Do the radiological changes of classic ankylosing spondylitis differ from the changes found in the spondylitis associated with inflammatory bowel disease, psoriasis, and reactive arthritis?

Disease-specific definitions of new bone formation on spine radiographs: a systematic literature review

Objectives

We aimed to explore the radiographic definitions of types of New Bone formation (NBF) by focusing on the terminology, description and location of the findings.

Methods

Three systematic literature reviews were conducted in parallel to identify the radiographic spinal NBF definitions for spondyloarthritis (SpA), Diffuse Idiopathic Skeletal Hyperostosis (DISH) and Osteorathritis (OA). Study characteristics and definitions were extracted independently by two reviewers. Definitions were analysed and collated based on whether they were unique, modified or established from previous research.

Results

We identified 33 studies that indicated a definition for the NBF in SpA, 10 for DISH and 7 for spinal OA. In SpA, the variations in syndesmophytes included the description as well as the subtypes and locations. The differentiation of syndesmophytes from osteophytes were included in 12 articles, based on the origin and the angle of the NBF and associated findings. The definitions of DISH varied in the number of vertebrae, level and laterality. For OA, five articles indicated that osteophytes arose from the anterior or lateral aspects of the vertebral bodies, and two studies required a size cut-off.

Discussion

Our ultimate aim is to create formal NBF definitions for SpA, DISH and OA guided by an atlas, through a Delphi exercise with international experts. The improved ability to differentiate these conditions radiographically will not only allow the clinicians to accurately approach patients but also will help the researchers to better classify patient phenotypes and focus on accurate radiographic outcomes.

Exploring radiographic patterns of the cervical spine, including zygapophyseal joints, in axial spondyloarthritis

INTRODUCTION

The assessment of the cervical spine (CS) in axial spondyloarthritis (axSpA) and its radiographic characteristics, including the zygapophyseal joints (ZJ), may be helpful for an accurate diagnosis, establishing a prognosis and enhancing treatment decisions.

OBJECTIVES

To describe the prevalence and characteristics of CS involvement in patients with axSpA and perform a comparison between groups according to cervical radiographic damage.

METHODS

Patients who fulfilled the Assessment of SpondyloArthritis International Society classification criteria were included from January 2011 to January 2021. Sociodemographic, clinical, radiographic and treatment variables were gathered. Patients were categorised into 'CS group' (Bath Ankylosing Spondylitis Radiology Index ≥2 or De Vlam score ≥3 for ZJ) and 'no CS group' as controls. ZJ fusion and interobserver reliability in ZJ scoring were analysed.

RESULTS

A total of 340 patients were included, 244 (71.7%) men, with mean age 57±15 years. CS involvement was observed in 181 (53.2%) patients. Patients in the CS group, as compared with no CS group, were predominantly men, older, had a higher body mass index, higher prevalence of smoking, showed higher disease activity, worse functionality and mobility, as well as more structural damage. Sixty-nine patients with CS involvement had ZJ fusion at some level. These patients showed worse mobility and more radiographic damage. Overall, ZJ involvement was observed in 99 patients (29.1%), 20 of whom did not present with vertebral body involvement.

CONCLUSION

Radiographic evaluation of CS is relevant in patients with axSpA and should be assessed routinely. Evaluation of the ZJ is particularly significant, as it is related to higher disease activity and worse function.

Disease characteristics, pathogenesis, and treatment controversies of axial psoriatic arthritis

Axial psoriatic arthritis (axPsA) has considerable overlap with axial spondyloarthritis (axSpA) but has some unique features that sometimes preclude classification into axSpA. It has some clinical and radiographic differences compared to axSpA. Imaging typically shows asymmetric syndesmophytes, mainly in the cervical spine, with less frequent sacroiliitis. It more commonly presents later in life and is associated with less severe inflammatory back pain than axSpA. The interleukin (IL) IL-23/IL-17 axis is central to the pathogenesis of both diseases. However, the response to therapies targeting these cytokines has been different. IL-23 inhibitors are ineffective in axSpA but may be effective in psoriatic arthritis (PsA). Recent post hoc analyses of clinical trial data with IL-23 inhibitors in PsA have raised the possibility of their efficacy in axPsA and need evaluation in future clinical trials. Moreover, there is a need for classification criteria for axPsA and better tools to assess therapeutic response.

Predominant ligament-centric soft-tissue involvement differentiates axial psoriatic arthritis from ankylosing spondylitis

Since the original description of spondyloarthritis 50 years ago, results have demonstrated similarities and differences between ankylosing spondylitis (AS) and axial psoriatic arthritis (PsA). HLA-B27 gene carriage in axial inflammation is linked to peri-fibrocartilaginous sacroiliac joint osteitis, as well as to spinal peri-entheseal osteitis, which is often extensive and which provides a crucial anatomical and immunological differentiation between the AS and PsA phenotypes. Specifically, HLA-B27-related diffuse bone marrow oedema (histologically an osteitis) and bone marrow fatty corners detected via magnetic resonance imaging, as well as radiographic changes such as sacroiliitis, vertebral squaring, corner erosions and Romanus lesions, all indicate initial bone phenotypes in HLA-B27+ axial disease. However, in much of PsA with axial involvement, enthesitis primarily manifests in ligamentous soft tissue as 'ligamentitis', with characteristic lesions that include para-syndesmophytes and sacroiliac joint bony sparing. Like axial PsA, diffuse idiopathic skeletal hyperostosis phenotypes, which can be indistinguishable from PsA, exhibit a thoracic and cervical spinal ligamentous soft-tissue tropism, clinically manifesting as syndesmophytosis that is soft-tissue-centric, including paravertebral soft-tissue ossification and sacroiliac soft-ligamentous ossification instead of joint-cavity fusion. The enthesis bone and soft tissues have radically different immune cell and stromal compositions, which probably underpins differential responses to immunomodulatory therapy, especially IL-23 inhibition.

Costovertebral and costotransverse joint involvement in spondyloarthritis

OBJECTIVES

Costovertebral (CV), costotransverse (CTr), sternoclavicular (SC), and manubriosternal (MS) joints are impacted in spondyloarthritis (SpA) patients; however, clinical aspects of these involvements require additional evaluation.

METHODS

A total of 281 SpA patients who had undergone chest computed tomography (CT) for any reason between 2010 and 2020 were included in the study. SpA patients were divided into three groups, ankylosing spondylitis (AS), non-radiographic axial SpA, and psoriatic arthritis. Thirty age- and sex-matched rheumatoid arthritis (RA) patients and 30 non-rheumatic disease individuals were selected for comparison. An experienced radiologist reviewed 24 CV, 20 CTr, 2 SC, and 1 MS joints from a thorax CT for each patient. All joints were classified as: normal (0); suspicious (1), mild (2), moderate (3), or severe (4).

RESULTS

Total CV and CTr joint scores differed between diseases (p < .001). Male AS patients had higher CV and CTr scores than female AS patients (male CV score: 52 [range 0-96] and CTr score: 22 [range 0-80]; female CV score: 20 [range 0-96] and CTr score: 12 [range 0-79]). Strong negative correlations were detected in AS patients between chest expansion and CV (r = -0.703 p = .007) and CTr (r = -0.763 p = .002) joint involvement; positive correlations between CV and CTr joints, and modified Stoke Ankylosing Spondylitis Spinal Score (p < .05); and no significant association for MS and SC joints.

CONCLUSIONS

CV and CTr joint involvement on thorax CT was more severe in AS and negatively affected chest expansion. The use of thorax CT scans performed for other indications in the examination of these joints may be advantageous for the early beginning of rehabilitation programs targeted at maintaining chest mobility.

Characterisation of patients with axial psoriatic arthritis and patients with axial spondyloarthritis and concomitant psoriasis in the SCQM registry

BACKGROUND

Within the spectrum of spondyloarthritides, axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) present with overlapping features. Axial involvement in PsA (axial PsA) is treated according to recommendations for axSpA, as specific studies in axial PsA are scarce. We compared characteristics of patients with axSpA (particularly of patients with axSpA and concomitant psoriasis (pso)) with those of patients with axial PsA.

METHODS

Patients with axSpA and PsA in the Swiss Clinical Quality Management (SCQM) registry were included if information on pso and axial involvement was available. Patients with AxSpA were stratified by axSpA with and without pso (axSpA±pso) and patients with PsA were stratified to axial PsA or strictly peripheral PsA.

RESULTS

Previous or current psoriasis was observed in 479/4489 patients with axSpA (10.7%). Of 2631 patients with PsA, 1153 (43.8%) presented with axial involvement (opinion of the treating rheumatologist). Compared with patients with axSpA+pso, patients with axial PsA were older at symptom onset and at inclusion in SCQM, were less frequently HLA-B27 positive, had back pain less frequently and a higher prevalence of dactylitis and peripheral arthritis. A positive family history of pso or PsA was more frequent in axial PsA, while a positive family history of axSpA was more frequent in patients with axSpA+pso. Disease activity, function and mobility were comparable in axSpA+pso versus axial PsA.

CONCLUSION

Patients with axial PsA differ from patients with axSpA+pso in important demographic and clinical characteristics, and genetically, but present with a comparable disease burden. Treatment studies specifically dedicated to axial PsA seem warranted.

Extent of axial damage in psoriatic arthritis and spondyloarthritis: comparative data from the BEPAS and (Be-)GIANT multicentre cohorts

BACKGROUND

To examine radiographic axial damage of the sacroiliac joints and spine in patients with psoriatic arthritis (PsA) and spondyloarthritis (SpA) in private and academic Belgian practices.

METHODS

Patients with PsA with clinical diagnosis of PsA and fulfilling the Classification Criteria for Psoriatic Arthritis from the prospective Belgian Epidemiological Psoriatic Arthritis Study and patients with SpA fulfilling the Assessment of SpondyloArthritis international Society classification criteria for SpA originate from the Ghent and BelGian Inflammatory Arthritis and spoNdylitis cohorTs were included in this study. Baseline pelvic and spinal radiographs were analysed by two calibrated readers. Blinded for the origin of the cohort or clinical data readers assessed the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and modified New York criteria on spinal and pelvic radiographs, respectively. Data were compared between both patient groups.

RESULTS

Of the 525 patients included (312 PsA and 213 SpA), most patients showed normal spinal radiographs: 87.5% of the patients with PsA and 92.0% of the patients with SpA. Patients with SpA with spinal damage show higher mSASSS than the patients with PsA (p<0.05). In patients with PsA, cervical spine is more often affected; 24/33 patients (72.7%) compared with lumbar spine 11/33 (33.3%). While in patients with SpA, syndesmophyte location was more evenly distributed; cervical 9/14 (64.3%) and lumbar 10/14 (71.4%).

CONCLUSION

Minimal radiographic spinal damage was observed in Belgian patients with PsA or SpA. Patients with SpA tend to have higher mSASSS values and more syndesmophytes compared with PsA. Syndesmophytes were more often located in the cervical spine of patients with PsA, while the location was equally distributed in axSpA.

Comparison of patients with axial PsA and patients with axSpA and concomitant psoriasis: an analysis of the German register RABBIT-SpA

BACKGROUND

Psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) show certain overlaps: A subset of patients with PsA can develop axial involvement (axial PsA, axPsA), while a subset of patients with axSpA presents with psoriasis (axSpA+pso). Treatment strategy for axPsA is mostly based on axSpA evidence.

OBJECTIVES

To compare demographic and disease-specific parameters of axPsA and axSpA+pso.

METHODS

RABBIT-SpA is a prospective longitudinal cohort study. AxPsA was defined based on (1) clinical judgement by rheumatologists; (2) imaging (sacroiliitis according to modified New York criteria in radiographs or signs of active inflammation in MRI or syndesmophytes/ankylosis in radiographs or signs of active inflammation in spine MRI). axSpA was stratified into axSpA+pso and axSpA without pso.

RESULTS

Psoriasis was documented in 181/1428 axSpA patients (13%). Of 1395 PsA patients, 359 (26%) showed axial involvement. 297 patients (21%) fulfilled the clinical definition and 196 (14%) the imaging definition of axial manifestation of PsA. AxSpA+pso differed from axPsA regardless whether clinical or imaging definition was used. axPsA patients were older, more often female and less often HLA-B27+. Peripheral manifestations were more often present in axPsA than in axSpA+pso, whereas uveitis and inflammatory bowel disease were more common in axSpA+pso. Burden of disease (patient global, pain, physician global) was similar among axPsA and axSpA+pso patients.

CONCLUSIONS

AxPsA differs from axSpA+pso in its clinical manifestations, irrespective of whether axPsA is defined clinically or by imaging. These findings support the hypothesis that axSpA and PsA with axial involvement are distinct entities, so extrapolation of treatment data from randomised controlled trials in axSpA should be performed with caution.

Management of Axial Disease in Patients With Psoriatic Arthritis: An Updated Literature Review Informing the 2021 GRAPPA Treatment Recommendations

OBJECTIVE

Axial involvement in patients with psoriatic arthritis (PsA) is a common subset of this condition, but a unanimous definition has yet to be established. It has been defined by using different criteria, ranging from the presence of at least unilateral grade 2 sacroiliitis to those used for ankylosing spondylitis (AS), or simply the presence of inflammatory low back pain (IBP). Our aim was to identify and evaluate the efficacy of therapeutic interventions for treatment of axial disease in PsA.

METHODS

This systematic review is an update of the axial PsA (axPsA) domain of the treatment recommendations project by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

RESULTS

The systematic review of the literature showed that new biologic and targeted synthetic disease-modifying antirheumatic drug classes, namely interleukin (IL)-17A and Janus kinase inhibitors, could be considered for the treatment of axPsA. This would be in addition to previously recommended treatments such as nonsteroidal antiinflammatory drugs, physiotherapy, simple analgesia, and tumor necrosis factor inhibitors. Conflicting evidence still remains regarding the use of IL-12/23 and IL-23 inhibitors.

CONCLUSION

Further studies are needed for a better understanding of the treatment of axPsA, as well as validated outcome measures.

Axial involvement in psoriatic arthritis

Among the variety of clinical manifestations of psoriatic arthritis (PsA) – including peripheral arthritis, dactylitis, enthesitis, and axial disease – spondylitis is the least studied. There is no generally accepted definition of axial PsA (axPsA), nor is there any common terminology or diagnostic criteria for it. In the rheumatology community, there is also no consensus regarding radiological and MRI assessment of axial involvement in PsA patients, while disease activity indexes and the therapeutic tactics are borrowed from those used in treating axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS). However, despite a range of similarities in immunopathogenetic mechanisms of axPsA and axSpA, there are also certain differences that may affect the treatment response in these patients. The aim of this review is the analysis of data on axial disease in PsA. The article discusses the genetic features, clinical presentations, imaging techniques, differential diagnostics and treatment options of axPsA.

Characterising the axial phenotype of psoriatic arthritis: a study comparing axial psoriatic arthritis and ankylosing spondylitis with psoriasis from the REGISPONSER registry

AIMS

To explore the clinical and radiographical characteristics of axial psoriatic arthritis (PsA) and to compare it with ankylosing spondylitis (AS) with psoriasis.

METHODS

Cross-sectional study from the national multicentre registry REGISPONSER where participants fulfilled the European Spondyloarthropathy Study Group spondyloarthritis criteria at entry. Clinical, laboratory and radiographical characteristics between patients classified as axial PsA and AS with psoriasis by their rheumatologist are compared according to HLA-B27 status.

RESULTS

Of 2367 patients on REGISPONSER, n=405 had PsA, of whom 27% (n=109) had axial involvement as per the treating rheumatologist. 30% (n=26/86) of axial PsA were HLA-B27 positive. In the AS group, 9% (127/1422) had a history of psoriasis and were more frequently male, with longer diagnostic delay and more anterior uveitis than those with axial PsA who had more peripheral involvement and nail disease. Patients with HLA-B27-negative axial PsA reported less inflammatory pain and structural damage compared with AS with psoriasis. By contrast, HLA-B27-positive axial PsA shared clinical characteristics similar to AS and psoriasis although with a lower BASRI score. In the multivariable analysis, patients with AS and psoriasis were independently associated with HLA-B27 positivity (OR 3.34, 95% CI 1.42 to 7.85) and lumbar structural damage scored by BASRI (OR 2.14, 95% CI 1.4 to 3.19).

CONCLUSION

The more prevalent axial PsA phenotype is predominantly HLA-B27 negative and presents different clinical and radiological manifestations when compared with AS with psoriasis. There is great heterogeneity in what rheumatologists consider axial PsA from a clinical and imaging perspective, highlighting the need for research into possible genetic drivers and a consensus definition.

Cardiovascular and disease-related features associated with extra-articular manifestations in axial spondyloarthritis. A multicenter study of 888 patients

OBJECTIVES

To determine the potential impact of extra-articular manifestations (EAMs) on disease characteristics and cardiovascular (CV) risk in patients with axial spondylarthritis (axSpA).

METHODS

This is a cross-sectional study from the AtheSpAin cohort, a Spanish multicenter cohort to study atherosclerosis in axSpA. Data on the history of CV events, subclinical carotid atherosclerosis, and disease-related features, including EAMs, were collected.

RESULTS

888 axSpA patients were recruited. Concomitant acute anterior uveitis (AAU), psoriasis (PSO), and inflammatory bowel disease (IBD) were present in 177 (19.9%), 96 (10.8%), and 57 (6.4%) patients, respectively. When compared with axSpA patients without EAMs, a significant increase in past CV events was observed in patients with PSO (9% versus 4%, p = 0.048) and in those with at least one EAM (7% versus 4%, p = 0.032) or with more than one EAM (11% versus 4%, p = 0.022). The frequency of carotid plaques and the values of cIMT were higher in patients with EAMs than in those without EAMs, although only the univariable analysis for carotid plaques in patients with PSO (39% versus 30%, p = 0.038) and for cIMT in patients with AAU (665 ± 156 µm versus 637 ± 139 µm, p = 0.042) and those with at least one EAM (661 ± 155 µm versus 637 ± 139 µm, p = 0.024) showed significant results. In addition, patients with PSO or IBD were found to have specific disease-related features, such as higher ESR at diagnosis, and more frequent use of glucocorticoids and TNF inhibitors than those without EAMs. Also, PSO patients had more commonly peripheral involvement and those with AAU more severe radiographic damage than those without EAMs. The frequency of HLA B27 was higher in patients with AAU and lower in those with PSO or IBD compared to those without EAMs.

CONCLUSION

Patients with axSpA and EAMs, in addition to displaying their own disease-related features, are likely to have an increased CV risk that appears proportional to the number of EAMs and could be related to proatherogenic factors other than traditional CV risk factors, such as the inflammatory load and the use of glucocorticoids.

Isolated axial disease in psoriatic arthritis and ankylosing spondylitis with psoriasis

OBJECTIVES

To compare isolated axial psoriatic arthritis (PsA), axial PsA with peripheral involvement and isolated axial ankylosing spondylitis (AS) with psoriasis. To evaluate predictors for developing peripheral disease from isolated axial PsA over time.

METHODS

Two PsA and AS cohorts identified patients with PsA with axial disease and isolated axial patients with AS with psoriasis. Logistic regression compared isolated axial PsA to axial PsA with peripheral involvement and isolated axial AS with psoriasis. Cox proportional hazards model evaluated predictors for developing peripheral disease from isolated axial PsA.

RESULTS

Of 1576 patients with PsA, 2.03% had isolated axial disease and 29.38% had axial and peripheral disease. human leucocyte antigen HLA-B*27 positivity (OR 25.00, 95% CI 3.03 to 206.11) and lower Health Assessment Questionnaire scores (OR 0.004, 95% CI 0.00 to 0.28) were associated with isolated axial disease. HLA-B*27 also predicted peripheral disease development over time (HR 7.54, 95% CI 1.79 to 31.77). Of 1688 patients with AS, 4.86% had isolated axial disease with psoriasis. Isolated axial patients with PsA were older at diagnosis (OR 1.06, 95% CI 1.01 to 1.13), more likely to have nail lesions (OR 12.37, 95% CI 2.22 to 69.07) and less likely to have inflammatory back pain (OR 0.12, 95% CI 0.02 to 0.61) compared with patients with isolated axial AS with psoriasis.

CONCLUSIONS

Isolated axial PsA and AS with psoriasis are uncommon. HLA-B*27 positivity is associated with isolated axial PsA and may identify those who develop peripheral disease over time. Isolated axial PsA is associated with better functional status. Isolated axial PsA appears clinically distinct from isolated axial AS with psoriasis.

Degenerative and Inflammatory Osteoproliferations in Lumbar Radiographs in Psoriatic Arthritis Patients

The aim of this study was to determine the distribution different types of osteoproliferative lesions on the lumbar spine and their relations in patients with psoriatic arthritis (PsA) under biologic-disease-modifying anti-rheumatic drug therapy. T12-S1 corners were evaluated in 182/274 (66.4%) patients with lumbar radiographs. Lesions were determined as osteophyte (grade 0–3), erosion, sclerosis, squaring, corner syndesmophyte, and bridging syndesmophyte. Lesions with no clear distinction were defined as ambiguous. The mean (SD) age of 182 PsA (69.2% female) patients was 47.6 years (12.7), the mean age at diagnosis of PsA was 39.7 years (12.7). Of the patients, 112 (61.5%) met the criteria for mNY. Osteophytes were the most frequently detected lesions (42.3%), with 18.1% of patients having osteophyte grade 2 and above (mostly on L2-L4). Syndesmophytes were present in 24.2% of all patients (mostly on T12-L4), and ambiguous lesions were detected in 13 (4.7%) patients. Changes were observed in five ambiguous lesions in patients with follow-up lumbar radiography, four of them transformed into corner syndesmophytes at follow-up, and one was evaluated as osteophyte grade 2. Approximately one fifth of patients presented with significant degenerative new bone formation, and syndesmophytes were found in one fourth. In approximately 7% of all patients, lesions were ambiguous. The nature of these lesions needs to be evaluated in further imaging studies.

Characterising axial psoriatic arthritis: correlation between whole spine MRI abnormalities and clinical, laboratory and radiographic findings

OBJECTIVE

To describe the prevalence of inflammatory and structural lesions using whole spine MRI in patients with psoriatic disease, and to assess their correlation with clinical features and with axial spondyloarthritis (axSpA) classification criteria.

METHODS

This retrospective analysis included patients with whole spine and sacroiliac joints (SIJ) MRI, selected from 2 populations: (1) active psoriatic arthritis (PsA), irrespective of axial symptoms; (2) psoriasis with confirmed or suspected PsA and axSpA symptoms. MRI spondylitis and/or sacroiliitis (MRI-SpA) was defined according to Assessment of Spondyloarthritis International Society (ASAS) consensus and by radiologist impression. Agreement between MRI-SpA and different inflammatory back pain (IBP) definitions (Berlin/ASAS/rheumatologist criteria) and the axSpA classification criteria were calculated considering MRI as gold standard. Logistic regression determined MRI-SpA-associated factors.

RESULTS

93 patients were analysed (69.9% PsA; 30.1% psoriasis). Back pain was present in 81.7%, defined as IBP in 36.6%-57%. MRI-SpA was found in 9.7% of patients by ASAS definition and in 12.9% by radiologist impression, of which 25% had isolated spondylitis.Low agreement was found between the three IBP definitions and MRI-SpA. Rheumatologist criteria was the most sensitive (50%-55.6%) while ASAS and Berlin criteria were the most specific (61.9%-63%). axSpA criteria had poor sensitivity for MRI-SpA (22.2%-25%). Late onset of back pain or asymptomatic patients accounted for most cases with MRI-SpA not meeting axSpA or IBP criteria. Male sex was associated with MRI-SpA (OR 6.91; 95% CI 1.42 to 33.59) in multivariable regression analysis.

CONCLUSION

Prevalence of MRI-defined axSpA was low and showed poor agreement with IBP and axSpA criteria.

Psoriatic Spondylitis: A Disease Manifestation in Debate: Evidences to Know for the Clinical Rheumatologist

ABSTRACT

With the advent of classification criteria for psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), patients with axial manifestations associated with psoriasis, initially described in the l950s as a specific entity termed psoriatic spondylitis (PS), are now categorized within PsA, ankylosing spondylitis (AS), and axSpA. Thus, different terms are used to describe axial disease in patients with PsA including PS, axial psoriatic arthritis (axPsA), and psoriatic spondyloarthritis. Patients with PS may present with inflammatory and/or mechanical back pain, but also may display axial disease on imaging despite not complaining of back pain. Cervical spondylitis has been reported in 35% to 75% of patients with PsA. Axial disease is silent in 20% and 25% of patients with axial PsA and PsA, respectively. The majority of axPsA patients have peripheral arthritis alongside the axial involvement, whereas only 2% to 5% of PsA patients have solely axial arthritis with no peripheral arthritis.A debate is currently underway as to whether inflammatory axial disease and psoriasis represent axSpA with psoriasis or a subset of PsA named axPsA. Studies have recognized that axial disease in PsA patients seems to be different demographically, genetically, clinically, and radiographically when compared with AS with or without psoriasis. This narrative review summarizes current knowledge regarding axial involvement of PsA in terms of history, terminology, classification, epidemiology, clinical presentation, imaging, diagnosis, and treatment, with the aim of providing advice for management of PS in clinical evidence-based practice. Data-driven studies are needed to develop clear, nonoverlapping classification criteria for spinal involvement in PsA.

New Perspectives on Diagnosing Psoriatic Arthritis by Imaging Techniques

Psoriatic arthritis is a chronic inflammatory condition that can lead to severe functional impairment and irreversible damage. The diagnosis can be difficult in early cases where the clinical exam is often scarce. The lack of a serological biomarker can lead to a considerable delay in diagnosis. In this review, we discuss the existent imaging methods that have improved the diagnosis of psoriatic arthritis (PsA). The degree and type of musculoskeletal involvement cannot be assessed by only one imaging method. We think that a combination of methods is the best approach to evaluate both structural damage and inflammatory lesions and that ultrasound (US) could be the best tool to screen a patient when considering the diagnosis of PsA. US is an accessible, non-ionizing technique that offers information regarding active inflammation in joints, entheses, and soft tissues.

Psoriasis and Imaging Progression in early Axial Spondyloarthritis: Results from a 48-month follow-up (Italian arm of SPACE study)

OBJECTIVES

To assess the influence of psoriasis on spinal/pelvic radiographic progression and magnetic resonance imaging (MRI) features in early-stage axial spondyloarthritis (axSpA).

METHODS

Analysis of baseline data from the Italian SPACE cohort, including patients with chronic-back-pain (CBP; duration ≥ 3 months and ≤2 years; onset <45 years) was performed. Patients underwent a diagnostic work-up, including MRI and X-rays of the sacroiliac joints (SIJ), to establish diagnosis of axSpA (ASAS criteria). Clinical features, disease activity and functional indices, imaging were collected at baseline and yearly during 48-months. Spinal and SIJ X-rays and MRIs were scored by 2 readers following SPARCC, mSASSS and mNY-criteria. Characteristics of axSpA patients with/without psoriasis were compared over-time with descriptive statistics; multivariate-logistic-regression model was constructed to assess predictors of spinal/pelvic radiographic progression.

RESULTS

88 patients had axSpA (84.1% non-radiographic; 15.9% radiographic); 36.4% had psoriasis. Patients with psoriasis were older; less frequently had HLA-B27+ and radiographic sacroiliitis with unilateral/asymmetric pattern and more signs of spondylitis. Functional and disease activity indices decreased with slightly higher BASDAI and BASFI in axSpA with psoriasis. All patients showed slight spinal/pelvic radiographic progression. Patients without psoriasis showed increased sacroiliitis progression and low-grade spinal progression. More inflammatory corner lesions on cervical/thoracic MRI-spine were observed in patients with psoriasis. Significant downtrend of SPARCC SIJ/spine scores in all patients was found. Psoriasis was a predictor of increased spinal progression (OR = 0.18; 95%CI : 0.04-0.78).

CONCLUSIONS

Psoriasis was associated with distinct axSpA features, increased spinal radiographic progression and low-grade radiographic sacroiliitis.

Reactive arthritis and undifferentiated peripheral spondyloarthritis share human leucocyte antigen B27 subtypes and serum and synovial fluid cytokine profiles

OBJECTIVES

Peripheral SpA (pSpA) is comprised of ReA, PsA, enteritis-associated arthritis and undifferentiated pSpA (upSpA). ReA and upSpA share T cell oligotypes and metabolomics in serum and SF. We investigated HLA-B27 subtypes and cytokines in serum and SF that were compared between ReA and upSpA.

METHODS

ReA and upSpA were compared in two cohorts. In cohort I (44 ReA and 56 upSpA), HLA-B27 subtyping was carried out. In cohort II (17 ReA and 21 upSpA), serum and SF cytokines were compared using a multiplex cytokine bead assay (27 cytokines). A total of 28 healthy controls with similar age and sex to cohort II were included for comparison of serum cytokine levels.

RESULTS

In cohort I, HLA-B27 was positive in 81.8% (36/44) of ReA and 85.71% (48/56) of upSpA patients. HLA-B27 typing was successful in 70 patients (30 ReA and 40 uSpA). HLA-B*2705 was the most common, followed by HLA-B*2704 and HLA-B*2707. Frequencies were the same between ReA and upSpA. In cohort II, 14 cytokines were detectable in the serum of patients. The levels of eight cytokines were higher than in the controls. The cytokine levels of ReA and upSpA were similar. Sixteen cytokines were detectable in the SF of patients. There was no statistical difference in the levels between ReA and upSpA. The cytokine profiles in sera and SF were also similar among HLA-B27-positive and negative patients.

CONCLUSION

ReA and upSpA have similar HLA-B27 subtype associations and similar cytokine profiles. They should be considered as a single entity during studies as well as clinical management.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study

OBJECTIVES

PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis.

METHODS

This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment.

RESULTS

Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis.

CONCLUSION

Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

Psoriatic arthritis

Psoriatic arthritis (PsA) is a complex inflammatory disease with heterogeneous clinical features, which complicates psoriasis in 30% of patients. There are no diagnostic criteria or tests available. Diagnosis is most commonly made by identifying inflammatory musculoskeletal features in joints, entheses or the spine in the presence of skin and/or nail psoriasis and in the usual absence of rheumatoid factor and anti-cyclic citrullinated peptide. The evolution of psoriasis to PsA may occur in stages, although the mechanisms are unclear. In many patients, there may be little or no relationship between severity of musculoskeletal inflammation and severity of skin or nail psoriasis. The reason for this disease heterogeneity may be explained by differences in genotype, especially in the HLA region. New targeted therapies for PsA have been approved with additional therapies in development. These developments have substantially improved both short-term and long-term outcomes including a reduction in musculoskeletal and skin manifestations and in radiographic damage. With efforts underway aimed at improving our understanding of the molecular basis for the heterogeneity of PsA, a personalized approach to treating PsA may become possible.

The transition from enthesis physiological responses in health to aberrant responses that underpin spondyloarthritis mechanisms

PURPOSE OF REVIEW

Despite immunology and translational therapeutics advances in inflammatory arthritis over the past two decades, the enthesis, which is the epicentric of the spondyloarthritis family pathological process, retains many mysteries because of tissue inaccessibility that hampers direct immune study. As entheses are subject to almost continuous mechanical stress and spondyloarthritis is linked to microdamage or injury and joint stress, it is cardinal to understand the physiological changes occurring within the entheses not only to be able to differentiate disease from health but also to understand the transition normal physiology break down and its merges into spondyloarthritis-related disease.

RECENT FINDINGS

Imaging has played a major role in understanding the enthesis in human. Remarkable insights from enthesis functioning and microdamage in normal and with ageing including those linked to body mass index is emerging. The impact of mechanical stress and degenerative conditions on the development of the secondary entheseal vascular changes is not understood. Of note, ultrasound studies in psoriasis have shown higher power Doppler changes compared to controls pointing towards a role for vascular changes in the development of enthesitis in psoriatic arthritis.

SUMMARY

The literature pertaining to normal entheses changes with age, microdamage and vascular changes in health is providing a roadmap for understanding of the enthesis and its potential role in evolution of spondyloarthritis including psoriatic arthritis.

Axial Psoriatic Disease: Clinical and Imaging Assessment of an Underdiagnosed Condition

The frequent involvement of the spine and sacroiliac joint has justified the classification of psoriatic arthritis (PsA) in the Spondyloarthritis group. Even if different classification criteria have been developed for PsA and Spondyloarthritis over the years, a well-defined distinction is still difficult. Although the majority of PsA patients present peripheral involvement, the axial involvement needs to be taken into account when considering disease management. Depending on the definition used, the prevalence of axial disease may vary from 25 to 70% in patients affected by PsA. To date, no consensus definition has been reached in the literature and the definition of axial involvement in PsA has varied from isolated sacroiliitis to criteria used in ankylosing spondylitis. This article reviews the unmet needs in the clinical and radiological assessment of axial PsA, reporting the various interpretations of axial involvement, which have changed over the years. Focusing on both imaging and clinical standpoints, we reported the prevalence of clinical and radiologic features, describing the characteristics of axial disease detectable by X-rays, magnetic resonance imaging, and PET-CT, and also describing the axial symptoms and outcome measures in patients affected by axial disease.

Axial involvement in psoriatic arthritis: An update for rheumatologists

Psoriatic arthritis (PsA) is a heterogenous, chronic, inflammatory musculoskeletal disease that can lead to peripheral and axial damage and loss of function. Axial involvement occurs in 25% to 70% of patients with PsA, varying greatly depending on its definition, with the key manifestations being sacroiliitis and/or spondylitis. However, there are no agreed-upon classification or diagnostic criteria for axial involvement in PsA and no consensus on treatment paradigms, which complicates management of PsA. There have only been a few studies assessing biologics in patients with PsA with axial involvement, and most treatment plans are based on evidence from patients with axial spondyloarthritis. Rheumatologists therefore face many challenges in the management of axial PsA, including diagnosis, differential diagnosis, and choice of appropriate treatment. In this review, we summarize the clinical presentation, imaging characteristics, differential diagnoses, treatment options, and prognosis of axial PsA, with the aim of increasing rheumatologists' knowledge of this phenotype of PsA and thereby aiding its optimal management.

Axial Disease in Psoriatic arthritis: The presence and progression of unilateral grade 2 sacroiliitis in a psoriatic arthritis cohort

BACKGROUND/PURPOSE

A universally accepted definition of axial psoriatic arthritis (axPsA) is lacking. We aimed to 1) assess the presence of axial involvement as defined by "at least unilateral grade 2 sacroiliitis (Uni2SI)" and 2) assess the radiographic progression of Uni2SI and identify risk factors for progression.

METHODS

PsA patients participating in a prospective observational cohort were classified according to their highest sacroiliitis grade. The baseline features of patients with Uni2SI were compared to patients meeting the radiographic criteria of the modified New York Ankylosing Spondylitis (mNY AS) criteria. Risk factors were examined for progression from Uni2SI in a sub-group of patients with >1 follow-up radiographs. Logistic regression and a survival analysis were carried out and identified risk factors associated with radiographic mNY AS compared to Uni2SI.

RESULTS

Axial disease defined as ≥Uni2SI was detected in 612/1354 patients (45%). mNY AS sacroiliitis was observed in 477 patients (35%). Radiographic progression of Uni2SI was assessed in 154 patients, 80 (52%) progressed to mNY AS criteria within 5.5 years. At baseline, progressors were diagnosed at a younger age (35.6 vs. 38.9, p = 0.05), had less degenerative disc disease (OR = 0.47, p = 0.02), worse peripheral radiographic damage (OR=1.02, p = 0.03) and worse psoriasis (OR = 1.09, p = 0.01) compared to non-progressors. Patients with an elevated erythrocyte sedimentation rate were more likely to progress (HR = 1.83, p = 0.02), while patients with longer disease duration were less likely to progress (HR = 0.95, p = 0.02).

CONCLUSION

The radiographic mNY AS criteria appear to be suitable for defining axial PsA according to radiographs. MRI definitions are needed as well for the most appropriate definition of axial PsA.

The burden of psoriatic arthritis in the biological era: data from the Belgian Epidemiological Psoriatic Arthritis Study (BEPAS)

OBJECTIVES

To characterize the frequency of PsA subtypes, as well as to estimate the severity based on damage and inflammation, and to estimate the impact of PsA on patients' health-related quality of life.

METHODS

Longitudinal observational study in 17 academic and non-academic centres in Belgium. Patients with PsA fulfilling CASPAR criteria were recruited. Three visits were scheduled: at baseline (T0), at one year (± one month) (T1) and at two years (± one month) (T2) of follow-up. Demographics, clinical data and patient reported outcome measures were collected at T0, T1 and T2. X-rays of hand and feet were collected yearly (T0, T1 and T2). X-rays of the spine were collected at T0 and T2. Here we report on the burden of disease based on the clinical data and patient reported outcomes.

RESULTS

461 patients were recruited. 73.5% have combined peripheral and axial involvement. 13.7% had hip involvement. Plaque psoriasis was predominant (83.9%). At inclusion respectively 42.7% and 58.8% had no tender or swollen joints. Dactylitis and enthesitis were still present in 13.7% and 24.1% of the patients respectively. 68% and 44,2% of patients was treated with DMARD's and/or anti TNF, respectively. Forty-three percent of the patients had a state of minimal disease activity and 62% considered the actual state as satisfactory (PASS). The mean HAQ score was 0.7% with 32.5% of patients who had score normal score (<0.3).

CONCLUSION

Despite the availability of different treatment options, including biologicals (anti-TNF), still a substantial number of patients have active disease and have a high disease burden.

Measurement properties of radiographic outcome measures in Psoriatic Arthritis: A systematic review from the GRAPPA-OMERACT initiative

BACKGROUND

Structural damage is as an important outcome in the Psoriatic Arthritis (PsA) Core Domain Set and its assessment is recommended at least once in the development of a new drug.

OBJECTIVES

To conduct a systematic review (SR) to identify studies addressing the measurement properties of radiographic outcome instruments for structural damage in PsA and appraise the evidence through the Outcome Measures in Rheumatology (OMERACT) Filter 2.1 Framework Instrument Selection Algorithm (OFISA).

METHODS

A SR was conducted using search strategies in EMBASE and MEDLINE to identify full-text English studies which aimed to develop or assess the measurement properties of radiographic outcome instruments in PsA. Determination of eligibility and data extraction was performed independently by two reviewers with input from a third to achieve consensus. Two reviewers assessed the methodology and results of eligible studies and synthesized the evidence using OMERACT methodology.

RESULTS

Twelve articles evaluating radiographic instruments were included. The articles assessed nine peripheral (hands, wrists and/or feet) and six axial (spinal and/or sacroiliac joints) radiographic instruments. The peripheral radiographic instruments with some evidence for reliability, cross-sectional construct validity and longitudinal construct validity were the Ratingen and modified Sharp van der Heijde scores. No instruments had evidence for clinical trial discrimination or thresholds of meaning. There was limited evidence for the measurement properties of all identified axial instruments.

CONCLUSION

There are significant knowledge gaps in the responsiveness of peripheral radiographic instruments. Axial radiographic instruments require further validation, and the need to generate novel instruments and utilise other imaging modalities should be considered.

The role of radiography in the study of spinal disorders

Despite the growing use of computed tomography (CT) and magnetic resonance imaging (MRI) in the study of spinal disorders, radiography still plays an important role in many conditions affecting the spine. However, the study and interpretation of spine radiograph is receiving less attention and radiologists are increasingly unfamiliar with the typical findings in normal and pathologic conditions of the spine. The aim of this article is to review the radiologic indications of radiograph in different pathologic conditions that affect the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumour disorders, as well as their main radiographic manifestations.

Is axial psoriatic arthritis distinct from ankylosing spondylitis with and without concomitant psoriasis?

OBJECTIVE

The aim of this study was to compare patients with ankylosing spondylitis with psoriasis (ASP) and without psoriasis (AS), to axial PsA (axPsA) patients.

METHODS

Two adult cohorts were recruited from the AS clinic: ASP and AS. These two cohorts were compared with two adult cohorts recruited from the PsA clinic: axPsA (radiographic sacroiliitis: ⩾bilateral grade 2 or unilateral grade 3 or 4); and Peripheral PsA. All patients were followed prospectively according to the same protocol. The demographic, clinical and radiographic variables were compared. Adjusted means were used to account for varying intervals between visits. A logistic regression was performed and adjusted for follow-up duration.

RESULTS

There were 477 axPsA patients, 826 peripheral PsA, 675 AS and 91 ASP patients included. AS patients were younger (P < 0.001), more male and HLA-B*27 positive (76%, 72% vs 64%, P ⩽ 0.001, 82%, 75%, vs 19%, P = 0.001). They had more back pain at presentation (90%, 92% vs 19%, P = 0.001), worse axial disease activity scores (bath ankylosing spondylitis disease activity index: 4.1, 3.9 vs 3.5 P = 0.017), worse back metrology (bath ankylosing spondylitis metrology index: 2.9, 2.2 vs 1.8, P < 0.001), worse physician global assessments (2.4, 2.2 vs 2.1, P < 0.001), were treated more with biologics (29%, 21% vs 7%, P = 0.001) and had a higher grade of sacroiliitis (90%, 84% vs 51%, P < 0.001). Similar differences were detected in the comparison of ASP to axPsA and in a regression model.

CONCLUSION

AS patients, with or without psoriasis, seem to be different demographically, genetically, clinically and radiographically from axPsA patients. axPsA seems to be a distinct entity.

Axial Psoriatic Arthritis: A Distinct Clinical Entity in Search of a Definition

Axial involvement in psoriatic arthritis is a well-recognized manifestation with a prevalence between 12.5% and 78%. This huge heterogeneity is due to the different criteria used by authors to define psoriatic arthritis with axial involvement combining clinical features with radiographic evidence of disease. Specific genetic and clinical attributes of axial psoriatic arthritis might differentiate it from axial spondyloarthritis with concurrent skin psoriasis. Few studies address the specific management. The purpose of this review is to acknowledge the current understanding of axial involvement in psoriatic arthritis and highlight the need for a definition to facilitate research and clinical recognition.

Psoriatic spondylitis or ankylosing spondylitis with psoriasis: same or different?

PURPOSE OF REVIEW

Of the four musculoskeletal domains of psoriatic arthritis (PsA), the axial domain is the least studied. With the advent of targeted therapy that is efficacious in some but not all manifestations of spondyloarthritis (SpA), there is interest in understanding the similarities and differences between axial PsA (axPsA) and ankylosing spondylitis. Moreover, there is also interest in evaluating the axial domain in PsA clinical trials, domain that has traditionally been ignored in such studies. This review aims to summarize the current understanding of the differences between ankylosing spondylitis and axPsA.

RECENT FINDINGS

Recent observational studies have shown that axPsA forms part of the SpA spectrum, flanked by peripheral PsA on one side and ankylosing spondylitis on the other. Thus, axial disease is more severe in ankylosing spondylitis, whereas peripheral disease is more severe in axPsA. However, the overall disease burden and impact is similar. The expression of axPsA is influenced by age, disease duration, sex and HLA-B27 status.

SUMMARY

axPsA has not been properly defined hampering research into pathogenesis, disease impact and treatment. Research to define prevalence, clinical features, impact, similarities and differences with other axial SpA, and treatment is an unmet need.

Challenges in the clinical diagnosis of psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic heterogeneous inflammatory musculoskeletal disease. The non-specific and often subtle manifestations make early diagnosis and subsequent treatment challenging. In the absence of diagnostic criteria and biomarkers, the diagnosis is often delayed leading to poor long-term outcomes. In addition, the differential diagnosis of a patient presenting with arthritis in the setting of skin psoriasis is wide due to symptom overlap with many other diseases. Peripheral arthritis, dactylitis, enthesitis and axial arthritis are the 4 domains of musculoskeletal involvement in PsA and careful examination of each domain by a rheumatologist is the first step for a correct diagnosis. Other extra-musculoskeletal features such as the presence of uveitis, inflammatory bowel disease, nail psoriasis and elevated acute phase reactants aid in the diagnosis of PsA. Screening patients with skin psoriasis using validated questionnaires might help in early diagnosis especially when coupled with imaging.

[Imaging of psoriatic arthritis and aspects of radiographic progression]

Psoriatic arthritis (PsA) is a heterogeneous multifactorial disease with musculoskeletal involvement, which can be manifested as monoarthritis, oligoarthritis or polyarthritis and in some patients can also affect the axial skeleton. The most frequent indications of inflammation are bone marrow edema and enthesitis. The early and differential diagnosis of PsA is a clinical challenge, particularly as a differential diagnosis from other inflammatory or degenerative diseases of joints. Inflammatory joint and tendon alterations in the region of the extremities and the spine can be visualized with high sensitivity by the use of magnetic resonance imaging (MRI), musculoskeletal sonography (US) and fluorescence optical imaging (FOI). The use of MRI has a prognostic value with respect to the further radiographic course of the disease, particularly in the initial stages of the disease. Structural damage can be specifically and also partially demonstrated 3‑dimensionally in peripheral joints and the spine by the use of computed tomography (CT) and conventional X‑ray imaging. High-resolution peripheral quantitative CT (HR-pQCT) in particular, can visualize pathophysiological processes and the morphological consequences even in early stages of the disease. The values of conventional X‑ray diagnostics, CT, MRI, musculoskeletal US and alternative imaging procedures are presented with respect to the diagnostics and prognosis of the progression of patients with PsA.

Greater magnitude of entheseal microdamage and repair in psoriatic arthritis compared with ankylosing spondylitis on ultrasound

Objectives

AS and PsA share clinical and immunological features centred on enthesitis. However, a strong association between PsA and preceding injury has been recognized. The aim of this study was to test the hypothesis that the entheseal damage seen by US is commoner in PsA patients than in AS patients.

Methods

Seventy-nine AS and 85 PsA patients had US scans of 1640 entheses to calculate entheseal inflammation (hypoechogenicity, thickening and Doppler) and damage scores (calcifications, enthesophytes and erosions). Regression modelling was done to evaluate the effect of diagnoses on outcomes, controlling for age, gender, BMI, clinical enthesitis, HLA-B27, and anti-TNF use.

Results

Both inflammation and damage scores on US were correlated with BMI (r = 0.392; r = 0.320) and age (r = 0.308; r = 0.538) (P < 0.001), and men had higher inflammation scores than women [12.3 (7.5) vs 8.9 (7.3), P = 0.001]. In multivariate analysis, despite similar (anti-TNF-treated patients) or slightly less inflammation (anti-TNF-naïve patients) in the PsA group, they had 4.22 times more US damage than their counterparts with AS. The difference was even higher in the anti-TNF-naïve patients (5.6 times).

Conclusion

On US assessment, PsA patients have greater entheseal insertion damage scores compared with AS, suggesting potential differences in tissue repair, immunobiology or response to injury at insertions.

Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison

Ankylosing spondylitis (AS) was first identified in the late 17th century. 250 years later, inflammatory spine disease was recognized to be one of the patterns of psoriatic arthritis (PsA). Isolated spondylitis is rare among patients with PsA, occurring in less than 5% of patients; however, many patients with PsA have axial disease that is concurrent with peripheral arthritis. At the other end of the spondyloarthritis spectrum, psoriasis is observed in 10% of patients with AS. Although axial involvement in PsA can be indistinguishable from axial disease in AS, it can also differ in several respects, raising the question of whether axial PsA and AS (with or without psoriasis) are different clinical presentations of the same disease, or whether they are separate diseases that have overlapping features. In this Review, the clinical presentation, metrology, radiographic characteristics, genetic factors, treatment options and axial prognosis of the two diseases are addressed. The aim of this Review is to capture all available comparisons made to date, to highlight the similarities and differences between AS and axial PsA and to propose a research agenda.

Association of Inflammatory Bowel Disease and Acute Anterior Uveitis, but Not Psoriasis, With Disease Duration in Patients With Axial Spondyloarthritis: Results From Two Belgian Nationwide Axial Spondyloarthritis Cohorts

OBJECTIVE

To determine the link between extraarticular manifestations (EAMs) and baseline characteristics in patients with axial spondyloarthritis (SpA), and to define their potentially differential prognostic value in 2 large, independent Belgian axial SpA cohorts with distinct recruitment periods.

METHODS

Information on demographic and clinical characteristics and extraarticular manifestations (EAMs) was obtained from patients with axial SpA originating from the (Be)Giant (Belgian Inflammatory Arthritis and Spondylitis) cohort, which includes consecutive axial SpA patients whose data have been collected since 2010, and from the ASPECT (Ankylosing Spondylitis Patients Epidemiological Cross-sectional Trial) cohort, a Belgian registry of cross-sectional data collected between February 2004 and February 2005 from consecutive patients with ankylosing spondylitis (AS) or probable AS.

RESULTS

Among the 1,250 Belgian patients studied, disease duration was associated with risk of developing inflammatory bowel disease (IBD), with an increase in risk by 20% per 10 years of disease duration (relative risk [RR] 1.2, P = 0.026), and associated with risk of developing acute anterior uveitis, with an increase in risk by 30% per 10 years of disease duration (RR 1.3, P < 0.001). In the subgroup of 171 newly diagnosed patients with prospective follow-up data, higher mean C-reactive protein levels over time were demonstrated in those with acute anterior uveitis or IBD compared to those without EAMs or those with psoriasis alone (each P = 0.01).

CONCLUSION

The risk of developing acute anterior uveitis or IBD, but not psoriasis, in patients with axial SpA seems to increase with disease duration and appears to be linked to a higher cumulative exposure to inflammation, thus providing a possible explanation for the differential structural progression observed in those with axial SpA.

MR distribution of active inflammatory and chronic structural sacroiliac joint changes in axial spondyloarthropathy: Challenging conventional wisdom

OBJECTIVE

Evaluate the MR distribution of inflammatory sacroiliac joint changes in axial spondyloarthritis phenotypes, including Ankylosing Spondylitis (AS) and non-radiographic Axial Spondyloarthritis (nrAxSpA).

METHODS

A retrospective review of 94 patients seen for treatment of axial spondyloarthritis (SpA) who underwent sacroiliac joint MRI between January 2011 and December 2015 was performed. MR images from 68 patients (20 with AS and 48 with nrAxSpA) were reviewed independently by two radiologists. Images were scored on presence of active inflammatory and chronic structural lesions. These lesions were further categorized as unilateral, bilateral and asymmetric, or bilateral and symmetric.

RESULTS

No statistically significant difference was found in the distribution (laterality or symmetry) of bone marrow edema or sclerosis between the AS and nr-axSpA groups. Osseous erosions were more commonly bilateral symmetric in AS than nr-axSpA (11/20 vs. 8/48, p = 0.01). No statistically significant difference was noted between bone marrow edema scores in the AS and nr-axSpA subgroups (2.6 vs 3.3, p = 0.514). Patients with AS had a significantly higher fat metaplasia score compared to patients with nr-axSpA (7.3 vs 1.1, p = 0.001). Patients with nr-axSpA had a higher mean score for erosions (11.6 vs 4.2, p = 0.001). Only patients classified as AS were found to have bony ankylosis. Inter-observer reliability was strong to excellent.

CONCLUSION

Ankylosing spondylitis findings at the sacroiliac joints are classically described as bilateral and symmetric on radiographs. Our study demonstrates that distribution on MRI at an individual time point is variable. The variable distribution should be considered when radiologists evaluate MRI exams of AS patients.

Back pain in psoriatic arthritis: defining prevalence, characteristics and performance of inflammatory back pain criteria in psoriatic arthritis

OBJECTIVE

We aimed to determine the agreement between rheumatologist-judged inflammatory back pain (IBP) and criteria defining IBP in patients with psoriatic arthritis (PsA) and predictive value of IBP in identifying axial involvement in PsA.

METHODS

Using prospectively collected data, we investigated the agreement between rheumatologist judgement of IBP and IBP criteria (Calin, Rudwaleit and Assessment of Spondyloarthritis International Society) using the kappa coefficient. We also determined the sensitivity, specificity and likelihood ratios of the presence of back pain, rheumatologist-judged IBP and the three IBP criteria for detecting axial PsA (AxPsA). Finally, we compared the clinical and genetic markers in patients with PsA with axial radiological changes with and without back pain.

RESULTS

171 patients (52% male, mean age 46.6 years) were identified. Ninety-six (56.13%) patients reported chronic back pain. Sixty-five (38.01%) had IBP. 54 (32%) patients had evidence of radiological change in the spine. The agreement between rheumatologist judgement of IBP and IBP criteria was highest for the Calin criteria (0.70). Positive likelihood ratio for the presence of radiological axial involvement was highest for Rudwaleit criteria (2.17). No differences between patients with AxPsA with or without back pain were found, except for higher Bath Ankylosing Spondylitis Disease Activity Index and lower prevalence of human leucocyte antigen-B*38 in those with back pain.

CONCLUSION

Rheumatologist-judged IBP or the criteria for IBP developed for ankylosing spondylitis may not perform well when ascertaining axial involvement in PsA.

Influence of Axial Involvement on Clinical Characteristics of Psoriatic Arthritis: Analysis from the Corrona Psoriatic Arthritis/Spondyloarthritis Registry

Objective.

We analyzed the characteristics of patients with psoriatic arthritis (PsA) with and without axial involvement in the US-based Corrona Psoriatic Arthritis/Spondyloarthritis Registry.

Methods.

All patients were included who had PsA and data on axial involvement, defined as physician-reported presence of spinal involvement at enrollment, and/or radiograph or magnetic resonance imaging showing sacroiliitis. Demographics, clinical measures, patient-reported outcomes, and treatment characteristics were assessed at enrollment.

Results.

Of 1530 patients with PsA, 192 (12.5%) had axial involvement and 1338 (87.5%) did not. Subgroups were similar in sex, race, body mass index, disease duration, presence of dactylitis, and prevalence of most comorbidities. However, patients with axial involvement were younger and more likely to have enthesitis, a history of depression, and more frequently used biologics at enrollment. They were also more likely to have moderate/severe psoriasis (body surface area ≥ 3%, 42.5% vs 31.5%) and significantly worse disease as measured by a lower prevalence of minimal disease activity (30.1% vs 46.2%) and higher nail psoriasis scores [visual analog scale (VAS) 11.4 vs 6.5], enthesitis counts (5.1 vs 3.4), Bath Ankylosing Spondylitis Disease Activity Index (4.7 vs 3.5) scores, Bath Ankylosing Spondylitis Functional Index (3.8 vs 2.5) scores, C-reactive protein levels (4.1 vs 2.4 mg/l), and scores for physical function (Health Assessment Questionnaire, 0.9 vs 0.6), pain (VAS, 47.7 vs 36.2), and fatigue (VAS, 50.2 vs 38.6).

Conclusion.

Presence of axial involvement was associated with a higher likelihood of moderate/severe psoriasis, with higher disease activity and greater effect on quality of life. These findings highlight the importance of monitoring patients with PsA for signs of axial symptoms or spinal involvement.

Altered Bone Remodeling in Psoriatic Disease: New Insights and Future Directions

Psoriatic arthritis (PsA) is an inflammatory rheumatic disorder that occurs in patients with psoriasis and predominantly affects musculoskeletal structures, skin, and nails. The etiology of PsA is not well understood but evidence supports an interplay of genetic, immunologic, and environmental factors which promote pathological bone remodeling and joint damage in PsA. Localized and systemic bone loss due to increased activity of osteoclasts is well established in PsA based on animal models and translational studies. In contrast, the mechanisms responsible for pathological bone remodeling in PsA remain enigmatic although new candidate molecules and pathways have been identified. Recent reports have revealed novel findings related to bone erosion and pathologic bone formation in PsA. Many associated risk factors and contributing molecular mechanisms have also been identified. In this review, we discuss new developments in the field, point out unresolved questions regarding the pathogenetic origins of the wide array of bone phenotypes in PsA, and discuss new directions for investigation.

Inflammatory back pain in psoriatic arthritis is significantly more responsive to corticosteroids compared to back pain in ankylosing spondylitis: a prospective, open-labelled, controlled pilot study

BACKGROUND

The efficacy of corticosteroids in patients with psoriatic arthritis (PsA) and inflammatory back pain has not been studied to date. In this controlled trial, we aimed to investigate the comparative performance of corticosteroids in patients with active axial-PsA (AxPsA) versus those with active ankylosing spondylitis (AS).

METHODS

Patients with AxPsA and AS (naïve to biologic therapies), who not only had clinically active disease, but also had bone marrow oedema on magnetic resonance imaging of the sacroiliac joints, were recruited. Clinically active disease was defined as inflammatory back pain (fulfilling Assessment of Spondyloarthritis International Society (ASAS) expert criteria), with spinal pain score (numerical rating scale 0-10) ≥4 and Bath AS Disease Activity Index (BASDAI) score ≥4 despite taking nonsteroidal anti-inflammatory drugs. Moreover, we recruited a control group of patients with non-inflammatory lower back pain. All patients received a single, intra-muscular dose of depot corticosteroid injection (triamcinolone acetonide 80 mg) at baseline. The intra-muscular corticosteroid option was used to overcome any drug compliance issues. Clinical outcome assessments were made at the following time points: baseline, week 2, and week 4. The primary efficacy end point was mean change in Ankylosing Spondylitis Disease Activity Score (ASDAS) at week 2. Key secondary outcomes were mean change in the BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI) and Ankylosing Spondylitis Quality of Life (ASQoL) at weeks 2 and 4.

RESULTS

In total, 40 patients were recruited (15 with AxPsA, 15 with AS, and 10 controls). At week 2 following corticosteroid treatment, patients with AxPsA had significantly greater improvement in the mean ASDAS compared to patients with AS (1.43 ± 0.39 vs. 1.03 ± 0.30, p = 0.004), and also when compared to controls (p < 0.001). At week-4, similar significant trend of ASDAS improvement was seen among AxPsA patients compared to AS patients (1.09 ± 0.32 vs. 0.77 ± 0.27, p = 0.007) and controls (p < 0.001). Similarly, the mean BASDAI, visual analogue scale spinal pain score, ASQoL and BASFI improved significantly among patients with AxPsA compared to patients with AS and controls at week 2 (p < 0.05), with this trend also largely maintained at week 4.

CONCLUSIONS

Axial inflammation in patients with PsA responds significantly better to corticosteroids than in patients with AS. This furthers the argument and adds to the growing evidence that AxPsA and AS are distinct entities.

Thoracic Syndesmophytes Commonly Occur in the Absence of Lumbar Syndesmophytes in Ankylosing Spondylitis: A Computed Tomography Study

OBJECTIVE

To determine the extent of thoracic involvement with syndesmophytes in ankylosing spondylitis (AS) relative to lumbar involvement.

METHODS

We performed thoracolumbar spine computed tomography (CT) and lumbar radiography on 18 patients. We quantitated syndesmophytes in 11 intervertebral disc spaces and related these to the presence of syndesmophytes on lumbar radiographs.

RESULTS

Syndesmophytes were slightly more common in the thoracic than in the lumbar spine and bridging was significantly more common. Thoracic syndesmophytes were universally present in patients without visible lumbar syndesmophytes on either radiographs or CT.

CONCLUSION

Syndesmophytes predominate in the thoracic spine. Lumbar radiographs underestimate the degree of thoracic involvement.