The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection

Investigating the genetic association between ERAP1 and spondyloarthritis

OBJECTIVE

A robust association between polymorphisms in the non-major histocompatibility complex gene ERAP1 and ankylosing spondylitis (AS) in several populations was recently identified. The aim of the current study was to determine the level of association of ERAP1 polymorphisms with spondyloarthritis (SpA) in French/Belgian populations with particular attention to genotype-phenotype correlations.

METHODS

We studied 734 independent SpA cases and 632 controls from two European cohorts. Five single-nucleotide polymorphisms (SNPs), rs27044, rs17482078, rs10050860, rs30187 and rs2287987 were genotyped, and case-control association analyses were carried using PLINK 1.07 software. Linkage disequilibrium and haplotypes were estimated with Haploview. Analysis was first carried out in SpA as a whole group, and then separately in AS and non-radiographic SpA (non-AS) patients.

RESULTS

Consistent with previous studies conducted in AS, rs30187 was the most significantly associated SNP with SpA (p=0.008 in the French, and p=6.46×10(-4) in the Belgian cohorts). In the combined cohorts, this SNP was associated with both AS and non-AS (P(combined)= 3.9×10(-5) and P(combined)= 0.005, respectively). A similar trend was observed with other SNPs. The rs17482078/rs10050860/rs30187-CCT haplotype was significantly associated with increased risk of SpA in both cohorts (P(combined)= 9.08×10(-4)), including AS and non-AS (P(combined)=6.16×10(-4) and P(combined)=0.049, respectively), whereas the -TTC haplotype was associated with reduced risk of SpA, including AS and non-AS (P(combined)=2.36×10(-7), P(combined)= 5.69×10(-6) and P(combined)= 2.13×10(-4), respectively).

CONCLUSIONS

This is the first study to show an association between several polymorphisms located in ERAP1 and SpA as a whole. Our findings demonstrate consistent association of the same SNPs and haplotypes with both AS and non-AS subtypes of SpA.

HLA-B27 predicts a more chronic disease course in an 8-year followup cohort of patients with juvenile idiopathic arthritis

OBJECTIVE

We investigated associations of HLA-B27 with clinical manifestations and longterm outcome in a near population-based setting among patients with juvenile idiopathic arthritis (JIA).

METHODS

We studied clinical and serological data from 410 patients with HLA-B27 results among 440 prospectively collected patients with JIA with 8-year followup data in a Nordic database. The study was structured to be as close to a population-based study as possible.

RESULTS

HLA-B27 was analyzed in 93% of patients, and was positive in 21% of the cohort, in 18.4% of the girls and in 25.9% of the boys. Boys who were HLA-B27-positive had significantly higher age at onset compared to HLA-B27-negative boys and compared to both HLA-B27-negative and positive girls. This difference in onset age in relation to HLA-B27 was not found in girls. HLA-B27 was associated with clinical signs of sacroiliitis, enthesitis, and tenosynovitis in boys, but not in girls. After 8 years of disease, 46 children (11.2%) were classified as having enthesitis-related arthritis (ERA). Boys with ERA had clinical signs of sacroiliitis more often than girls with ERA. HLA-B27-positive children, as well as children with clinical signs of sacroiliitis, enthesitis, and hip arthritis, had higher odds of not being in remission off medication after 8 years of disease.

CONCLUSION

In this near population-based Nordic JIA cohort we found significant differences between HLA-B27-positive boys and girls in age at disease onset, clinical signs of sacroiliitis, and ERA classification. HLA-B27 was negatively associated with longterm remission status, possibly because of its association with clinical disease characteristics, such as sacroiliitis, rather than being a general marker of persistent disease.

Improving musculoskeletal health: global issues

Musculoskeletal (MSK) disorders are among the leading reasons why patients consult a family or primary health practitioner, take time off work and become disabled. Many of the MSK disorders are more common in the elderly. Thus, as the proportion of the elderly increases all over the world, MSK disorders will make a greater contribution to the global burden of disease. Epidemiological studies have shown that the spectrum of MSK disorders in developing countries is similar to that seen in industrialised countries, but the burden of disease tends to be higher due to a delay in diagnosis or lack of access to adequate health-care facilities for effective treatment. Musculoskeletal pain is very common in the community while fibromyalgia is being recognised as part of a continuum of chronic widespread pain rather than a narrowly defined entity. This will allow research to improve our understanding of pain in a variety of diffuse pain syndromes. The availability of newer more effective therapies has resulted in efforts to initiate therapy at an earlier stage of diseases. The new criteria for rheumatoid arthritis, and the diagnosis of axial and peripheral involvement in spondyloarthritis, permit an earlier diagnosis without having to wait for radiological changes. One of the major health challenges is the global shortage of health workers, and based on current training of health workers and traditional models of care for service delivery, the global situation is unlikely to change in the near future. Thus, new models of care and strategies to train community health-care workers and primary health-care practitioners to detect and initiate the management of patients with MSK disorders at an earlier stage are required. There is also a need for prevention strategies with campaigns to educate and raise awareness among the entire population. Lifestyle interventions such as maintaining an ideal body weight to prevent obesity, regular exercises, avoidance of smoking and alcohol abuse, intake of a balanced diet and nutrients to include adequate calcium and vitamin D, modification of the work environment and avoidance of certain repetitive activities will prevent or ameliorate disorders such as osteoarthritis, osteoporosis, rheumatoid arthritis, gout and MSK pain syndromes including low back pain and work-related pain syndromes. These prevention strategies also contribute to reducing the prevalence and outcome of diseases such as hypertension, cardiovascular diseases, diabetes and respiratory diseases. Thus, prevention strategies require urgent attention globally.

Validation of a patient self-reported screening questionnaire for axial spondyloarthropathy in a UK Population

STUDY DESIGN

Cross-sectional cohort study.

OBJECTIVE

The aim of this study was to develop and validate a patient-completed screening questionnaire for axial spondyloarthropathy for use in the United Kingdom.

SUMMARY OF BACKGROUND DATA

Axial spondyloarthropathy (axial SpA) can be difficult to diagnose in the early stages of disease, leading to diagnostic delay and morbidity. Existing population screening tools lack sensitivity or have not been validated in the UK population.

METHODS

Questionnaires were sent to 295 patients with definite ankylosing spondylitis (meeting modified New York criteria), nonradiographical axial SpA (sacroiliitis on magnetic resonance imaging), or mechanical back pain. Responses from 190 patients were analyzed. Binary logistic regression was used to develop a model differentiating inflammatory from mechanical pain.

RESULTS

The final model (male sex, onset of symptoms by age 33 years, no radiation of pain, pain gets better as day goes on, pain increases with rest, and personal history of iritis) correctly classified 86% of cases with Nagelkerke R = 0.486. A numerical score (with 1 point assigned for each feature present) was calculated and receiver operating characteristic curve was constructed, with area under the curve of 0.911 (95% confidence interval: 0.87-0.96). A score of ≥3/6 had sensitivity of 75.6% and specificity of 87.9% for inflammation.

CONCLUSION

We have developed a model that differentiates patients with ankylosing spondylitis/axial SpA from those with mechanical spinal disease and can be used as a self-completed screening tool.

Microscopic gut inflammation in axial spondyloarthritis: a multiparametric predictive model

OBJECTIVE

To assess the rates and explore predictors of microscopic gut inflammation in a cohort of patients with axial and peripheral spondyloarthritis (SpA).

METHODS

Ileocolonoscopy was performed in 65 patients with axial and peripheral SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT. Histopathological analysis and scoring were performed by an experienced pathologist.

RESULTS

Overall, 46.2% of the patients with SpA showed microscopic gut inflammation. In axial SpA, the following parameters were independently associated with gut involvement: male sex (OR=8.9, p=0.035); high disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (OR=2.05, p=0.032); restricted spinal mobility measured by the Bath Ankylosing Spondylitis Metrology Index (OR=1.94, p=0.009); and younger age (OR=0.85, p=0.013). No clear association was found for human leucocyte antigen-B27 status, presence of peripheral arthritis, enthesitis, uveitis, psoriasis, intake of non-steroidal anti-inflammatory drugs and family history of SpA. The prevalence of gut inflammation in non-radiographic axial SpA and ankylosing spondylitis was comparable.

CONCLUSIONS

The prevalence of microscopic gut inflammation in SpA remains unaltered over time. Younger age (shorter symptom duration), progressive disease, male sex and higher disease activity are independently associated with microscopic gut inflammation in axial SpA.

Evaluation of spondylarthritis activity by patients and physicians: ASDAS, BASDAI, PASS, and flares in 200 patients

OBJECTIVES

In patients with spondyloarthritis, to determine Ankylosing Spondylitis Disease Activity Score (ASDAS) cutoffs matching the patient-acceptable symptom state (PASS) and patient-reported levels of disease activity, to assess associations between disease activity levels and presence of depression, and to identify ASDAS and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) cutoffs indicating a flare and indicating a remission.

METHODS

Prospective single-center study of patients meeting ASAS criteria for spondyloarthritis receiving follow-up at the Besançon teaching hospital, France, between February 2011 and February 2012. In each patient, the BASDAI, ASDAS, Bath Ankylosing Spondylitis Functional Index (BASFI), patient-acceptable symptom state (PASS) and signs of depression were assessed. Receiver-operating characteristic (ROC) curves were drawn to identify the ASDAS cutoffs separating different levels of disease activity. The kappa coefficient was computed to evaluate agreement between patients and physicians regarding the presence of flares.

RESULTS

Two hundred patients with a mean age of 44.4 ± 12.5 years and mean disease duration of 12.9 ± 10.5 years were included. Mean BASDAI was 4.1 ± 2.2, mean ASDAS-C-reactive protein (CRP) was 2.4 ± 1, mean BASFI was 3.3 ± 2.7, and 58.9% of patients reported being in the PASS. The PASS was associated with BASDAI values inferior or equal to 4.1 and ASDAS-CRP values inferior or equal to 2.3. Mild patient-reported disease activity was associated with BASDAI values inferior or equal to 3.8 and ASDAS-CRP values inferior or equal to 2.3; corresponding values for high patient-reported disease activity were superior to 5.2 and superior to 3.1. Among patients reporting high disease activity, 64.5% had Beck Depression Inventory scores consistent with severe depression. At the time of the visit, 36.9% of the patients and 28.3% of the physicians felt there was a flare. Cutoffs indicating a flare were superior or equal to 5.2 for the BASDAI and superior or equal to 2.3 for the ASDAS-CRP. Agreement between patients and physicians regarding flares was good (Kappa, 0.61). An evaluation in 43 patients indicated that an ASDAS-CRP cutoff inferior or equal to 2.2 separated the 25.6% of patients who reported being in remission from the other patients.

CONCLUSION

Our results show a significant association between disease activity and depression severity, as well as good agreement between BASDAI and ASDAS. The ASDAS cutoffs for the various levels of patient-reported disease activity differed from the cutoffs suggested by ASAS; a 2.3 cutoff was found for both patient-reported absence of disease activity and PASS, indicating that achieving PASS should be included among our treatment objectives.

Limitations in Screening Instruments for Psoriatic Arthritis: A Comparison of Instruments in Patients with Psoriasis

Objective.

To compare the abilities of 3 validated screening instruments to predict the diagnosis of psoriatic arthritis (PsA) in patients with psoriasis.

Methods.

Prior to a rheumatologic evaluation, 213 participants in the Utah Psoriasis Initiative completed the Psoriasis Epidemiology Screening project (PEST), the Toronto Psoriatic Arthritis Screen (ToPAS), and the Psoriatic Arthritis Screening and Evaluation (PASE). Previously established instrument cutoff scores were used to designate positive and negative classifications. Sensitivities and specificities were determined by comparing instrument classifications to the rheumatologist’s diagnosis. Phenotypic features and alternative diagnoses were compared between participants who screened positively and negatively on each instrument. Discrepancies between the rheumatologist’s examination findings and responses to specific instrument questions were compared.

Results.

The sensitivities of PEST, ToPAS, and PASE were 85%, 75%, and 68%, and the specificities were 45%, 55%, and 50%, respectively. The instruments were less sensitive in patients with lower disease activity, fewer PsA features, and shorter disease duration. The instruments did not consistently differentiate between PsA and other types of musculoskeletal disease. Discrepancies between examination findings and responses to instrument questions occurred more frequently with ToPAS than with PEST and PASE.

Conclusion.

Sensitivities and specificities for PEST, ToPAS, and PASE were lower than previously reported. This population included patients with PsA and other types of musculoskeletal disease and may represent those most likely to complete a screening instrument and follow through with a rheumatology referral. Further analyses may enable the development of more successful screening strategies for PsA in psoriasis patients with musculoskeletal complaints.

Axial spondyloarthritis: a new disease entity, not necessarily early ankylosing spondylitis

New classification criteria for axial spondyloarthritis have been developed with the goal of increasing sensitivity of criteria for early inflammatory spondyloarthritis. However these criteria substantially increase heterogeneity of the resulting disease group, reducing their value in both research and clinical settings. Further research to establish criteria based on better knowledge of the natural history of non-radiographic axial spondyloarthritis, its aetiopathogenesis and response to treatment is required. In the meantime the modified New York criteria for ankylosing spondylitis remain a very useful classification criteria set, defining a relatively homogenous group of cases for clinical use and research studies.

Axial spondyloarthritis: is there a treatment of choice?

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease predominantly affecting the axial skeleton (sacroiliac joints and spine). Nonradiographic axSpA (axSpA without radiographic sacroiliitis) and ankylosing spondylitis (AS; radiographic form of axSpA) are considered nowadays as two consecutive stages of one disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) are highly effective against the major symptoms of axSpA (pain and stiffness) and may have disease-modifying properties including retarding progression of structural damage in the spine. Therefore, NSAIDs, unless contraindicated, are the treatment of choice for the majority of patients with axSpA. Beyond NSAIDs, only tumour necrosis factor (TNF) α blockers are effective and approved for the treatment of active axSpA. Several novel drugs (i.e. monoclonal antibodies targeting interleukin-17, interleukin-12/23, inhibitors of phosphodiesterase-4 and kinases), which might be effective in axSpA, are currently under investigation. Pharmacological therapy of axSpA should always be combined with nonpharmacological treatment including education and regular exercise/physiotherapy.

High prevalence of spondyloarthritis and ankylosing spondylitis among familial Mediterranean fever patients and their first-degree relatives: further evidence for the connection

INTRODUCTION

Familial Mediterranean fever (FMF) is an auto-inflammatory disease characterized by recurrent attacks of fever and serositis. Limited data suggest that the prevalence of sacroiliitis is increased in patients with FMF. In our present study, we assessed the prevalence of spondyloarthritis (SpA), including ankylosing spondylitis (AS), among a cohort of FMF patients and their unaffected first-degree relatives (FDRs).

METHODS

The current study cohort comprised a consecutive group of 201 unrelated patients with FMF and 319 FDRs (≥16 years old). These subjects were examined according to a standard protocol.

RESULTS

A total of 157 FMF patients (78.1%) and 233 (73%) unaffected FDRs reported back pain. Fifteen FMF patients (7.5%) and nine unaffected FDRs fulfilled the modified New York (mNY) criteria for AS. One additional FDR with AS was identified after review of the medical records. None of the FMF patients with AS was HLA-B27 positive. The allele frequency of M694V among the FMF patients with radiographic sacroiliitis was significantly higher in comparison with those without sacroiliitis (OR 4.3). When compared with the general population, the risk ratios for SpA and AS among the FDRs of our FMF patients were 3.3 (95% CI; 2.0 to 5.5) and for AS 2.9 (95% CI; 1.3 to 6.4), respectively.

CONCLUSIONS

Our study suggests that a) factors other than HLA-B27 play a role in the association of FMF and SpA/AS; b) MEFV gene variations may be one of the geographic/region-specific potential pathogenetic links between these two disorders in the Turkish population.

Current concept of spondyloarthritis: special emphasis on early referral and diagnosis

Ankylosing spondylitis is the prototype of inflammatory rheumatic diseases grouped under the term spondyloarthritis or spondyloarthropathy (SpA). New classification criteria for SpA have now been proposed; the patients are subgrouped into (1) a predominantly axial disease, termed axial SpA, which includes AS, and (2) peripheral SpA. There is an unacceptable delay in the diagnosis of axial SpA, and there are still no validated diagnostic criteria for SpA. An early diagnosis has now become increasingly important because effective therapies in the form of TNF antagonists have become available that are even more effective if used in early stages of the disease. Therefore, new strategies are being proposed that will assist in making an early diagnosis and will also help primary care physicians in screening for these patients so that they can be referred to rheumatologists when the disease is still in its early stages. These strategies may be less efficient for early referral of children and adolescents suffering from SpA, because their most important early manifestation is not inflammatory back pain but peripheral arthritis and enthesitis. There is, therefore, a need to develop a different strategy for children and adolescents with SpA through the use, preferably, of the ASAS/EULAR classification criteria for peripheral SpA, more so than the classification criteria for axSpA.

[ASAS recommendations on the use of TNF inhibitors for patients with axial spondyloarthritis : evaluation of the 2010 update in the German-speaking area]

The ASAS recommendations on the use of tumor necrosis factor (TNF) inhibitors for patients with axial spondyloarthritis were amended in 2010. Essential new aspects have been included in the update. The diagnosis is extended from patients with ankylosing spondlitis (AS) to all patient groups of axial spondyloarthritis. Pretreatment with at least two non-steroidal anti-rheumatic drugs (NSARD) for 4 weeks is recommended. The success of therapy with TNF inhibitors is to be compiled after at least 12 weeks.This article presents the results of the evaluation of the German translation of these recommendations. A total of 25 experts from Germany, Austria and Switzerland have scored the translation on a scale between 0 (no agreement) and 10 (full agreement) with respect to the recommendation grade. The agreement on the recommendations between the experts was very high (8.98 ± 1.25).

Improvement in deployment of MRI of the sacroiliac joints in patients suspected for spondyloarthritis using a targeted intervention: a case study

OBJECTIVE

To assess characteristics of deployment of MRI of the SI joints (MR-SI) in patients with suspected axial spondyloarthritis (SpA) before and after a targeted intervention.

METHODS

In a retrospective chart review study, all MR-SI performed in the period 1 April 2004 to 31 December 2010 were collected. Inclusion criteria were complete patient data and MR-SI ordered by a rheumatologist for suspicion of axial SpA. MR-SI reports were graded as normal, suspected sacroiliitis or sacroiliitis. In April 2007 an intervention was made to improve deployment. Rheumatologists were provided with data on ordering behaviour, patient characteristics and MRI outcomes. An introduction on the effect of pretest chance on positive and negative predictive value was given; the burden for patients and costs was illustrated. An alternative behavioural strategy was offered in the form of a simple diagnostic algorithm. Percentages of MRIs and positive MRI for sacroiliitis were compared before and after intervention.

RESULTS

From April 2004 to April 2007, 198 MR-SIs were performed, of which 166 (83.9%) were normal, 5 (2.5%) were suspicious and 27 (13.6%) were positive. After the intervention, patients displayed significantly more SpA features. More optimal patient selection resulted in 79 MR-SI requests, a decrease of 60.1%. Fifty-seven (72.2%) reports were normal, 0 were suspicious and 22 (27.8%) were positive.

CONCLUSION

A simple, one-time, five-step feedback intervention resulted in a 60% reduction in MR-SI requests with a doubling of the percentage of MR-SI positive for sacroiliitis. This approach may benefit future research in areas with diagnostic uncertainty and suboptimal testing.

Emerging drugs for axial spondyloarthritis including ankylosing spondylitis

INTRODUCTION

Only non-steroidal anti-inflammatories (NSAIDs) and TNF inhibitors (TNFi) are effective in ankylosing spondylitis (AS). However, not all patients successfully respond to these drugs and a subset may have contraindications to their use.

AREAS COVERED

In the last decade, an earlier diagnosis of AS has been achieved due to the increasing availability of MRI. This has led to prompt treatment initiation with improved outcomes. NSAIDs and TNFi are the current treatments for AS which lead to sustained clinical responses in the long term. Recent studies have shown other potential biomarkers in AS, such as the IL-17/IL-23 axis. This has translated into the development of new drugs which interfere with these pathways, such as apremilast and secukinumab, which have shown efficacy in early clinical trials.

EXPERT OPINION

AS carries considerable short- and long-term disabilities. Anti-TNF-α therapies reduce pain, improve function and decrease inflammation as seen by MRI. New treatment options are being developed which may prove efficacious on those patients not responding to anti-TNF. The ultimate research goal should focus on treatments to prevent and stop new bone formation.

Phenotypic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis living in North East London

To test for demographic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis (PsA) living in the same environment and for differences between sexes. The demographic characteristics of patients attending outpatient clinics were obtained using a semi-structured questionnaire. Clinical parameters included disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), C-reactive protein), function (Bath Ankylosing Spondylitis Functional Index (BASFI)) and visual analogue scale (VAS) scores for well-being and night pain (10 cm, where 10 = worst possible response). The first symptom experienced at disease onset and the main symptoms during the disease course were recorded in the questionnaire. A total of 217 patents were assessed of whom 151 were Caucasians and 66 were Asians. South Asian patients were significantly younger [(mean) 45.9 years [(SD)(±11.4)] for Asians and 53.1 years (±14.2) for Caucasians (p < 0.005)] and were diagnosed at an earlier age [40.7 years (±11.7) for Asians and 46.7 years (±15.8) for Caucasians (p < 0.05)] compared to Caucasians patients. Asian females with PsA had worse disease in terms of activity (ESR = 23.9 mmHg/h; BASDAI = 6.7), function (BASFI = 5.5), night pain (7.1 on VAS) and well-being (6.6 on VAS) compared with Asian males (13.2 mmHg/h, 5.3, 3.6, 4.1, 4.6, respectively) or Caucasian males and females (15.8 mmHg/h, 5.9, 5.3, 5.4, 5.4; 18.9 mmHg/h, 6.1, 6.1, 5.3, 5.8, respectively). There were no significant differences in symptoms at disease onset or the main symptoms during the disease course between Caucasian and Asian patients, although there was a trend towards more frequent enthesitis in Asian females during the course of disease suggested by pain with pressure compared to Asian males. South Asian patients may develop PsA earlier in life than Caucasian patients do, but their clinical characteristics are generally similar. Asian females with PsA have worse disease activity, function, night pain and well-being than Asian males and Caucasian males and females.

[Diagnosis and therapy of axial spondyloarthritis including ankylosing spondylitis (Bechterew's disease)]

The term axial spondyloarthritis covers patients with established structural changes visible on x-ray in sacroiliac joints and/or in the spine (classical ankylosing spondylitis) but also patients with non-radiographic axial spondyloarthritis in whom early inflammatory signs of the disease can only be visualized with magnetic resonance imaging (MRI). The MRI technique plays an important role in the diagnosis of this disease and an early diagnosis is normally based on a combination of clinical, laboratory and imaging parameters. Only non-steroidal anti-inflammatory drugs and TNF-α blockers are effective in the treatment of axial spondyloarthritis. Patients with short disease duration and elevated acute phase reactant levels demonstrate best therapy response and, therefore, should be closely followed-up and consistently treated.

The frequency of non-radiographic axial spondyloarthritis in relation to symptom duration in patients referred because of chronic back pain: results from the Berlin early spondyloarthritis clinic

OBJECTIVE

This study was aimed at investigating the frequencies of non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) diagnoses and their ratios in relation to symptom duration in patients referred because of chronic back pain and suspicion of axial SpA.

METHODS

In this monocentre study, orthopaedists and primary care physicians were requested to refer patients with chronic low back pain (duration >3 months) and onset of back pain before 45 years of age to a SpA-specialised rheumatology outpatient clinic for further diagnostic investigation, if proposed screening parameters were present. The ratio of nr-axSpA to AS was analysed in relation to the duration of symptoms.

RESULTS

A diagnosis of definite axial SpA was made in 43.7% of the referred patients (n=522). Axial SpA was diagnosed in a similar percentage of about 50% if back pain duration was <9 years but decreased to 36% if symptom duration was >9 years. Nr-axSpA represented the majority of patients (67.3%) only if duration of back pain was 1 year and less at the time of referral. Between 1 and 6 years of back pain duration the probability of nr-axSpA and AS was nearly equal (1-3 years: 52.5% and 47.5%, respectively; 3-6 years: 53.7% and 46.3%, respectively). In patients with back pain duration of 6-9 years, AS was more likely (61.1%) to be diagnosed than nr-axSpA (38.9%), and this increased further over time.

CONCLUSIONS

Non-radiographic axial SpA represents an important differential diagnosis of back pain, especially in patients with recent symptom onset.

High frequency of inflammatory back pain and other features of spondyloarthritis in patients with rheumatoid arthritis

The aim of this study was to investigate the frequency of patients with rheumatoid arthritis (RA) who have inflammatory back pain (IBP) and meet the existing classification criteria for ankylosing spondylitis (AS) and spondyloarthritis (SpA). We included 167 patients fulfilling the ACR 1987 revised criteria for RA. After obtaining a medical history and performing a physical examination, standard pelvic X-rays for examination of the sacroiliac joints (SIJ) were ordered in all patients. A computed tomography (CT) or magnetic resonance imaging (MRI) of SIJ was performed in patients with suspected radiographic sacroiliitis and MRI of SIJ in those who have IBP but no radiographic sacroiliitis. IBP was defined according to both Calin and experts' criteria. The modified New York (mNY) criteria were used to classify AS, both ESSG and Amor criteria for SpA and ASAS classification criteria for axial SpA. There were 135 female and 32 male patients with a mean age of 54.8 years. The mean disease duration was 9.8 years. RF was positive in 128 patients (79.2 %) and anti-CCP in 120 patients (81.1 %). Twenty-eight patients with RA (16.8 %) had IBP (Calin criteria), and four (2.4 %) had radiographic sacroiliitis of bilateral grade 3. Three patients (1.8 %) fulfilled the mNY criteria for AS, 31 (18.6 %) ESSG and 26 (15.6 %) Amor criteria for SpA. Nine patients (five with MRI sacroiliitis) (5.3 %) were classified as having axial SpA according to new ASAS classification criteria. This study suggests that the prevalence of SpA features in patients with RA may be much higher than expected.

Do patients with non-radiographic axial spondylarthritis differ from patients with ankylosing spondylitis?

OBJECTIVE

Patients with axial spondylarthritis (SpA) who have structural changes in the sacroiliac joints and/or the spine have been classified as having ankylosing spondylitis (AS), while those without such changes are now classified as having nonradiographic axial SpA (nr-axSpA). The differentiating features are incompletely understood.

METHODS

Data from 100 consecutive patients with axial SpA not treated with tumor necrosis factor antagonists were compared clinically and with laboratory parameters, spinal radiographs, and magnetic resonance imaging (MRI) of the spine. Standardized clinical assessment tools were used to assess health status.

RESULTS

AS was diagnosed in 56 patients and nr-axSpA in 44 patients. Signs of inflammation were significantly higher in patients with AS than in patients with nr-axSpA, with a median C-reactive protein level of 8.0 versus 3.8 mg/liter, a median Ankylosing Spondylitis Disease Activity Score of 2.2 versus 2.8, respectively, and a median amount of spinal inflammatory lesions on MRI of 2.0 versus 0.0, respectively. Significant differences between these 2 groups were seen in sex (76.8% male AS patients versus 31.8% male nr-axSpA patients). Clinical variables did not differ between patients with AS and nr-axSpA (Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Quality of Life questionnaire, Short Form 36 health survey).

CONCLUSION

Patients with nr-axSpA were characterized by the low proportion of male patients and the low burden of inflammation compared to patients with AS. While both groups did not differ regarding health status, disease activity, and physical function, they did differ in signs of inflammation; all were higher in patients with AS. Since many patients with nr-axSpA had not developed structural changes after years of symptoms, we propose that those patients should not be regarded as having preradiographic AS but rather as having nr-axSpA.

Differential diagnosis and management of ankylosing spondylitis masked as adhesive capsulitis: a resident's case problem

STUDY DESIGN

Resident's case problem.

BACKGROUND

Ankylosing spondylitis is a potentially debilitating seronegative spondyloarthropathy, with inflammatory low back pain as the most commonly reported symptom. In the absence of low back pain, identification of other diagnostic criteria or associated impairments and joint involvement, such as involvement of the hip or shoulder, may be beneficial.

DIAGNOSIS

A 32-year-old man with right shoulder pain and decreased range of motion was referred with a diagnosis of adhesive capsulitis. He had been managed by multiple healthcare providers for 3 years before being referred to a physical therapist. Glenoid labral pathology was evident on prior magnetic resonance imaging, which had led to a persistent focus on the shoulder. The evaluation by the physical therapist revealed significant mobility deficits in the cervical, thoracic, and lumbar spine. Radiographs and laboratory tests were ordered and a referral was made to rheumatology after the initial physical therapy assessment. The diagnostic work-up confirmed the diagnosis of ankylosing spondylitis and led to multidisciplinary management of the disease.

DISCUSSION

Low back pain is often the primary symptom of ankylosing spondylitis later in the disease process. Earlier indicators of ankylosing spondylitis, such as severely impaired mobility and spine stiffness, may help guide detection in the absence of spinal pain. In this case, an appropriate diagnosis led to improvement in the management strategy of what might have appeared to be unrelated shoulder pain. Early differential diagnosis is important, as emerging interventions show promise when used earlier in the disease process.

Imaging in axial spondyloarthritis: diagnostic problems and pitfalls

Magnetic Structural changes in axial Spondyloarthritis (axSpA) are best identified by conventional radiographs, while magnetic resonance imaging (MRI) is considered the gold standard for assessment of inflammatory changes. Imaging of the axial skeleton is crucial for the diagnosis but also for classification to non-radiographic axSpA according to the 2009 ASAS classification criteria. Despite the existing definitions for a positive MRI for the sacroiliac joints and the spine, these predefined lesions can also be seen in other conditions, representing pitfalls and false-positive conclusions in patients with similar clinical symptoms who do not have SpA. Diagnosis of SpA should result from the combination of clinical, laboratory and imaging findings.

The genetics of ankylosing spondylitis and axial spondyloarthritis

Ankylosing spondylitis (AS) and spondyloarthritis are strongly genetically determined. The long-standing association with HLA-B27 is well described, although the mechanism by which that association induces AS remains uncertain. Recent developments include the description of HLA-B27 tag single nucleotide polymorphisms in European and Asian populations. An increasing number of non-MHC genetic associations have been reported, which provided amongst other things the first evidence of the involvement of the IL-23 pathway in AS. The association with ERAP1 is now known to be restricted to HLA-B27 positive disease. Preliminary studies on the genetics of axial spondyloarthritis demonstrate a lower HLA-B27 carriage rate compared with AS. Studies with larger samples and including non-European ethnic groups are likely to further advance the understanding of the genetics of AS and spondyloarthritis.

Incidence of spondyloarthropathy in patients with Crohn's disease: a population-based study

OBJECTIVE

Spondyloarthritis (SpA) is an extraintestinal manifestation of inflammatory bowel disease with significant clinical effects, although the frequency is uncertain. We assessed the cumulative incidence and clinical spectrum of SpA in patients with Crohn's disease (CD) in a population-based cohort.

METHODS

The medical records of a population-based cohort of Olmsted County, Minnesota, residents diagnosed with CD between 1970 and 2004 were reviewed. Patients were followed longitudinally until migration, death, or December 31, 2010. We used the European Spondylarthropathy Study Group, Assessment of Spondyloarthritis international Society (ASAS) criteria and modified New York criteria to identify patients with SpA. The Kaplan-Meier method was used to estimate the cumulative incidence of SpA following diagnosis of CD.

RESULTS

The cohort included 311 patients with CD (49.8% females; median age 29.9 yrs, range 8-89). Thirty-two patients developed SpA based on ASAS criteria. The cumulative incidence of SpA after CD diagnosis was 6.7% (95% CI 2.5%-6.7%) at 10 years, 13.9% (95% CI 8.7%-18.8%) at 20 years, and 18.6% (95% CI 11.0%-25.5%) at 30 years. The 10-year cumulative incidence of ankylosing spondylitis was 0, while both the 20-year and 30-year cumulative incidences were 0.5% (95% CI 0-1.6%).

CONCLUSION

We have for the first time defined the actual cumulative incidence of SpA in CD using complete medical record information in a population-based cohort. The cumulative incidence of all forms of SpA increased to approximately 19% by 30 years from diagnosis of CD. Our results emphasize the importance of maintaining a high level of suspicion for SpA when following patients with CD.

MR-defined fat infiltration of the lumbar paravertebral muscles differs between non-radiographic axial spondyloarthritis and established ankylosing spondylitis

OBJECTIVE

The aim of our study was to compare the magnetic resonance imaging (MRI)-defined cross-sectional area and semi-quantitative grading of fatty degeneration of lumbar paravertebral muscles in patients with non-radiographic axial spondyloarthritis (nr-axSpA) and established ankylosing spondylitis (AS).

METHODS

Cross-sectional area (CSA) of lumbar paravertebral muscles, including the right and left multifidus (MF), erector spina (ES), psoas (PS), vertebral body and muscle:vertebra ratio (MVr), was measured. Fat infiltration of the paravertebral muscles was graded semi-quantitatively.

RESULTS

The CSA of the MF, ES and PS muscles and the MVr (at the L2, L3, L4 and L5 levels) were quite similar between patients with nr-axSpA (n = 14) and AS (n = 22). However, patients with AS had higher grades of fat infiltration than those with nr-axSpA (Right L4 grading of MF + ES muscles: 1.4 ± 0.73 vs. 0.51 ± 0.52, respectively, p = 0.001; left L4 grading: 1.36 ± 0.65 vs. 0.38 ± 0.50, respectively, p < 0.0001). This difference remained significant after adjusting for age and symptom duration. The inter-rater reliability was good (intraclass correlation coefficient 0.75 and 0.85).

CONCLUSIONS

This is first study demonstrating that MRI-defined fatty degeneration differs between patients with nr-axSpA and established AS. Semi-quantitative grading is reliable, and fatty degeneration of paravertebral muscles seems to be related to chronicity and spinal functions in patients with nr-axSpA and AS.