Do we believe in non-radiographic axial spondyloarthritis? A debate

Comparison of established and preliminarily proposed ASAS MRI working group cut-offs for inflammatory MRI lesions in the sacroiliac joints in radiographic and non-radiographic axial spondyloarthritis

BACKGROUND

A consensus definition for active sacroiliitis by MRI, mentioned in the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axial spondyloarthritis (axSpA), was published in 2009 and included a qualitative and quantitative MRI cut-off component. In 2021, updates to the quantitative component were preliminarily proposed. This post hoc analysis of part A of the phase 3 open-label C-OPTIMISE study (NCT02505542) explores the differences by applying the 2009 and preliminary 2021 inflammatory cut-offs on clinical outcomes of axSpA patients treated with certolizumab pegol.

METHODS

Baseline MRI scans were used to classify 657 patients as MRI+ or MRI- according to the quantitative components of the 2009 and preliminary 2021 MRI cut-offs for inflammatory lesions. Clinical outcomes, including ASAS ≥40% improvement (ASAS40), Ankylosing Spondylitis Disease Activity Score and Bath Ankylosing Spondylitis Disease Activity Index, were reported to week 48.

RESULTS

Across all analysed outcomes, 2009 MRI+ and preliminary 2021 MRI+ subgroups showed similar results. Notably, clinical outcomes for the discordant group (2009 MRI+but preliminary 2021 MRI- group; 53/657 [8.1%]) were close to those seen in MRI- patients according to either 2009 or preliminary 2021 inflammatory cut-offs, and notably different from the totality of MRI+ subgroups.

CONCLUSION

This analysis suggests that the preliminary 2021 cut-offs for MRI inflammatory lesions may slightly increase the specificity of the quantitative part of the 2009 MRI inflammatory lesion definition. The effects of the updated MRI cut-offs need to be assessed on the basis of efficacy outcomes and with the inclusion of aspects of structural changes.

TRIAL REGISTRATION NUMBER

NCT02505542.

The role of ixekizumab in the treatment of nonradiographic axial spondyloarthritis

Nonradiographic axial spondyloarthritis (nr-axSpA) is a subtype of SpA with undeveloped definite radiographic sacroiliitis. Tumor necrosis factor inhibitors have demonstrated effectiveness in nr-axSpA patients who do not respond to first-line therapy. More recently, accumulated data from genetic, experimental, and clinical studies revealed that IL-17 is a key player in the pathogenesis of SpA, leading to development of new biologics directly inhibiting IL-17. Among them, ixekizumab is a high-affinity monoclonal antibody that selectively targets IL-17A and has exhibited significant efficacy and acceptable safety profiles in the treatment of nr-axSpA. The aim of this paper is to narratively review the recent insights of IL-17 in the pathogenesis of axSpA and discuss the effectiveness and safety of ixekizumab in treatment of nr-axSpA.

Pain in axial spondyloarthritis: role of the JAK/STAT pathway

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that is characterized by new bone formation in the axial musculoskeletal system, with X-ray discriminating between radiographic and non-radiographic forms. Current therapeutic options include non-steroidal anti-inflammatory drugs in addition to biological disease-modifying anti-rheumatic drugs that specifically target tumor necrosis factor-alpha (TNFα) or interleukin (IL)-17. Pain is the most critical symptom for axSpA patients, significantly contributing to the burden of disease and impacting daily life. While the inflammatory process exerts a major role in determining pain in the early phases of the disease, the symptom may also result from mechanical and neuromuscular causes that require complex, multi-faceted pharmacologic and non-pharmacologic treatment, especially in the later phases. In clinical practice, pain often persists and does not respond further despite the absence of inflammatory disease activity. Cytokines involved in axSpA pathogenesis interact directly/indirectly with the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling cascade, a fundamental component in the origin and development of spondyloarthropathies. The JAK/STAT pathway also plays an important role in nociception, and new-generation JAK inhibitors have demonstrated rapid pain relief. We provide a comprehensive review of the different pain types observed in axSpA and the potential role of JAK/STAT signaling in this context, with specific focus on data from preclinical studies and data from clinical trials with JAK inhibitors.

Relationship between sex and clinical and imaging features of early axial spondyloarthritis: results from a 48 month follow-up (Italian arm of the SPondyloArthritis Caught Early (SPACE) study)

OBJECTIVES

To assess the association between sex and clinical and disease activity indices, and X-rays and magnetic resonance imaging (MRI) features, in early-stage axial spondyloarthritis (axSpA).

METHOD

Baseline data analysis was conducted on the Italian SPACE cohort, including patients with chronic back pain (duration ≥ 3 months and ≤ 2 years; onset < 45 years). Patients underwent MRI and X-rays of the sacroiliac joints (SIJs) to establish the diagnosis of axSpA, according to Assessment of SpondyloArthritis international Society criteria and physician's judgement. Clinical features, disease activity and functional indices, and images were collected at baseline and yearly during 48 months. Spinal and SIJ X-rays and MRI images were scored by two readers following Spondyloarthritis Research Consortium of Canada (SPARCC), modified Stoke Ankylosing Spondylitis Spinal Score, and modified New York criteria. Characteristics of axSpA patients according to sex (male/female) were compared over time using descriptive statistics.

RESULTS

Ninety-one patients had axSpA (83.5% non-radiographic; 16.5% radiographic); 47.3% were male. Males were younger, with shorter duration of axial symptoms, and more frequently had HLA-B27 positivity, radiographic sacroiliitis with a bilateral/symmetric pattern, and more signs of spondylitis. Females more frequently showed peripheral/entheseal involvement and the non-radiographic phenotype. Males showed increased pelvic/spinal radiographic progression and more often had active sacroiliitis on MRI. Although the frequency of inflammatory corner lesions did not differ between males and females, localization varied, with more cervical/thoracic MRI-spine lesions in females and more lumbar lesions in males. We observed a significant downward trend of SPARCC SIJ/spine scores in all patients, irrespective of sex. More fat lesions were observed on MRI-spine in females and on MRI-SIJ in males.

CONCLUSION

Sex was associated with distinct axSpA features: females showed low-grade radiographic sacroiliitis and spinal progression, and a higher prevalence of cervical and thoracic spine MRI signs.

Thrombocytosis in patients with spondyloarthritis: a case-control study

OBJECTIVE

This study aimed to investigate the clinical and laboratory as well as radiological features of spondyloarthritis (SpA) patients with thrombocytosis and to explore risk factor for thrombocytosis in SpA patients and to assess the effect of antitumor necrosis factor-α (anti-TNF-α) therapy on platelet count in SpA patients with thrombocytosis.

METHODS

A total of 145 patients with SpA were included in this study, and non-thrombocytosis was identified in 76 patients while thrombocytosis was found in 69 patients, 38 out of the 69 patients received anti-TNF-α therapy. Logistic regression analysis was performed to investigate risk factors that associated with thrombocytosis. The platelet count of patients in the thrombocytosis group treated with anti-TNF-α therapy on week 0, week 6 and week 12 were collected and compared with conventional therapy group.

RESULTS

The proportion of hip involvement (60.86% vs 36.84%, p = 0.004), bath ankylosing spondylitis disease activity index score (4.24 ± 0.55 vs 3.69 ± 0.67, p < 0.001), erythrocyte sedimentation rate (62.22 ± 41.97 mm/hour vs 27.00 ± 25.93 mm/hour, p < 0.001), C-reactive protein (53.45 ± 47.45 mg/L vs 18.91 ± 31.09 mg/L, p < 0.001), fibrinogen (5.77 ± 1.48 g/L vs 4.01 ± 1.32 g/L, P < 0.001), white blood cells (8.15 ± 1.90 × 10⁹/L vs 6.85 ± 2.39 × 10⁹/L, p < 0.001) and neutrophils (5.08 ± 1.55 × 10⁹/L vs 4.01 ± 2.04 × 10⁹/L, p = 0.001) are higher in thrombocytosis group, but hemoglobin and albumin are lower compared to non-thrombocytosis group (122.88 ± 17.25 g/L vs 131.51 ± 16.03 g/L, p = 0.002; 37.19 ± 4.73 g/L vs 39.67 ± 3.99 g/L, p = 0.001, respectively). Multivariable logistic regression analysis indicated that higher white blood cells (OR, 1.644; 95% CI, 1.045-2.587; P = 0.032) and fibrinogen (OR, 2.169; 95% CI, 1.237-3.804; P = 0.007) were independently associated with thrombocytosis in SpA patients. The platelet count in the thrombocytosis group treated with anti-TNF-α therapy on week 6 and week 12 were statistically lower than week 0 (225.05 ± 60.58 × 10⁹/L vs 368.26 ± 54.34 × 10⁹/L, p < 0.001; 201.26 ± 51.48 × 10⁹/L vs 368.26 ± 54.34 × 10⁹/L, p < 0.001) and conventional therapy (week 6, 225.05 ± 60.58 × 10⁹/L vs 370.00 ± 74.05 × 10⁹/L, p < 0.001; week 12, 201.26 ± 51.48 × 10⁹/L vs 303.13 ± 71.49 × 10⁹/L, p < 0.001).

CONCLUSION

SpA patients with thrombocytosis have a higher proportion of hip involvement and disease activity compared to non-thrombocytosis SpA patients. The potential risk factors for thrombocytosis in SPA patients were higher white blood cells and fibrinogen. Anti-TNF-α therapy can reduce the increased platelets more effectively and rapidly than conventional treatments in SpA patients with thrombocytosis.

The impact of diet on disease activity in spondyloarthritis: A systematic literature review

OBJECTIVES

Our study aimed to systematically review the evidence about the effect of diet or dietary supplements on spondyloarthritis (SpA) disease activity.

METHODS

a systematic literature review (SLR) was conducted in MEDLINE, EMBASE, Cochrane and SCOPUS according to the "PEO" format (Population, Exposure, Outcome). The population was SpA (axial or peripheral, axSpA/pSpA, including Psoriatic Arthritis-PsA); the intervention any kind of diet/dietary supplement; the outcome disease activity. Inclusion criteria were: adult patients, Randomized Controlled Trials (RCTs) and longitudinal studies (so that a pre-and post-intervention assessment were available), papers in English. Risk of bias (RoB) was conducted with different tools according to the design of the study.

RESULTS

Literature search yielded 1390 publications, of which 15 were finally inlcuded: 12 interventional and 3 observational studies. Among those with the lower RoB: a) 2 RCTs, one at unclear and one at low RoB, failed to show benefit of probiotics in SpA b) Two RCTs at unclear RoB provided evidence that weight loss, but not hypocaloric diet, was associated to MDA achievement in PsA. The remaining interventional studies were at high RoB. Among the observational studies, one study on Mediterranean diet demonstrated an association between diet adherence and a ≥ 20% decrease of ASDAS in axSpA. The other two observational studies were judged of poor quality.

CONCLUSIONS

weight loss seem to be able to impact disease activity in PsA, while probiotics do not seem useful in SpA; evidence for dietary behaviors is scarce and heterogeneous.

Sex Disparities of the Sacroiliac Joint: Focus on Joint Anatomy and Imaging Appearance

The sacroiliac joint (SIJ) is an anatomically complex joint which, as a functional unit with the pelvis and spine, is of decisive biomechanical importance for the human body. It is also a commonly overlooked source of lower back pain. Like the entire bony pelvis, the SIJ exhibits major sexual dimorphisms; thus, the sex-dependent evaluation of this joint is becoming increasingly important in clinical practice, both anatomically with joint shape variations and biomechanical differences as well as in terms of image appearance. The influence of the SIJ shape, which differs in women and men, is crucial for the different biomechanical joint properties. These differences are important in the development of joint diseases at the SIJ, which shows a specific difference between the sexes. This article aims to provide an overview of sex disparities of the SIJ regarding different anatomical and imaging appearances to further understand the insights into the interplay of sex differences and SIJ disease.

Fetuin-A: A Novel Biomarker of Bone Damage in Early Axial Spondyloarthritis. Results of an Interim Analysis of the SPACE Study

Our study aimed to evaluate the association between fetuin-A levels and the presence of radiographic sacroiliitis and syndesmophytes in patients with early axial spondyloarthritis (axSpA) and to identify potential predictors of radiographic damage in the sacroiliac joints (SIJs) after 24 months. Patients diagnosed with axSpA in the Italian cohort of the SpondyloArthritis-Caught-Early (SPACE) study were included. Physical examinations, laboratory tests (including fetuin-A), SIJ,+ and spinal X-rays and MRIs at T0 (diagnosis) and at T24 were considered. Radiographic damage in the SIJs was defined according to the modified New York criteria (mNY). Fifty-seven patients were included in this analysis (41.2% male, median (interquartile range), chronic back pain [CBP] duration of 12 (8-18) months). Fetuin-A levels were significantly lower in patients with radiographic sacroiliitis compared to those without at T0 (207.9 (181.7-215.9) vs. 239.9 (217.9-286.9), respectively, p < 0.001) and at T24 (207.6 (182.5-246.5) vs. 261.1 (210.2-286.6) µg/mL, p = 0.03). At T0, fetuin-A levels were significantly higher in non-smokers, in patients with heel enthesitis and in those with a family history of axSpA; fetuin-A levels at T24 were higher in females, in patients with higher ESR or CRP at T0 and in those with radiographic sacroiliitis at T0. Fetuin-A levels at T0 were independently negatively associated with the likelihood of radiographic sacroiliitis (OR = 0.9 per 10-unit increase (95% CI 0.8, 0.999), p = 0.048); but not with the presence of syndesmophytes. After adjustment for confounders, fetuin-A levels at T0 and T24 were also negatively associated with mNY at T0 (β -0.5, p < 0.001) and at T24 (β -0.3, p < 0.001), respectively. Among other variables at T0, fetuin-A levels did not achieve statistical significance in predicting mNY at T24. Fetuin-A levels were negatively associated with radiographic damage of the SIJs, but not of the spine, in early axSpA and after 2 years of follow-up. Our findings suggest that fetuin-A levels may serve as a biomarker to identify patients with a higher risk of developing severe disease and early structural damage.

Residual Disease in Patients with Axial Spondyloarthritis: A Post-Hoc Analysis of the QUASAR Study

In this study, we evaluated the presence of residual disease in patients with axial spondyloarthritis (axSpA) in remission/low disease activity (LDA) status. This cross-sectional post-hoc analysis of the QUASAR study involving 23 rheumatology centres across Italy included adults with axSpA classified according to the Assessment of SpondyloArthritis International Society criteria. Patients with inactive disease (score < 1.3) or at least LDA status (score < 2.1) at baseline visit according to Ankylosing Spondylitis Disease Activity Score were investigated to evaluate how residual disease activity impacts patients’ quality of life. They were assessed using the Ankylosing Spondylitis Quality of Life (ASQoL) and EuroQoL 5-Dimension 5-Level (EQ-5D-5L) questionnaires. This study included 480 patients with axSpA (mean age, 47.5 ± 12.9 years, 64% male). In total, 123 patients (25.6%) had inactive disease and 262 (54.6%) had at least LDA. Using the ASQoL, ranges of 10−25% and 20−40% of patients with inactive disease and with LDA status, respectively, experienced tiredness/fatigue. Despite being classified with inactive disease, 48.8% of patients reported light pain/discomfort according to the EQ-5D-5L, with 4.1% reporting moderate pain/discomfort, whereas 55.7% of patients with LDA reported light pain/discomfort and 13% had moderate pain/discomfort. Using the ASQoL questionnaire, in patients with at least LDA, a higher proportion of women compared with males and a higher proportion of patients > 48 years of age (vs. patients ≤ 48 years) experienced tiredness. In this post-hoc analysis, ≥25% of axSpA patients in remission/LDA status were still burdened by residual disease, mainly characterised by pain and fatigue.

How good is the agreement between clinical diagnoses and classification criteria fulfilment in axial spondyloarthritis? Results from the SPARTAKUS cohort

OBJECTIVES

To study the agreement between clinical axial spondyloarthritis (axSpA) diagnoses and fulfilment of the Assessment of SpondyloArthritis international Society (ASAS) axSpA and modified New York (mNY) classification criteria, and to compare disease/health status between axSpA subtypes.

METHOD

Patients with prevalent, clinical axSpA attending a rheumatology clinic were enrolled in a cross-sectional study. Assessments included physical evaluation, laboratory testing, questionnaires, and appropriate imaging, allowing classification. Standard axSpA outcome measures were compared between patients fulfilling mNY/radiographic versus non-radiographic axSpA (r-axSpA/nr-axSpA) criteria.

RESULTS

Of 239 consecutively included patients, 141 fulfilled ASAS r-axSpA and/or mNY criteria, while 57 fulfilled nr-axSpA criteria. The agreement between r-axSpA and mNY criteria fulfilment was 94%. The positive predictive value (PPV) of a clinical ankylosing spondylitis (AS) diagnosis for mNY criteria fulfilment was 71%; the PPV of an undifferentiated axSpA (u-axSpA) diagnosis for fulfilment of nr-axSpA criteria was 30% and 40% for mNY criteria. Patients with r-axSpA/AS were older, more often men, and had longer disease duration, more uveitis, and worse spinal mobility than nr-axSpA patients, who had more enthesitis and dactylitis.

CONCLUSION

We found an overall good concordance between clinical axSpA diagnoses and classification criteria fulfilment, with 83% fulfilling ASAS axSpA and/or mNY criteria. Regarding axSpA subtypes, the concordance was weaker, and although the ICD-10 code for AS correctly identified patients meeting mNY criteria in 71% of cases, one-third of mNY-positive patients lacked an AS diagnosis. Moreover, clinical u-axSpA diagnoses could not serve as a proxy to identify nr-axSpA, highlighting the importance of thorough classification in research on axSpA subtypes.

Sex-associated and gender-associated differences in the diagnosis and management of axial spondyloarthritis: addressing the unmet needs of female patients

Emerging evidence suggests that axial spondyloarthritis (axSpA) should not be seen as a predominantly male disease, as the non-radiographic form occurs with roughly equal frequency in women and men. However, men and women experience this disease differently. The purpose of this review is to highlight sex-associated and gender-associated differences in the patient's journey through the diagnosis and management of axSpA, in order to increase the awareness about the unmet needs of female axSpA patients.Female patients experience a longer diagnostic delay compared with men, possibly due to the different pattern of clinical presentations across genders. Therefore, it is crucial to sensitise physicians to pay attention and identify the red flags of axSpA in women and promote early referral to a rheumatologist. Women with a diagnosis of axSpA experience greater limitations in physical function, although they have less structural spinal damage compared with men. Women tend to have less adherence and a lower response to treatment, so more gender-oriented data are needed about drugs used for axSpA, especially biological disease-modifying antirheumatic drugs.Lifestyle factors have a strong impact on the disease course. Interventions regarding physical activity, smoking cessation and diet should be communicated to the patients, with particular attention to the gender-related cultural background.Patients of childbearing age living with axSpA should be engaged in a discussion about reproductive health, in terms of preservation of fertility, management of pregnancy and delivery and use of biologic drugs during pregnancy and breastfeeding.