohort).

Objectives: To assess if a change in disease activity is associated with a change in work productivity loss (WPL) over 1 year in early axial SpA (axSpA) patients. Methods: Baseline and 1 year data of axSpA patients in the SPondyloArthritis Caught Early cohort were analysed. Linear regression models were built explaining the change in the Ankylosing Spondylitis Disease Activity Score (ASDAS) over time by the change in absenteeism, presenteeism, WPL and activity impairment over time. Effect modification and confounding were tested for age, gender, arm of Assessment of SpondyloArthritis international Society classification criteria, HLA-B27, duration of chronic back pain, profession and medication. Results: At baseline, in 105 axSpA patients (48% female, mean age 30.8 years, mean symptom duration 13.6 months, 92% HLA-B27 positive, 24% radiographic sacroiliitis), the mean ASDAS was 2.4 (s.d. 1.0), absenteeism 9% (s.d. 23), presenteeism 33% (s.d. 28), WPL 36% (s.d. 30) and activity impairment 37% (s.d. 25). After 1 year, the mean ASDAS decreased to 2.0 (s.d. 0.8) and absenteeism, presenteeism, WPL and activity impairment improved to 6% (s.d. 22), 26% (s.d. 26), 27% (s.d. 29) and 27% (s.d. 26), respectively. Models showed that if ASDAS decreased 1 unit, absenteeism, presenteeism, WPL and activity impairment improved by 5, 17, 16 and 18%, respectively. The impact of disease activity on work productivity was higher in patients with shorter symptom duration and the impact on absenteeism was higher in patients starting pharmacological treatment. Conclusions: In early axSpA patients, work productivity and daily activities are seriously impacted at baseline and 1 year. However, decreasing disease activity is associated with marked improvements in work productivity and daily activities.

The yield of a positive MRI of the spine as imaging criterion in the ASAS classification criteria for axial spondyloarthritis: results from the SPACE and DESIR cohorts.

OBJECTIVES: To assess the prevalence of spinal inflammation on MRI in patients with chronic back pain (CBP) of maximally 3 years duration and to evaluate the yield of adding a positive MRI-spine as imaging criterion to the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA). METHODS: Baseline imaging of the sacroiliac joints (X-SI), MRI of the sacroiliac joints (MRI-SI) and MRI-spine were scored by ≥2 experienced central readers per modality in the SPondyloArthritis Caught Early (SPACE) and DEvenir des Spondylarthropathies Indifférenciées Récentes (DESIR) cohorts. Inflammation suggestive of axSpA was assessed in the entire spine. A positive MRI-spine was defined by the presence of ≥5 inflammatory lesions. Alternative less strict definitions were also tested. RESULTS: In this study, 541 and 650 patients with CBP from the SPACE and DESIR cohorts were included. Sacroiliitis on X-SI and MRI-SI was found in 40/541 (7%) and 76/541 (14%) patients in SPACE, and in DESIR in 134/650 (21%) and 231/650 (36%) patients, respectively. In SPACE and DESIR, a positive MRI-spine was seen in 4/541 (1%) and 48/650 (7%) patients. Of the patients without sacroiliitis on imaging, 3/447 (1%) (SPACE) and 8/382 (2%) (DESIR) patients had a positive MRI-spine. Adding positive MRI-spine as imaging criterion led to new classification in only one patient in each cohort, as the other patients already fulfilled the clinical arm. Other definitions of a positive MRI-spine yielded similar results. CONCLUSION: In two cohorts of patients with CBP with a maximum symptom duration of 3 years, a positive MRI-spine was rare in patients without sacroiliitis on MRI-SI and X-SI. Addition of MRI-spine as imaging criterion to the ASAS axSpA criteria had a low yield of newly classified patients and is therefore not recommended.

Sacroiliac radiographic progression in recent onset axial spondyloarthritis: the 5-year data of the DESIR cohort.

OBJECTIVE: To estimate sacroiliac joint radiographic (X-SIJ) progression in patients with axial spondyloarthritis (axSpA) and to evaluate the effects of inflammation on MRI (MRI-SIJ) on X-SIJ progression. METHODS: X-SIJ and MRI-SIJ at baseline and after 2 and 5 years in patients with recent onset axSpA from the DESIR cohort were scored by three central readers. Progression was defined as (1) the shift from non-radiographic (nr) to radiographic (r) sacroiliitis (by modified New York (mNY) criteria) or alternative criteria, (2) a change of at least one grade or (3) a change of at least one grade but ignoring a change from grade 0 to 1. The effects of baseline inflammation on MRI-SIJ on 5-year X-SIJ damage (mNY) were tested by generalised estimating equations. RESULTS: In 416 patients with pairs of baseline and 5-year X-SIJ present, net progression occurred in 5.1% (1), 13.0% (2) and 10.3% (3) respectively, regarding a shift from nr-axSpA to r-axSpA (1), a change of at least one grade (2) or a change of at least one grade but ignoring a change from grade 0 to 1 (3). Baseline MRI-SIJ predicted structural damage after 5 years in human leukocyte antigen-B27 (HLA-B27) positive (OR 5.39 (95% CI 3.25 to 8.94)) and in HLA-B27 negative (OR 2.16 (95% CI 1.04 to 4.51)) patients. CONCLUSIONS: Five-year progression of X-SIJ damage in patients with recent onset axSpA is limited but present beyond measurement error. Baseline MRI-SIJ inflammation drives 5-year radiographic changes.

Does body mass index (BMI) influence the Ankylosing Spondylitis Disease Activity Score in axial spondyloarthritis?: Data from the SPACE cohort.

OBJECTIVE: Obesity is associated with elevated C reactive protein (CRP) levels. The Ankylosing Spondylitis Disease Activity Score (ASDAS) combines patient-reported outcomes (PROs) and CRP. We evaluated the effect of body mass index (BMI) on CRP and on ASDAS, and studied if ASDAS can be used in obese axial spondyloarthritis (axSpA) patients to assess disease activity. METHODS: Baseline data of patients with chronic back pain of short duration included in the SPondyloArthritis Caught Early (SPACE) cohort were used. Collected data included BMI and ASDAS. Patients were classified according to the ASAS axSpA classification criteria and BMI (overweight ≥25 and obese ≥30). Correlation and linear regression analyses were performed to assess the relation between BMI and ASDAS. Linear regression models were performed to assess if age or gender were effect modifiers in the relation between BMI and CRP, and between BMI and ASDAS. RESULTS: In total, 428 patients were analysed (n=168 axSpA; n=260 no-axSpA). The mean age was 31.1 years, 36.9% were male, 26.4% were overweight and 13.3% obese, median CRP was 3 mg/L and the mean ASDAS was 2.6. Gender was the only factor modifying the relationship between BMI and CRP as BMI had an influence on CRP only in females (ß=0.35; p<0.001). Correlations between BMI and CRP or PROs were generally weak, and only significant for CRP in female patients. BMI was not related to ASDAS in axSpA patients. CONCLUSIONS: ASDAS is not affected by BMI in axSpA patients. Therefore, based on our data it is not necessary to take BMI in consideration when assessing disease activity using ASDAS in axSpA patients.