2019 Update of the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis

OBJECTIVE

To update evidence-based recommendations for the treatment of patients with ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (SpA).

METHODS

We conducted updated systematic literature reviews for 20 clinical questions on pharmacologic treatment addressed in the 2015 guidelines, and for 26 new questions on pharmacologic treatment, treat-to-target strategy, and use of imaging. New questions addressed the use of secukinumab, ixekizumab, tofacitinib, tumor necrosis factor inhibitor (TNFi) biosimilars, and biologic tapering/discontinuation, among others. We used the Grading of Recommendations, Assessment, Development and Evaluation methodology to assess the quality of evidence and formulate recommendations and required at least 70% agreement among the voting panel.

RESULTS

Recommendations for AS and nonradiographic axial SpA are similar. TNFi are recommended over secukinumab or ixekizumab as the first biologic to be used. Secukinumab or ixekizumab is recommended over the use of a second TNFi in patients with primary nonresponse to the first TNFi. TNFi, secukinumab, and ixekizumab are favored over tofacitinib. Co-administration of low-dose methotrexate with TNFi is not recommended, nor is a strict treat-to-target strategy or discontinuation or tapering of biologics in patients with stable disease. Sulfasalazine is recommended only for persistent peripheral arthritis when TNFi are contraindicated. For patients with unclear disease activity, spine or pelvis magnetic resonance imaging could aid assessment. Routine monitoring of radiographic changes with serial spine radiographs is not recommended.

CONCLUSION

These recommendations provide updated guidance regarding use of new medications and imaging of the axial skeleton in the management of AS and nonradiographic axial SpA.

Assessment of peripheral enthesitis in the spondylarthropathies by ultrasonography combined with power Doppler: a cross-sectional study

OBJECTIVE

To assess the prevalence and severity of peripheral enthesitis among the different subtypes of spondylarthropathy (SpA) by using ultrasonography (US) in B mode with power Doppler.

METHODS

One hundred sixty-four consecutive patients with SpA (according to the criteria of the European Spondylarthropathy Study Group) and 64 control patients (34 with mechanical low back pain [MBP] and 30 with rheumatoid arthritis [RA]) underwent US examination of major entheses of their limbs. Particular attention was given to the detection of vascularization at the following sites: cortical bone insertion of entheses, junction between tendon and entheses, body of tendon, and bursa.

RESULTS

Abnormal US findings consistent with at least one enthesitis were observed in 161 of 164 SpA patients (98%), affecting 1,131 of 2,952 entheses examined (38%). In contrast, only 132 of 1,152 entheses (11%) were found to be abnormal in 33 of 64 control patients (52%). US enthesitis was most commonly distributed in the distal portion of the lower limbs, irrespective of SpA subtype and of skeletal distribution of clinical symptoms. None of the abnormal entheses in control patients showed vascularization, compared with 916 of 1,131 abnormal entheses in SpA patients (81%), where it was always detected at the cortical bone insertion and sometimes also in the bursa. In SpA patients, the US pattern depended on the clinical presentation, with a higher prevalence of the most severe stages in those with peripheral forms.

CONCLUSION

US in B mode combined with power Doppler allowed the detection of peripheral enthesitis in a majority of SpA patients, but not in MBP or RA patients. The presence of entheseal involvement was independent of SpA subtype, but its degree of severity appeared to be greater in peripheral forms. US could be very useful for both the diagnosis and the assessment of SpA activity.

Ultrasonography of entheseal insertions in the lower limb in spondyloarthropathy

OBJECTIVE

To compare ultrasonography (US) with clinical examination in the detection of entheseal abnormality of the lower limb in patients with spondyloarthropathy (SpA).

METHODS

35 patients with SpA (ankylosing spondylitis 27; psoriatic arthritis 7; reactive arthritis 1) underwent independent clinical and ultrasonographic examination of both lower limbs at five entheseal sites-superior pole and inferior pole of patella, tibial tuberosity, Achilles tendon, and plantar aponeurosis. US was performed using an ATL (Advanced Technology Laboratories, Bothell, Washington, USA) high definition imaging 3000 machine with linear 7-4 MHz and compact linear 10-5 MHz probes to detect bursitis, structure thickness, bony erosion, and enthesophyte (bony spur). An enthesitis score was formulated from these US findings giving a possible maximum total score of 36.

RESULTS

On clinical examination 75/348 (22%) entheseal sites were abnormal and on US examination 195/348 (56%) sites were abnormal. In 19 entheseal sites with bursitis on US, only five were detected by clinical examination. Compared with US, clinical examination had a low sensitivity (22.6%) and moderate specificity (79.7%) for the detection of enthesitis of the lower limbs. There was no significant correlation between the US score of enthesitis and acute phase parameters such as erythrocyte sedimentation rate (ESR) or C reactive protein (CRP). The intraobserver kappa value for analysis of all sites was 0.9.

CONCLUSIONS

Most entheseal abnormality in SpA is not detected at clinical examination. US is better than clinical examination in the detection of entheseal abnormality of the lower limbs in SpA. A quantitative US score of lower limb enthesitis is proposed but further studies are required to validate it in SpA.

American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis

OBJECTIVE

To provide evidence-based recommendations for the treatment of patients with ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (SpA).

METHODS

A core group led the development of the recommendations, starting with the treatment questions. A literature review group conducted systematic literature reviews of studies that addressed 57 specific treatment questions, based on searches conducted in OVID Medline (1946-2014), PubMed (1966-2014), and the Cochrane Library. We assessed the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method. A separate voting group reviewed the evidence and voted on recommendations for each question using the GRADE framework.

RESULTS

In patients with active AS, the strong recommendations included use of nonsteroidal antiinflammatory drugs (NSAIDs), use of tumor necrosis factor inhibitors (TNFi) when activity persists despite NSAID treatment, not to use systemic glucocorticoids, use of physical therapy, and use of hip arthroplasty for patients with advanced hip arthritis. Among the conditional recommendations was that no particular TNFi was preferred except in patients with concomitant inflammatory bowel disease or recurrent iritis, in whom TNFi monoclonal antibodies should be used. In patients with active nonradiographic axial SpA despite treatment with NSAIDs, we conditionally recommend treatment with TNFi. Other recommendations for patients with nonradiographic axial SpA were based on indirect evidence and were the same as for patients with AS.

CONCLUSION

These recommendations provide guidance for the management of common clinical questions in AS and nonradiographic axial SpA. Additional research on optimal medication management over time, disease monitoring, and preventive care is needed to help establish best practices in these areas.

Effect of non-steroidal anti-inflammatory drugs on radiographic spinal progression in patients with axial spondyloarthritis: results from the German Spondyloarthritis Inception Cohort

OBJECTIVE

To investigate the influence of non-steroidal anti-inflammatory drugs (NSAIDs) intake on radiographic spinal progression over 2 years in patients with ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (SpA).

METHODS

164 patients with axial SpA (88 with AS and 76 with non-radiographic axial SpA) were selected for this analysis based on availability of spinal radiographs at baseline and after 2 years of follow-up and the data on NSAIDs intake. Spinal radiographs were scored by two trained readers in a concealed randomly selected order according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) system. An index of the NSAID intake counting both dose and duration of drug intake was calculated.

RESULTS

High NSAIDs intake (NSAID index≥50) in AS was associated with lower likelihood of significant radiographic progression defined as an mSASSS worsening by ≥2 units: OR=0.15, 95% CI 0.02 to 0.96, p=0.045 (adjusted for baseline structural damage, elevated C reactive protein (CRP) and smoking status) in comparison with patients with low NSAIDs intake (NSAID index<50). This effect was most pronounced in patients with baseline syndesmophytes plus elevated CRP: mean mSASSS progression was 4.36±4.53 in patients with low NSAIDs intake versus 0.14±1.80 with high intake, p=0.02. In non-radiographic axial SpA, no significant differences regarding radiographic progression between patients with high and low NSAIDs intake were found.

CONCLUSION

A high NSAIDs intake over 2 years is associated with retarded radiographic spinal progression in AS. In non-radiographic axial SpA this effect is less evident, probably due to a low grade of new bone formation in the spine at this stage.

Validity of enthesis ultrasound assessment in spondyloarthropathy

OBJECTIVES

To develop an ultrasound enthesis score and to assess its validity in the diagnostic classification of the spondyloarthropathies (SpAs).

METHODS

Twenty-five patients with SpA and 29 healthy controls participated in a blinded, gender-matched, cross-sectional study involving ultrasound assessment. The following entheses were explored bilaterally: proximal plantar fascia, distal Achilles tendon, distal and proximal patellar ligament, distal quadriceps and brachial triceps tendons. The ultrasound score evaluated enthesis thickness, structure, calcifications, erosions, bursae and power Doppler signal. The value of each elemental lesion was calculated using a three-model analysis. Validity was analysed by receiver operating characteristic (ROC) curves. Inter-reader and interexplorer intraclass correlation coefficients (ICCs) were calculated.

RESULTS

The logistic regression model overestimated the score of three elemental lesions: calcification (0-3), Doppler (0 or 3) and erosion (0 or 3), while scoring tendon structure, tendon thickness and bursa as 0 or 1. ROC curves established an ultrasound score of >or=18 as the best cut-off point for differentiation between cases and controls. This cut-off point was exceeded by 5/29 controls (17%) and by 21/25 patients with SpA (84%). The sensitivity, specificity, positive and negative likelihood ratios (LR+, LR-) were 83.3%, 82.8%, 4.8% and 0.2%, respectively. The inter-reader and interexplorer ICCs were 0.60 and 0.86, respectively.

CONCLUSION

The findings suggest that the ultrasound enthesis score could be a valid tool in the diagnosis of SpA.

Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study

OBJECTIVE

Radiographs of sacroiliac (SI) joints are used for the detection of structural damage in patients with axial spondyloarthritis (axSpA), but are often difficult to interpret. Here, we address the question how the T1-weighted MRI (T1w MRI) sequence compares with radiography for SI joints' structural lesions using low-dose CT as the standard of reference.

METHODS

Radiographs, T1w MRI and low-dose CT of the SI joints from 110 patients (mean age 36.1 (19-57) years, 52% males and 48% females; 53% with axSpA, 21 non-radiographic axSpA and 32% radiographic axSpA, 47% with non-SpA) referred to the rheumatologist because of unclear chronic back pain, but possible axSpA, were scored for structural lesions (erosions, sclerosis, joint space changes and an overall impression of positivity).

RESULTS

Using low-dose CT as the standard of reference, T1w MRI showed markedly better sensitivity with significantly more correct imaging findings compared with radiography for erosions (79% vs 42%; p=0.002), joint space changes (75% vs 41%; p=0.002) and overall positivity (85% vs 48%; p=0.001), respectively, while there were no differences between X-rays and MRI-T1 sequence regarding specificity (>80% for all scores). Only for sclerosis, MRI-T1 was inferior to radiography (sensitivity 30% vs 70%, respectively), however, not statistically significant (p=0.663).

CONCLUSIONS

T1w MRI was superior to radiography in the detection of structural lesion of the SI joints in patients with axSpA. Future studies should focus on finding an agreement on the definition of MRI-T1 positivity.

Impaired quality of life in adults with X-linked hypophosphatemia and skeletal symptoms

OBJECTIVE

Adults with X-linked hypophosphatemia (XLH) may suffer from skeletal symptoms leading to functional disability. No data on their quality of life (QoL) have been reported so far. Our objectives were to evaluate the QoL and its determinants in XLH adults.

PATIENTS AND METHODS

We conducted a prospective study in XLH adults, who consulted for musculoskeletal symptoms between 2013 and 2014. We assessed their QoL using HAQ, RAPID3 and SF36, and analysed the variables associated with low QoL. We compared their QoL to that of patients affected with axial spondyloarthritis (ax-SpA) (paired on age and gender), a rheumatologic disorder with a known low QoL.

RESULTS

Fifty-two XLH adults (37 women (71.1%); mean age 41.8±13.3 years) were included; 44 (84.6%) patients had an altered QoL. Increased age and presence of structural lesions were significantly associated with worse QoL (HAQ, RAPID3) (P<0.05). Presence of enthesopathies was significantly associated with worse RAPID3 (OR=4.45 (1.09-18.29), P=0.038). Treatment with phosphate supplements and vitamin D in XLH adults were significantly associated with a better SF36-mental component score (OR=0.14 (0.03-0.57), P=0.007 and OR=0.26 (0.07-0.98), P=0.047 respectively). QoL was significantly worse in XLH than in ax-SpA adults (VAS pain, SF36-PCS, RAPID3) (P<0.05).

CONCLUSION

Our study showed i) QoL of XLH adults is altered and significantly worse than that of ax-SpA patients (VAS pain, SF36-PCS and RAPID3), ii) structural lesions and especially enthesopathies are associated with a worse QoL and iii) treatment using phosphate supplements and/or vitamin D is associated with a better mental health score.

Clinical, radiographic and MRI findings of the temporomandibular joint in patients with different rheumatic diseases

The aim of this study was to investigate the condition of the temporomandibular joint (TMJ) in patients with different rheumatic diseases, and report correlations between the clinical, radiographic and magnetic resonance imaging (MRI) findings. The 67 patients were divided into four groups: 16 with rheumatoid arthritis (RA), 15 with mixed connective tissue disease (MCTD), 18 with ankylosing spondylitis (AS) and 18 with spondyloarthropathy (SPA). They were clinically examined, and panoramic tomography, lateral panoramic radiography and MRI of the TMJ were performed. MRI showed reduced articular cartilage in 25% (4/16) of RA, 0% (0/15) of MCTD, 17% (3/18) of AS and 17% (3/18) of SPA patients. Condylar changes included erosion, osteophytes and abnormal shape. Disc alterations included perforation, abnormal anterior position and decreased movement. These abnormalities were most frequent in RA patients, and least frequent in MCTD and SPA patients. Crepitation and reduced maximum opening of the mouth correlated with abnormalities of the disc and articular cartilage as shown by MRI. Severe condylar erosion in panoramic tomograms significantly correlated with MRI findings of condylar erosion (P<0.01), diminished thickness of condylar cartilage, abnormal condylar shape, and abnormal shape of the temporal surface of the TMJ (P< or =0.001). The presence of crepitation, limited mandibular movement and/or pain on movement of the jaw often indicated structural damage to the TMJ. Panoramic radiographs provide an alternative method to MRI but, to obtain a more detailed anatomic picture, MRI is recommended for patients with acute unexplained pain or as part of preoperative work up. A panoramic recording is not indicated when MRI is planned.

Imaging of articular disorders in children

This article reviews aspects of arthritis imaging that are specific to children. The pediatric skeleton is unique and responds in characteristic ways to articular inflammation. Epiphyseal and physeal cartilage are affected by joint diseases, and disturbances of growth and maturation are sometimes the cardinal manifestations of arthritis. The target joints of pediatric articular diseases differ considerably from those of diseases in adults. Imaging techniques should be tailored to the children being studied.

Reliability of high-resolution ultrasonography in the assessment of Achilles tendon enthesopathy in seronegative spondyloarthropathies

OBJECTIVE

The present study was mainly aimed at investigating the interobserver and intraobserver reproducibility of ultrasound (US) results in the assessment of Achilles tendon enthesopathy in patients with seronegative spondyloarthropathies (SpA).

METHODS

A total of 28 patients with a diagnosis of SpA according to the European Spondyloarthropathy Study Group criteria were included. The patient female/male ratio was 1.8 (18/10), mean age was 42 (range 25-75) years and mean disease duration was 9 (range 1-35) years. Mean (SD) Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores were 32.4 (14.5) and 26.3 (9.2), respectively. Bilateral Achilles tendon US examinations were carried out independently by three investigators using a MyLab70 XVG (Esaote Biomedica, Genoa, Italy), equipped with a broadband 6-18 MHz linear probe. Each Achilles tendon was scanned for assessing the presence/absence of US findings indicative of enthesopathy according to the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) preliminary definition. The same findings were also scored on a 3-grade semiquantitative scoring system on which investigators reached a consensus prior to the study. Total additive scores per Achilles tendon were calculated.

RESULTS

Moderate to excellent interobserver and intraobserver agreements were found for most of the US findings indicative of enthesopathy. Similar results were obtained using semiquantitative assessments, with weighted kappa values estimating the interobserver and intraobserver agreements for soft tissue inflammation of 0.696 and 0.816, respectively and for tissue damage 0.711 and 0.901, respectively.

CONCLUSION

US assessment of Achilles tendon enthesopathy in patients with SpA, using the OMERACT preliminary definition, was found to be reliable. Bone irregularity and entheseal hypoechogenicity were the most difficult abnormalities to reach agreement on.

Raised granzyme B levels are associated with erosions in patients with early rheumatoid factor positive rheumatoid arthritis

BACKGROUND

Raised granzyme B in serum and synovium of patients with rheumatoid arthritis suggests a role for cytotoxic T cells and natural killer cells in the pathogenesis of this disease.

OBJECTIVE

To evaluate serum granzyme B in patients with early arthritis and correlate it with specific diagnosis and clinical indices of disease severity.

METHODS

257 patients with inflammatory arthritis for less than one year (46% rheumatoid arthritis, 17% spondyloarthropathy, 37% undifferentiated arthritis) had a prospective clinical, serological, and radiographic evaluation. Granzyme B was measured in initial sera by ELISA. Patients were HLA typed for DR alleles using sequence specific primers. A logistic regression model was used to evaluate the potential prognostic value of serum granzyme B in predicting radiographic erosions after one year of follow up.

RESULTS

Granzyme B values were similar in rheumatoid arthritis, spondyloarthropathy, and undifferentiated arthritis. Concentrations were higher in rheumatoid factor (RF) positive patients than in RF negative patients (mean (SD): 3.15 (0.92) v 2.89 (0.71) pg/ml; p<0.05). After one year, erosions were present in 30% of patients in the overall cohort, and in 44% of patients with rheumatoid arthritis. In the entire cohort, serum granzyme B did not predict erosions independently. However, high granzyme B was an independent predictor of early erosions in patients with RF positive rheumatoid arthritis (odds ratio = 4.83 (95% confidence interval, 1.13 to 20.59)) (p<0.05).

CONCLUSIONS

Granzyme B may be a useful prognostic marker in early rheumatoid arthritis and may provide important clues to the pathogenesis of this disease.

Phenotypic diversity is not determined by independent genetic factors in familial spondylarthropathy

OBJECTIVE

To analyze the segregation of manifestations belonging to the spectrum of spondylarthropathy (SpA) among patients and unaffected siblings within SpA multiplex families.

METHODS

Ninety-five multiplex families have been investigated. The diagnosis of SpA was made according to European Spondylarthropathy Study Group criteria. The prevalence of SpA manifestations was determined in unaffected siblings and compared with their prevalence in patients.

RESULTS

We compared 241 SpA patients with 259 unaffected siblings. The prevalence of skeletal and extraarticular features not used as diagnostic criteria, i.e., radiographic sacroiliitis, peripheral enthesitis, uveitis, psoriasis, and inflammatory bowel disease, was significantly increased in patients compared with unaffected siblings. This result was not accounted for by sex or HLA-B27 distribution differences.

CONCLUSION

In familial SpA, skeletal and extraarticular manifestations tend to segregate together, implying that all subsets are predominantly determined by a shared component, and that accessory factors must be responsible for phenotype diversity.

Value of contrast-enhanced ultrasound in rheumatoid arthritis

The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

Segmental lumbar spine instability at flexion-extension radiography can be predicted by conventional radiography

AIM

To identify plain radiographic findings that predict segmental lumbar spine instability as shown by functional flexion-extension radiography.

MATERIALS AND METHODS

Plain radiographs and flexion-extension radiographs of 215 patients with clinically suspected lumbar spine instability were analysed. Instability was classified into anterior or posterior sliding instability. The registered plain radiographic findings were traction spur, spondylarthrosis, arthrosis of facet joints, disc degeneration, retrolisthesis, degenerative spondylolisthesis, spondylolytic spondylolisthesis and vacuum phenomena. Factors reaching statistical significance in univariate analyses (P < 0.05) were included in stepwise multiple logistic regression analysis.

RESULTS

Degenerative spondylolisthesis (P = 0.004 at L3-4 level and P = 0.017 at L4-5 level in univariate analysis and odds ratio 16.92 at L4-5 level in multiple logistic regression analyses) and spondylolytic spondylolisthesis (P = 0.003 at L5-S1 level in univariate analyses) were the strongest independent determinants of anterior sliding instability. Retrolisthesis (odds ratio 10.97), traction spur (odds ratio 4.45) and spondylarthrosis (odds ratio 3.20) at L3-4 level were statistically significant determinants of posterior sliding instability in multivariate analysis.

CONCLUSION

Sliding instability is strongly associated with various plain radiographic findings. In mechanical back pain, functional flexion-extension radiographs should be limited to situations when symptoms are not explained by findings of plain radiographs and/or when they are likely to alter therapy.

Ultrasound detection of entheseal insertions in the foot of patients with spondyloarthropathy

The aim of the study was to evaluate entheseal involvement in the foot of patients with spondyloarthropathy (SpA) by ultrasonographic (US) examination and compare the results with clinical and radiological findings. Forty-four patients (27 men, 17 women) with a diagnosis of SpA were recruited. Patient evaluation included physical examination (swelling and pain), Bath Ankylosing Spondylitis Radiological Index, Bath Ankylosing Spondylitis Disease Activity, Bath Ankylosing Spondylitis Metrological Index, and laboratory parameters (erythrocyte sedimentation rate, C-reactive protein). Foot x-rays of the patients were assessed and scored according to SpA Tarsal Radiographic Index (SpA-TRI). A high-resolution US was used to examine the tendon and ligament insertion sites in the foot, and the findings were scored according to Glasgow Ultrasound Enthesitis Scoring System (GUESS). The mean age and disease duration of the patients were 39.9+/-12.5 and 9+/-8.2 years, respectively. US revealed pathological findings in 25 of 44 (56.8%) patients, most of whom exhibited no clinical signs of foot involvement. Pain and swelling at entheseal insertions were detected in only 16 (37%) patients. The mean GUESS score and SpA-TRI score were 2.2+/-2.5 and 3.3+/-3.7, respectively. There was a correlation between the scores of GUESS and SpA-TRI, particularly at the Achilles and plantar fascia insertion sites. The mean score of SpA-TRI was higher in patients with enthesopathy, detected by US, than in patients without enthesopathy (4.6+/-4.4 vs 1.8+/-2.1). There was no significant correlation between the mean GUESS score and clinical and laboratory variables. In conclusion, involvement of tendon and entheses is not rare, and US is a valuable diagnostic method in detecting subclinical enthesopathic changes. The GUESS and SpA-TRI are suggested in quantifying US and radiological changes in the foot of patients with SpA.

Similarities and differences in fluorodeoxyglucose positron emission tomography/computed tomography findings in spondyloarthropathy, polymyalgia rheumatica and rheumatoid arthritis

OBJECTIVES

We assessed fluorine-18 ((18)F)-labelled fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) findings in patients with seronegative spondyloarthritis (SpA), polymyalgia rheumatica (PMR), and rheumatoid arthritis (RA).

METHODS

We studied 53 patients with SpA (n=21), PMR (n=16), or RA (n=16) admitted to our hospital between 2006 and 2011. Disease activity in the ischial tuberosities, greater trochanters, spinous processes, vertebral bodies, and sacroiliac joints (SIJ) were evaluated by determining FDG accumulation using maximum standardized uptake values (SUV(max)) and FDG scores.

RESULTS

SUV(max) for ischial tuberosities was significantly higher in PMR than SpA or RA. SUV(max) for greater trochanters and spinous processes was significantly higher in PMR than RA (P<0.001) and significantly higher in SpA than in PMR or RA for SIJ (P=0.01). No significant difference in vertebral scores was observed among groups (P=0.488). FDG scores yielded similar results. X-ray findings were consistent with PET/CT findings in 3/15 (20%) patients with sacroiliitis, whereas magnetic resonance imaging findings were consistent with PET/CT findings in 4/7 (57.1%) patients.

CONCLUSIONS

PET/CT detection of inflammation in the ischial tuberosities, greater trochanters, and spinous processes discriminated between PMR and RA, but not between SpA and PMR. PET/CT findings can distinguish SpA from RA and PMR and are useful for the early diagnosis of sacroiliitis.

Performance of the ASAS classification criteria for axial and peripheral spondyloarthritis: a systematic literature review and meta-analysis

OBJECTIVE

To summarise the evidence on the performance of the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) (also imaging and clinical arm separately), peripheral (p)SpA and the entire set, when tested against the rheumatologist's diagnosis ('reference standard').

METHODS

A systematic literature review was performed to identify eligible studies. Raw data on SpA diagnosis and classification were extracted or, if necessary, obtained from the authors of the selected publications. A meta-analysis was performed to obtain pooled estimates for sensitivity, specificity, positive and negative likelihood ratios, by fitting random effects models.

RESULTS

Nine papers fulfilled the inclusion criteria (N=5739 patients). The entire set of the ASAS SpA criteria yielded a high pooled sensitivity (73%) and specificity (88%). Similarly, good results were found for the axSpA criteria (sensitivity: 82%; specificity: 88%). Splitting the axSpA criteria in 'imaging arm only' and 'clinical arm only' resulted in much lower sensitivity (30% and 23% respectively), but very high specificity was retained (97% and 94% respectively). The pSpA criteria were less often tested than the axSpA criteria and showed a similarly high pooled specificity (87%) but lower sensitivity (63%).

CONCLUSIONS

Accumulated evidence from studies with more than 5500 patients confirms the good performance of the various ASAS SpA criteria as tested against the rheumatologist's diagnosis.

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.

Evaluation of technetium-99m-ciprofloxacin (Infecton) for detecting sites of inflammation in arthritis

OBJECTIVE

To study the frequency of technetium-99m-positive ciprofloxacin scans (Infecton scintigraphy) thought to be specific for bacterial DNA in patients with arthritis and to assess the clinical relevance of positive scans.

METHODS

Four groups of adults with arthritis were studied. Group 1: 53 patients with inflammatory arthritis, 36 with spondylarthropathy (SpA) and 17 with rheumatoid arthritis (RA); group 2: five patients with crystal arthropathy; group 3: those patients with osteoarthritis (OA) of the knee, wrist or spine; and group 4: 28 patients who had no arthritis but were being investigated for renal infection. Patients were injected with 10 mCi 99Tcm-ciprofloxacin with isotope uptake analysis at 4 h. Clinically swollen joints were assessed by a rheumatologist and the positive scans assessed by a physician in nuclear medicine.

RESULTS

Increased Infecton uptake was noted in inflamed joints independent of the pathology. It was seen in 10 of 17 patients with SpA, 12 of 17 with RA, all five with crystal arthropathy, eight with knee OA, two with wrist OA, none with spinal OA and none in uninflamed joints. A close correlation between clinically swollen joints and articular Infecton uptake was noted (P = 0.0003), with the uptake being in the distribution of the synovial perimeter. Additional uptake was noted in the abdomen (n = 9) and pulmonary region (n = 2) of SpA patients.

CONCLUSION

The Infecton scan is not specific for infection but may be a reliable procedure for identifying the presence and distribution of the inflammation within joints. It has the potential for monitoring the response of inflamed joints to treatment.

Imaging of the seronegative spondyloarthropathies

The group of seronegative spondyloarthropathies consists of ankylosing spondylitis, psoriatic arthritis, Reiter's disease, enteropathic spondylitis, and a fifth entity known as undifferentiated spondyloarthropathy. All of these diseases share common clinical and radiographic features with characteristic involvement of the sacroiliac joints, spine, and to various degrees, the peripheral joints. Although plain radiographs are the first line of imaging investigation, they are often insensitive for demonstrating the early changes of sacroiliitis, an important feature for establishing the early diagnosis of seronegative spondyloarthropathy. Other imaging modalities, including conventional tomography, bone scintigraphy, and computed tomography, have improved visualization of inflammatory changes at the sacroiliac joints. This article will review these modalities and emphasize the role of magnetic resonance imaging. By directly imaging changes in the synovium, articular cartilage, and subchondral bone, findings on magnetic resonance imaging are the most sensitive and specific for sacroiliitis and other changes in the axial skeleton. Its role and that of ultrasound in the assessment of the peripheral joints will also be highlighted.

ASAS definition for sacroiliitis on MRI in SpA: applicable to children?

BACKGROUND

The Assessment of Spondyloarthritis International Society (ASAS) definition for a 'positive' Magnetic Resonance Imaging (MRI) for sacroiliitis is well studied and validated in adults, but studies about the value of this definition in children are lacking. The aim of this study is to evaluate whether the adult ASAS definition of a positive MRI of the sacroiliac joints can be applied to children with a clinical suspicion of Juvenile Spondyloarthritis (JSpA).

METHODS

Two pediatric musculoskeletal radiologists blinded to clinical data independently retrospectively reviewed sacroiliac (SI) joint MRI in 109 children suspected of sacroiliitis. They recorded global impression (sacroiliitis yes/no) and whether the adult ASAS definition for sacroiliitis was met at each joint. This was compared to gold-standard clinical diagnosis of JSpA. Additionally, MRI were scored according to'adapted' ASAS definitions including other features of sacroiliitis on MRI.

RESULTS

JSpA was diagnosed clinically in 47/109 (43%) patients. On MRI, sacroiliitis was diagnosed by global assessment in 30/109 patients, of whom 14 also fulfilled ASAS criteria. No patients with negative global assessment for sacroiliitis fulfilled ASAS criteria. Sensitivity (SN) for JSpA was higher for global assessment (SN = 49%) than for ASAS definition (SN = 26%), but the ASAS definition was more specific (SP = 97% vs. 89%). Modifying adult ASAS criteria to allow bone marrow edema (BME) lesions seen on only one slice, synovitis or capsulitis, increased SN to 36%, 32% and 32% respectively, only slightly lowering SP. Including structural lesions increased SN to 28%, but lowered specificity to 95%.

CONCLUSION

The adult ASAS definition for sacroiliitis has low sensitivity in children. A pediatric-specific definition of MRI-positive sacroiliitis including BME lesions visible on one slice only, synovitis and/or capsulitis may improve diagnostic utility, and increase relevance of MRI in pediatric rheumatology practice.

Validation of ultrasound imaging for Achilles entheseal fibrocartilage in bovines and description of changes in humans with spondyloarthritis

BACKGROUND

Entheseal fibrocartilage (EF) derangement is hypothesised to be pivotal to the pathogenesis of spondyloarthritis. Ultrasound is useful for visualisation of the enthesis but its role in EF visualisation is uncertain. This work aimed to demonstrate face and content validity of ultrasound for EF visualisation both by bovine histological evaluation and EF imaging in spondyloarthritis.

METHODS

Achilles enthesis of 18 bovine hindfeet was visualised using a MyLab 70 ultrasound machine. The presence of tissue with EF characteristics was documented and histological confirmation was performed on five randomly selected sections using Masson trichrome staining. Ultrasound of the Achilles tendon (AT) was performed in 19 patients with spondyloarthritis and 21 healthy controls (HC).

RESULTS

The bovine EF could be visualised in all cases and seen as a thin, uncompressible, well-defined, anechoic layer between the hyperechoic bone and the hyperechoic fibrils of the enthesis both in longitudinal and transverse scans. This region corresponded to EF on histological examination. The same pattern of low signal corresponding to EF location was seen in 17/19 patients and all HC. Discontinuities of the anechoic layer around the erosions and enthesophytes were observed in the spondyloarthritis group. The thickness of the anechoic layer was not significantly different in spondyloarthritis and HC (0.5 ± 0.1 vs 0.5 ± 0.2 mm, p=0.9) whereas the thickness of the EF was greater in men (0.6 ± 0.2 vs 0.5 ± 0.1 mm; p=0.009) compared with women.

CONCLUSION

Ultrasound can visualise EF of the AT insertion, which can be abnormal in cases of spondyloarthritis. This has implications for a better understanding of enthesopathy.

Sensitivity and Specificity of Autoantibodies Against CD74 in Nonradiographic Axial Spondyloarthritis

OBJECTIVE

Autoantibodies against CD74 (anti-CD74) are associated with ankylosing spondylitis (AS). The present multicenter study, the International Spondyloarthritis Autoantibody (InterSpA) trial, was undertaken to compare the sensitivity and specificity of anti-CD74 and HLA-B27 in identifying patients with nonradiographic axial spondyloarthritis (axSpA).

METHODS

Patients ages 18-45 years with inflammatory back pain of ≤2 years' duration and a clinical suspicion of axSpA were recruited. HLA-B27 genotyping and magnetic resonance imaging of sacroiliac joints were performed in all patients. One hundred forty-nine patients with chronic inflammatory back pain (IBP) not caused by axSpA served as controls, and additional controls included 50 AS patients and 100 blood donors whose specimens were analyzed.

RESULTS

One hundred patients with inflammatory back pain received a diagnosis of nonradiographic axSpA from the investigators and fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criteria. The mean age was 29 years, and the mean symptom duration was 12.5 months. The sensitivity of IgA anti-CD74 and IgG anti-CD74 for identifying the 100 axSpA patients was 47% and 17%, respectively. The specificity of both IgA anti-CD74 and IgG anti-CD74 was 95.3%. The sensitivity of HLA-B27 was 81%. The positive likelihood ratios were 10.0 (IgA anti-CD74), 3.6 (IgG anti-CD74), and 8.1 (HLA-B27). Assuming a 5% pretest probability of axSpA in chronic back pain patients, the posttest probability, after consideration of the respective positive test results, was 33.3% for IgA anti-CD74, 15.3% for IgG anti-CD74, and 28.8% for HLA-B27. A combination of IgA anti-CD74 and HLA-B27 results in a posttest probability of 80.2%.

CONCLUSION

IgA anti-CD74 may be a useful tool for identifying axSpA. The diagnostic value of the test in daily practice requires further confirmation.