Peripheral disease contributes significantly to the level of disease activity in axial spondyloarthritis

Peripheral Spondyloarthritis: Conceptualization and Diagnosis as a Distinct Rheumatologic Subset of Disease

Peripheral spondyloarthritis (pSpA) encompasses multiple entities affecting the musculoskeletal system with classic findings of synovitis, enthesitis, and tenosynovitis. It remains poorly defined when compared with the axial spondyloarthritides due to nonspecific symptoms, ill-defined imaging findings, and lack of specific testable biomarkers. Previous research has tried to distinguish between the two disease entities using clinical presentations, scoring systems, and radiographic findings; however, overlap remains. We summarize the current classification of pSpA, imaging findings, and the distinction between these entities and axial spondyloarthritis.

Diagnostic delay in patients from the International Map of Axial Spondyloarthritis: geographic, sociodemographic and disease-related factors

OBJECTIVES

To assess diagnostic delay and its associated factors globally, in a large sample of patients included in the International Map of Axial Spondyloarthritis (IMAS).

METHODS

IMAS is a cross-sectional online survey (2017-22) of 5557 axial spondyloarthritis (axSpA) patients from 27 countries. Diagnostic delay was calculated as the difference between age at diagnosis and age at first symptom onset reported by patients. Associations between diagnostic delay and regions, sociodemographic characteristics and disease-related factors were explored through univariable and multivariable linear regression analysis.

RESULTS

Data from 5327 patients who reported data on diagnostic delay in IMAS survey were analysed: 3294 were from Europe, 752 from North America, 590 from Asia, 545 from Latin America and 146 from Africa. Overall, patients reported a mean diagnostic delay of 7.4 years (median: 4.0) since symptom onset, with substantial variation across regions; the highest delay was in South Africa and the lowest in Asia. The variables associated with longer diagnostic delay in the final multivariable regression model were: younger age at symptom onset (b = -0.100), female gender (b = 2.274), being diagnosed by a rheumatologist (b = 1.163), greater number of heathcare professionals (HCPs) seen before diagnosis (b = 1.033) and history of uveitis (b = 1.286).

CONCLUSION

In this global sample of axSpA patients the mean diagnostic delay was 7.4 years, and showed significant differences across regions. Younger age at symptom onset, female gender, diagnosis made by a rheumatologist, greater number of HCPs seen before diagnosis and history of uveitis were the parameters associated with a longer diagnostic delay in axSpA patients.

Associations of sociodemographic, clinical factors and HLA-B alleles with enthesitis and peripheral arthritis in patients with ankylosing spondylitis

OBJECTIVES

Factors associated with peripheral arthritis and enthesitis, especially Achilles tendonitis and plantar fasciitis, were examined in a longitudinal cohort of 1075 patients with ankylosing spondylitis (AS) (also known as radiographic axial spondyloarthritis).

METHODS

Patients were derived from the Prospective Study of Outcomes in Ankylosing Spondylitis cohort. Disease activity and functional indices, as well as physical examination and medications used, were measured at every study visit. Univariable and multivariable analyses of the association of peripheral arthritis and enthesitis with clinical, sociodemographic factors were performed. Human leucocyte antigen (HLA)-B alleles were analysed by single-stranded conformational polymorphism analysis.

RESULTS

Those with peripheral arthritis on examination were more likely to have psoriasis (p=0.001, OR=1.68; CI, 1.11, 2.54), greater functional impairment (p<0.001 OR=1.72; CI, 1.31, 2.27), higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels (p<0.001), greater tumour necrosis factor (TNF) inhibitor (p<0.001, OR=1.50; CI, 1.14, 1.97) and use methotrexate/sulfasalazine (p<0.001, OR=2.25, CI [1.57, 3.23]). Patients with enthesitis were less likely to be male (p<0.001, OR=0.57; CI, 0.43, 0.75) and have peripheral arthritis (p<0.001, OR=2.35; CI, 1.47, 3.75), greater functional impairment (p<0.001, OR=1.91; CI, 1.43, 2.55) and higher ESR/CRP levels (p<0.001). Patients with plantar fasciitis and/or Achilles' tendonitis on examination were less likely to male (p<0.001 OR=0.57; CI, 0.43, 0.75), to have significant functional impairment (p<0.001), to be using TNF inhibitors (p<0.001, OR=1.48; CI 1.13, 1.93) and to be using either sulfasalazine or methotrexate (p<0.001, OR=1.86, CI, 1.30, 2.67). HLA-B*15 (p=0.03, OR=1.84; CI, 1.05, 3.21) and HLA-B*37 (p=0.04, OR=3.00; CI, 1.03, 8.74) were marginally increased in frequency in those with peripheral arthritis on examination compared with those without.

CONCLUSION

There was a higher prevalence of peripheral musculoskeletal manifestations in women with AS, with significant impact on physical function and greater use of methotrexate or sulfasalazine and TNF inhibitors and enrichment for certain non-HLA-B27 HLA-B alleles.

Radiographic entheseal lesions of the pelvic region are more prevalent in radiographic axSpA than in age- and sex-matched controls and are associated with more severe spinal disease

OBJECTIVES

In axial spondyloarthritis (axSpA), entheseal involvement is common, which contributes significantly to disease burden and may also lead to structural damage. Although radiographs of the pelvis are widely available in axSpA, information on entheseal damage and associated characteristics are lacking. Therefore, we assessed the prevalence of radiographic entheseal lesions at the pelvic region in radiographic (r-) axSpA compared with controls and explored associations with patient and disease characteristics.

METHODS

Pelvic radiographs of 167 consecutive r-axSpA patients were randomized with 100 pelvic radiographs from age- and sex-matched controls. Radiographs were blinded for patient information and sacroiliac joints and bilaterally evaluated for erosions/cortical irregularities, enthesophytes, and calcifications by two trained readers at the greater and lesser trochanter, os ischium, and iliac crest.

RESULTS

Entheseal lesions were observed in 127 (76%) of r-axSpA patients and 58 (58%) controls. R-axSpA patients showed significantly more (bilateral) entheseal lesions than controls at all entheseal sites. Most lesions were found at the os ischium, erosions/cortical irregularities were most prevalent, and calcification was the most specific lesion in r-axSpA. Patients with lesions were significantly older, had longer symptom duration, and more severe spinal radiographic damage than patients without lesions. Enthesophytes were found significantly more often in patients with body mass index (BMI) ≥ 25.

CONCLUSION

Structural entheseal lesions observed at pelvic radiographs are not specific but occur often in r-axSpA patients. Treating physicians should keep in mind that these entheseal lesions are associated with more severe axial disease and high BMI which may be relevant for treatment decisions. Key Points • Pelvic radiographic entheseal lesions are significantly more prevalent in r-axSpA patients than in controls. • Radiographic entheseal lesions are associated with longer symptom duration and more spinal radiographic damage. • Pelvic enthesophytes are found significantly more often in r-axSpA patients with BMI ≥ 25.

Difficult-to-Treat Spondyloarthritis in Morocco: A Real-World Study

Objectives

High biologic requirement in inflammatory rheumatic diseases (IRD) may indicate a difficult to treat (D2T) condition. In axial spondyloarthritis (axSpA), a consensual definition for this concept is still lacking. Our objectives are to identify the prevalence and characteristics of multiswitcher patients with axSpA, and to analyse the number and reasons for switches.

Methods

This is a longitudinal observational study including patients treated with biologic agents for axSpA. We propose to define D2T patients as those who required more than 2 b/tsDMARD. Patients who did not fulfil this definition were used as controls. The prevalence of multiswitchers was calculated, and characteristics were compared between the two groups. The number and reasons for switches were analysed in the D2T group.

Results

124 patients were included. The prevalence of multiswitchers was 24.19%. There were no significant differences between the two groups in the age, sex, and comorbidities. D2T patients have more arthritis (p=0.01), and fibromyalgia (p=0.04), and higher disease activity before initiating biotherapy, (BASDAI:p=0.04), (ASDAS:p=0.04). Additionally, the time from diagnosis to the first use of biologic was longer (p=0.04). In the multivariate analysis, the D2T condition was found to be associated with fibromyalgia (p=0.01). Among this group, the prevalence of those treated with 3, 4, and 5 b/tsDMARD was 86%, 9%, and 5%, respectively, the primary and secondary failures were the most common reasons for switching.

Conclusion

We suggest that D2T-axSpA present several characteristics. Identification of this category in large studies is necessary to establish a consensus definition.

Difficult-to-treat axial spondyloarthritis patients

Objectives

This study aimed to formulate D2T (difficult to treat) criteria for axial spondyloarthritis (AxSpA) patients and identify the prevalence of D2T patients and their characteristics.

Patients and methods

The cross-sectional study was conducted with 166 AxSpA patients (93 males, 73 females; mean age: 47.1±12.9 years; range, 19 to 78 years) between February 2023 and March 2023. The criteria were based on patients treated according to the European Alliance of Associations for Rheumatology (EULAR) recommendations for AxSpA. Entry criteria were treatment failure to ≥2 biological/targeted synthetic disease-modifying antirheumatic drugs with two different mechanisms of action or ≥3 biological/targeted synthetic disease-modifying antirheumatic drugs. Potential preliminary factors for D2T criteria were analyzed, and the characteristics of the subjects matching D2T criteria were compared with those of others.

Results

One hundred forty-two ankylosing spondylitis patients and 24 nonradiographic AxSpA patients were included in the study. The rate of fulfilling the D2T criteria was 22.9% (n=38) among AxsPA patients treated with biological agents. The potential D2T criteria were met by 23.2% of ankylosing spondylitis and 20.8% of nonradiographic AxSpA patients. Baseline characteristics, such as sex, age, diagnosis age, occupation, and education, of D2T patients were not statistically different from other patients. The prevalence of fibromyalgia was higher in D2T patients (p<0.001). Disease activity indices and acute phase response indicators were higher and quality of life was worse in D2T patients.

Conclusion

There was a considerable amount of AxSpA patients fulfilling the D2T criteria despite new and effective treatment agents.

Clinical and imaging outcomes of different phenotypes of axial spondyloarthritis: 5-year analysis of the DESIR cohort

OBJECTIVES

To compare the long-term outcomes of three phenotypes of axial SpA (axSpA).

METHODS

Patients with a clinical diagnosis of axSpA from the DESIR cohort were grouped into three phenotypes at baseline: 'Pure axSpA' ('Axial'), 'axSpA with peripheral signs' ('IBP+Peripheral') and 'axSpA at risk' ('At risk') by latent class analysis. Clinical and imaging data were collected up to 5 years. Clinical outcomes, measured in each visit, included disability (BASFI) and quality of life (QoL; SF36). Imaging outcomes included inflammatory and structural lesions on MRI and radiographs of spine and SIJ. The association between phenotype membership at baseline and each outcome was tested in multivariable GEE models.

RESULTS

In total, 576 patients with axSpA were included. 'At risk' patients had worse disability and QoL than 'Axial' patients over time. For instance, 'At risk' patients had on average 0.4 more points in BASFI over time than 'Axial' patients [β (95 % CI): 0.4 (0.2; 0.7)]. This difference was mostly noted in female patients who were HLA-B27 positive. In addition, the difference between the 'At risk' and 'Axial' phenotypes was higher in patients receiving bDMARDs than in those not (β=0.6 vs 0.5), since BASFI improved more in 'Axial' (∆BASFI: -1.3) than in 'At risk' (∆BASFI: -0.9) treated patients. There were no differences in disability and QoL between 'Axial' and 'IBP+Peripheral' patients. Imaging outcomes were worse in the 'Axial' phenotype than in the others over time.

CONCLUSION

Patients with 'axSpA at risk' show worse self-reported outcomes over time and are less likely to benefit from anti-inflammatory treatment than those with a classical axSpA phenotype.

Different Therapeutic Response to Anti-TNF Drugs in Patients with Axial Spondyloarthritis Depending on Their Clinical Profile: An Unsupervised Cluster Analysis

Background: The objectives were as follows: (a) to identify, among patients with axial spondyloarthritis (axSpA), "clusters" of patients based on the presence of peripheral and extra-musculoskeletal manifestations (EMMs) and (b) to compare the effectiveness of the first anti-TNF drugs across the different clusters after 6 months of follow-up. Methods: An observational and retrospective study of 90 axSpA patients naïve to bDMARDs was conducted. An unsupervised cluster analysis using the "k-means" technique was performed using variables of peripheral and EMMs. Baseline clinical and sociodemographic characteristics were evaluated, and the response to anti-TNF treatment (considering responders as those with an improvement ≥1.1 for the Ankylosing Spondylitis Disease Activity Score (ASDAS) or ≥2.0 for the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)) was compared across the clusters after 6 months of follow-up. Results: Two clusters were identified: cluster 1 (n = 14), with a higher prevalence of peripheral manifestations, inflammatory bowel disease (IBD), and HLA-B27-positive status, and a lower prevalence of uveitis in comparison with cluster 2 (n = 76). Patients from cluster 1 experienced a more pronounced absolute improvement in ASDAS and BASDAI indices after 6 months. The percentage of responders after 6 months of follow-up was superior in cluster 1 compared to cluster 2 (85.7% vs. 48.7%, p = 0.011). Conclusion: This study suggests the existence of two clinical profiles in axSpA patients according to the peripheral and EMMs, with higher rates of anti-TNF effectiveness after 6 months in those with a greater presence of peripheral features.

Axial Involvement in Psoriatic Arthritis: A Cross-sectional Clinical and Radiologic Studies

OBJECTIVE

This study aimed to investigate spinal involvement in psoriatic arthritis (PsA) patients using clinical and radiographic methods.

METHODS

A cross-sectional clinical study was conducted on 50 PsA patients diagnosed according to the CASPAR criteria. Clinical examinations and functional assessments were performed. A radiographic assessment of the spine was performed.

RESULTS

Out of 50 PsA patients (mean age of 45.50 ± 9.90 years), (males and females constituted 27 (54.0%) and 23 (46.0%) respectively), 76% had radiological axial involvement; (26%) with inflammatory axial pain and (50%) without inflammatory axial pain (subclinical). Three axial radiographic patterns were detected including spondylitis without sacroiliitis (15.78%), spondylitis with sacroiliitis (78.94%), and sacroiliitis without spondylitis (5.26%). In axial PsA patients, males were more affected than females (χ2=11.679, p = 0.003), with older age (H = 15.817, p < 0.001) and higher body mass index (BMI) (F = 5.145, p = 0.010), increased psoriasis duration (H = 9.826, p = 0.007) and severity (Η=25.171, p < 0.001), and more spinal movement limitations than PsA patients without axial involvement (F = 26.568, p < 0.001). Cervical involvement was higher than lumbar involvement. Axial radiographic severity assessed by the PsA Spondylitis Radiology Index was associated with increased disability as assessed by the Health assessment questionnaire (rs = 0.533, p = 0.001) and decreased quality of life assessed by short form-36 score (rs = -0.321, p = 0.050).

CONCLUSION

This study shows that a high percentage of PsA patients had axial involvement with a high percentage of them having asymptomatic radiological findings. The cervical spine is more frequently and severely affected than the lumbar spine. Axial PsA occurs in males more than females with characteristic older age and higher BMI, increased psoriasis duration, and more limitation of spinal mobility.

The role of γδ T cells in the immunopathogenesis of inflammatory diseases: from basic biology to therapeutic targeting

The γδ T cells are lymphocytes with an innate-like phenotype that can distribute to different tissues to reside and participate in homeostatic functions such as pathogen defense, tissue modeling, and response to stress. These cells originate during fetal development and migrate to the tissues in a TCR chain-dependent manner. Their unique manner to respond to danger signals facilitates the initiation of cytokine-mediated diseases such as spondyloarthritis and psoriasis, which are immune-mediated diseases with a very strong link with mucosal disturbances, either in the skin or the gut. In spondyloarthritis, γδ T cells are one of the main sources of IL-17 and, therefore, the main drivers of inflammation and probably new bone formation. Remarkably, this population can be the bridge between gut and joint inflammation.

A mixed methods study to uncover impediments to accurate diagnosis of nonradiographic axial spondyloarthritis in the USA

INTRODUCTION/OBJECTIVES

Delayed diagnosis of axial spondyloarthritis (axSpA) is well documented; little is known about the diagnostic journey and impediments for US patients with nonradiographic axSpA (nr-axSpA). It is hypothesized that impediments are varied and exist at both the healthcare provider (HCP) and patient levels. This study aims to understand patient experiences and contributors to delayed nr-axSpA diagnosis in the USA.

METHOD

Interviews of adults with rheumatologist-diagnosed nr-axSpA, recruited through Spondylitis Association of America outreach and patient panels, and of rheumatologists, explored the diagnostic journey and diagnostic barriers. Emerging themes were further explored in an online patient survey. A multiple logistic regression analysis evaluated the main outcome variable, factors affecting time to nr-axSpA diagnosis.

RESULTS

Interviews were conducted with 25 patients and 16 rheumatologists. Survey responses from 186 eligible patients revealed median time from symptom onset to diagnosis of nr-axSpA was 3.25 years. Delayed diagnosis was significantly more likely for women and people in rural areas. Most patients consulted ≥4 different types of HCPs before a rheumatologist and ≥2 rheumatologists before diagnosis. Impediments to timely diagnosis included insidious chronic pain; episodic symptom patterns attributed to activity; symptoms other than chronic lumbosacral back pain requiring medical consultation; and unfamiliarity with and misperceptions about nr-axSpA among HCPs, radiologists, and rheumatologists.

CONCLUSIONS

Delayed nr-axSpA diagnosis is common and reflects HCP knowledge gaps and frequent patient presentation with dominant nonaxial symptoms. Targeted HCP education, research into early disease patterns, and interventions sensitive to the broader spectrum of nr-axSpA manifestations are needed to improve timely diagnosis. Key Points • Patients with nr-axSpA often see multiple types of HCPs, and multiple rheumatologists, before receiving a diagnosis. • Both patients and HCPs are unfamiliar with nr-axSpA and its symptoms, lacking understanding that nr-axSpA can occur in young people, females, and those presenting with normal x-rays. • Disease recognition by nonrheumatology HCPs is key for early referral. • Education on cardinal features, epidemiology, burden, and benefits of timely nr-axSpA diagnosis is warranted for HCPs who commonly manage back pain.

Peripheral spondyloarthritis: What have we learned?

The peripheral spondyloarthritis (pSpA) entity remains poorly defined in comparison with axial SpA and psoriatic arthritis, as the clinical symptoms have low specificity, the biological markers are virtually lacking, and dedicated randomized controlled trials in this specific indication remain scarce. In addition, clinical similarities between pSpA and psoriatic arthritis (PsA) have been described, partly explained by a resemblance in the pathophysiology of both entities. Thus, diagnosing pSpA can be challenging because of the overlap with other entities and the absence of a specific test or imaging study that can definitively diagnose the condition. The aim of this review is to summarize the current understanding of pSpA, its epidemiology, physiopathology, clinical diagnosis, and classification criteria. In addition, we present patient-reported outcomes used in pSpA clinical studies, available evidence on therapies, and future directions.

Extra-musculoskeletal manifestations driving the therapeutic decision-making in patients with Spondyloarthritis: a 12-month follow-up prospective cohort study

BACKGROUND

The extra-musculoskeletal manifestations (EMMs) such as recurrent acute anterior uveitis (rAAU), psoriasis (Ps), and inflammatory bowel disease (IBD), are related to the Spondyloarthritis (SpA), as well as they are associated with disease activity and poor prognosis. However, there are no data addressing its relevance regarding therapeutic decision-making in clinical practice.

OBJECTIVE

To evaluate the impact of EMMs to drive the treatment decision-making in patients with SpA in a 12-month follow-up.

PATIENTS AND METHODS

SpA patients, according to the axial and peripheral ASAS classification criteria, as well as CASPAR criteria, with any active EMM, defined as main entry criteria, were included in this longitudinal cohort study. Individuals with a history of any disease or condition that could be associated with some of the studied endpoints, including neoplasms and infectious diseases, were excluded. Specific tools related to each EMM, including Psoriasis Area Severity Index (PASI), ophthalmologic evaluation, according to the Standardization of Uveitis Nomenclature (SUN) criteria, and gut complaints were used at baseline and during the 3-, 6- and 12-month of follow-up as outcomes measures over time. Descriptive and inferential analyses were used appropriately, including Pearson's correlation test, chi-squared test, and ANOVA. P value less than 0.05 was considered as significant.

RESULTS

A total of 560 patients were enrolled, of whom 472 meet the eligibility criteria. The majority (N = 274; 59.6%) had one or more EMM related to SpA umbrella concept. Among the EMM, the one that most influenced therapeutic decision-making was psoriasis (28.5%), followed by uveitis (17.5%) and IBD (5.5%), regardless of musculoskeletal manifestations. Clinical improvement of EMMs outcomes was observed in most patients over 12-month follow-up, especially in those with rAAU and IBD (P < 0.001).

CONCLUSION

Our results showed that EMMs guided the therapeutic decision-making in half of SpA patients, regardless of musculoskeletal condition, suggesting the inter-disciplinarity among the rheumatologist, ophthalmologist, dermatologist, and gastroenterologist plays a crucial role to manage them.

Human leucocyte antigen-B27 testing in clinical practice: a global perspective

PURPOSE OF REVIEW

The association between human leucocyte antigen (HLA)-B27 and spondyloarthritis (SpA) was described half a century ago. New insights about pathophysiologic pathways and their role in bone formation were reported in recent years and will be discussed in this review.

RECENT FINDINGS

There is a considerable variation in the association between HLA-B27 and SpA across the globe, with the strongest association reported in populations of Northern European and Asian descent and the lowest in the Middle East and Africa. Other genes are also involved in disease susceptibility, highlighting the importance of newly proposed weighted genetic scores to support the diagnosis. On the global level, the interaction between genetic background and gut dysbiosis seems critical for disease predisposition. As for the individual patient, the presence of HLA-B27 can have a significant influence on SpA diagnosis and disease phenotype. More importantly, new studies suggested a role for HLA-B27 in radiographic damage in the sacroiliac joints and the progression of bone formation in the spine.

SUMMARY

Findings in recent years have enhanced our understanding of the role of HLA-B27 in the pathophysiology and in disease-related bone formation in SpA, which may pave the way for new therapeutic targets.

The identification of association between ultrasonographic enthesitis and the ASAS Health Index in patients with axial spondyloarthritis

This study aimed to evaluate association between the entheseal abnormalities in ultrasound and the Assessment of Spondyloarthritis International Society Health Index (ASAS HI) in patients with axial spondyloarthritis (axSpA). Seventy-four patients with axSpA were enrolled in this study. Ultrasonographic evaluation of entheses was performed by a blinded rheumatologist with the Madrid Sonographic Enthesitis Index (MASEI). The MASEI total score and the MASEI sub-scores (e.g., structural damage and activity scores) were calculated. The ASAS HI and the other SpA tools (e.g., Bath Ankylosing Spondylitis Disease Index, the Ankylosing Spondylitis Disease Activity Score) were used to evaluate patients' health and disease activity. Correlation and multivariate linear regression analyses were performed to assess the relationship between the MASEI and the ASAS HI. The mean score of the ASAS HI was 7.7 ± 4.6. The MASEI total score was calculated as 8.4 ± 6.8, while the mean MASEI-activity was 4.7 ± 3.6 and the mean MASEI-structural damage was 3.8 ± 4.5. There was no correlation between ASAS HI and MASEI total scores (r = 0.11, p = 0.34). However, the ASAS HI had a positive correlation with the MASEI-activity (r = 0.49, p < 0.001) and had a low negative correlation with the MASEI-structural damage (r = - 0.29, p < 0.05). In the linear regression model, the MASEI-activity and MASEI-structural damage were significantly related to the ASAS HI (β = 0.72 and - 0.58, respectively; R² = 0.53 p < 0.001). This study reported that the ASAS HI score was more negatively affected by active entheseal lesions rather than structural lesions. We suggest adding the entheses evaluation with ultrasonography to other tools for monitoring the health status of patients with axSpA.

The impact of psoriasis on the clinical characteristics, disease burden and treatment patterns of peripheral spondyloarthritis

OBJECTIVES

To evaluate the clinical characteristics, disease burden, and treatment patterns of peripheral spondyloarthritis (pSpA) patients with and without psoriasis using data from the ASAS-perSpA study.

METHODS

We included 433 patients who had a diagnosis of pSpA according to the rheumatologist's diagnosis from the ASAS-PerSpA study. The presence of a personal history of psoriasis was defined as the presence of signs of psoriasis at physical examination or the presence of psoriatic nail dystrophy, including onycholysis, pitting and hyperkeratosis, or a history of psoriasis diagnosed by a physician. Clinical characteristics, patient-reported outcomes and treatment pattern were compared between subgroups with and without psoriasis.

RESULTS

A total of 83 patients (19.2%) had a personal history of psoriasis. Patients with psoriasis were older (48.4 vs 43.2 years) and had a longer diagnostic delay (7.4 vs 3.5 years), a higher frequency of dactylitis (36.1 vs 20.0%) and enthesitis (65.1 vs 55.4%) than patients without psoriasis. A longer diagnostic delay (odds ratio [OR] = 1.06 [95% CI 1.01, 1.11]), lower odds for HLA-B27 positivity (OR = 0.31 [95% CI 0.15, 0.65]) and higher odds for enthesitis (OR = 2.39 [95% CI 1.16, 4.93]) were associated with the presence of psoriasis in a multivariable regression analysis. While patient-reported outcomes were comparable between groups, a higher use of biologic DMARDs was observed in patients with vs without psoriasis.

CONCLUSION

The presence of psoriasis has an impact on clinical characteristics of pSpA. pSpA patients without psoriasis were less frequently treated with biologic DMARDs despite similar disease burden as compared with patients with psoriasis.

The Impact of Vedolizumab and Ustekinumab on Articular Extra-Intestinal Manifestations in Inflammatory Bowel Disease Patients: A Real-Life Multicentre Cohort Study

BACKGROUND AND AIMS

Extra-intestinal manifestations are frequently reported in inflammatory bowel diseases. However, data comparing the effect of vedolizumab and ustekinumab on articular extra-intestinal manifestations are limited. The aim here was to evaluate differences in new-onset and the evolution of pre-existing joint extra-intestinal manifestations during both treatments.

METHODS

An international multicentre retrospective study was performed on inflammatory bowel disease patients who started vedolizumab or ustekinumab between May 2010 and December 2020. Extra-intestinal manifestations were assessed at baseline and joint extra-intestinal manifestations were evaluated throughout the 2-year follow-up. Arthropathy was defined by joint inflammation [arthritis/sacroiliitis], diagnosed by a rheumatologist, and arthralgia as articular pain without confirmed inflammation. Additionally, skin, ocular and hepatic extra-intestinal manifestations were assessed at baseline. Uni- and multivariate analyses were performed.

RESULTS

In total, 911 patients [vedolizumab: 584; ustekinumab: 327] were included. Deterioration of pre-existing arthropathy and rate of new-onset arthropathy were not significantly associated with vedolizumab over ustekinumab. Arthropathy was used as reason to stop treatment in six vedolizumab and two ustekinumab patients. The odds of developing new arthralgia within 6 months was higher in patients who took vedolizumab compared to ustekinumab (adjusted odds ratio [aOR]: 2.28 [1.01-5.15], p = 0.047). However, this effect was not sustained during the 2-year follow-up (aOR: 1.35 [0.80-2.29], p = 0.259). Deterioration of pre-existing arthralgia was comparable between ustekinumab and vedolizumab-treated patients. In two vedolizumab-treated patients arthralgia was given as the reason to stop treatment.

CONCLUSIONS

Vedolizumab and ustekinumab can be used safely in patients with articular extra-intestinal manifestations. Only a temporary increased risk for developing arthralgia has been observed under vedolizumab.

Peripheral spondyloarthritis and psoriatic arthritissine psoriase: are we dealing with semantics or clinically meaningful differences?

Diagnosing peripheral spondyloarthritis (pSpA) remains a significant challenge due to the lack of specific disease biomarkers and the overlap with other SpA subtypes, mainly psoriatic arthritis (PsA), which represents a diagnostic challenge particularly in the absence of skin psoriasis (PsAsine psoriase). This narrative review aimed to compare the epidemiology, genetic susceptibility, pathophysiology, classification criteria, disease phenotype and burden, and therapeutic guidelines between patients diagnosed with pSpA and those with PsAsine psoriase,to determine if the two entities should be considered jointly or distinctly. Globally, pSpA appears to be more inclusive compared with PsAsine psoriase. Areas of similarities include age of onset, number of joints involved and prevalence of axial involvement. However, patients with pSpA have a male gender predominance, a higher prevalence of HLA-B27, enthesitis and involvement of large joints of the lower limbs, whereas patients with PsAsine psoriasehave a higher prevalence HLA-Cw6, dactylitis and involvement of hand distal interphalangeal joints. Therefore, the difference between pSpA and PsAsine psoriasegoes beyond semantics. The few dissimilarities should drive scientific efforts to reach a better characterisation of pSpA as an individual disease. Accordingly, randomised clinical trials should target patients with well-defined pSpA to identify effective therapies in this population.

Peripheral manifestations are major determinants of disease phenotype and outcome in new onset spondyloarthritis

OBJECTIVES

To delineate the impact of peripheral musculoskeletal manifestations on stratification of disease phenotype and outcome in new-onset spondyloarthritis (SpA), using a prospective observational nationwide inception cohort, the BelGian Inflammatory Arthritis and spoNdylitis cohorT (Be-Giant).

METHODS

Newly diagnosed adult SpA patients, fulfilling the Assessment of SpondyloArthritis International Society (ASAS) criteria for axial or peripheral SpA, were included in Be-Giant and prospectively followed every six months. Peripheral involvement (defined as arthritis, enthesitis and/or dactylitis) was determined in relation to clinically similar patient subsets at baseline and disease activity patterns during two-year follow-up, identified through K-means cluster analysis and latent class growth analysis.

RESULTS

From November 2010 to March 2020, 367 patients were enrolled in Be-Giant, of whom 162 (44%) had peripheral manifestations. Two patient clusters [A, axial predominant (n = 248) and B, peripheral predominant (n = 119)] were identified at diagnosis. Longitudinal analysis (n = 115) revealed two trajectories of disease activity in each cluster: one with persistently high disease activity over time ('High'), the other rapidly evolving to low disease activity ('Low'). In cluster A patients, peripheral manifestations predisposed to the 'High' trajectory [odds ratio (OR) = 2.0, 95% CI: 1.3, 3.1, P = 0.001], despite more rapid initiation of biologics compared with patients without peripheral manifestations (hazard ratio (HR)  = 2.1, 95% CI: 1.0, 4.4, P = 0.04 - Cox proportional-hazards model).

CONCLUSION

Peripheral musculoskeletal manifestations are major determinants of phenotypical diversity in new-onset SpA. Intriguingly, stratification of axial SpA according to concomitant peripheral involvement identified an endotype with an unfavorable outcome despite more prompt therapeutic intensification with biologics. These observations justify an endotype-tailored approach beyond current ASAS/EULAR management recommendations.

What is peripheral spondyloarthritis? Identifying proportion, phenotype and burden in post hoc analysis of the ASAS-PerSpA study

BACKGROUND

Little is known about the prevalence, phenotype, and burden of peripheral spondyloarthritis (pSpA). The objective of the study is to compare the phenotype and burden of disease of pure pSpA to that of pure psoriatic arthritis (PsA), pure axial SpA (axSpA), and combined forms of SpA.

METHODS

This is a post hoc analysis of 4,185 patients from the cross-sectional ASAS-Peripheral involvement in SpA (PerSpA) study. Patients were approached in 2 ways: the first approach was based on the rheumatologist's diagnosis (diagnostic approach) and the second one was based on the fulfillment of ASAS or CASPAR classification criteria (classification criteria approach). Demographics, disease phenotype, and burden were compared among pure pSpA, PsA, axSpA, and the combined forms.

FINDINGS

The proportion of pSpA was 31.5% of SpA using the classification criteria approach and 10.3% using the diagnostic approach. pSpA was pure (i.e. without axSpA or PsA) in 16.8% of pSpA using the criteria, and in 62.3% using the diagnostic approach. Using classification criteria and diagnostic approach, respectively, pure pSpA patients had a high prevalence of peripheral joint disease (86 and 96%), synovitis (76 and 91%), and enthesitis (57 and 55%), a positive HLA-B27 in 65 and 59%, a high C-Reactive Protein level in 51% and inflammatory back pain in 52 and 42%. However, compared to pure PsA and pure axSpA, they had a significantly higher disease burden, but lower use of biologics using both approaches.

INTERPRETATION

The proportion of pSpA varies when using the classification criteria or the diagnostic approach. pSpA occurred in a pure form less frequently than PsA and axSpA and had intermediate features but a higher disease burden.

FUNDING

The PerSpA main study has been conducted under the umbrella of ASAS thanks to unrestricted grants from PFIZER, LILLY, ABBVIE, NOVARTIS, UCB, JANSSEN, MERCK.

2021 clinical practice guidelines for the diagnosis, treatment, and follow-up of patients with peripheral spondyloarthritis. Colombian Association of Rheumatology

BACKGROUND

Peripheral spondyloarthritis is a chronic inflammatory disease in which clinical presentation is related to the presence of arthritis, enthesitis and/or dactylitis. This term is used interchangeably with some of its subtypes such as psoriatic arthritis, reactive arthritis, and undifferentiated spondyloarthritis.

OBJECTIVE

To develop and formulate a set of specific recommendations based on the best available evidence for the diagnosis, treatment and monitoring of adult patients with peripheral spondyloarthritis.

METHODS

A working group was established, clinical questions were formulated, outcomes were graded, and a systematic search for evidence was conducted. The guideline panel was multidisciplinary (including patient representatives) and balanced. Following the formal expert consensus method, the GRADE methodology "Grading of Recommendations Assessment, Development and Evaluation" was used to assess the quality of the evidence and generate the recommendations. The Clinical Practice Guideline includes ten recommendations; related to monitoring of disease activity (n = 1) and treatment (n = 9).

RESULTS

In patients with peripheral spondyloarthritis, the use of methotrexate or sulfasalazine as the first line of treatment is suggested, and local injections of glucocorticoids is recommended conditionally. In patients with failure to cDMARDs, an anti TNFα or an anti IL17A is recommended. In case of failure to bDMARDs, it is suggested to use another bDMARD or JAK inhibitor. In patients with peripheral spondyloarthritis associated to inflammatory bowel disease, it is recommended to start treatment with cDMARDs; in the absence of response, the use of an anti TNFα over an anti-IL-17 or an anti-IL-12-23 is recommended as a second line of treatment. In patients with psoriatic arthritis, the combined use of methotrexate with bDMARD is conditionally recommended for optimization of dosing. To assess disease activity in Psoriatic Arthritis, the use of DAPSA or MDA is suggested for patient monitoring.

CONCLUSIONS

This set of recommendations provides an updated guide on the diagnosis and treatment of peripheral spondyloarthritis.

Enthesitis in patients with psoriatic arthritis and axial spondyloarthritis - data from the Danish nationwide DANBIO registry

OBJECTIVE

To explore the registration, pattern and burden of clinical enthesitis among routine-care patients with psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) in the Danish nationwide DANBIO registry.

METHODS

In patients with PsA and axSpA in DANBIO, prospectively registered data from 2010 to 2020 on clinical entheseal assessment using SPARCC score were compared with demographic, clinical and patient-reported-outcome (PRO) data.

RESULTS

6582 PsA and 5547 axSpA patients had their first registration in DANBIO in 2010 or later ("incident cohort"). At these registrations, 1037 (16%) PsA and 1188 (21%) axSpA patients had entheseal assessments, with ≥1 enthesitis being found in 66% and 39%, respectively. Mean enthesitis scores were 2.5 (PsA) and 1.3 (axSpA). Most common sites were: Achilles tendon (right/left/symmetrical: PsA:24.4%/23.3%/17.1%; axSpA:10.4%/10.6%/8.0%), lateral epicondyle (PsA:22.2%/20.1%/16.2%; axSpA:.4%/9.7%/7.6%), plantar fascia (PsA:17.1%/17.0%/12.6%; axSpA:10.4%/10.6%/8.0%), greater trochanter (PsA:14.2%/15.4%/11.7%; axSpA:9.9%/11.2%/8.2%). Enthesitis was more frequent in women (PsA/axSpA 61%/62%) than men (39%/37%). Patients with vs without enthesitis had higher overall burden (higher physician global, swollen/tender joint counts, pain, fatigue, patient global; fewer in patient-acceptable-symptom-state (PASS)) (all p < 0.05). Comparable demographic, clinical and PRO-results in patients with missing entheseal assessments, support the data being representative. In an "overall" cohort of all patients with ≥1 entheseal assessments after 2010, results on enthesitis were comparable.

CONCLUSION

Entheseal assessments were only performed at a minority of clinical visits. Clinical enthesitis was frequent, particularly in women, often symmetrical and associated with a higher physician- and patient-reported disease burden in patients with PsA and axSpA treated in routine practice, emphasizing the need for systematic assessment in routine care.

Cluster analysis in early axial spondyloarthritis predicts poor outcome in the presence of peripheral articular manifestations

OBJECTIVES

To assess whether two cluster analysis-based axial SpA (axSpA) endotypes (A for purely axial; B for both axial and peripheral) are stable over time and are associated with different long-term disease outcomes.

METHODS

K-means cluster analysis was performed at each visit (until 5 years) on 584 patients from the DESIR cohort, who completed all planned visits, and validated in 232 consecutive axSpA patients from the BeGiant cohort. Cluster stability overtime was assessed by kappa statistics. A generalized linear mixed-effect analysis was applied to compare outcomes between clusters. Classification and regression tree (CART) analysis was performed to determine a decision rule able to assign a given patient to a definite cluster at onset.

RESULTS

Both endotypes remained remarkably stable over time. In the DESIR cohort, patients in cluster B showed higher disease activity, worse functional outcome and higher need for anti-rheumatic drugs than patients in cluster A. CART analysis yielded three main clinical features (arthritis, enthesitis, and dactylitis) that accurately determined cluster assignment. These results could be replicated in the Be-GIANT cohort.

CONCLUSION

Cluster-based axSpA endotypes were reproducible in two different cohorts, stable over time and associated with different long-term outcome. The axSpA endotype with additional peripheral disease manifestations is associated with more severe disease and requires more intensive drug therapy.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov, https://clinicaltrials.gov, NCT01648907.

An Italian Disease-Based Registry of Axial and Peripheral Spondyloarthritis: The SIRENA Study

Introduction: Data about the clinical presentation and management of early and mild spondyloarthritis (SpA) are limited.

Objectives: The objective of this study was to describe the baseline characteristics of disease-modifying antirheumatic drug (DMARD)-naïve patients with axial or peripheral SpA.

Methods: The Spondyloarthritis Italian Registry: Evidence from a National Pathway (SIRENA) study is an ongoing, Italian, multicenter, prospective registry of patients with a first or newly confirmed diagnosis of SpA according to the Assessment of SpondyloArthritis International Society (ASAS) criteria. To be included, patients had to be naïve to conventional, targeted, and biological DMARDs for SpA. Patients were enrolled between June 2017 and June 2019 and classified into groups according to disease presentation: predominantly axial or peripheral manifestations. The study is ongoing, and patients are being followed for 2 years, with an evaluation every 6 months according to clinical practice. Differences in baseline demographics, lifestyle, and clinical characteristics between axial and peripheral SpA were evaluated.

Results: In this study, 350 patients were enrolled, of which 123 (35.1%) were axial and 227 (64.9%) were peripheral patients. Patients with axial SpA were significantly younger at enrollment (median age: 44 vs. 53 years), had significantly more anxiety/depression (13 vs. 2.6%), and expressed higher disease activity compared to patients with peripheral SpA. Patients with peripheral SpA had significantly more cardiometabolic disorders (33 vs. 18.7%), skin psoriasis (65.2 vs. 21.1%), and nail psoriasis (35.5 vs. 17.1%) than patients with axial SpA. Dactylitis, enthesitis, and fibromyalgia were observed, respectively, in 17.6, 51.2, and 5.7% of patients with axial SpA and 24.3, 40, and 3.1% of patients with peripheral SpA. In both disease groups, women tended to report depression, joint tenderness, and higher disease activity more frequently than their male counterparts. At inclusion, a new diagnosis of SpA was performed in 58% of axial and 77% of peripheral patients, with a median time from symptom onset to diagnosis of 36 and 24 months, respectively. At baseline, most patients with axial SpA (77%) started a biological DMARD, while over half of the peripheral patients started a conventional DMARD.

Conclusions: Based on a well-characterized clinical registry of SpA, we provided real-world insights on the clinical features of DMARD-naïve SpA patients, pointing out major differences between axial and peripheral disease in terms of clinical characteristics and treatment pattern. Future prospective evaluations within the SIRENA study will improve knowledge on SpA and contribute to defining the best therapeutic approach.

Hidden in plain sight: Is there a crucial role for enthesitis assessment in the treatment and monitoring of axial spondyloarthritis?

OBJECTIVE

To review the evidence surrounding the pathophysiology of enthesitis in axial spondyloarthritis (axSpA), its prevalence and contribution to the overall disease burden, and response to treatment at axial and peripheral sites.

METHODS

Literature searches of the Cochrane Library, PubMed, and Embase / Medline using the terms "enthesitis", "enthesopathy", "spondyloarthritis", "axial spondyloarthritis", and "ankylosing spondylitis" were conducted. Publications mentioning enthesitis or enthesopathy in the context of pathophysiology, diagnosis, or treatment were included.

RESULTS

Enthesitis is a common symptom of axSpA, occurring with high prevalence at axial and several peripheral sites. Inflammation at the site of enthesis is an early key manifestation of axSpA. Clinically evaluable enthesitis contributes significantly to the burden of disease, correlating with worse symptomatology and downstream structural damage. Despite its importance in driving axSpA disease processes, enthesitis is somewhat neglected in current approaches to disease assessment and management. Enthesitis is excluded from some commonly used disease activity measures, is not routinely assessed in clinical practice, and many methods of clinical assessment omit key accessible axial sites, such as the spinous processes.

CONCLUSION

Enthesitis plays a central role in driving the pathophysiology of axSpA. There is a need for a renewed focus on the early detection, measurement and treatment of enthesitis.

Physical therapy in axial spondyloarthritis: guidelines, evidence and clinical practice

PURPOSE OF REVIEW

Physical therapy is recommended for the management of axial spondyloarthritis (axSpA) with the focus of promoting physical activity and prescribing exercise within four domains, outlined recently by the European League against Rheumatism (EULAR): aerobic, resistance, flexibility and neuro-motor exercise. There is an increasing evidence base to support physical therapy interventions in axSpA.

RECENT FINDINGS

We present evidence supporting the use of exercise as treatment for patients with axSpA, recent updates among different exercise modalities, and make clear its critical place in the management of this condition. Recent large, multicentre data have shown that high-intensity exercise can improve disease activity and also positively impact cardiovascular risk factors in these patients. Although international treatment guidelines advocate the inclusion of physical activity and exercise for the optimal management of axSpA, specific guidance about the amount of exercise required to produce a beneficial effect is lacking.

SUMMARY

Exercise must be used in the management of axSpA, and whilst hydrotherapy and flexibility exercises are traditionally the main focus, other applications, such as strength training, may be underutilized domains. Further studies are needed to determine the dose-response relationship between exercise and axSpA patient subsets.

Spondyloarthritis evolution: what is in your history?

PURPOSE OF REVIEW

This review encompasses a detailed history of spondyloarthritis (SpA) evolution as early as the 17th century, continues on to the current concept of SpA, and ends with current gaps in our understandings of SpA.

RECENT FINDINGS

Until the early 1960s, ankylosing spondylitis and other SpA family members were considered to be variants of rheumatoid arthritis (RA). The formal medical community separated them from RA at that time, and shortly thereafter they were recognized to be inter-connected based on shared clinical, laboratory, and imaging features. The last two decades have witnessed the formal distinction between axial and peripheral SpA and the connections that exist between nonradiographic and radiographic axial SpA. Recent studies have revealed different microbial compositions among patients with SpA and healthy controls and also between HLA-B27 positive and negative healthy individuals.

SUMMARY

Further investigation of the roles of intestinal microbiome and physical force transduction toward SpA pathogenesis, strategies to improve delay in SpA diagnosis, biomarkers to better predict radiographic progression, and modification of current classification criteria to better address the axial and peripheral groups are gaps in our understandings that pose top priorities for SpA research.

Prevalence of extra-articular manifestations in psoriatic arthritis: a systematic review and meta-analysis

OBJECTIVE

To describe the prevalence of extra-articular manifestations-enthesitis, dactylitis, nail disease, uveitis and IBD-in PsA, and their impact on longitudinal disease outcomes.

METHODS

We searched Medline, PubMed, Scopus and Web of Science using a predefined protocol in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies using imaging to define extra-articular manifestations (EAMs) were excluded. Where possible, we performed meta-analyses of prevalence estimates, reported as percentages (95% CI). Heterogeneity (I2 statistic) was examined according to study characteristics.

RESULTS

We identified 65 studies amounting to a total of 163 299 PsA patients. Enthesitis was assessed in 29 studies with an average prevalence of 30% (95% CI: 24%, 38%). Dactylitis was reported in 35 studies with an average prevalence of 25% (95% CI: 20%, 31%). Nail disease was present in 60% (95% CI: 52%, 68%) across 26 studies, but definitions were often unclear. Uveitis (3.2%; 95% CI: 1.9%, 5.3%) and IBD (3.3%; 95% CI: 1.5%, 7.1%) were less common. Heterogeneity was high (>95%) in all meta-analyses, but could not be explained by study characteristics. No studies examined the impact of EAMs on longitudinal disease outcomes, except that dactylitis increases radiographic progression.

CONCLUSION

Enthesitis, dactylitis and nail disease are highly prevalent in PsA, but not uveitis and IBD. EAM patterns differ from axial SpA despite their shared disease mechanisms, which may help further understand differences between spondyloarthritides. More studies are needed on the impact of EAMs on disease outcomes such as response to treatment.

Revisiting the gut-joint axis: links between gut inflammation and spondyloarthritis

Gut inflammation is strongly associated with spondyloarthritis (SpA), as exemplified by the high prevalence of inflammatory bowel disease (IBD) and the even higher occurrence of subclinical gut inflammation in patients with SpA. The gut-joint axis of inflammation in SpA is further reinforced by similarities in immunopathogenesis at both anatomical sites and by the clinical success of therapies blocking TNF and IL-23 in IBD and in some forms of SpA. Many genetic risk factors are shared between SpA and IBD, and changes in the composition of gut microbiota are seen in both diseases. Current dogma is that inflammation in SpA initiates in the gut and leads to joint inflammation; however, although conceptually attractive, some research does not support this causal relationship. For example, therapies targeting IL-17A are efficacious in the joint but not the gut, and interfering with gut trafficking by targeting molecules such as α4β7 in IBD can lead to onset or flares of SpA. Several important knowledge gaps remain that must be addressed in future studies. Determining the true nature of the gut-joint axis has real-world implications for the treatment of patients with co-incident IBD and SpA and for the repurposing of therapeutics from one disease to the other.

Characterization of Patients With Axial Spondyloarthritis by Enthesitis Presence: Data from the Corrona Psoriatic Arthritis/Spondyloarthritis Registry

OBJECTIVE

To compare the characteristics of patients with axial spondyloarthritis (axSpA) who had enthesitis versus those without enthesitis.

METHODS

This study included adult patients with axSpA enrolled in the Corrona Psoriatic Arthritis/Spondyloarthritis Registry (March 2013 to August 2018). Enthesitis was assessed at enrollment via the Spondyloarthritis Research Consortium of Canada Enthesitis Index. Characteristics were compared between patients with and without enthesitis using t tests or Wilcoxon rank-sum tests for continuous variables and χ2 or Fisher exact tests for categorical variables.

RESULTS

Of 477 patients with axSpA, 121 (25.4%) had enthesitis (mean, 3.9 sites) at enrollment. Higher proportions of patients with enthesitis were female and had nonradiographic axSpA than those without enthesitis (both P < 0.05). Additionally, higher proportions of patients with enthesitis had prior biologic (38.8% vs 27.2%) and conventional synthetic disease-modifying antirheumatic drug (csDMARD; 24.8% vs 13.3%) use and were currently receiving a combination of biologics and csDMARDs (28.6% vs 18.1%) than those without enthesitis. Patients with enthesitis had worse disease activity (tender and swollen joint counts, physician global assessment, Ankylosing Spondylitis Disease Activity Score, Bath Ankylosing Spondylitis Disease Activity Index, and Bath Ankylosing Spondylitis Functional Index), spinal mobility, and quality of life (pain, fatigue, Health Assessment Questionnaire, and EuroQol visual analog scale scores); greater work impairment; and had a history of depression and fibromyalgia than those without enthesitis (all P < 0.05).

CONCLUSION

In this US-based real-world study, enthesitis in patients with axSpA was associated with worse disease activity and quality of life than those with no enthesitis.

Peripheral spondyloarthritis: a neglected entity-state of the art

Peripheral spondyloarthritis (pSpA) refers to a number of seemingly different spondyloarthritis subsets in which psoriatic arthritis (PsA) is the most common, and symptoms of arthritis, enthesitis or dactylitis predominate the clinical presentation. Although formal classification criteria for pSpA have been introduced in 2011, only a minority of epidemiological and clinical studies addressed this clinical entity as a separate disease. Moreover, research on outcome measures and treatment modalities in pSpA has been mainly focused on PsA. Subsequently, all biological treatments are off-label in patients with non-psoriatic pSpA. Its neglected status has important implications for clinical practice since the emerging group of early-diagnosed non-psoriatic pSpA patients remains poorly characterised and lacks specific treatment recommendations. This review summarises what is currently known regarding pSpA in terms of epidemiology, clinical presentation, diagnosis and therapeutic approach.

What is axial spondyloarthritis? A latent class and transition analysis in the SPACE and DESIR cohorts

OBJECTIVES

To gain expert-judgement-free insight into the Gestalt of axial spondyloarthritis (axSpA), by investigating its 'latent constructs' and to test how well these latent constructs fit the Assessment of SpondyloArthritis international Society (ASAS) classification criteria.

METHODS

Two independent cohorts of patients with early onset chronic back pain (SPondyloArthritis Caught Early (SPACE)) or inflammatory back pain (IBP) (DEvenir des Spondylarthopathies Indifférenciées Récentes (DESIR)) were analysed. Latent class analysis (LCA) was used to estimate the (unobserved) potential classes underlying axSpA. The best LCA model groups patients into clinically meaningful classes with best fit. Each class was labelled based on most prominent features. Percentage fulfilment of ASAS axSpA, peripheral SpA (pSpA) (ignoring IBP) or both classification criteria was calculated. Five-year data from DESIR were used to perform latent transition analysis (LTA) to examine if patients change classes over time.

RESULTS

SPACE (n=465) yielded four discernible classes: 'axial' with highest likelihood of abnormal imaging and HLA-B27 positivity; 'IBP+peripheral' with 100% IBP and dominant peripheral symptoms; 'at risk' with positive family history and HLA-B27 and 'no SpA' with low likelihood for each SpA feature. LCA in DESIR (n=576) yielded similar classes, except for the 'no-SpA'. The ASAS axSpA criteria captured almost all (SPACE: 98%; DESIR: 93%) 'axial' patients, but the 'IBP+peripheral' class was only captured well by combining the axSpA and pSpA criteria (SPACE: 78%; DESIR: 89%). Only 4% of 'no SpA' patients fulfilled the axSpA criteria in SPACE. LTA suggested that 5-year transitions across classes were unlikely (11%).

CONCLUSION

The Gestalt of axSpA comprises three discernible entities, only appropriately captured by combining the ASAS axSpA and pSpA classification criteria. It is questionable whether some patients with 'axSpA at risk' will ever develop axSpA.

Disease Activity Influences Cardiovascular Risk Reclassification Based on Carotid Ultrasound in Patients with Psoriatic Arthritis

OBJECTIVE

Because the addition of carotid ultrasound (US) into composite cardiovascular (CV) risk scores has been found effective for identifying patients with inflammatory arthritis and high CV risk, we aimed to determine whether its use would facilitate the reclassification of patients with psoriatic arthritis (PsA) into the very high Systematic Coronary Risk Evaluation (SCORE) risk category and whether this might be related to disease features.

METHODS

This was a cross-sectional study involving 206 patients who fulfilled ClASsification for Psoriatic ARthritis criteria for PsA, and 179 controls. We assessed lipid profile, SCORE, disease activity measurements, and the presence of carotid plaques and carotid intima-media thickness by ultrasonography. A multivariable regression analysis, adjusted for classic CV risk factors, was performed to evaluate whether the risk of reclassification could be explained by disease-related features and to assess the most parsimonious combination of risk reclassification predictors.

RESULTS

Forty-seven percent of patients were reclassified into a very high SCORE risk category after carotid US compared to 26% of controls (p < 0.001). Patients included in the low SCORE risk category were those who were more commonly reclassified (30% vs 14%, p = 0.002). The Disease Activity Index for PsA (DAPSA) score was associated with reclassification (β 1.10, 95% CI 1.02-1.19; p = 0.019) after adjusting for age and traditional CV risk factors. A model containing SCORE plus age, statin use, and DAPSA score yielded the highest discriminatory accuracy compared to the SCORE-alone model (area under the receiver-operating characteristic curve 0.863, 95% CI 0.789-0.936 vs 0.716, 95% CI 0.668-0.764; p < 0.001).

CONCLUSION

Patients with PsA are more frequently reclassified into the very high SCORE risk category following carotid US assessment than controls. This was independently explained by the disease activity.

Variations in gut microbial profiles in ankylosing spondylitis: disease phenotype-related dysbiosis

Background

Microbial involvement in ankylosing spondylitis (AS) has been suggested; however, the relationship between gut microbiome and the disease phenotypes of AS remains to be established. This study was to characterize and investigate differences in the gut microbiome between AS patients and healthy controls (HCs), and to determine whether the gut microbiome profile associated with the disease phenotypes.

Methods

16S rRNA gene V4 region sequencing was performed on fecal DNA isolated from stool samples collected from 41 patients with AS [20 axial AS (axAS) and 21 peripheral AS (pAS)] and 19 HCs. QIIME based pipeline was used to process the raw sequence data. Alpha and beta diversities were assessed using QIIME, and comparisons of gut microbiome profile were performed using linear discriminant analysis (LDA) effect size (LEfSe) to examine differences between groups and subgroups. A gut microbiota-based model for predictive diagnosis of AS was constructed using random forest algorithm and its predictive value was assessed by receiver-operating characteristic analyses.

Results

Our results showed that fecal microbial communities in patients with AS differ significantly from those in HCs, driven by a higher abundance of 7 genera (Prevotella_9, Dialister, Comamonas, Collinsella, Streptococcus, Alloprevotella and Prevotella_2) and a lower abundance of 4 genera (Eubacterium_ruminantium_group, Ruminococcus_gnavus_group, Lachnospira and Bacteroides). In addition, pAS patients were more enriched in Comamonas, Streptococcus and Collinsella, while axAS patients were more enriched in Prevotella_2. An 8 genera-based model showed high accuracy for distinguishing AS patients from HCs with an area under the curve (AUC) up to 0.950.

Conclusions

Our results revealed specific alterations in the gut microbiome in patients with different phenotypes of AS, and the classification model based on gut microbial features might provide a new direction for future clinical diagnosis. Lastly, discovery of the associated microbes of AS in the gut microbiome may help us to seek more treatments for this disease.

Metabolites of type I, II, III, and IV collagen may serve as markers of disease activity in axial spondyloarthritis

Local inflammation in axial spondyloarthritis (axSpA) leads to the release of collagen metabolites from the disease-affected tissue. We investigated whether collagen metabolites were associated with disease activity and could distinguish non-radiographic(nr)-axSpA from ankylosing spondylitis (AS). A total of 193 axSpA patients (nr-axSpA, n = 121 and AS, n = 72) and asymptomatic controls (n = 100) were included. Serum levels of metalloproteinase (MMP)-degraded collagen type I (C1M), type II (C2M), type III (C3M) and type IV (C4M2) were quantified by enzyme-linked immunosorbent assay (ELISA). All metabolites were higher in axSpA than in controls (all p < 0.001). Serum levels of C1M, C3M, and C4M2 were increased in AS compared to nr-axSpA (43.4 ng/mL vs. 34.6; p < 0.001, 15.4 vs. 12.8; p = 0.001, and 27.8 vs. 22.4; p < 0.001). The best metabolite to differentiate between axSpA and controls was C3M (AUC 0.95; specificity 92.0, sensitivity 83.4). C1M correlated with ASDAS-CRP in nr-axSpA (ρ = 0.37; p < 0.001) and AS (ρ = 0.57; p < 0.001). C1M, C3M, and C4M2 were associated with ASDAS-CRP in AS and nr-axSpA after adjustment for age, gender, and disease duration. Serum levels of collagen metabolites were significantly higher in AS and nr-axSpA than in controls. Moreover, the present study indicates that collagen metabolites reflect disease activity and are useful biomarkers of axSpA.