Tumor Necrosis Factor Inhibitors Reduce Spinal Radiographic Progression in Patients With Radiographic Axial Spondyloarthritis: A Longitudinal Analysis From the Alberta Prospective Cohort

Decreasing incidence of cervical spine fractures in patients with ankylosing spondylitis: a population-based study in Southeast Norway

BACKGROUND CONTEXT

Individuals diagnosed with ankylosing spondylitis (AS) face an increased risk of spine fractures, specifically cervical spine fractures (CS-Fxs). In the past two decades, biological disease-modifying antirheumatic drugs (bDMARDs) have provided considerable relief from pain and an enhanced sense of wellbeing for a large segment of AS patients. Despite these improvements, it remains unclear whether extended use of bDMARDs can indeed reduce the risk of spine fractures.

PURPOSE

In this study, we aimed to investigate the evolving patterns and epidemiology of traumatic CS-Fxs in both AS and non-AS populations. We hypothesized that the risk of CS-Fxs among AS patients would show a decreasing trend over time, while the risk among non-AS patients would remain constant.

STUDY DESIGN/SETTING

Retrospective cohort study based on a prospective database.

PATIENT SAMPLE

A total of 3,598 consecutive patients with CS-Fxs were treated at Oslo University Hospital over an 8-year period.

OUTCOME MEASURES

CS-Fxs in AS patients were contrasted with non-AS-related CS-Fxs in terms of temporal trends, age, sex, injury mechanism, associated cervical spinal cord injury (cSCI), need for surgical fixation, and 30-day mortality.

METHODS

Data regarding all CS-Fxs diagnosed between 2015 and 2022 were extracted from the Southeast Norway population-based quality control database for traumatic CS-Fxs. Categorical data were summarized using frequencies, and continuous data were summarized using medians. The Wilcoxon rank-sum test was used to compare continuous variables, and the chi-squared test and Fischer exact test were used to compare categorical variables. To investigate the trend in the incidence of fractures, two different Poisson models were fitted with the number of non-AS and AS fractures as dependent variables and the year as the explanatory variable.

RESULTS

Over an 8-year period, we registered 3,622 CS-Fxs in 3598 patients, with AS patients accounting for 125 of these fractures. Relative to their non-AS counterparts, AS patients presented a 9-fold and 8-fold higher risk of initial and subsequent CS-Fxs, respectively. We observed a declining trend in AS-related CS-Fxs with an annual linear decrease of 8.4% (p=.026), whereas non-AS-related CS-Fxs showed an annual linear increase of 3.7% (p<.001). AS patients sustaining CS-Fxs were typically older (median age 70 vs 63 years), predominantly male (89% vs 67%), and more frequently experienced injuries due to falls (82% vs 57%). They also exhibited a higher prevalence of subaxial CS-Fxs (91% vs 62%), fewer C0-C2 CS-Fxs (14% vs 44%), a higher rate of associated cSCI (21% vs 11%), and a greater tendency for surgical fixation (66% vs 21%). We observed a 30-day mortality rate of 11% in AS patients and 5.4% in non-AS patients (p=.005).

CONCLUSIONS

The results of this study confirm the elevated risk of CS-Fxs among AS patients, although this risk appears to show a decreasing trend. The most plausible explanation for this risk reduction is the widespread application of bDMARDs.

Disease modification in axial spondyloarthritis - still a controversy?

PURPOSE OF REVIEW

This review evaluates recent advancements in disease-modifying therapies for axial spondyloarthritis (axSpA).

RECENT FINDINGS

A recent study could not demonstrate an additional effect of NSAID therapy on golimumab [Tumor Necrosis Factor-α inhibitor (TNFi)] on structural progression; however, this might be due to the fact that the study was underpowered. While DMARDs have shown promise in suppressing inflammation, their impact on structural progression remains uncertain. A well powered trial showed no difference in spinal progression between secukinumab [Interleukin17A inhibitor (IL17Ai)] and adalimumab-biosimilar (TNFi). Preliminary data on Janus kinase inhibitors (JAKi) focus on MRI findings but lack evidence on radiographic spinal progression. While some studies suggest promising outcomes, others reveal limitations and inconclusive findings.

SUMMARY

Recent studies explore the effectiveness of NSAIDs, biological disease-modifying antirheumatic drugs like TNFi and IL-17i, as well as JAK inhibitors in axSpA. Conflicting evidence surrounds these therapies' ability to impede structural progression, with challenges in study design and interpretation. Moreover, changes in demographics and treatment methods underscore the importance of examining trends over time when assessing disease outcomes. Ultimately, ongoing research could benefit from new imaging tools when evaluating therapeutic strategies for modifying disease progression in axSpA.

An update in the pharmacological management of axial spondyloarthritis

INTRODUCTION

Significant progress has been made in the diagnosis and management of axial spondyloarthritis (AxSpA) over recent decades. A greater understanding of the immunopathogenesis of the disease has paved the way for the development of targeted treatments. Their efficacy has been demonstrated in randomized controlled trials, meta-analyses and one head-to-head study of biologic DMARDs. Treatment decisions in AxSpA are currently influenced by patient choice, co-morbidity, clinician familiarity and cost.

AREAS COVERED

We review the clinical trials that underpin the evidence base for treatments in AxSpA. We also cover the meta-analyses and head-to-head data that seek to support clinicians in personalizing treatment decisions. Further, we discuss the recent international guidelines that provide clinicians with treatment pathways and guidance.

EXPERT OPINION

We conclude that treatment decisions in managing both radiographic and non-radiographic AxSpA should be based on shared decision-making with patients, the clinical effectiveness of drug class, co-morbidity and cost. At present, we have limited head-to-head data to prioritize one drug class over another for first-line treatment but can recommend tumor necrosis factor (TNF), interleukin 17 (IL17) and JAK inhibition as being comparable in terms of clinical, structural and patient-reported outcome measures. Further real-world data may guide treatment decision-making in individual patients.

Comparison of the effect of treatment with NSAIDs added to anti-TNF therapy versus anti-TNF therapy alone on the progression of structural damage in the spine over 2 years in patients with radiographic axial spondyloarthritis from the randomised-controlled CONSUL trial

OBJECTIVES

The study aimed to evaluate the effect of adding a non-steroidal anti-inflammatory drug (NSAID), celecoxib (CEL), to a tumour necrosis factor inhibitor (TNFi), golimumab (GOL), compared with TNFi monotherapy on radiographic spinal progression in patients with radiographic axial spondyloarthritis (r-axSpA) over 2 years.

METHODS

R-axSpA patients, having risk factors for radiographic progression (high disease activity plus C reactive protein >5 mg/L and/or ≥1 syndesmophyte(s)), underwent a 12-week run-in phase with GOL 50 mg every 4 weeks. In the core phase (96 weeks), only patients with a good clinical response at week 12 were randomised (1:1) to GOL+CEL 200 mg two times per day (combination therapy) or GOL monotherapy. The primary endpoint was radiographic progression assessed by modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) change at week 108 in the intent-to-treat population.

RESULTS

A total of 128 patients were enrolled in the run-in phase; and 109 patients were randomised at week 12 to monotherapy (n=55) or combination therapy (n=54). At week 108, 97 (52 vs 45) patients completed the study. The change in mSASSS at week 108 was 1.7 (95% CI 0.8 to 2.6) in the monotherapy vs 1.1 (95% CI 0.4 to 1.8) in the combination therapy groups (p=0.79). New syndesmophytes occurred in 25% of patients in the monotherapy vs 11% of patients in the combination therapy groups (p=0.12). During the study, no significant differences in adverse events and serious adverse events were observed between the groups.

CONCLUSIONS

Combination therapy with GOL+CEL did not demonstrate statistically significant superiority over GOL monotherapy in retarding radiographic spinal progression over 2 years in r-axSpA.

Biomechanics in the onset and severity of spondyloarthritis: a force to be reckoned with

Increasing evidence suggests that there is a pivotal role for physical force (mechanotransduction) in the initiation and/or the perpetuation of spondyloarthritis; the review contained herein examines that evidence. Furthermore, we know that damage and inflammation can limit spinal mobility, but is there a cycle created by altered spinal mobility leading to additional damage and inflammation?Over the past several years, mechanotransduction, the mechanism by which mechanical perturbation influences gene expression and cellular behaviour, has recently gained popularity because of emerging data from both animal models and human studies of the pathogenesis of ankylosing spondylitis (AS). In this review, we provide evidence towards an appreciation of the unsolved paradigm of how biomechanical forces may play a role in the initiation and propagation of AS.

Angiotensin receptor blockers, but not angiotensin-converting enzyme inhibitors, inhibit abnormal bone changes in spondyloarthritis

Spondyloarthritis (SpA) is a chronic inflammatory disease that results in bone ankylosis. The tissue renin-angiotensin system (RAS) is an emerging pathway potentially implicated in SpA-associated bone changes. The aim of the present study was to determine the mechanisms underlying this relationship. Sakaguchi (SKG) mice injected with curdlan (SKGc), animal models for SpA, were treated with RAS modulators, angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEis). Disease activity was assessed using clinical scores and computed tomography scans. Mouse primary bone marrow monocytes (BMMs), osteoblast (OB) progenitor cells, peripheral blood monocytes (PBMCs), and bone-derived cells (BdCs) from patients with radiographic axial SpA (r-axSpA) were used to investigate the role of RAS in SpA pathogenesis. The expression of RAS components was significantly increased in SKGc mouse joints, and ARBs significantly reduced erosion and systemic bone loss, whereas ACEis did not. Osteoclast (OC) differentiation from primary BMMs, mediated by TRAF6, was inhibited by ARBs but promoted by ACEis; the modulators also exerted opposite effects on OB differentiation. Expression of RAS molecules was higher in PBMCs and BdCs of patients with r-axSpA than in control participants. ARBs inhibited OB differentiation in the BdCs of patients with r-axSpA, whereas ACEis did not. Neither ARBs nor ACEis affected OB differentiation in the control participants. In SpA, a condition characterized by RAS overexpression, ARBs, but not ACEis, inhibited OC and OB differentiation and bone progression. The findings should be taken into account when treating patients with SpA using RAS modulators.

Treatment overview of axial spondyloarthritis in 2023

The treatment of patients with axial spondyloarthritis (axSpA) is characterized by non-pharmacological and pharmacological treatment options. It may depend on the type and extent of musculoskeletal and extramusculoskeletal manifestations. Recent data on non-pharmacological treatment options, such as physical activity, physiotherapy, and modification of lifestyle factors, are summarized in this review. Moreover, we have provided an overview on non-steroidal anti-inflammatory drugs and the ever-expanding number of biological and targeted synthetic disease-modifying antirheumatic drugs (bDMARDs and tsDMARDs, respectively). In addition to data on efficacy and safety, the review also encompasses data on switching/cycling, tapering, and treatment selection for specific patient subgroups to optimize treatment outcomes.

Tofacitinib Reduces Spinal Inflammation in Vertebral Bodies and Posterolateral Elements in Ankylosing Spondylitis: Results from a Phase 2 Trial

INTRODUCTION

This post hoc analysis of phase 2 trial data assessed the efficacy of tofacitinib on magnetic resonance imaging (MRI) outcomes with the detailed anatomy-based Canada-Denmark (CANDEN) MRI scoring system and evaluated tofacitinib suppression of spinal inflammation in patients with active ankylosing spondylitis (AS).

METHODS

Patients with active AS (per modified New York criteria) were randomized 1:1:1:1 to receive tofacitinib 2, 5, or 10 mg twice daily (BID), or placebo, in a 16-week, phase 2, double-blind clinical trial. Spine MRI assessments were performed at baseline and week 12. For post hoc analysis, MRI images from patients receiving tofacitinib 5 or 10 mg BID, or placebo, were re-evaluated by two readers blinded to time point/treatment and assessed by the CANDEN MRI scoring system. Least squares mean changes from baseline to week 12 were reported for CANDEN-specific MRI outcomes, with analysis of covariance used for comparisons of pooled tofacitinib and tofacitinib 5 or 10 mg BID versus placebo. p values without multiplicity adjustment were reported.

RESULTS

MRI data from 137 patients were analyzed. At week 12, CANDEN spine inflammation score and vertebral body, posterior elements, corner, non-corner, facet joint, and posterolateral inflammation subscores were significantly reduced with pooled tofacitinib versus placebo (p < 0.0001; except non-corner subscore, p < 0.05). Total spine fat score was numerically increased with pooled tofacitinib versus placebo.

CONCLUSIONS

In patients with AS, tofacitinib treatment was associated with significant reductions in MRI scores of spinal inflammation versus placebo, as assessed by the CANDEN MRI scoring system. Tofacitinib reduced inflammation in posterolateral elements of the spine and facet joints, which has not been described previously.

TRIAL REGISTRATION

ClinicalTrials.gov registry (NCT01786668).

Association between changes in serum alkaline phosphatase levels and radiographic progression in ankylosing spondylitis

This retrospective study evaluated the electronic medical records of patients with ankylosing spondylitis (AS) (January 2001-December 2018) to determine the relationship between serum alkaline phosphatase (ALP) levels and radiographic changes over time. Longitudinal data, including serum ALP levels, were imputed by linear interpolation at 3-month intervals. Among the serum ALP levels calculated for 8 years prior to modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) measurement, those having the highest beta coefficient with the mSASSS were selected in the correlation between ALP and longitudinal mSASSS. Linear mixed models with the selected serum ALP levels, mSASSS, and clinical variables were investigated. We included 1122 patients (mean follow-up, 8.20 [standard deviation: 2.85] years). The serum ALP level from 5 years and 3 months prior showed the highest beta coefficient with the mSASSS. In the linear mixed model, the serum ALP level at 5 years and 3 months before radiographic changes was significantly associated with the mSASSS (β = 0.021, 95% confidence interval: 0.017-0.025, p < 0.001). Serum ALP levels measured approximately 5 years before may be a surrogate marker for predicting spinal radiographic changes. Long-term prospective clinical and experimental studies of > 5 years are required for biomarker discovery or therapeutic research on AS radiographic progression.

Syndesmophyte Growth in Ankylosing Spondylitis: from Laboratory to Bedside

PURPOSE OF REVIEW

This study aims to review recent studies on risk factors for syndesmophyte growth in ankylosing spondylitis (AS) and on treatment effects.

RECENT FINDINGS

New genetic studies, including a genome-wide association study, provided only limited evidence of specific genetic associations with radiographic severity. Measures of inflammation, including vertebral osteitis and C-reactive protein level, were strongly associated with radiographic progression, while studies of adipokines had mixed results. Mesenchymal stem cells from HLA-B27 positive AS patients were found to promote vertebral ossification via a pathway of B27 misfolding, retinoic acid receptor-β activation, and increased bone alkaline phosphatase. Low vertebral trabecular bone density is associated with syndesmophyte growth, with reciprocal effects when bridged. Several observational studies suggested radiographic severity was reduced by treatment with tumor necrosis factor inhibitors, particularly when longer than 2 years. Syndesmophyte development in AS is the result of a complex, incompletely understood, interplay of inflammatory and mechanical factors.

Sustained low functional impairment in axial spondyloarthritis (axSpA): which are the primary outcomes that should be targeted to achieve this?

OBJECTIVES

To (i) determine whether sustained disease activity states, as measured by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS), impact function, and (ii) evaluate characteristics predicting sustained low functional impairment in a prospective axial spondyloarthritis (axSpA) cohort.

METHODS

Biologic Treatment Registry Across Canada (BioTRAC) was a multi-center, prospective registry that collected real-world data on axSpA patients receiving infliximab or golimumab between 2006 and 2017. Generalized estimating equations (GEE) were used to test baseline characteristics, treatment, and duration (at 6 and 12 months vs. only at 6 or 12 months vs. neither) of low BASDAI (< 3), ASDAS-inactive disease (ID)(< 1.3), and ASDAS-low disease activity (LDA) in predicting sustained low Bath Ankylosing Spondylitis Functional Index (BASFI)(< 3) between 12 and 18 months. The adjusted impact of achieving low disease state at 6 and/or 12 months on BASFI at 18 months was analyzed by generalized linear models.

RESULTS

Eight hundred ten patients were enrolled. 33.7%, 13.4%, and 24.7% achieved sustained low BASDAI, ASDAS-ID, and ASDAS-LDA, respectively. In univariable GEE of baseline variables, age and baseline BASDAI, BASFI, and ASDAS significantly predicted sustained low BASFI. In multivariable GEE, sustained low BASDAI (p < 0.001), low BASDAI only at 6 or 12 months (p = 0.001), and baseline BASFI (p < 0.001) were the only predictors of sustained low BASFI. Sustained ASDAS-ID (p = 0.040) and ASDAS-LDA (p < 0.001) were also predictors when forced into the model. Similar results were obtained when evaluating the BASFI score at 18 months.

CONCLUSION

Sustained BASDAI < 3 may be a valid and feasible target for a treat-to-target strategy in axSpA having function as treatment goal.

Quantitative prediction of radiographic progression in patients with axial spondyloarthritis using neural network model in a real-world setting

BACKGROUND

Predicting radiographic progression in axial spondyloarthritis (axSpA) remains limited because of the complex interaction between multiple associated factors and individual variability in real-world settings. Hence, we tested the feasibility of artificial neural network (ANN) models to predict radiographic progression in axSpA.

METHODS

In total, 555 patients with axSpA were split into training and testing datasets at a 3:1 ratio. A generalized linear model (GLM) and ANN models were fitted based on the baseline clinical characteristics and treatment-dependent variables for the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) of the radiographs at follow-up time points. The mSASSS prediction was evaluated, and explainable machine learning methods were used to provide insights into the model outcome or prediction.

RESULTS

The R² values of the fitted models were in the range of 0.90-0.95 and ANN with an input of mSASSS as the number of each score performed better (root mean squared error (RMSE) = 2.83) than GLM or input of mSASSS as a total score (RMSE = 2.99-3.57). The ANN also effectively captured complex interactions among variables and their contributions to the transition of mSASSS over time in the fitted models. Structural changes constituting the mSASSS scoring systems were the most important contributing factors, and no detectable structural abnormalities at baseline were the most significant factors suppressing mSASSS change.

CONCLUSIONS

Clinical and radiographic data-driven ANN allows precise mSASSS prediction in real-world settings. Correct evaluation and prediction of spinal structural changes could be beneficial for monitoring patients with axSpA and developing a treatment plan.

Uncovering the Underworld of Axial Spondyloarthritis

Axial spondyloarthritis (axial-SpA) is a multifactorial disease characterized by inflammation in sacroiliac joints and spine, bone reabsorption, and aberrant bone deposition, which may lead to ankylosis. Disease pathogenesis depends on genetic, immunological, mechanical, and bioenvironmental factors. HLA-B27 represents the most important genetic factor, although the disease may also develop in its absence. This MHC class I molecule has been deeply studied from a molecular point of view. Different theories, including the arthritogenic peptide, the unfolded protein response, and HLA-B27 homodimers formation, have been proposed to explain its role. From an immunological point of view, a complex interplay between the innate and adaptive immune system is involved in disease onset. Unlike other systemic autoimmune diseases, the innate immune system in axial-SpA has a crucial role marked by abnormal activity of innate immune cells, including γδ T cells, type 3 innate lymphoid cells, neutrophils, and mucosal-associated invariant T cells, at tissue-specific sites prone to the disease. On the other hand, a T cell adaptive response would seem involved in axial-SpA pathogenesis as emphasized by several studies focusing on TCR low clonal heterogeneity and clonal expansions as well as an interindividual sharing of CD4/8 T cell receptors. As a result of this immune dysregulation, several proinflammatory molecules are produced following the activation of tangled intracellular pathways involved in pathomechanisms of axial-SpA. This review aims to expand the current understanding of axial-SpA pathogenesis, pointing out novel molecular mechanisms leading to disease development and to further investigate potential therapeutic targets.

Inflammation, bone loss and 2-year bone formation at the same vertebra in axial spondyloarthritis: a multilevel MRI and low-dose CT analysis

OBJECTIVE

To investigate whether in radiographic axial spondyloarthritis (r-axSpA) inflammation is associated with lower trabecular bone density (TBD), and subsequently, if a lower TBD increases the likelihood of 2-year bone formation at the same vertebra.

METHODS

Whole spine (C3-L5) data from patients included in the multicentre 2-year Sensitive Imaging in Ankylosing Spondylitis cohort was used. Two readers measured baseline TBD by Hounsfield units (HU) on low-dose CT (ldCT). Baseline MRI bone marrow oedema (BME) status scores and ldCT syndesmophyte formation and/or growth change-from-baseline scores were assessed by three and two readers, respectively. Average of readers' continuous measurements or readers' agreement in binary scores generated within the same vertebra (1-present in ≥1 quadrant/0-absent in all quadrants) were used. Multilevel generalised estimating equations models were used, the unit of analysis being the vertebra.

RESULTS

In 50 patients with r-axSpA, TBD HU decreased from cranial to caudal vertebrae. Baseline MRI-BME was present in 300/985 (30%) and syndesmophytes in 588/910 (65%) vertebrae, both most prevalent at thoracolumbar region. Syndesmophyte formation or growth was observed in 18% of at-risk vertebrae (124/691). A significant confounder-adjusted association was found between inflammation and lower TBD (regression coefficient=-51; 95% CI-63 to -39). TBD was not associated with 2-year syndesmophyte formation or growth (adjusted OR 1.00; 95% CI 0.99 to 1.00).

CONCLUSION

In r-axSpA, while vertebral inflammation was associated with lower vertebral TBD, lower vertebral TBD itself did not increase the risk for new bone formation at the same vertebra. In preventing syndesmophyte progression, targeting local inflammation seems more important than targeting vertebral trabecular bone loss.

Effects of ixekizumab treatment on structural changes in the sacroiliac joint: MRI assessments at 16 weeks in patients with non-radiographic axial spondyloarthritis

BACKGROUND

There is limited understanding regarding the inhibition of structural damage in the sacroiliac joint of patients with non-radiographic axial spondyloarthritis. This study evaluated the effect of the interleukin-17A inhibitor ixekizumab versus placebo on structural lesions in the sacroiliac joints as assessed by MRI at week 16 in patients with non-radiographic axial spondyloarthritis from the COAST-X study.

METHODS

COAST-X was a 52-week, randomised, double-blind, placebo-controlled, parallel-group study done at 107 sites in 15 countries in Europe, Asia, North America, and South America. Eligible participants were adults (aged ≥18 years) with active axial spondyloarthritis without definite radiographic sacroiliitis (non-radiographic axial spondyloarthritis), objective signs of inflammation (via MRI or C-reactive protein), and an inadequate response or intolerance to non-steroidal anti-inflammatory drugs. Patients were randomly allocated to placebo or double-blind ixekizumab 80 mg every 4 weeks (Q4W) or 2 weeks (Q2W), with an 80 mg or 160 mg starting dose. We report a post-hoc analysis of 266 patients with available MRI scans from baseline and week 16. MRI scans were scored using the Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joint structural score (SSS) method independently by two masked readers. Treatment comparisons used analysis of covariance based on observed cases. Correlations were evaluated among changes in SPARCC SSS for erosion, fat lesions, and backfill, and between changes in SPARCC SSS and sacroiliac joint inflammation scores and clinical measures. COAST-X was registered with ClinicalTrials.gov, NCT02757352.

FINDINGS

Between Aug 2, 2016, and Jan 29, 2018, 303 patients were enrolled to the COAST-X study. 290 (96%) of 303 participants completed the week 16 visit (95 in the ixekizumab Q4W group, 98 in the ixekizumab Q2W group, and 97 in the placebo group), and MRI scans were available for 266 patients at baseline and week 16 (85 in the ixekizumab Q4W group, 91 in the ixekizumab Q2W group, and 90 in the placebo group). Changes from baseline to week 16 in mean SPARCC SSS for erosion were -0·39 for ixekizumab Q4W (p=0·003 vs placebo), -0·40 for ixekizumab Q2W (p=0·002), and 0·16 for placebo; for fat lesions: 0·16 for ixekizumab Q4W (p=0·013), 0·10 for ixekizumab Q2W (p=0·067), and -0·04 for placebo; and for backfill: 0·21 for ixekizumab Q4W (p=0·011), 0·22 for ixekizumab Q2W (p=0·006), and -0·10 for placebo. Ankylosis did not change. Effects of ixekizumab versus placebo on structural changes were most pronounced in patients with baseline inflammation in the sacroiliac joints. Changes from baseline at week 16 in erosion, fat lesions, and backfill were correlated.

INTERPRETATION

Although the clinical relevance is not yet clear, patients with non-radiographic axial spondyloarthritis receiving ixekizumab had significant reductions in erosions and increases in fat lesions and backfill in the sacroiliac joints versus placebo at week 16, suggesting an early repair process with ixekizumab treatment.

FUNDING

Eli Lilly and Company.

Treatment with tumour necrosis factor inhibitors is associated with a time-shifted retardation of radiographic spinal progression in patients with axial spondyloarthritis

OBJECTIVE

The objective of the current study was to analyse the association between treatment with tumour necrosis factor inhibitors (TNFi) and radiographic spinal progression in patients with axial spondyloarthritis (axSpA) from a long-term inception cohort.

METHODS

A total of 243 patients with axSpA from the German Spondyloarthritis Inception Cohort with at least two sets of spinal radiographs obtained at least 2 years apart during a 10-year follow-up were included. Spinal radiographs were evaluated by three trained and calibrated readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The association between the current TNFi, previous TNFi and radiographic spinal progression defined as the absolute mSASSS change score over 2 years was analysed using longitudinal generalised estimating equations analysis.

RESULTS

TNFi treatment in the current 2-year interval was not associated with retardation of radiographic spinal progression (β=-0.02 (95% CI -0.37 to 0.34) and -0.17 (95% CI -0.54 to 0.20) for any and ≥12 months treatment duration, respectively, adjusted for sex, the Ankylosing Spondylitis Disease Activity Score, smoking, presence of definite radiographic sacroiliitis, mSASSS at baseline and non-steroidal anti-inflammatory drug intake). TNFi treatment in the previous 2-year interval, was, however, significantly associated with reduction of mSASSS progression, which was especially evident in patients who received TNFi in the previous and in the current intervals: β=-0.58 (95% CI -1.02 to -0.13), adjusted for the same variables.

CONCLUSION

TNFi treatment was associated with a time-shifted effect on radiographic spinal progression in axSpA that became evident between years 2 and 4 after treatment initiation.

Inflammation, new bone formation and aorta

OBJECTIVES

This study describes the characteristics of vertebral osteophytes in different inflammatory and non-inflammatory diseases aiming to reflect the aortic-vertebrae interaction.

METHODS

We conducted a cross-sectional study including 4 group of patients, ankylosing spondylitis (AS, n = 52), Takayasu's arteritis (TKA, n = 31), diffuse idiopathic skeletal hyperostosis (DISH, n = 30), coronary artery disease (CAD, n = 10), 100 and also age-matched healthy controls (HC, n = 143). All subjects underwent a chest computed tomography scan and images of the upper and lower border of 7 adjacent thoracic vertebrae (T5 to T12) were captured. An "aorta ipsilateral ratio" (AIR) of the osteophyte was calculated as the area across the midline toward the aorta side divided by the total osteophyte area.

RESULTS

The frequency of subjects with osteophytes and osteophyte counts increased with age across the board. Frequencies of osteophytes in AS and TKA were much higher than age-matched HCs. The AIRs were significantly elevated in AS, TKA and CAD compared with DISH or age-matched HCs. In addition, the AIR of patients with higher C-reactive protein levels (>8 mg/L) were greater than those with lower levels, both among AS and CAD patients.

CONCLUSIONS

Our findings indicate that, in an inflammatory niche, regardless of the origin or the grade of the inflammation, ossification will be facilitated and screwed toward the aorta. There is a possible mechanistic connection between large vessel and new bone formation in the context of inflammation.

Treatment with Tumour Necrosis Factor Inhibitors is Associated with a Time-Shifted Retardation of Radiographic Sacroiliitis Progression in Patients with Axial Spondyloarthritis: 10-year Results from the German Spondyloarthritis Inception Cohort

OBJECTIVES

To investigate the longitudinal association between radiographic sacroiliitis progression and treatment with tumour necrosis factor inhibitors (TNFi) in patients with early axial Spondyloarthritis (axSpA) in a long-term inception cohort.

METHODS

We included patients from the German Spondyloarthritis Inception Cohort who had baseline plus at least one sacroiliac radiograph during follow-up. Two central readers scored the radiographs according to modified New York criteria. The sacroiliac sum score was calculated as a mean of both readers. TNFi use was assessed according to exposure in the current and/or previous 2-year radiographic interval. The association between TNFi use and radiographic sacroiliitis progression was examined by longitudinal generalized estimating equations analysis with adjustment for potential confounders.

RESULTS

In total, 301 axSpA patients (166 non-radiographic [nr-axSpA] and 135 radiographic [r-axSpA]) contributed 737 radiographic intervals. While receiving ≥12 months TNFi in the previous interval was associated with a significant decrease in the sacroiliitis sum score (β=-0.09 [95% CI -0.18, -0.01], adjusted for age, sex, symptom duration, HLA-B27 status, Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], C-reactive protein [CRP], and Non-steroidal anti-inflammatory drugs [NSAIDs] intake), this was not the case in patients who received TNFi in the current interval (β=0.05 [95% CI -0.05, 0.14]). This effect was stronger in patients with nr-axSpA as compared to patients with r-axSpA (β=-0.16 [95% CI -0.28, -0.03] vs β=-0.04 [95% CI -0.15, 0.07], respectively).

CONCLUSION

TNFi was associated with reduction of radiographic sacroiliitis progression in patients with axSpA. This effect became evident between 2 and 4 years after treatment initiation.

Bone Involvement in Patients with Spondyloarthropathies

Spondyloarthropathies (SpA) are common systemic inflammatory rheumatic diseases, in which, as in other rheumatic diseases, levels of markers of bone resorption are elevated, leading to bone loss and elevated risk of vertebral fractures. However, the diseases are also associated with new bone formation in the spine, the so-called syndesmophytes. We tried to unravel the pathogenesis of formation and growth of syndesmophytes and evaluated new diagnostic and treatment options. After a successful meeting of the Working Group on Rheumatic Diseases at the ECTS 2020, we (WL and CR) were excited about the quality of the speakers (CM, JH, AG, and GL) and their complimentary lectures. Given the relative lack of reviews on spondyloarthropathies and bone, we decided to work together on a comprehensive review that might be interesting for basic scientists and clinically relevant for clinicians. Radiographic progression in axSpA is linked to several risk factors, like male sex, smoking, HLA-B-27, increased levels of CRP, presence of syndesmophytes, and marked inflammation on MRI. The potential role of mechanical stress in the context of physically demanding jobs has been also suggested to promote structural damages. Different treatment options from NSAIDs to biologic agents like TNF inhibitors (TNFi) or IL-17inhibitors (IL-17i) result in a reduction of inflammation and symptoms. However, all these different treatment options failed to show clear and reproducible results on inhibition on syndesmophyte formation. The majority of data are available on TNFi, and some studies suggested an effect in subgroups of patients with ankylosing spondylitis. Less information is available on NSAIDs and IL-17i. Since IL-17i have been introduced quite recently, more studies are expected. IL-17 inhibitors (Il-17i) potently reduce signs and symptoms, but serum level of IL-17 is not elevated, therefore, IL-17 probably has mainly a local effect. The failure of anti-IL-23 in axSpA suggests that IL-17A production could be independent from IL-23. It may be upregulated by TNFα, resulting in lower expression of DKK1 and RANKL and an increase in osteogenesis. In active AS markers of bone resorption are increased, while bone formation markers can be increased or decreased. Bone Turnover markers and additional markers related to Wnt such as DKK1, sclerostin, and RANKL are valuable for elucidating bone metabolism on a group level and they are not (yet) able to predict individual patient outcomes. The gold standard for detection of structural lesions in clinical practice is the use of conventional radiographics. However, the resolution is low compared to the change over time and the interval for detecting changes are 2 years or more. Modern techniques offer substantial advantages such as the early detection of bone marrow edema with MRI, the fivefold increased detection rate of new or growing syndesmophytes with low-dose CT, and the decrease in 18F-fluoride uptake during treatment with TNFα-inhibitors (TNFi) in a pilot study in 12 AS patients. Detection of bone involvement by new techniques, such as low-dose CT, MRI and 18-Fluoride PET-scans, and bone turnover markers, in combination with focusing on high-risk groups such as patients with early disease, elevated CRP, syndesmophytes at baseline, male patients and patients with HLA-B27 + are promising options for the near future. However, for optimal prevention of formation of syndesmophytes we need more detailed insight in the pathogenesis of bone formation in axSpA and probably more targeted therapies.

Sustained low disease activity measured by ASDAS slow radiographic spinal progression in axial spondyloarthritis patients treated with TNF-inhibitors: data from REGISPONSERBIO

Background

To evaluate the influence of the disease activity on radiographic progression in axial spondyloarthritis (axSpA) patients treated with TNF inhibitors (TNFi).

Methods

The study included 101 axSpA patients from the Spanish Register of Biological Therapy in Spondyloarthritides (REGISPONSERBIO), which had clinical data and radiographic assessment available. Patients were classified into 2 groups based on the duration of TNFi treatment at baseline: (i) long-term treatment (≥4 years) and (ii) no long-term treatment (< 4 years). Radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with known chronology. Disease activity differences between patients’ groups at each time point were assessed using a linear mixed-effect model.

Results

Radiographic progression was defined as an increase in ≥2 mSASSS units. At inclusion, approximately half of the patients (45.5%) were receiving long-term treatment with TNFi (≥4 years). In this group of subjects, a significant difference in averaged Ankylosing Spondylitis disease Activity Score (ASDAS) across follow-up was found between progressors and non-progressors (2.33 vs 1.76, p=0.027, respectively). In patients not under long-term TNFi treatment (54.5%) though, no significant ASDAS differences were observed between progressors and non-progressors until the third year of follow-up. Furthermore, no significant differences were found in progression status, when disease activity was measured by Bath Ankylosing spondylitis Disease Activity Index (BASDAI) and C reactive protein (CRP).

Conclusions

Patients on long-term TNFi treatment with a mean sustained low disease activity measures by ASDAS presented lower radiographic progression than those with active disease.

New developments in ankylosing spondylitis-status in 2021

Axial SpA (axSpA) is a common rheumatic disease characterized by inflammation leading to bone formation and functional impairment. TNF-α and IL-17 represent established targets in axSpA. TNF-α and IL-17 inhibitors have demonstrated efficacy in clinical trials and are currently approved biologic DMARDs for all subsets of the disease. Several lines of evidence implicate a role of an IL-23–IL-17 axis in the disease pathogenesis. In this light, and given the success of IL-17 blockade in axSpA, a similar good response to IL-23 was anticipated. Nevertheless, two clinical trials of anti-IL-23 monoclonal antibodies in axSpA have clearly exhibited negative results. This failure has raised theories for a degree of IL-23 independent pathway. The Janus kinase (JAK) pathway is also a potential therapeutic target, since several cytokines, including those involved in the IL-23–IL-17 axis, signal through the JAK family of tyrosine kinases. Further studies and more extended evaluation of response to cytokine inhibition across different tissues will be required to improve our understanding of SpA pathogenesis and determine its optimal management.

Biological DMARDs and disease modification in axial spondyloarthritis: a review through the lens of causal inference

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterised by inflammation predominantly involving the spine and the sacroiliac joints. In some patients, axial inflammation leads to irreversible structural damage that in the spine is usually quantified by the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Available therapeutic options include biological disease-modifying antirheumatic drugs (bDMARDs), which have been proven effective in suppressing inflammation in several randomised controlled trials (RCT), the gold standard for evaluating causal treatment effects. RCTs are, however, unfeasible for testing structural effects in axSpA mainly due to the low sensitivity to change of the mSASSS. The available literature therefore mainly includes observational research, which poses serious challenges to the determination of causality. Here, we review the studies testing the effect of bDMARDs on spinal radiographic progression, making use of the principles of causal inference. By exploring the assumptions of causality under counterfactual reasoning (exchangeability, positivity and consistency), we distinguish between studies that likely have reported confounded treatment effects and studies that, on the basis of their design, have more likely reported causal treatment effects. We conclude that bDMARDs might, indirectly, interfere with spinal radiographic progression in axSpA by their effect on inflammation. Innovations in imaging are expected, so that placebo-controlled trials can in the future become a reality. In the meantime, causal inference analysis using observational data may contribute to a better understanding of whether disease modification is possible in axSpA.

From Science to Success? Targeting Tyrosine Kinase 2 in Spondyloarthritis and Related Chronic Inflammatory Diseases

Spondyloarthritis (SpA) is a family of inflammatory arthritic diseases, which includes the prototypes of psoriatic arthritis and ankylosing spondylitis. SpA is commonly associated with systemic inflammatory diseases, such as psoriasis and inflammatory bowel disease. Immunological studies, murine models and the genetics of SpA all indicate a pathogenic role for the IL-23/IL-17 axis. Therapeutics targeting the IL-23/IL-17 pathway are successful at providing symptomatic relief, but may not provide complete protection against progression of arthritis. Thus there is still tremendous interest in the discovery of novel therapeutic targets for SpA. Tyrosine kinase 2 (TYK2) is a member of the Janus kinases, which mediate intracellular signaling of cytokines via signal transducer and activator of transcription (STAT) activation. TYK2 plays a crucial role in mediating IL-23 receptor signaling and STAT3 activation. A plethora of natural mutations in and around TYK2 have provided a wealth of data to associate this kinase with autoimmune/autoinflammatory diseases in humans. Induced and natural mutations in murine Tyk2 largely support human data; however, key inter-species differences exist, which means extrapolation of data from murine models to humans needs to be done with caution. Despite these reservations, novel selective TYK2 inhibitors are now proving successful in advanced clinical trials of inflammatory diseases. In this review, we will discuss TYK2 from basic biology to therapeutic targeting, with an emphasis on studies in SpA. Seminal studies uncovering the basic science of TYK2 have provided sound foundations for targeting it in SpA and related inflammatory diseases. TYK2 inhibitors may well be the next blockbuster therapeutic for SpA.