Inflammatory back pain in ankylosing spondylitis: a reassessment of the clinical history for application as classification and diagnostic criteria

Age at onset in axial spondyloarthritis around the world: data from the ASAS-PerSpA study

Objective

Age at onset is useful in identifying chronic back patients at an increased risk of axial SpA (axSpA). However, the majority of data on which the criterion of age at onset <45 years is based originates from Europe. Therefore it is unknown if this criterion applies in other parts of the world. We aimed to assess the age at onset of axSpA and its relationship with HLA-B27 and gender across the world.

Methods

Analyses were applied to patients from 24 countries across the world with an axSpA diagnosis and known age at onset of axial complaints. Cumulative probability plots were used to display the cumulative distribution of age at onset of axial symptoms. Linear regression models were built to assess the effect of HLA-B27 and gender on age at onset of axial symptoms.

Results

Of 2579 axSpA patients, 92% had an age at onset of axial symptoms <45 years, with only small variations across the geographical regions [Asia, n = 574 (94%); Europe and North America, n = 988 (92%); Latin America, n = 246 (89%); Middle East and North Africa, n = 771 (91%)]. Age at onset of axial symptoms was consistently lower in HLA-B27-positive patients {median 25 years [interquartile range (IQR) 19–32] vs 31 [IQR 22–39]} and male patients [median 25 years (IQR 19–33) vs 28 (IQR 21–37)], but in multivariable models an additional statistically significant effect of male gender independent of HLA-B27 was only found in Asia.

Conclusion

Around the world, the great majority of axSpA patients had an age at onset of axial disease of <45 years, with HLA-B27 and male gender associated with earlier disease onset.

Imbalance of Peripheral Lymphocyte Subsets in Patients With Ankylosing Spondylitis: A Meta-Analysis

Ankylosing spondylitis is a complicated consequence of genetic predisposition and environmental factors. Enthesitis is believed to be the hallmark of ankylosing spondylitis, and the chronic inflammatory state of this disease is perpetuated by the disturbances of both the innate immune system and the acquired immune system. To clarify the alteration of immune system in patients with AS, we conducted a meta-analysis concerning the proportions of major lymphocyte subsets in the peripheral blood of AS patients. We systematically searched PubMed and China National Knowledge Infrastructure (CNKI) for articles related to this subject. A total of 95 articles involving 4,020 AS patients and 3,065 healthy controls were included in the analysis. This meta-analysis is performed on R platform using R package "meta", and Egger's tests were used to determine the presence of publication bias. Results showed that the percentages of T cells, NK cells and NKT cells were not significantly different between AS patients and healthy controls, but B cells were significantly increased. Among the subsets of T cells, the proportions of CD4+ T cells, Th17 cells, Tfh cells as well as Th1/Th2 ratio were significantly increased, while Tregs were significantly decreased. Subgroup analysis showed that the proportions of Th17 among both PBMCs, T cells and CD4+ T cells were significantly elevated, while Tregs were only significantly lower in PBMCs. Subgroup analysis also demonstrated that Tregs defined by "CD4+CD25+FoxP3+", "CD4+CD25+CD127low"or "CD4+CD25+CD127-"were significantly downregulated, indicating that the selection of markers could be critical. Further study is warranted in order to elucidate the complicated interactions between different lymphocyte subsets in AS patients. This study implied that the disequilibrium between Th17 and Tregs, as well as between Th1 and Th2 could contribute to the pathogenesis of ankylosing spondylitis, further cementing the understanding that ankylosing spondylitis is a consequence of disrupted balance of innate immune system and acquired immune system.

Inflammatory back pain: a concept, not a diagnosis

PURPOSE OF REVIEW

The concept of inflammatory back pain (IBP) describes a cohort of patients with chronic back pain (CBP) who have distinct clinical characteristics, rather than being a diagnosis in and of itself. IBP is a common and important feature of axial spondyloarthritis (axSpA) but this is not the only differential. This review examines the utility of IBP in both primary and secondary care settings.

RECENT FINDINGS

There are a number of suggested referral strategies for patients with suspected axSpA that include IBP. These strategies attempt to strike a balance between ensuring potential axSpA patients are not overlooked, whilst simultaneously not overwhelming secondary care services. Their success relies on the clinicians who first encounter these patients being familiar with IBP as a concept; however, it is still poorly recognized by many healthcare professionals. IBP may be helpful as part of a referral strategy; however, other clinical features, laboratory investigations and radiology must be incorporated for the final diagnostic outcome in axSpA.

SUMMARY

Delayed diagnosis is a major clinical problem in axSpA and is associated with worse clinical outcomes. When recognized and utilized correctly, IBP can be a useful tool to promote prompt referral to rheumatology services.

Prevalence of Rheumatic Diseases and Quality of Life in the Saraguro Indigenous People, Ecuador: A Cross-sectional Community-Based Study

Rheumatic diseases are more prevalent and aggressive in indigenous population groups, providing medical attention for which poses a challenge for the rheumatologist.

OBJECTIVE

To estimate the prevalence of musculoskeletal (MSK) disorders and rheumatic diseases in the Saraguro indigenous people in Ecuador, as well as to identify the main factors associated with the health status of this population.

METHODS

This observational, cross-sectional study focused on the community was conducted using the COPCORD (Community-Oriented Program for Control of Rheumatic Diseases) methodology. The required data were obtained using the following instruments: (1) a screening for MSK disorders and rheumatic diseases; (2) a sociodemographic questionnaire; (3) a functional capacity Health Assessment Questionnaire Disability Index questionnaire; and (4) the quality of life EQ-5D-3L (EuroQoL) questionnaire. The rheumatologists working with the indigenous community were responsible for examining and treating study participants suffering from MSK disorders.

RESULTS

The study sample comprised 2687 individuals, with mean age of 44 (SD, 19.9) years, 1690 (62.9%) of whom were women; Kichwa speakers comprised 32.4% (872), and 1244 (46.3%) reported MSK pain. The most prevalent conditions were as follows: low back pain (9.3%), hand osteoarthritis (OA, 7.2%), knee OA (6.5%), rheumatic regional pain syndrome (5.8%), fibromyalgia (1.8%), and rheumatoid arthritis (1.3%). Lower education level, unemployment, cooking with firewood, and rheumatic diseases were associated with a lower quality of life.

CONCLUSIONS

Musculoskeletal disorders, rheumatic diseases, and rheumatoid arthritis were found to be highly prevalent in the studied population. Rheumatoid arthritis and hand OA had the most significant impact on the quality of life.

Personal Experiences with Diagnostic Delay Among Axial Spondyloarthritis Patients: A Qualitative Study

INTRODUCTION

On average, patients with axial spondyloarthritis (axSpA) suffer from symptoms up to 13 or more years before diagnosis, contributing to psychological distress and healthcare burden METHODS: We conducted six semi-structured focus groups with 26 axSpA patients (from 3 rheumatology practices located in the states of Massachusetts, Colorado, and Pensylvania, USA) exploring early disease and diagnostic experiences. Verbatim transcripts were coded using a start list with emerging thematic codes added. A qualitative thematic analysis was performed RESULTS: Many participants described meandering and frustrating diagnostic journeys. Participants reported that intermittent axSpA symptoms and idiopathic pain contributed to physician confusion and delay in patients seeking care. Participants were sometimes perceived as somaticizing, drug-seeking, or "crazy." Diagnostic delay led to frustration and mental suffering. Doctors "giving up" was considered profoundly negative. Stories of symptoms fell into five areas: (1) pain; (2) stiffness; (3) impact on sleep; (4) impact on daily activities; and (5) changes with weather. Self-advocacy and family advocacy were considered essential. Participants suggested wider use of HLA-B27 testing and development of a definitive diagnostic test CONCLUSION: Most participants described significant suffering prior to axSpA diagnosis which could have been avoided with earlier intervention. Further research on the early disease experiences of axSpA patients is needed.

Differentiation of inflammatory from degenerative changes in the sacroiliac joints by machine learning supported texture analysis

PURPOSE

To compare the diagnostic performance of texture analysis (TA) against visual qualitative assessment in the differentiation of spondyloarthritis (SpA) from degenerative changes in the sacroiliac joints (SIJ).

METHOD

Ninety patients referred for suspected inflammatory lower back pain from the rheumatology department were retrospectively included at our university hospital institution. MRI at 3 T of the lumbar spine and SIJ was performed with oblique coronal T1-weighted (w), fluid-sensitive fat-saturated (fs) TIRM and fsT1w intravenously contrast-enhanced (CE) images. Subjects were divided into three age- and gender-matched groups (30 each) based on definite clinical diagnosis serving as clinical reference standard with either degenerative, inflammatory (SpA) or no changes of the SIJ. SIJ were rated qualitatively by two independent radiologists and quantitatively by region-of-interest-based TA with 304 features subjected to machine learning logistic regression with randomized ten-fold selection of training and validation data. Qualitative and quantitative results were evaluated for diagnostic performance and compared against clinical reference standard.

RESULTS

Agreement of radiologist's diagnose with clinical reference was fair for both readers (κ = 0.32 and 0.44). ROC statistics revealed significant outperformance of TA compared to qualitative ratings for differentiation of SpA from remainder (AUC = 0.89 vs. 0.75), SpA from degenerative (AUC = 0.91 vs. 0.67) and TIRM-positive SpA (i.e. with bone marrow edema) from remainder cases (AUC = 0.95 vs. 0.76). T1w-CE images were the most important discriminator for detection of SpA.

CONCLUSIONS

TA is superior to qualitative assessment for the differentiation of inflammatory from degenerative changes of the SIJ. Intravenous CE-images increase diagnostic yield in quantitative TA.

Axial Psoriatic Arthritis

PURPOSE OF REVIEW

To review current understanding of the prevalence, clinical features, outcome measures and recent therapeutic trials in axial psoriatic arthritis (axPsA).

RECENT FINDINGS

The prevalence of axPsA is estimated at 40-50%. However, the definition of axPsA remains unclear, therefore these estimates may be inaccurate. Ax PsA appears to be distinct from ankylosing spondylitis in demographic, clinical, genetic and therapeutic features. Because of the lack of widely accepted definition of axPsA it has been difficult to design therapeutic trials for this domain of PsA. Several studies have demonstrated the uniquness of axPsA. Few recent trials suggest that therapies that work for peripheral arthritis also work for axPsA.

Methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a systematic review

ABSTRACT

Mechanism-based classification of pain has been advocated widely to aid tailoring of interventions for individuals experiencing persistent musculoskeletal pain. Three pain mechanism categories (PMCs) are defined by the International Association for the Study of Pain: nociceptive, neuropathic, and nociplastic pain. Discrimination between them remains challenging. This study aimed to build on a framework developed to converge the diverse literature of PMCs to systematically review methods purported to discriminate between them; synthesise and thematically analyse these methods to identify the convergence and divergence of opinion; and report validation, psychometric properties, and strengths/weaknesses of these methods. The search strategy identified articles discussing methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system. Studies that assessed the validity of methods to discriminate between categories were assessed for quality. Extraction and thematic analysis were undertaken on 184 articles. Data synthesis identified 200 methods in 5 themes: clinical examination, quantitative sensory testing, imaging, diagnostic and laboratory testing, and pain-type questionnaires. Few methods have been validated for discrimination between PMCs. There was general convergence but some disagreement regarding findings that discriminate between PMCs. A combination of features and methods, rather than a single method, was generally recommended to discriminate between PMCs. Two major limitations were identified: an overlap of findings of methods between categories due to mixed presentations and many methods considered discrimination between 2 PMCs but not others. The results of this review provide a foundation to refine methods to differentiate mechanisms for musculoskeletal pain.

Clinical features of psoriatic arthritis

Psoriatic arthritis (PsA) is associated with decreased quality of life. As delayed diagnosis may lead to progressive joint destruction and long-term disability, the key clinical features of PsA should be recognizable to a wide range of clinicians to facilitate early diagnosis. In addition to assessment and identification of skin and nail lesions, which occur in up to 85% of those with musculoskeletal manifestations, clinicians should be aware of both the peripheral and axial manifestations of musculoskeletal disease reviewed here. Peripheral joint diseases include polyarticular, oligoarticular, distal, and arthritis mutilans subtypes, and cognizance of these patterns of disease, as well as periarticular manifestations, including dactylitis and enthesitis, is useful for swift diagnosis of PsA. Axial psoriatic arthritis (axial PsA), also known as the spondylitis subtype, may be limited to the spine and sacroiliac joints, but may also affect peripheral structures. Meticulous history-taking and physical examination and familiarity with appropriate imaging studies are often necessary to distinguish axial-PsA from other differential diagnoses. Swift diagnosis and treatment are necessary to both control PsA disease and mitigate the risks of the many associate comorbidities that may accompany it.

Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis

In recent years, significant progress has been made in improving the early diagnosis of spondyloarthritides (SpA), including axial SpA. Nonetheless, there are still issues related to the application of classification criteria for making the primary diagnosis of SpA in the daily practice. There are substantial conceptional and operational differences between the diagnostic vs classification approach. Although it is not possible to develop true diagnostic criteria for natural reasons as discussed in this review, the main principles of the diagnostic approach can be clearly defined: consider the pre-test probability of the disease, evaluate positive and negative results of the diagnostic test, exclude other entities, and estimate the probability of the disease at the end. Classification criteria should only be applied to patients with an established diagnosis and aimed at the identification of a rather homogeneous group of patients for the conduction of clinical research.

Predictive values of inflammatory back pain, positive HLA B27 antigen and acute and chronic magnetic resonance changes in early diagnosis of Spondyloarthritis. A study of 133 patients

OBJECTIVES

To analyse the predictive values of inflammatory back pain (IBP), positive HLA B27 antigen, increased C-reactive protein (CRP), Spondyloarthritis (SpA) features, familial history (FH), magnetic resonance sacroiliac joints (MRI-SIJ) imaging and its weight in early SpA diagnosis.

METHODS

133 patients with back pain, aged <50, duration of the pain <2 years were included. Data such as IBP, HLA B27, increased CRP, SpA features, FH, SIJ´s radiography and MRI were collected for each patient. STIR sequences were classified as strongly positive bone morrow oedema (SPBME ≥2), clearly present and easily recognisable as positive according to the ASAS criterion, weakly positive (WPBME ≥2), suggestive, but not easily recognisable and, clearly negative none of those features. T1-weighted sequences were assessed as positive/negative for erosion, fat metaplasia, backfill and sclerosis, if ≥1, for each lesion was present. MRI images were read by three blinded readers.

RESULTS

The average age was 38.9 years. 47 (35.3%) patients received SpA diagnosis according to the clinical opinion. IBP was highly specific, 0.81 and sensitive, 0.83. HLA B27 was positive in a half of the SpA patients. SPBME ≥2 provided a great specificity, 0.94 and an acceptable sensitivity, 0.79. Erosion was significantly more frequent in SpA patients (72% vs 7%), specificity 0.93. The addition of erosion ≥1 to the WPBME ≥2 noticeably improved specificity, 0.98, although slightly decreased sensitivity, 0.64. Fat metaplasia and backfill were highly specific, but poorly sensitive. Factors forecasting positive diagnosis were IBP, followed by SpA features and increased CRP.

CONCLUSIONS

At the onset, IBP might be a good marker for selecting patients with suspicion of SpA. The addition of erosion to the ASAS criterion might be helpful for early diagnosis, especially in patients with doubtful STIR imaging where BME is present but it is hard to determinate whether the ASAS "highly suggestive" criterion is met.

Evaluating Inflammatory Versus Mechanical Back Pain in Individuals with Psoriatic Arthritis: A Review of the Literature

Psoriatic arthritis (PsA) is a chronic immune-mediated disease characterized by psoriatic skin and nail changes, peripheral joint inflammation, enthesitis, dactylitis, and/or axial involvement, either alone or in combination with each other. The presence of axial involvement has been shown to be a marker of PsA severity; however, there is no widely accepted definition of axial involvement in PsA (axPsA) or consensus on how or when to screen and treat patients with suspected axPsA. Chronic back pain is a prominent feature of axPsA and is thought to have a relevant role in early identification of disease. Chronic back pain can be caused by inflammatory back pain (IBP) or mechanical back pain (MBP). However, MBP can complicate recognition of IBP and delay diagnosis of axPsA. While MBP can also be associated with chronic back pain of ≥ 3 months in duration that is typical of IBP, IBP is characterized by inflammation of the sacroiliac joint and lower spine that is differentiated from MBP by key characteristic features, including insidious onset at age < 40 years, improvement with exercise but not with rest, and nighttime pain. This review discusses the differences in identification and management of IBP and MBP in patients with PsA with axPsA. The summary of available evidence highlights the importance of appropriate and timely screening, difficulties and limitations of differential diagnoses and treatment, and unmet needs in axPsA.

Chronic back pain in first-degree relatives (FDRs) of patients with ankylosing spondylitis: predictive value of HLA-B27 and persistence of inflammatory back pain over time

Background/Purpose

First-degree relatives (FDRs) of patients with ankylosing spondylitis (AS) may be at high risk of spondyloarthritis. We examined the frequency, characteristics of chronic back pain (CBP), associated features, persistence of symptoms, and HLA-B27 allele frequency in FDRs of AS patients, also comparing those FDRs with participants in NHANES 2009–2010 with CBP.

Methods

399 FDRs of AS probands were divided into: (1) No CBP (subjects >40 years old at study visit without CBP) (n=162); (2) NICBP (non-inflammatory CBP) (n=82), and (3) CIBP (inflammatory CBP) (n=155). White FDRs with CBP were compared with 772 participants in NHANES 2009–2010 with CBP. FDRs were invited to return for reassessment.

Results

FDRs with CIBP had earlier onset of CBP than those with NICBP (p<0.001) and had higher frequency of heel pain than those without CBP (p=0.002). HLA-B27 occurred in 57% of FDRs with CIBP vs 39.6% of those without CBP (p=0.005, OR=1.9). Of 23 patients with CIBP at baseline re-evaluated 67.04±31.02 months later, 16 (73%) still had CIBP, whereas 4 (31%) of 13 NICBP patients seen 61.23±31.84 months later remained symptomatic.

Conclusion

CIBP in FDRs of AS patients is HLA-B27-associated, has earlier onset and tends to persist compared to NICBP.

Long-term association between disease activity and disability in early axial spondyloarthritis: results from the DESIR cohort

OBJECTIVES

Our primary objective was to study the long-term association between disease activity and disability in axial spondyloarthritis (axSpA). Our secondary objective was to define patient profiles according to their level of disability.

METHODS

We analysed data collected during the first five years of follow-up of a large early axSpA cohort - the Devenir des Spondylarthropathies Indifferénciées Récentes (DESIR) cohort. Multivariable models were built to study the association between Ankylosing Spondylitis Health Assessment Questionnaire (HAQ-AS) and Ankylosing Spondylitis Disease Activity Score C-reactive protein (ASDAS-CRP), adjusting for potential confounders. Hierarchical multivariable analysis was conducted using the Chi-square Automatic Interaction Detector (CHAID) method, to help determine how variables best cluster to explain HAQ-AS.

RESULTS

Data from 644 patients and 5152 visits were analysed. HAQ-AS was longitudinally, independently and positively associated with ASDAS-CRP [adjusted (adj) B=0.205, (95% confidence interval (CI)= 0.187 to 0.222], enthesitis score (adjB=0.011, CI=0.008 to 0.015), Bath Ankylosing Spondylitis Metrology Index (BASMI) (adjB=0.087, CI=0.069 to 0.105) and female gender (adjB=0.172, CI=0.120 to 0.225). The CHAID decision tree revealed ASDAS-CRP as the first variable with discriminative power on HAQ-AS. The cut-offs that separated different patient disability profiles were obtained.

CONCLUSION

Disease activity contributes longitudinally to disability and is hierarchically superior to any other variable in explaining this health domain. Enthesitis and spinal mobility are also key drivers of disability in early axSpA. ASDAS-CRP cut-offs that separated different patient disability profiles largely mimicked the cut-offs previously defined for ASDAS-CRP disease activity states.

Comorbid pain in axial spondyloarthritis, including fibromyalgia

The main symptom in patients with axial spondyloarthritis (axSpA) is inflammatory back pain, caused principally by inflammation of the sacroiliac joints and the spine. However, not all back pain in patients with axSpA is related to active inflammation: other types of pain can occur in these patients, and may be related to structural damage (e.g. ankylosis), degenerative changes, vertebral fractures or comorbid fibromyalgia, which are not uncommon in these patients. Structural damage and ankylosis may lead to a biomechanical stress, which can lead to chronic mechanical pain; and degenerative changes of the spine may also exist in patients with axSpA also leading to mechanical pain. Osteoporosis is more prevalent in axSpA patients than in the general population, and vertebral fractures may result in acute bone pain, which can persist for several months. Fibromyalgia, which is also more prevalent in patients with chronic inflammatory diseases (including axSpA), presents with widespread pain which can mimic entheseal pain. A correct diagnosis of the origin of the pain is crucial, since treatments and management may differ considerably. Recognizing these causes of pain may be a challenge in clinical practice, especially for fibromyalgia, which can coexist with axSpA and may have a significant impact on biologic drug response.

In this review, we provide an update of the most common causes of pain other than inflammatory back pain in axSpA patients, and we discuss the latest management options for such causes.

Non-radiographic axial spondyloarthritis

Non-radiographic axial spondyloarthritis (nr-axSpA) is a subgroup of axial spondyloarthritis (axSpA) without fulfilling the modified New York criteria of sacroiliac joint radiographs for ankylosing spondylitis (AS). AS and nr-axSpA share various demographic and clinical features and disease burden, although sex and objective inflammatory findings such as elevated serum C-reactive protein level are slightly different between AS and nr-axSpA. Recently, diagnostic guidance for nr-axSpA in Japan was proposed for epidemiological studies of a population with a low prevalence of HLA-B27 positivity and the use of molecular targeted agents suitable for the unique medical care system in Japan. A biological agent targeting interleukin-17 was approved for nr-axSpA by the Pharmaceutical and Medical Devices Agency (PMDA) in August 2020. Some other biological agents will be also available for Japanese patients with nr-axSpA in the near future.

Understanding Barriers in the Pathway to Diagnosis of Ankylosing Spondylitis: Results From a US Survey of 1690 Physicians From 10 Specialties

Objective

Early diagnosis of ankylosing spondylitis (AS) remains challenging because of the high prevalence of chronic back pain in patients initially treated by nonrheumatology health care providers (HCPs). We assessed the patient pathway to rheumatology referral, including HCP recognition of inflammatory back pain (IBP) and other features suggestive of AS, diagnostic workup, treatment, and referral to a specialist with the goal of identifying barriers to patient referral to a rheumatologist.

Methods

US HCPs from 10 specialties were invited to participate in a cross‐sectional web‐based survey on clinical characteristics and diagnostic measures leading to IBP suspicion and the subsequent referral process. Eligible HCPs were actively practicing and had referred a patient with suspected IBP or ocular findings (ophthalmology only) within 12 months. Data were analyzed descriptively.

Results

Of 1690 HCPs, 61% identified morning stiffness lasting more than 30 minutes, 29% sleep disturbance due to back pain, and 28% pain that improves with activity as features suggestive of IBP. Nearly two‐thirds of primary care HCPs reported that they were the first HCPs consulted by patients with suspected IBP. Among HCPs ordering diagnostic blood work, approximately 90% selected antinuclear antibody and rheumatoid factor, whereas 76% selected human leukocyte antigen B27. Almost 40% would treat patients with suspected IBP themselves. HCPs cited lack of adequate specialists nearby (35.1%), insurance restrictions (47.1%), and long wait time (77.0%) as barriers to early referral.

Conclusion

Most HCPs had difficulty identifying features suggestive of IBP and indicated insurance restrictions and long wait times as barriers to early referral of patients with potential AS.

Comparative analysis of the diagnostic values of T2 mapping and diffusion-weighted imaging for sacroiliitis in ankylosing spondylitis

OBJECTIVE

To investigate the diagnostic values of T2 mapping and diffusion-weighted imaging (DWI) for active sacroiliitis in ankylosing spondylitis (AS) and to evaluate the correlations of T2 and ADC values with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Spondyloarthritis Research Consortium of Canada (SPARCC) scores.

METHODS

A total of 77 AS patients with sacroiliitis and 45 healthy controls were enrolled. All patients were scanned by standard magnetic resonance imaging longitudinal relaxation time (T1)-weighted imaging (T1WI), fat-saturated T2-weighted imaging (FS-T2WI)] and DWI, and T2 mapping of the sacroiliac joints. According to whether subchondral bone marrow edema was present in the FS-T2WI sequence, the 77 patients were divided into an active group (41 cases) and an inactive group (36 cases). The T2 and apparent diffusion coefficient (ADC) values of the subchondral bone marrow were measured in the active group, the inactive group, and the healthy control group. The average T2 and ADC values were compared among the three groups. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic efficacy of T2 and ADC values for sacroiliitis. The correlations of T2 and ADC values with the BASDAI score and the SPARCC score were analyzed.

RESULTS

The T2 and ADC values in the active group were higher than those in the inactive group, while that in the inactive group were significantly higher than those in the healthy control group (p < 0.0001). The T2 and ADC values of the AS patients were positively correlated with BASDAI scores, and the correlation coefficients (r) were 0.786 (p < 0.0001) and 0.842 (p < 0.0001), respectively. The areas under the ROC curves (AUCs) of T2 and ADC values between the active and inactive groups, the active group and the healthy control group, and the inactive group and the healthy control group were 0.889 (95% CI, 0.80-0.95) and 0.917 (95% CI, 0.83-0.97), 0.982 (95% CI, 0.93-1.00) and 0.984 (95% CI, 0.93-1.00), and 0.628 (95% CI, 0.51-0.73) and 0.871 (95% CI, 0.78-0.94), respectively. The T2 and ADC values of the AS patients in the active group were positively correlated with SPARCC scores, and the correlation coefficients (r) were 0.757 (p < 0.0001) and 0.764 (p < 0.0001), respectively.

CONCLUSION

T2 and ADC values can be used to quantitatively assess the activity of AS, and the efficacy of the ADC value in the diagnosis of AS was higher than that of the T2 value.

Uveitis in spondyloarthritis

Uveitis is the most frequent extra-articular manifestation of axial spondyloarthritis (SpA), occurring in up to one-third of the patients. In the majority of patients, uveitis is acute, anterior and unilateral and presents with photosensitivity, sudden onset of pain and blurred vision. Topical steroids are an effective treatment; however, recurrent or refractory cases may need conventional disease-modifying antirheumatic drugs or biological treatment with monoclonal tumor necrosis factor (TNF) inhibitors, thus also influencing treatment strategy of the underlying SpA. Though the exact pathogenesis of SpA and uveitis remains unknown, both seem to result from the interaction of a specific, mostly shared genetical background (among other HLA-B27 positivity), external influences such as microbiome, bacterial infection or mechanical stress and activation of the immune system resulting in inflammation. Up to 40% of patients presenting with acute anterior uveitis (AAU) have an undiagnosed SpA. Therefore, an effective referral strategy for AAU patients is needed to shorten the diagnostic delay of SpA and enable an early effective treatment. Further, the risk for ophthalmological manifestations increases with the disease duration in SpA; and patients presenting with ocular symptoms should be referred to an ophthalmologist. Thus, a close collaboration between patient, rheumatologist and ophthalmologist is needed to optimally manage ocular inflammation in SpA.

T2 mapping of the sacroiliac joints in patients with axial spondyloarthritis

PURPOSE

To test whether T2 mapping of the sacro-iliac joints (SIJs) might help identifying patients with spondyloarthritis.

METHOD

This study included 20 biologic-naive patients with axial spondyloarthritis (10 females; mean age: 38 ± 9years; range, 19-47) and 27 controls (16 males; mean age = 39 ± 13years; range = 28-71) who prospectively underwent SIJs MRI at 1.5 T, including a multislice multiecho spin-echo sequence. Standard MRIs were reviewed to assess the SIJs according to the Assessment of SpondyloArthritis International Society (ASAS) criteria and SPondyloArthritis Research Consortium of Canada (SPARCC) MRI index. T2 maps obtained from multiecho sequences were used to draw regions of interests in the cartilaginous part of the SIJs. Disease activity was assessed using BASDAI questionnaire. Bland-Altman method, ROC curve analysis, Chi square, Mann-Whitney U, Pearson's and Spearman's correlation coefficient were used for data analysis.

RESULTS

According to ASAS criteria, MRI was positive for sacroiliitis in 5/20 patients (25 %). Inter-observer reproducibility of T2 values was 87 % (coefficient of repeatability = 7.0; bias = 0.49; p < .001). Mean T2 values of patients (58.5 ± 4.4 ms, range: 52.6-68.2 ms) were significantly higher (p < .001) than those of controls (44.1 ± 6.6 ms, range: 33.6-67.2 ms). A T2 value of 52.51 ms yielded 100 % sensitivity and 91.7 % specificity to differentiate patients from controls. No statistically significant association/correlation was found between T2 values and BASDAI (r=-.026, p = .827), disease duration (r = .024, p = .871), SPARCC (r=-.004, p = .981), ASAS criteria (p = .476), HLA-B27-positivity (p = .139), age (r=-.2.53, p = .891), and gender (p = .404).

CONCLUSIONS

T2 relaxation times of the SIJs were significantly higher in patients than in healthy controls, making this tool potentially helpful to early identify patients with spondyloarthritis.

Prevalence of Spondyloarthritis Among Patients Who Underwent Lumbar Disc Herniation Surgery

Objectives

This study aims to estimate the prevalence of spondyloarthritis (SpA) among patients who had been surgically treated for lumbar disc herniation (LDH), according to the modified New York (mNY) criteria for the diagnosis of ankylosing spondylitis and Amor, the European Spondyloarthropathy Study Group (ESSG), the Assessment of Spondyloarthritis International Society (ASAS) classification criteria for SpA.

Patients and methods

The study included 321 patients (142 males, 179 females; mean age 49±10.8 years; range, 18 to 79 years) who underwent LDH surgery between April 2008 and May 2012 in the neurosurgery clinic of our hospital. Patients were contacted by phone on at least two attempts. Totally, 123 patients accepted to come to the outpatient clinic, while the remaining 198 agreed to be interviewed on the phone. Patients who agreed to come to the outpatient rheumatology clinic underwent clinical examination, and pelvic X-ray and magnetic resonance imaging (MRI) scan of the sacroiliac joints when indicated.

Results

Inflammatory back pain was diagnosed in 108 patients (34%) and 40 patients (13%) according to Calin criteria and the ASAS criteria, respectively. Prevalence of SpA among all patients was estimated as 17.7% according to the ESSG criteria, and 8.7% according to Amor criteria. Five of the 308 pelvic radiographs had definite radiographic sacroiliitis as required by the mNY criteria. Four patients had a characteristic pattern of bone marrow edema on MRI examination in accordance with the ASAS definitions. The overall prevalence of sacroiliitis (MRI sacroiliitis+X-ray sacroiliitis) among the patients who came to the clinic was 7.3% ([4+5]/123).

Conclusion

The relatively increased prevalence of SpA among patients who underwent LDH surgery indicates the necessity of increasing awareness on the new concept of axial SpA for specialists treating patients with low back pain.

Sacroiliitis in Systemic Lupus Erythematosus Revisited

Objectives

This study aims to investigate the prevalence of inflammatory back pain (IBP) and sacroiliitis in a systemic lupus erythematosus (SLE) population as well as the association between IBP and the frequency of human leukocyte antigen B27 (HLA-B27).

Patients and methods

The study included 281 SLE patients (16 males, 265 females; mean age 39.9±11.9 years; range, 20 to 69 years) and 100 healthy controls (HCs) (2 males, 98 females; mean age 41.2±10.1 years; range, 19 to 64 years). Participants were administered a five-item Assessment of SpondyloArthritis international Society-IBP questionnaire. Patients and controls with IBP underwent detailed clinical and laboratory examinations to detect sacroiliitis. Radiographic evaluations were performed by a blinded rheumatologist and radiologist. Interobserver reliability was assessed with Cohen's kappa test.

Results

According to the questionnaire, IBP was present in 46 SLE patients (46/281; 16.3%) whereas none of the HC had IBP (p<0.001). In radiological assessment, 22 SLE patients (7.8%) had sacroiliitis detected by conventional X-ray and/or magnetic resonance imaging. Only one SLE patient with sacroiliitis had HLA-B27.

Conclusion

Our study showed that IBP is increased in SLE patients and IBP in SLE is not associated with HLA-B27.

Axial psoriatic arthritis: An update for dermatologists

Psoriasis is a chronic, immune-mediated, systemic, inflammatory disorder characterized by skin plaques and, often, nail disease and arthritis that contribute to reduced quality of life. Psoriatic arthritis-a heterogeneous, inflammatory, musculoskeletal disease that can cause permanent damage to both peripheral and axial joints-is the most common comorbidity of psoriasis. Axial disease occurs in 25% to 70% of patients with PsA, with some patients exclusively experiencing axial joint involvement. Early therapeutic intervention is important for preventing permanent joint and spine damage and loss of functionality in these patients. Because skin symptoms associated with psoriasis often precede psoriatic arthritis, dermatologists are uniquely positioned to play an important role in identifying and treating patients with psoriatic arthritis. Proactive screening of patients with all severities of psoriasis for the signs and symptoms of psoriatic arthritis is key to early diagnosis and intervention. In this review, we discuss the clinical presentation, risk factors, and treatment options for psoriatic arthritis with axial involvement, with the aim of helping dermatologists understand the disease and identify patients who might benefit from further assessment, treatment, and/or referral to a rheumatology practice.

Comparative study of imaging and histology of sacroiliac joint in normal rats based on IVIM-DWI and DCE-MRI

Background

Currently, few studies have described the relationship between functional MRI findings and histology of normal sacroiliac joint (SIJ). Besides, due to the difficulties in access to SIJ, authentic animal models are important in providing opportunities for quantitative parameter extraction on imaging.

Aims

This study aimed at exploring the parameters of Intravoxel Incoherent Motion Diffusion-Weighted Imaging (IVIM-DWI) and Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) and comparing them with the histology of the SIJ in normal rats with different ages.

Methods

A total of thirty 7-week-old male Wistar rats were included in the study. The parameters of IVIM-DWI and DCE-MRI in the bone marrow and the joint space of SIJ were measured at 8, 13, 18, 23, 28, and 33 weeks. The histological analysis of the SIJ was examined using light microscopy. One-way ANOVA was used for statistical analysis.

Results

The D values in the sacral and iliac bone marrow of normal rats decreased with an increase in age. One-way ANOVA analysis indicated a significant difference in D values in different age groups (P<0.005). The normal values of D*, f, Fenh (%), Senh (%/s) in the sacral bone marrow, the iliac bone marrow, and the joint space in SIJ of normal rats were obtained. The results showed that in the six groups of rats of different ages, the histology of the SIJ surface was smooth and clear, the cartilage cells were intact, and no thickening or pannus formation was observed.

Conclusions

This study obtained the IVIM-DWI and DCE-MRI parameters of the sacral and iliac bone marrow and the synovial area of the joint space in normal rats. The parameters in normal rats can be used in future research to compare to similar parameters in animal models or patients with SIJ diseases. This study serves as a guide for future research in SIJ diseases.

Prevalence of musculoskeletal disorders and rheumatic diseases in an Argentinean indigenous Wichi community

OBJECTIVE

To estimate the prevalence of musculoskeletal disorders (MSK) and rheumatic diseases in an indigenous Wichi population in Argentina.

METHODS

This is a cross-sectional, community-based study using the Community-Oriented Program for the Control of Rheumatic Diseases (COPCORD) methodology in ≥ 18-year-old subjects. Validated surveys were conducted by trained interviewers. Subjects with MSK pain (positive cases) were evaluated by internists and rheumatologists for diagnosis and treatment.

RESULTS

A total of 648 interviews were performed (90.4% of the census population). Mean age was 37.5 years (SD 14.8), and 379 (58.5%) were female. The mean years of education was 7.0 (SD 3.7); 552 subjects (85.2%) were covered by the public health care system. A total of 216 (33.3%) subjects had MSK pain in the last 7 days. Rheumatic disease prevalence was as follows: mechanical back pain (19.0%), rheumatic regional pain syndrome (5.2%), osteoarthritis (3.2%), rheumatoid arthritis (RA) (3.2%), inflammatory back pain (1.2%), undifferentiated arthritis (0.3%), Sjögren syndrome (0.15%), and fibromyalgia (0.15%). RA patients included 19 (90.5%) women and 9 (42.9%) with RA family history. One hundred percent were seropositive and 66.7% showed radiologic erosions. The mean of Disease Activity Score [DAS-28 (ESR)] at the time of diagnosis was 5.1 (SD 1.5) and the Health Assessment Questionnaire Disability Index (HAQ-DI) was 0.8 (SD 0.4).

CONCLUSION

RA prevalence was 3.2%, one of the highest reported using the COPCORD methodology in indigenous and non-indigenous peoples in Latin America, with a high percentage of family cases. Pain and functional capacity were the variables allowing patients' early referral to a specialist. Key Points • The RA prevalence was 3.2%, one of the highest reported using COPCORD methodology in indigenous and non-indigenous peoples in Latin America. • The patients with RA had high percentage of familiar history of RA. • The pain and functional capacity were the variables associated with a diagnosis of any rheumatic disease and should be considered for early referral. • The mean of the delay in the diagnosis was 5.8 years. In this community, the lack of the "migration health" phenomenon may be a social determinant that negatively impacts their health.

Early recognition of patients with axial spondyloarthritis—evaluation of referral strategies in primary care

Objective

Chronic inflammatory back pain (IBP) is frequently reported in axial SpA (axSpA) but also in the general population. We evaluated a recently proposed two-step referral system for early recognition of axSpA in primary care and compare it with other combinations of symptoms and SpA-related items.

Methods

Consecutive chronic back pain patients ≤45 years of age answered a questionnaire and were seen by a primary care physician who decided whether HLA-B27 needed to be determined. They were then referred to a rheumatologist who made the diagnosis. Generally sticking to the two-step system with HLA-B27 as an additional option, combinations with a sensitivity ≥90% and a likelihood ratio &gt;4 were compared.

Results

A total of 326 patients were included, 46 of whom were diagnosed with axSpA (14.1%). The sensitivity of the strategy was 87%, the specificity was 56.8% and the positive and negative predictive values were 24.8% and 96.4%, respectively. A ‘good response to NSAIDs’, ‘morning stiffness &gt;30 min’ and ‘elevated C-reactive protein’ performed best, with a sensitivity of 91%, specificity of 67%, positive predictive value of 31% and negative predictive value of 98%. On that basis, only three patients had to be seen by a rheumatologist to diagnose one.

Conclusion

The earlier proposed referral system worked well but was outperformed by other combinations with high sensitivity and better specificity, which deserve to be prospectively studied.

Data to be collected for an optimal management of axial spondyloarthritis in daily practice: Proposal from evidence-based and consensual approaches

OBJECTIVE

To propose a list of variables to be collected right after the diagnosis has been made and during the follow-up of patients with axial spondyloarthritis (ax-SpA) for an optimal management in daily practice.

METHODS

The process comprised (1) the evaluation of the interest of 51 variables proposed for the assessment of ax-SpA by means of a systematic literature research; (2) a consensus process involving 78 hospital-based or office-based rheumatologists, considering the collection of each variable in a 4 grade scale from "not very useful/useless" to "mandatory"; (3) a consensus on the minimum interval of time for periodic assessment of the selected variables on a 5 grade scale from "at each visit" to "never to be re-collected".

RESULTS

The systematic literature research retrieved a total of 14,133 abstracts, of which 213 were included in the final qualitative synthesis. Data to be collected at the initial systematic review comprised 5 patient's self-administered questionnaires, 3 variables of the physician's interview, 2 variables of the physical examination, 2 variables of the specific ax-SpA imaging and 2 other investigations. Two variables were recommended to be systematically collected at each visit, 1 variable twice a year, 6 variables yearly and 1 variable every 2 years.

CONCLUSIONS

Using an evidence-based and an expert consensus approaches, this initiative defined a core set of variables to be collected and reported right after the diagnosis and during follow-up of patients with ax-SpA in daily practice.

Recommendations by the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the treatment of patients with inflammatory bowel disease associated with spondyloarthritis

Extraintestinal manifestations, in general, and in particular arthropathies, are a common problem in patients with inflammatory bowel disease. In fact, the relationship between those 2entities is close and there are increasingly more data which suggest that the bowel plays a significant role in the aetiopathogenesis of spondyloarthritis. The association of inflammatory bowel disease with any kind of spondyloarthritis represents a challenging clinical scenario. It is therefore necessary that both gastroenterologists and rheumatologists work together and establish a fluent communication that enables the patient to receive the most appropriate treatment for each specific situation. The aim of this review is to make some recommendations about the treatment of patients with inflammatory bowel disease and associated spondyloarthritis, in each different clinical scenario.

The occurrence of sacroiliitis in HLA-B*35-positive patients with undifferentiated spondyloarthritis. A cross sectional MRI study

OBJECTIVE

To investigate possible association between sacroiliitis and HLA-B*35 positivity.

METHOD

After excluding patients with axial spondyloarthritis and HLA-B*27 positivity, psoriasis inflammatory bowel disease, preceding infections, or juvenile type of spondyloarthritis, 110 patients were recruited with a diagnosis of undifferentiated axial spondyloarthritis. All of them had inflammatory back pain of short duration (3 months to 2 years) and 72 were HLA-B*35 positive. In order to determine if there is a possible association of sacroiliitis and HLA-B*35 positivity, all patients underwent MRI of sacroiliac joints.

RESULTS

A statistically significant association between the detection of bone marrow edema at sacroiliac joints on MRI and HLA-B*35 positivity (χ2 = 6.25; p = 0.022) was found. A logistic regression analysis revealed that the presence of HLA-B*35 allele was associated with a 6 times greater chance of identifying bone marrow edema at sacroiliac joints on MRI (OR 6, 95% CI 1.3-27, p = 0.021). HLA-B*35 positivity was also associated with a 4.7 times greater chance of finding elevated CRP (OR 4.7, 95% CI 1-11.9, p = 0.047) and a 5 times greater chance of finding peripheral joint synovitis (OR 5, 95% CI 1.75-14.3, p = 0.003). HLA-B*35-positive patients had high disease activity (mean ± SD of Bath Ankylosing Spondylitis Disease Activity Index 6.1 ± 1.72 and Ankylosing Spondylitis Disease Activity Score C-reactive protein Index 3 ± 0.64) with a high degree of functional limitations (mean ± SD of Bath Ankylosing Spondylitis Functional Index 5.3 ± 2.16).

CONCLUSION

The data clearly show the association between bone marrow edema on MRI at sacroiliac joints and HLA-B*35 allele in patients with undifferentiated spondyloarthritis. Further work is needed to understand how much this result may influence follow-up of these patients. Key Points • HLA-B*35 allele was associated with a 6 times greater chance of identifying bone marrow edema at sacroiliac joints on MRI in un-axSpa patients. • HLA-B*35 allele was also associated with a 4.7 times greater chance of finding elevated CRP and a 5 times greater chance of finding peripheral joint synovitis in un-axSpa patients. • HLA-B*35 allele could be a potential risk factor for developing sacroiliitis and axSpA.

Relationship between sleep quality and physical activity level in patients with ankylosing spondylitis

Introduction: Aim of this study was to investigate whether there is a relationship between exercise level and sleep quality in AS patients.Method: In our study, 150 AS patients and 80 healthy controls were included. Physical activity levels of both groups were evaluated using International Physical Activity Questionnaire (IPAQ-s) short form. Sleep quality of the participants was evaluated using Pittsburgh Sleep Quality Index (PSQI). Disease activity and functional status were measured by Bath AS Disease Activity Index and Bath AS Functional Index.Results: Subjective sleep quality, habitual sleep efficiency, sleep disturbance and Total PSQI scores were significantly higher in the patient group compared to healthy participants. The IPAQ score was found to be significantly lower in the patient group. Sleep disturbance, one of the components of PSQI, was found to be significantly higher in patients with low IPAQ score.Conclusions: Sleep disorders were found to be higher in AS patients than normal population and physical activity levels of AS patients were lower than normal population. In addition, Sleep disturbance was found to be high in patients with low physical activity. Therefore, it should be remembered that one of the causes of sleep disorders in AS patients may be related to low physical activity.

[Establishment of the current classification criteria for axial spondylarthritis, rheumatoid arthritis and SLE in routine practice of German rheumatologists]

BACKGROUND

In Germany, the numbers of patients with spondylarthritides (SpA) and rheumatoid arthritis (RA) have increased. This rise was possibly promoted by the introduction of new classification criteria (CC) that enable an earlier recognition and the inclusion of less severe cases. The study explores how the new CC for axial SpA (axSpA) are incorporated into the clinical practice, compared with the CC for RA and systemic lupus erythematosus (SLE). In addition, the study investigated whether the new entity of non-radiographic axSpA (nr-axSpA) is accepted and used in Germany.

MATERIAL AND METHODS

In 2016, an online survey was performed among all rheumatologists registered in the German Society of Rheumatology (DGRh). In addition, 150 rheumatologists were invited to the survey at the national meeting of the DGRh in 2016.

RESULTS

Among 119 participating rheumatologists, 99% were familiar with the new CC for SpA and 82% applied them in practice (RA 99% and 80%, SLE 50% and 56%). 78% differentiated between radiographic and nr-axSpA and 80% believed that a significant proportion of patients with nr-axSpA will never develop radiographic changes. 91% agreed that the new CC facilitated an earlier treatment start and 58% that the CC enabled more patients to receive biologicals. 50% shared the opinion that the criterion "chronic back pain" could lead to the classification of too many patients as having axSpA. It deemed possible to 65% that patients with nr-axSpA would be treated with biologicals in whom the diagnosis of axSpA could not be confirmed later on. 81% voted against the initiation of TNF inhibitors in nr-axSpA patients with normal CRP levels and normal MRI. 67% interpreted the MRI themselves and 30% stated that the MRI is evaluated according to validated standards by the radiologists. Among all axSpA criteria, HLA B27 and inflammatory back pain received the highest significance and the response to NSAID the lowest.

CONCLUSION

The new CC and the entity of nr-axSpA are accepted by German rheumatologists. A relevant proportion saw weaknesses of the new CC in the differentiation between nr-axSpA and non-specific chronic back pain. In practise, the interpretation of the CC with respect to the start of biologics is relatively strict, especially in cases with normal CRP and MRI. A ranking of axSpA criteria is commonly applied, although this was not initially intended in the CC.

Clinical manifestations, disease activity and disease burden of radiographic versus non-radiographic axial spondyloarthritis over 5 years of follow-up in the DESIR cohort

Objectives

To compare the clinical manifestations, disease activity and disease burden between patients with radiographic (r-axSpA) and non-radiographic axial spondyloarthritis (nr-axSpA) over a 5-year follow-up period in the Devenir des Spondylarthropathies Indifferénciées Récentes (DESIR) cohort.

Methods

Patients from the DESIR cohort who had X-ray images of the sacroiliac joints available at baseline and did not leave the study during the 5-year follow-up period because of a diagnosis other than axSpA were included. A unilateral rating of ‘obvious sacroiliitis’ by the local reader was considered sufficient for classification as r-axSpA. The incidence of first episodes of peripheral and extra-rheumatic manifestations was compared between the two groups using the incidence rate ratio and Cox regressions adjusted for sex, age and tumour necrosis factor blocker (TNFb) intake. Mean values of patient-reported outcomes (PROs) and days of sick leave over 5 years of follow-up were compared using mixed models adjusted for sex, age, TNFb intake and baseline values.

Results

In total, 669 patients were included, of whom 185 (27.7%) and 484 (72.3%) were classified as r-axSpA and nr-axSpA, respectively. At baseline, the r-axSpA patients showed a significantly higher prevalence of males. After adjusting for age, sex and TNFb intake, Cox regressions for peripheral and extra-rheumatic manifestations did not show any significant differences between groups. Mixed models also showed similar mean levels in PROs and days of sick leave between groups over time.

Conclusion

The incidence of peripheral and extra-rheumatic manifestations as well as the disease burden over time remained similar between r-axSpA and nr-axSpA groups after adjusting for intermediate variables.

Trial registration number

NCT01648907

The LMP2 CfoI polymorphism is associated with ankylosing spondylitis (AS) risk but not with acute anterior uveitis (AAU): A meta-analysis

BACKGROUND

Ankylosing spondylitis (AS) is one of the most common chronic inflammatory disorders affecting the sacroiliac joints, spine, and peripheral joints. Apart from HLA-B27, the LMP2 gene has been shown to play a role in the pathogenesis of AS as well as AAU in AS. However, genetic associations between LMP2 CfoI polymorphism and AS and AAU were inconclusive. We aimed to investigate the correlation of LMP2 CfoI polymorphism and AS and AAU using meta-analysis.

METHODS

An exhaustive search was conducted using the PubMed, Embase, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) electronic databases. The strength association was assessed by crude ORs with 95% CI.

RESULTS

Eight eligible records with 449 AS patients and 317 healthy controls were included in the present study. The allelic model of the LMP2 CfoI polymorphism is associated with AS risk (OR = 0.60, 95%CI = [0.32, 1.11], P = .003). A stratified analysis based on ethnicity has shown that the allelic model of LMP2 CfoI was associated with AS in the Caucasian population (OR = 0.72, 95%CI = [0.55, 0.93], P = .01) but not in the Asian population (P > .05). Furthermore, no association was detected between LMP2 CfoI polymorphism and AS complication (AAU).

CONCLUSION

Our combined results revealed that the allelic model of LMP2 CfoI might be a protective factor for AS in the Caucasian population. Nevertheless, future studies on different ethnicities with larger sample sizes are needed to obtain a more convincing result.

Diagnostic efficacy of ultrasound detection of enthesitis in peripheral spondyloarthritis

Objective: We investigated the diagnostic efficacy of power Doppler ultrasound (PDUS) to detect enthesitis in Japanese patients with peripheral spondyloarthritis (SpA).Methods: This was a single-center cohort study of patients with peripheral symptoms suggestive of SpA. Articular synovia, tendons, and entheses were assessed by PDUS at baseline. Clinical, laboratory, and radiologic findings and classification criteria for SpA were also evaluated.Results: 136 patients were consecutively evaluated. A definite diagnosis was obtained in 111 patients, including 72 with SpA and 39 non-SpA. Among the patients with SpA, PDUS demonstrated articular synovitis in 40 of the 72 patients (56%), tenosynovitis or peritendinitis in 48 (67%), and enthesitis in 63 (88%). Considering PDUS alone, enthesitis in at least one site was the most useful means of differentiating SpA from non-SpA (sensitivity 87.5%; specificity 82.1%; accuracy 85.6%; positive likelihood ratio 4.88). Combining that finding along with fulfillment of Amor, European Spondyloarthropathy Study Group, or Assessment of SpondyloArthritis international Society criteria for peripheral SpA increased the specificity of the diagnosis (92.5%, 92.3%, and 97.4%, respectively).Conclusion: PDUS enthesitis is useful for the diagnosis of SpA with peripheral symptoms. Combining PDUS enthesitis with established SpA classification criteria is beneficial in diagnosing peripheral SpA.

[Rheumatoid arthritis-mimics : When appearances are deceptive]

Rheumatology represents a discipline full of differential diagnoses. Even for classical diseases, such as rheumatoid arthritis as the most frequent chronic inflammatory joint disease and described so clearly in many textbooks, it is not uncommon that it can be a diagnostic challenge in daily practice. This applies to arthritic joint involvement and also to frequently associated extra-articular manifestations. The patient history and results of the clinical examination are essential; however, laboratory and imaging findings often make a significant contribution to confirming the diagnosis, especially in early phases of the disease. This article, which makes no claims to completeness, focuses on diseases that in the opinion of the authors can imitate rheumatoid arthritis due to similar joint and other organ manifestations. These include metabolic, inflammatory infective and non-infective as well as tumorous diseases. A misinterpretation as rheumatoid arthritis as a rule leads to long-term and severe consequences for affected patients. Thus, the diagnosis of rheumatoid arthritis should be questioned and re-evaluated in cases of unusual accompanying symptoms, atypical course of disease and a lack of response to standard treatment approaches.

Associations of lumbar scoliosis with presentation of suspected early axial spondyloarthritis

OBJECTIVE

Scoliosis may impact the mechanical loading and cause secondary changes of the sacroiliac joints and lumbar spine. Our goal was to look how lumbar scoliosis modify the clinical and imaging-study in patients with recent-onset inflammatory back pain (IBP) suggesting axial spondyloarthritis (axSpA).

METHODS

Baseline weight-bearing lumbar-spine radiographs obtained in the DESIR cohort of patients aged 18-50 years and having IBP for at least 3 months but less than 3 years suggesting axSpA were studied. After training on scoliosis detection based on Cobb's angle>10° plus Nash-Moe grade≥1, readers blinded to patient data measured spine lumbar scoliosis, sacral horizontal angle, lumbosacral angle and lumbar lordosis on the radiograph of the lumbar and scored sacroiliitis on the radiograph of the pelvis. Baseline MRIs T1 and STIR of the lumbar spine and sacroiliac joints were evaluated for respectively degenerative changes and signs of axSpA.

RESULTS

Of the 360 patients (50.8% females) 88.7% had lumbar pain and 69.3% met ASAS criteria for axSpA. Mean Cobb's angle was 3.2°±5.0° and 28 (7.7%) patients had lumbar scoliosis. No statistical differences were observed for radiographic sacroiliitis, MRI sacroiliitis, modified Stoke Ankylosing Spondylitis Spinal Score, Pfirmmann score, high-intensity zone, protrusion, extrusion, MODIC score between patients with and without scoliosis. In both groups, degenerative changes by MRI were rare and predominated at L4-L5 and L5-S1.

CONCLUSION

In patients with early IBP suggesting axSpA, lumbar scoliosis was not associated with inflammatory or degenerative changes.

Evaluation of concomitant peripheral arthritis in patients with recent onset axial spondyloarthritis: 5-year results from the DESIR cohort

BACKGROUND

(a) To describe the prevalence and incidence of peripheral arthritis during 5 years of follow-up in recent axial spondyloarthritis (axSpA), (b) to evaluate factors associated with their appearance and (c) to assess their impact on treatment, patient-reported outcomes and sick leave after follow-up.

METHODS

Data from the early axSpA patients from the DESIR cohort (first 5 years of follow-up) were analysed. Prevalence and incidence of peripheral arthritis at each study visit were calculated. A multivariate analysis was performed to evaluate baseline factors associated with the development of the arthritis. The use of drugs, the impact on patient-reported outcomes and days of sick leave were compared in both groups over time.

RESULTS

Out of the 708 patients included in DESIR, 255 (36.0%) showed at least one episode of arthritis (151 before the inclusion visit and 104 during the follow-up), with an incidence of 3.7 cases per 100 person-years. Patients with peripheral arthritis were more likely (OR, 95%CI) to be aged ≥ 33 years (1.60, 1.12-2.27), non-smokers (1.58, 1.10-2.27) and HLAB27 negative (1.47, 1.04-2.08) and have presented with at least one episode of dactylitis (8.50, 4.96-14.60) and enthesitis (2.00, 1.41-2.84). Patients with peripheral arthritis showed a significant greater use of TNFb, csDMARDs and corticosteroids over follow-up; higher levels on BASDAI (40.46 vs. 34.28) and BASFI (27.89 vs. 22.52); poorer quality of life; and higher number of days of sick leave (17.97 vs. 12.78) over time.

CONCLUSION

In recent axSpA, 36% of patients reported peripheral arthritis at any time of the disease, being associated with negative HLAB27, non-smokers and with other peripheral manifestations. Patients with arthritis showed a higher burden of disease.

Sensitivity and Specificity of Autoantibodies Against CD74 in Nonradiographic Axial Spondyloarthritis

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

[Spondyloarthritides]

Spondyloarthritides (SpA) are inflammatory rheumatic diseases affecting the axial skeleton, peripheral joints and entheses, and also manifest at extraskeletal sites. According to the more recently introduced nomenclature, predominant axial SpA is distinguished from predominant peripheral SpA. Axial SpA is further divided into radiographic and nonradiographic axial SpA. Genetic factors are relevant, with HLA-B27 being most important. The interleukin 23/17 pathway seems to be relevant and points towards new therapeutic targets. Inflammatory back pain is the leading symptom in axial SpA and has certain characteristics. In addition, HLA-B27 and sacroiliitis on imaging are important for diagnosis. Therapy consists of physiotherapy, nonsteroidal anti-inflammatory drugs (first line) and biologicals (second line). Conventional disease-modifying antirheumatic drugs are effective only in peripheral arthritis.

Characteristics of late-onset spondyloarthritis in Japan: A retrospective cohort study

Spondyloarthritis may be increasingly present in older patients as life expectancy increases. We investigated clinical differences between early-onset and late-onset spondyloarthritis in Japan.We retrospectively reviewed 114 patients consecutively diagnosed with spondyloarthritis. The clinical course of each patient was observed for ≥1 year. We defined early-onset and late-onset spondyloarthritis as <57 or ≥57 years at a median age of this study group, respectively. We compared clinical characteristics between these 2 groups.Disease duration was significantly shorter before diagnosis in the late-onset group (P < .01). Inflammatory back pain (IBP) was significantly more common in the early-onset group (P < .01), whereas dactylitis frequency was significantly higher in the late-onset group. Significantly more patients with early-onset spondyloarthritis were human leukocyte antigen (HLA) B27-positive (P < .01). Articular synovitis, particularly of the wrist, was significantly more common on power Doppler ultrasound (PDUS) in the late-onset group (P < .01). Tenosynovitis or peritendinitis, particularly in the finger and wrist flexors were also more frequent in the late-onset group (P < .001 and P < .05, respectively). Enthesitis of the finger collateral ligament and lateral collateral ligament were significantly more common in the late-onset group (both P < .05). Multiple logistic regression analysis revealed that, comparatively, IBP was significantly and independently much more likely to occur in the early-onset group.The patients with late-onset spondyloarthritis had a lower frequency of IBP and HLA B27 and a higher frequency of dactylitis and PDUS findings in peripheral involvement.