Effect of TNF-inhibitor therapy on spinal structural progression in ankylosing spondylitis patients: A systematic review and meta-analysis

Prognostic value of the clinical and imaging arm of the ASAS criteria for progression of structural sacroiliac joint lesions

OBJECTIVE

To investigate the prognostic value of the two arms of the Assessment of SpondyloArthritis international Society (ASAS) criteria regarding the progression of structural lesions in the sacroiliac joints (SIJs).

METHODS

Information on baseline fulfilment of the ASAS criteria and baseline and follow-up magnetic resonance imaging of the SIJ in 603 patients aged 18-40 years referred with low back pain to an outpatient spine were collected. Magnetic resonance imaging positivity was defined as bone marrow oedema (BMO) in two or more consecutive slices or two or more lesions in one slice, as described in the ASAS definition of sacroiliitis.

RESULTS

Of 71 participants fulfilling the ASAS criteria at baseline, 66 (93%) fulfilled the 'imaging arm' and 14 (20%) fulfilled the 'clinical arm'. The 'clinical arm' predicted the progression of erosions with an odds ratio of 55 (compared with not fulfilling the ASAS criteria), while the 'imaging arm' predicted the progression of erosions with an odds ratio of 8. Moreover, in 24% of the patients in the 'imaging arm', all having BMO at the SIJ at baseline, the BMO disappeared without neither erosions nor ankylosis emerging.

CONCLUSION

We found that the 'clinical arm' was a strong predictor for the progression of SIJ erosion, while the 'imaging arm' had a more modest prognostic value for structural progression.

Management of Specific Clinical Profiles in Axial Spondyloarthritis: An Expert's Document Based on a Systematic Literature Review and Extended Delphi Process

INTRODUCTION

The management of specific clinical scenarios is not adequately addressed in national and international guidelines for axial spondyloarthritis (axSpA). Expert opinions could serve as a valuable complement to these documents.

METHODS

Seven expert rheumatologists identified controversial areas or gaps of current recommendations for the management of patients with axSpA. A systematic literature review (SLR) was performed to analyze the efficacy and safety of non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, conventional synthetic, biologic and targeted synthetic disease-modifying antirheumatic drugs (csDMARDs, b/tsDMARDs) in axSpA regarding controversial areas or gaps. In a nominal group meeting, the results of the SLR were discussed and a set of statements were proposed. A Delphi process inviting 150 rheumatologists was followed to define the final statements. Agreement was defined as if at least 70% of the participants voted ≥ 7 (from 1, totally disagree, to 10, totally agree).

RESULTS

Three overarching principles and 17 recommendations were generated. All reached agreement. According to them, axSpA care should be holistic and individualized, taking into account objective findings, comorbidities, and patients' opinions and preferences. Integrating imaging and clinical assessment with biomarker analysis could also help in decision-making. Connected to treatments, in refractory enthesitis, b/tsDMARDs are recommended. If active peripheral arthritis, csDMARD might be considered before b/tsDMARDs. The presence of significant structural damage, long disease duration, or HLA-B27-negative status do not contraindicate for the use of b/tsDMARDs.

CONCLUSIONS

These recommendations are intended to complement guidelines by helping health professionals address and manage specific groups of patients, particular clinical scenarios, and gaps in axSpA.

Risk of Ankylosing Spondylitis in Patients With Endometriosis: A Population-Based Retrospective Cohort Study

Objectives

Previous research has shown a possible relationship between endometriosis and autoimmune diseases. However, the relationship between endometriosis and ankylosing spondylitis (AS) is lacking. Therefore, we intended to find possible associations between endometriosis and AS using ICD-9 coding data in a population-based retrospective cohort study in Taiwan.

Method

Data for this retrospective cohort study were collected from the Taiwan National Health Insurance Research Database (NHIRD) between 2000–2012. We collected 13,145 patients with endometriosis and a 78,870 non-endometriosis comparison cohort. Diagnoses of endometriosis and AS were defined by the International Classification of Diseases-9 (ICD-9-CM) code for at least 3 outpatients or 1 hospitalization. Propensity score matching by comorbidities, corticosteroids, and non-steroidal anti-inflammatory drugs (NSAIDs) usage were done for baseline comparability. Cox proportional hazard models were used to evaluate crude and adjusted hazard ratios.

Results

The cumulative incidence of AS was higher in patients with endometriosis compared to the non-endometriosis comparison cohort (log-rank test, p = 0.015). The adjusted hazard ratio (aHR) of incidental AS in patients with endometriosis was 1.61 (95% CI = 1.11 to 2.35) in comparison to the non-endometriosis comparison cohort. An increased risk of AS was also observed in subjects with major depressive disorder (aHR = 5.05, 95% CI = 1.85 to 13.78). Stratified analyses of age subgroups showed consistent results. NSAID users had a lower risk of AS than NSAID non-users (aHR 4.57 vs 1.35, p for interaction = 0.031).

Conclusions

In this retrospective population-based cohort study, we found a higher risk of AS in patients with endometriosis. We suggest that clinicians should pay attention to the occurrence of AS in patients with endometriosis.

Effects of Biological/Targeted Therapies on Bone Mineral Density in Inflammatory Arthritis

Inflammatory arthritis has been reported to be associated with the development of osteoporosis. Recent research has investigated the mechanisms of bone metabolism in chronic inflammatory arthritis such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). Progress in both animal and clinical studies has provided a better understanding of the osteoclastogenesis-related pathways regarding the receptor activator of nuclear factor-κB ligand (RANKL), anti-citrullinated protein antibodies (ACPAs), and Wnt signaling and Dickkopf-related protein 1 (Dkk-1). The complex interplay between inflammatory cytokines and bone destruction has been elucidated, especially that in the interleukin-17/23 (IL-17/23) axis and Janus kinase and signal transducer and activator of transcription (JAK-STAT) signaling. Moreover, advances in biological and targeted therapies have achieved essential modifications to the bone metabolism of these inflammatory arthritis types. In this narrative review, we discuss recent findings on the pathogenic effects on bone in RA and SpA. Proinflammatory cytokines, autoantibodies, and multiple signaling pathways play an essential role in bone destruction in RA and SpA patients. We also reviewed the underlying pathomechanisms of bone structure in biological and targeted therapies of RA and SpA. The clinical implications of tumor necrosis factor inhibitors, abatacept, rituximab, tocilizumab, Janus kinase inhibitors, and inhibitors of the IL-17/23 axis are discussed. Since these novel therapeutics provide new options for disease improvement and symptom control in patients with RA and SpA, further rigorous evidence is warranted to provide a clinical reference for physicians and patients.

CXCL12/CXCR4-Rac1-mediated migration of osteogenic precursor cells contributes to pathological new bone formation in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by inflammatory back pain and spinal ankylosis due to pathological new bone formation. Here, we identified CXCL12 as a critical contributor to pathological new bone formation through recruitment of osteogenic precursor cells (OPCs). CXCL12 was found highly expressed in the regions that would potentially develop pathological new bone. OPCs were recruited to the regions where CXCL12 was up-regulated. Inhibition of CXCL12/CXCR4 axis with AMD3100 or conditional knockout of CXCR4 attenuated OPCs migration and subsequent pathological new bone formation in animal models of AS. By contrast, a genetically engineered animal model with CXCL12 overexpression developed a joint ankylosis phenotype. Furthermore, Rac1 was found essential for OPCs migration and pathological new bone formation. These findings ravel the novel role of CXCL12 in AS and indicate a potential strategy for targeting the CXCL12/CXCR4-Rac1 axis to prevent progression of axial skeleton ankylosis.

Treatment Failure in Axial Spondyloarthritis: Insights for a Standardized Definition

Axial spondyloarthritis is a chronic inflammatory rheumatic disease that affects the axial skeleton and causes severe pain and disability. It may be also associated with extra-articular manifestations. Early diagnosis and appropriate treatment can reduce the severity of the disease and the risk of progression. The biological disease-modifying antirheumatic drugs (bDMARDs) tumor necrosis factor alpha (TNFα) inhibitors (TNFi) and the anti-interleukin (IL)-17A antibodies secukinumab and ixekizumab are effective agents to reduce disease activity and minimize the inflammation that damages the joints. New alternatives such as Janus kinase (JAK) inhibitors are also available. Unfortunately, response rates to bDMARDs are far from optimal, and many patients experience so-called treatment failure. The definition of treatment failure definition is often vague and may depend on the rigorousness of the therapeutic goal, the inclusion or not of peripheral symptoms/extra-articular manifestations, or patients' overall health. After an exhaustive bibliographic review, we propose a definition based on loss of the following status: low disease activity assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, absence of extra-articular manifestations, and low disease impact on the patients' general health. Apart from discontinuing the therapy because of safety or intolerance reasons, two types of treatment failure can be differentiated depending on when it occurs: primary failure (no response within 6 months after treatment initiation, or lack of efficacy) and secondary failure (response within 6 months but lost thereafter, or loss of efficacy over time). Physicians should carefully consider the moment and the reason for the treatment failure to decide the next therapeutic step. In the case of primary failure on a first TNFi, it seems reasonable to switch to another class of drugs, i.e., an anti-IL-17 agent, as phase III trials showed that the response to IL-17 blockade was higher than to placebo in patients previously exposed to TNFi. When secondary failure occurs, and loss of efficacy is suspected to be caused by antidrug antibodies (ADAs), it is advisable to analyze serum TNFi and ADAs concentrations, if possible; in the presence of ADAs and low TNFi levels, changing the TNFi is rational as it may restore the TNFα blocking capacity. If ADAs are absent/low with adequate drug therapeutic levels, switching to another target might be the best strategy.

Structural Lesion Progression of the Sacroiliac Joint and Clinical Features in axSpA During TNFi Reduction: A Retrospective Cohort Study

Objective: In the clinic, some patients with axial spondyloarthritis (axSpA) have to reduce tumor necrosis factor inhibitor (TNFi) for various reasons. However, there are few studies about how to balance the relapse and TNFi reduction. Here we retrospectively analyzed the structural progression of the sacroiliac joint (SIJ) and clinical features in axSpA during TNFi reduction.

Methods: A total of 108 patients with axSpA who followed up for 2 years and completed at least baseline, 12-month, and 24-month MRI scans of SIJ were divided into the tapering group (n = 63) and withdrawal group (n = 45) according to whether TNFi was stopped. We divided 2 years into five intervals, calculating the average dose quotient (DQ) for each of 540 intervals from 108 patients. By using generalized estimation equations with inverse probability of treatment weighting, we investigated the unbiased effects of average DQ on structural progression and treatment response.

Results: The disease activity (such as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, and ASDAS-ESR) and relapse rate were lower in the tapering group at 12 and 24 months (p < 0.05). Δerosion (β = −0.0100, p = 0.00026) and Δthe Spondyloarthritis Research Consortium of Canada (SPARCC; β = −0.0959, p < 0.0001) were negatively correlated with average DQ. The average DQ 30 (74.8%, 80.0%) or 41.6 (76.5%, 83%) was best to discriminate the status of treatment response or the status of bone marrow edema, but considering operability, the average DQ 25 (78.0%, 63.3%) was also acceptable especially for patients with HLA-B27 negative and non-severe fat metaplasia.

Conclusion: Complete TNFi withdrawal was not recommended. Our study provided a referable strategy (tapering then maintained the average DQ over 30 or even 25) for patients who need TNFi reduction. Higher dose usage of TNFi was associated with a slower erosion progression of SIJ.