M. van Lunteren

FRI0514 Adding Mri of The Spine To The Asas Classification Criteria for Axial Spondyloarthritis, Redundant or Beneficial? Data from The Spondyloarthritis Caught Early (Space)-Cohort

Background The ASAS definition of a positive MRI is solely based on inflammation in the sacroiliac joints (SIJ), although spinal inflammatory lesions on MRI suggestive of axial Spondyloarthritis (axSpA) may also occur. It is not well known how often inflammation in the spine occurs in absence of inflammation in the SIJ and consequently what the utility is of including inflammation in the spine in the definition of a positive MRI. Objectives To analyze the prevalence of spinal inflammation on MRI in patients with chronic back pain (CBP) at baseline and one-year follow-up, and to evaluate the yield of adding MRI-spine as imaging criterion to the ASAS classification criteria for axial SpA. Methods The SPACE-cohort includes patients with CBP (≥3 months, ≤2 years, onset <45 years) from five participating centres in Europe. All available baseline (BL) and one-year follow-up (FU) MRI of SIJ and spine were scored by 2 well-calibrated readers. MRI-SI were scored according to the ASAS definition. Bone marrow oedema suggestive of axSpA was assessed in the entire spine and only counted if visible on ≥2 consecutive slices. To define a positive MRI-spine, two cut-off values were used: ≥3 inflammatory lesions (ASAS consensus definition) and ≥5 inflammatory lesions (defined as the best cut-off in earlier analyses). Adjudication for the ASAS definition by an experienced reader was performed in case of disagreement and all modalities were considered positive if 2/3 readers agreed. Results All patients with both MRI-spine and MRI-SIJ available at BL (n=329) and FU (n=168) were included in the analyses. At BL 43/329 (13.1%) of patients had a positive MRI-SIJ, of which 7/43 (16.3%) patients had a positive MRI-spine (ASAS consensus definition, ≥3 inflammatory lesions) and 2/43 (4.7%) if defined by ≥5 inflammatory lesions. Positive MRI-SIJ at FU was seen in 28/168 (16.7%) patients, 14 of which were also positive at BL; MRI-spine positivity was identified in 2/28 (7.1%) and 1/28 (3.6%) patients for the ASAS definition defined by ≥3 and ≥5 inflammatory lesions, respectively. In total, 4 patients had a positive MRI-spine and a negative MRI-SIJ: at BL 2 patients according to the ASAS definition of whom 1 also fulfilled the alternative definition. At FU this was 2 (different patients than at baseline) and 0 patients, respectively. Addition of MRI-spine to the classification criteria by the ASAS definition of ≥3 inflammatory lesions would lead to classification of 3 additional patients via imaging arm, with 1 patient already fulfilling the clinical arm. Conclusions In this cohort, a positive MRI-spine in the absence of sacroiliitis on MRI was rarely seen Addition of MRI-spine as an imaging criterion to the ASAS criteria had a low yield in number of classifications. Therefore, performing MRI of the spine at either baseline or one-year follow-up is of little value in patients with short duration of CBP and suspicion of axial SpA. Disclosure of Interest None declared

OP0085 Does The Presence of Multiple SpA-Features in Patients with Chronic Back Pain Always Lead To Diagnosis of Axial Spondyloarthritis?

Background The number of clinical SpA-features plays an important role in the Assessment of SpondyloArthritis international Society (ASAS) modified Berlin algorithm for the diagnostic work-up of patients (pts) with a suspicion of axial SpA (axSpA). Objectives To investigate whether all pts with short duration chronic back pain (CBP) and multiple SpA-features are always diagnosed as axSpA by the rheumatologist and to describe the features of these patients. Methods The SPondyloArthritis Caught Early (SPACE)-cohort includes CBP pts (≥3 months, ≤2 years, onset <45 years) from various European rheumatology centres. Baseline data were used for the analyses. Following a fixed protocol all pts underwent a full diagnostic work-up consisting of performance of MRI and radiographs of sacroiliac joints (MRI-SI and X-SI), acute phase reactants, HLA-B27 testing, and assessment of other SpA-features (inflammatory back pain (IBP), good response to NSAIDs, family history for SpA, peripheral arthritis, dactylitis, enthesitis, uveitis, inflammatory bowel disease (IBD), and psoriasis). Local radiologists or rheumatologists from the different centres interpreted MRI-SI and X-SI on presence of sacroiliitis (yes/no) using global assessment as part of routine clinical practice. Total number of SpA-features was calculated excluding sacroiliac imaging and HLA-B27 status. The treating rheumatologist provided clinical diagnosis of pts and the ASAS-criteria for axSpA were used for classification. Results A total of 522 pts were analysed in this study: before sacroiliac imaging and HLA-B27 testing 164/522 (31.4%) pts had no or 1 SpA-feature, 148/522 (28.4%) pts had 2 SpA-features, 85/522 (16.3%) pts had 3 SpA-features, and 125/522 (23.9%) pts had ≥4 SpA-features respectively. IBP, good response to NSAIDs, and positive family history for SpA were most common in all subgroups (0 or 1 feature: 26.8%, 8.5%, and 16.5% of pts; 2 features: 72.3%, 34.5%, 39.9%; 3 features: 87.1%, 60.0%, 54.1%; ≥4 features: 94.4%, 83.2%, 68.0% respectively). Of the pts with 2 and 3 SpA-features with negative X-SI 20/132 (15.2%) and 9/78 (11.5%) did not have axSpA diagnosis despite being HLA-B27+ (Figure 1). All pts with ≥4 SpA-features and X-SI+ (n=28) were diagnosed with axSpA. In contrast to what would be expected by following the modified Berlin algorithm for pts with ≥4 SpA-features, 18/94 pts (19.1%) with negative imaging (of which 4 HLA-B27+), were not diagnosed with axSpA by their rheumatologist. Multivariate regression analysis of presence of SpA-features identified MRI-SI+ (OR 41.7;95%CI 17.3.1–100.5), X-SI+ (OR 31.5;95%CI 3.1–321.0), HLA-B27+ (OR 4.7;95%CI 2.5–8.6), uveitis (OR 4.3;95%CI 1.5–12.7), IBP (OR 2.5;95%CI 1.4–4.7), heel enthesitis (OR 5.5;95%CI 2.7–11.4), IBD (OR 3.2;95%CI 1.2–8.8), elevated CRP/ESR (OR 2.7;95%CI 1.4–5.3), and psoriasis (OR 2.5;95%CI 1.0–6.0) as significant independent predictors of axSpA diagnosis. Conclusions In this cohort of pts with CBP having numerous SpA-features did not automatically lead to a clinical axSpA diagnosis but positive imaging was the main driving factor to diagnosis of axSpA. Disclosure of Interest None declared

FRI0404 Illness Perceptions and Health-Related Quality of Life in Patients with Axial Spondyloarthritis and Other Forms of Chronic Back Pain in The Space-Cohort

Background Knowledge about the impact of illness perceptions on Health-Related Quality of Life (HRQoL) in patients (pts) with axial Spondyloarthritis (axSpA) and other forms of chronic back pain (CBP) is lacking. Objectives To explore the association between illness perceptions and HRQoL in pts with short symptom duration of axSpA and other forms of CBP at baseline. Methods The Spondyloarthritis Caught Early (SPACE) study includes pts with CBP (≥3 months, ≤2 years, onset <45 years) recruited from 5 European centres. The Revised Illness Perception Questionnaire (IPQ-R) was completed at baseline. In the illness identity dimension, pts reported if they have experienced and believed that a certain symptom is CBP related. Other illness perceptions and causal dimensions used 5-point Likert scales (1 strongly disagree, 5 strongly agree). HRQoL was assessed by 36-item Short-Form (SF-36). Scale scores ranged from 0 (worst) to 100 (best). Physical (PCS) and Mental Component Summary (MCS) scores were calculated. Univariable regression models were built for each IPQ-R subscale as independent and PCS or MCS as dependent variable. The models were adjusted for age and gender and stratified in case of effect modification by gender (p<0.10). Results 315 pts were included; 123 fulfilled axSpA ASAS criteria and 192 did not fulfil the criteria. Mean age was 31.3 (SD 8.3) years, mean duration of CBP was 13.2 (SD 7.2) months and 36.5% was male. Mean PCS was 28.0 (SD 16.3) for axSpA pts and 24.9 (SD 14.4) for CBP. As the MCS was only slightly decreased compared to the general population (48.0 (SD 13.3) axSpA and 49.7 (SD 11.5) CBP pts), analyses focused on PCS. Pts reported a mean of 4.3 (axSpA) and 4.8 (CBP) symptoms to be associated with back pain. Most reported symptoms were pain and joint stiffness. All other subscales showed a mean of approximately 3, except psychological attributions, risk factors, immunity and accident (mean approximately 2). All pts attributed their complaints mostly to genetic factors. In both pts groups attribution of multiple symptoms to CBP (Figure 1;-1.8 axSpA, -2.1 CBP) was associated with lower PCS. However more dimensions showed association with PCS in axSpA (8) than CBP pts (6). In male axSpA pts belief in severe consequences (-12.1), more negative emotions towards their complaints (-9.3), and stronger belief of psychological attributions as a cause (-8.8) were associated with lower PCS. Whereas in male CBP pts stronger belief in risk factors (-8.1) and immunity as a cause (-10.0) were associated with lower PCS. More illness coherence was associated with higher PCS in male axSpA (6.2) and all CBP pts (2.8). In women consequences (-6.3, axSpA) and strong emotional representations (-4.0, CBP) were statistically significant. No gender differences were found for risk factors (-6.0) or immunity (-5.7) in axSpA and consequences (-7.9) in CBP pts. Conclusions Negative illness perceptions are associated with lower PCS of HRQoL in pts with axSpA and other forms of CBP. The impact of negative illness perceptions on PCS was more pronounced in men than in women. Disclosure of Interest None declared

AB1096 Local Radiologists Score More Abnormalities in Comparison to Central Readers Leading to More Patients Fulfilling the Classification Criteria of Axial Spa: Data from the Space-Cohort

Background The interpretation of findings on MRI and radiographs of the sacroiliac joints (MRI-SI and X-SI respectively) is known to vary amongst radiologists and trained readers as recently shown in the DESIR-cohort in France1. Since imaging is used in the ASAS axial spondyloarthritis (axSpA) criteria for the classification of patients, different findings can result in a different SpA classification. Objectives To objectify if classification (ASAS axSpA criteria) of patients (pts) in the SPACE-cohort differed based on evaluation of MRI-SI and X-SI by radiologists (local evaluation) and two blinded readers (central reading). Methods The SpondyloArthritis Caught Early (SPACE)-cohort includes pts with chronic back pain (≥3 months, ≤2 years, onset <45 years) visiting the rheumatology outpatient clinics of five participating centres in the Netherlands, Norway and Italy. Local radiologists provided information on bone marrow oedema compatible with sacroiliitis and signs of radiographic sacroiliitis compatible with axSpA without formal scoring. MRI-SI were scored by the central readers according to the ASAS definition and X-SI were scored according to the mNY criteria. In case of disagreement, an experienced reader served as adjudicator. MRI-SI and X-SI were considered positive if 2/3 readers agreed. Pts were classified according to the ASAS axSpA criteria using the scores of local evaluation and again using the scores of central reading. Results In total, 143/395 pts (36.2%) fulfilled the ASAS axSpA criteria based on central reading and 170/395 pts (43,0%) based on local evaluation. MRI-SI was rated discordant in 34 pts (8.4%) and concordant in 27 pts (6.8%); these figures were 19 pts (4.8%) and 12 pts (3.0%) for X-SI. In 43 pts (10.9%) a different reading resulted in a different rating of presence of axSpA; 35 pts (8.9%) classified no SpA by central reading were identified as axSpA by local evaluation; 8 pts (2.0%) classified axSpA by central reading were no SpA by local evaluation. Furthermore, discrepancies were observed when interested in whether pts fulfilled the imaging and clinical arm within the ASAS axSpA criteria (see table). Twenty-two pts (5.6%) fulfilled the imaging arm by local evaluation, but fulfilled the clinical arm only based on central reading. In contrast only 4 pts (1.0%), who fulfilled only the clinical arm based on local evaluation, were reclassified into the imaging arm by central reading. Conclusions In pts with chronic back pain 10.9% of pts were classified differently based on scores of trained central readers and local evaluation of radiologists. This was due to difference in reading in both MRI-SI and X-SI. However, in a greater proportion of pts the classification did not change even with discrepant reading because of the clinical arm of the ASAS classification criteria. References van den Berg. Ann Rheum Dis 2014. Disclosure of Interest None declared

SAT0262 Should Imaging of the SI Joints be Repeated After 1 Year? Impact on the Classification of Patients According to the ASAS Axial SPA Criteria

Background It is known that in axial spondyloarthritis (axSpA) inflammatory lesions on MRI of the SI joints (MRI-SI) can change over time. The usefulness of repeating imaging in the diagnostic process is unclear. Objectives To investigate how patients with short-term chronic back pain are classified by the ASAS axSpA- criteria at baseline and after 1-year follow-up, focussing on the role of imaging. Methods Patients in the SPACE-cohort (back pain: ≥3 months, ≤2 years, onset <45 years) with (suspicion of) axSpA underwent MRI and X-rays of the SI-joints at baseline and 1-year follow-up. Patients with complete MRI- and X-SI data at both timepoints were included in the analysis (n=185). MRI-SI and X-SI were scored by 3 different well-calibrated readers independently according to the ASAS-definition for a positive MRI and the mNY-criteria, blinded for patient characteristics and time sequence. Fulfillment of ASAS-MRI or mNY-criteria was considered positive if 2/3 readers agreed. At each timepoint, patients were classified according the ASAS axSpA-criteria and grouped in the different arms (imaging arm: mNY+/- or MRI+/-; clinical arm, fulfilment of both arms and possible axSpA). At year one, in contrary to the normal application of the criteria, where a positive feature remains positive:we grouped patients according to the finding at that timepoint, ignoring previous imaging findings. Results At baseline, 92/185 patients (49.7%) fulfilled the ASAS criteria (clinical arm: 53; imaging arm: 15, both arms: 24) (table). At 1 year, 14 additional patients fulfilled the criteria (8 clinical arm; 5 imaging arm only; 1 both arms). After 1 year, in 12 patients MRI-SI became positive. As a result, 14/93 (15.1%) of the no SpA or possible SpA patients at baseline could be classified additionally as axSpA because of additional SpA features (n=8), a positive MRI (n=4) or sacroiliitis according to the mNY-criteria (n=2), On the other hand, MRI-SI became negative after 1 year in 12 other patients. Of these patients, 10 still fulfilled the ASAS criteria (clinical arm (n=7) or both arms (n=3)). Only 4 patients (classified as axSpA at baseline) would be missed if imaging would have been performed only at 1 year (due to negative MRI or x-ray findings). Conclusions In our cohort, a signifcant number of patients with no SpA or possible SpA at baseline developed (additional) SpA features leading to fulfilment of axSpA criteria at year one. However, our data show the robustness of the axSpA criteria and there is only limited evidence for repeating imaging after one year. Disclosure of Interest None declared

SAT0589 Replacing Radiographic Sacroiliitis by Structural Lesions on MRI of the Sacroiliac Joints: Impact on the Classification of Patients According to the Asas Axial SPA Criteria

Background Conventional radiography is the most common used method to detect structural lesions in the sacroiliac joints (SIJ) in axial SpondyloArthritis (axSpA). However, reliability is a problem. Besides inflammatory lesions on MRI, which are used to define a positive MRI in the ASAS criteria, structural lesions are visible on MRI. Objectives To investigate the impact of replacement of x-rays by structural lesions on MRI on the ASAS axSpA classification of patients. Methods Patients in the SPACE cohort (chronic back pain: ≥3 months, ≤2 years, onset <45 years) with (suspicion of) axSpA underwent MRI and X-rays of the SIJs. Three well-calibrated readers, blinded for patient characteristics, read all available baseline MRI-SI (ASAS definition) and X-SI (mod New York). MRI-SI and X-SI were considered positive if 2/3 readers agreed. In addition, MRI T1-weighted images (viewed simultaneously with STIR) were assessed on the presence of structural lesions (in each of the quadrants of each SIJ). Lesions were marked present if 1 lesion was seen on ≥2 consecutive slices. Mean scores of 2 out of 3 agreeing readers (based on ASAS definition) were used. Earlier, we proposed cut-offs to define a positive MRI-SI based on structural lesions (MRI-SI-struct) based on <5% presence among no-SpA patients. These proposed cut-offs are: erosions ≥3, fatty lesions ≥3, fat lesions and/or erosions ≥5. Patients were classified according to the ASAS axSpA-criteria and grouped in the different arms, using the various definitions of MRI-SI-struct instead of X-SI. Results For this analysis 294 patients with complete imaging data were included. Using the cut-off for fatty lesions and/or erosions ≥5, classification did not change in 275+3+8 (286) patients (97.3%) (table). In the remaining 8 patients, 5 patients (1.7%) would not be classified axSpA if only MRI-SI-struct was performed, while 3 patients (1.0%) would be additionally classified as axSpA. Furthermore, an additional 8 patients would be classified by different arms. Very similar results were found when replacing X-rays by the definition of a positive MRI-SI-struct for the presence of fatty lesions or erosions alone (both cut-off of >3), and for the scores of the 2 readers individually. Conclusions The replacement of x-rays by assessment of structural lesions on MRI does not lead to a different ASAS axSpA classification in the majority of the patients;. These data are promising, however, this is in a cohort of patients with a relatively low number of patients fulfilling the axSpA criteria and in the early phases of the disease. Therefore these data need to be confirmed in patients with established disease. Disclosure of Interest None declared

FRI0554 Young Patients with Back Pain and Maximally 1 Spondyloarthritis Feature: Is it Necessary to Test HLA-B27 or Image the Sacroiliac Joints?

Background Axial SpondyloArthritis (axSpA) is a heterogeneous disease. The likelihood of diagnosis varies depending upon the presence of the specific SpA-features. It is debated whether additional examinations (i.e. HLA-B27 testing and imaging of the sacroiliac joints (SIJ)) should be performed in patients with a low suspicion of axSpA (0-1 present SpA-features) after clinical examination, physical examination, CRP/ESR measurement. Objectives To investigate if HLA-B27 testing and imaging of the SIJ is useful in young patients with back pain and maximally 1 SpA feature. Methods The SPACE cohort includes patients with chronic back pain (CBP; ≥3 months ≤2 years, onset <45 years) recruited from 5 participating centres across Europe. All patients underwent full diagnostic work-up: MRI and x-rays SIJ, HLA-B27 testing and assessment of all other SpA-features. Patients were classified according to the ASAS axSpA-criteria and according to the clinical rheumatologist diagnosis. Results In this analysis, 133 patients were included. Of the 38/133 (28.6%) patients without SpA-features; 4/38 (10.5%) were classified according to the ASAS-axSpA criteria after additional investigations (table). Three of them were also diagnosed as axSpA by the rheumatologist. Four additional patients were diagnosed axSpA but did not fulfil the ASAS axSpA criteria. Of the 95/133 (71.4%) patients with 1 SpA-feature; 22/95 (23.2%) patients fulfilled the ASAS criteria via the imaging arm. SpA features in these patients were: 7 IBP, 5 IBD, 4 positive family history for SpA, 3 good response to NSAIDs, 2 raised CRP/ESR, 1 enthesitis. Seventeen of these 22 patients were also diagnosed as axSpA by the rheumatologist. Six additional patients were diagnosed axSpA but did not fulfil the ASAS axSpA criteria. Conclusions In patients with CBP and maximally 1 SpA feature after medical history, physical examination and CRP/ESR measurement, subsequent HLA-B27 testing and imaging led to fulfilment of the ASAS axSpA-criteria in 11% and 23%, respectively. In addition axSpA was the clinical diagnosis in almost twenty percent of this group. Therefore, in patients with maximally 1 SpA feature, axSpA cannot be ruled out without additional imaging and/or HLA-B27 testing. Disclosure of Interest None declared