Although female patients with ankylosing spondylitis score worse on disease activity than male patients and improvement in disease activity is comparable, male patients show more radiographic progression during treatment with TNF-α inhibitors

Patients' Perspectives on Axial Pain in Relation to Inflammation and Structural Damage in a Large Cohort of Axial Spondyloarthritis Patients

OBJECTIVE

The objective of this study was to explore to what extent patients with axial spondyloarthritis (axSpA) link experienced pain in the neck, back, and hips to inflammation and/or structural damage.

METHODS

Patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort visiting the outpatient clinic between 2016 and 2019 filled out two additional questions in relation to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) question 2: (1) "To what extent do you think the pain you experience in your neck, back, and hips is related to inflammation caused by axSpA?" and (2) "To what extent do you think the pain you experience in your neck, back, and hips is related to damage of the spine and joints caused by axSpA?" Answers had to be depicted on a numeric rating scale from 0 (none) to 10 (very much); a difference of ≥2 points between the scores of these questions was considered clinically relevant in favor of the highest scoring question.

RESULTS

A total of 688 patients with axSpA (24% with nonradiographic axSpA [nr-axSpA]) were included (62% male, mean ± SD age 48 ± 14 years, and mean ± SD Ankylosing Spondylitis Disease Activity Score [ASDAS] 2.3 ± 1.0). Seventy-five percent of patients could not link the origin of their pain, 15% linked axial pain predominantly to inflammation, and 10% linked axial pain predominantly to damage. Patients in the inflammation group were younger, had shorter symptom duration, were more frequently diagnosed with nr-axSpA, had higher ASDASCRP , had more often elevated CRP levels, had fewer comorbidities, had better spinal mobility, and had less spinal radiographic damage.

CONCLUSION

In our large observational cohort, the majority of patients with axSpA could not differentiate the origin of experienced axial pain. If patients were able to link axial pain to clinical inflammation or damage, it was in concordance with clinical assessments and radiographic outcome, which may be helpful in establishing the origin of pain and supporting better patient-centered treatment decisions.

Male spondyloarthritis patients and those with longer disease duration have less severe disc degeneration: propensity score-matched comparison

Objective

Using whole spine sagittal T2 MRI, we aimed to compare the severity and prevalence of disc degeneration (DD) in axial SpA patients vs the general population and to determine any association between spinal inflammation, structural changes, mobility and DD among SpA patients.

Methods

Two prospectively collected cohorts of SpA patients (n = 411) and the general population (n = 2007) were recruited. Eventually, 967 participants from the populational cohort and 304 participants from the SpA cohort were analysed. Two hundred and nineteen matched pairs were generated by propensity score matching. Imaging parameters, including Pfirrmann grading, disc herniation, high-intensity zone, Schmorl's node, Modic change and anterior marrow change were studied and compared from C2/3 to L5/S1. DD was defined as Pfirrmann grade 4 or 5. Demographic factors, including age, sex and BMI, were collected. Multivariable linear regression was used to determine the association between spinal inflammation [Spondyloarthritis Research Consortium of Canada (SPARCC) spine MRI index], structural changes [modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS)] and mobility (BASMI) with lumbar Pfirrmann score.

Results

SpA patients had lower prevalence of DD (P < 0.001). The disease stage-stratified regression model showed that SPARCC spinal MRI index was associated with higher lumbar Pfirrmann scores in early disease (β = 0.196, P = 0.044), whereas mSASSS was associated with lower lumbar Pfirrmann scores in later disease (β = -0.138, P = 0.038). Males had higher mSASSS (P < 0.001) and lower odds of whole spine DD (odds ratio = 0.622, P = 0.028).

Conclusion

SpA patients had lower DD severity than the general population. Males had higher mSASSSs, and increased mSASSS at later disease was associated with less severe DD.

Impact of sex on spinal radiographic progression in axial spondyloarthritis: a longitudinal Swiss cohort analysis over a period of 10 years

OBJECTIVE

To investigate sex differences in spinal radiographic progression in axial spondyloarthritis (axSpA).

METHODS

AxSpA patients in the Swiss Clinical Quality Management cohort with available spinal radiographs every 2 years were included. Paired radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Progression was defined as an increase of ≥2 mSASSS units in 2 years. The relationship between sex and progression was investigated with binomial generalised estimating equation models, considering baseline spinal damage as an intermediate covariate. Additional analyses included adjustments for explanatory variables and multiple imputations for missingness.

RESULTS

In a total of 505 axSpA patients (317 men and 188 women), mean±SD radiographic progression over 2 years was 1.0±2.8 years in men and 0.3±1.1 years in women (p<0.001). Male sex was associated with enhanced progression in a small model not including baseline damage (OR 3.41, 95% CI 1.87 to 6.21). Both a direct effect of male sex on spinal progression, and an indirect effect, via enhancement of baseline spinal damage were significant (OR 2.06, 95% CI 1.15 to 3.67 and OR 1.04, 95% CI 1.01 to 1.07, respectively). A significant impact of male sex on spinal radiographic progression was still demonstrated after multiple adjustments for covariates known to potentially affect spinal radiographic progression (OR 1.97, 95% CI 1.04 to 3.71).

CONCLUSIONS

Spinal radiographic progression in axSpA is more severe in men than in women, with three times higher odds of progression in male patients and an effect that is mediated in part through an increase in baseline radiographic damage.

Central sensitization has major impact on quality of life in patients with axial spondyloarthritis

INTRODUCTION

Persistent pain has large potential impact on quality of life (QoL). During the course of the disease, many patients with axial spondyloarthritis (axSpA) report persistent pain. Central sensitization (CS) may explain part of this chronic pain. However, the role of CS in relation to QoL has been sparsely studied in axSpA. Therefore, our aim was to explore the relationship between CS and QoL in patients with axSpA.

METHODS

Consecutive outpatients from the Groningen Leeuwarden axSpA (GLAS) cohort completed the Central Sensitization Inventory (CSI; range 0-100) and the AS Quality of Life (ASQoL; range 0-18). Multivariable linear regression analysis was used to explore the relationship between CSI and ASQoL scores correcting for potential confounders.

RESULTS

Of the 178 included axSpA patients, mean CSI score was 38.0 ± 14.1 and 45% scored ≥40, which indicates a high probability of CS. Mean ASQoL score was 6.0 ± 5.3 and mean ASDAS_CRP 2.1 ± 1.0. A CSI score ≥40 was significantly associated with higher ASQoL score (mean 9.7 vs. 3.3), higher ASDAS_CRP (mean 2.6 vs. 1.7), female gender (60% vs. 29%) and more often entheseal involvement (61% vs. 26%). In univariable analysis, CSI score explained a large proportion of the variation in ASQoL (B = 0.06, 95%CI: 0.05-0.07; R²=0.46). This association remained significant after correction for ASDAS_CRP, gender, entheseal involvement, comorbidities, symptom duration, smoking status, BMI class and educational level (B = 0.04, 95%CI: 0.03-0.05).

CONCLUSION

CS is strongly related to patient-reported QoL in patients with axSpA independently from other patient- and disease-related aspects.

Central sensitization, illness perception and obesity should be considered when interpreting disease activity in axial spondyloarthritis

OBJECTIVES

Many patients with axial spondyloarthritis (axSpA) report persistent pain even when treated with anti-inflammatory agents. Our aim was to explore the presence of central sensitization (CS) and different types of illness perceptions in patients with axSpA, and to assess their associations with disease activity assessments.

METHODS

Consecutive outpatients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were included. Besides standardized assessments, patients filled out the Central Sensitization Inventory (CSI), Illness Perception Questionnaire (IPQ-R) and Pain Catastrophizing Scale (PCS). Univariable and multivariable linear regression analyses were used to investigate the association between questionnaire scores, patient characteristics and disease activity assessments ASDASCRP, BASDAI and CRP.

RESULTS

We included 182 patients with a mean symptom duration of 21.6 years. Mean ASDASCRP was 2.1, mean BASDAI 3.9, and median CRP 2.9. Mean CSI score was 37.8 (scale 0-100) and 45% of patients scored ≥40, indicating a high probability of CS. CSI score, IPQ-R domain identity (number of symptoms the patient attributes to their illness), and IPQ-R domain treatment control (perceived treatment efficacy), and obesity were significantly and independently associated with both ASDASCRP and BASDAI, explaining a substantial proportion of variation in these disease activity scores (R2=0.35 and R2=0.47, respectively). Only obesity was also independently associated with CRP.

CONCLUSION

CS may be common in patients with long-term axSpA. CS, as well as specific illness perceptions and obesity were all independently associated with the widely used (partially) patient-reported disease activity assessments ASDASCRP and BASDAI. Treating physicians should take this into account in the follow-up and treatment of their patients.

Reviewing Disease Activity Indices in Spondyloarthritis From the Sex Perspective: A Systematic Review and Metaanalysis

OBJECTIVE

To determine whether the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS) exhibited differences between women and men.

METHODS

We systematically searched MEDLINE, Embase, Web of Science, and other sources in English or Spanish from January 1, 1995, to July 31, 2020, to assess the differences according to sex in BASDAI and ASDAS. We performed a comparative analysis by sex using t test and mean difference by sex metaanalyses for BASDAI and ASDAS, as well as a random-effects model using the inverse-variance method.

RESULTS

Forty-one studies included BASDAI (6785 women, 12,929 men) and 16 of them included ASDAS (2046 women, 4403 men). Disease activity detected using BASDAI was significantly higher in women than in men (mean 4.9 vs 4.2, P = 0.02), whereas ASDAS did not detect differences between sexes (mean 2.8 women vs 2.8 men). In the metaanalyses, BASDAI detected significant differences between women and men (mean difference = 0.55 [95% CI 0.46-0.65], P < 0.00001), but ASDAS did not identify significant mean difference between sexes (0.04, 95% CI -0.05 to 0.12], P = 0.38).

CONCLUSION

The 2 most widely used indices of disease activity in spondyloarthritis (SpA) discriminate differently according to sex by their different evaluations of peripheral disease. The different components and weights in BASDAI and ASDAS influence their values. BASDAI may be affected by fatigue, and in predominantly peripheral manifestations such as enthesitis, ASDAS may not be sensitive enough to detect activity. This may represent a sex bias unfavorable to women, because peripheral SpA is more common in women than in men.

Gene-regulatory network analysis of ankylosing spondylitis with a single-cell chromatin accessible assay

A detailed understanding of the gene-regulatory network in ankylosing spondylitis (AS) is vital for elucidating the mechanisms of AS pathogenesis. Assaying transposase-accessible chromatin in single cell sequencing (scATAC-seq) is a suitable method for revealing such networks. Thus, scATAC-seq was applied to define the landscape of active regulatory DNA in AS. As a result, there was a significant change in the percent of CD8+ T cells in PBMCs, and 37 differentially accessible transcription factor (TF) motifs were identified. T cells, monocytes-1 and dendritic cells were found to be crucial for the IL-17 signaling pathway and TNF signaling pathway, since they had 73 potential target genes regulated by 8 TF motifs with decreased accessibility in AS. Moreover, natural killer cells were involved in AS by increasing the accessibility to TF motifs TEAD1 and JUN to induce cytokine-cytokine receptor interactions. In addition, CD4+ T cells and CD8+ T cells may be vital for altering host immune functions through increasing the accessibility of TF motifs NR1H4 and OLIG (OLIGI and OLIG2), respectively. These results explain clear gene regulatory variation in PBMCs from AS patients, providing a foundational framework for the study of personal regulomes and delivering insights into epigenetic therapy.

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

To review the effect of tumor necrosis factor-alpha inhibitor (TNFi) therapies on radiographic progression in ankylosing spondylitis (AS) patients as evaluated by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Pubmed, MEDLINE, EMBASE, and the Cochrane Library databases were searched from inception to August 2019. All comparative and non-comparative studies that evaluated the clinical effectiveness of TNFi on radiographic progression as assessed by mSASSS change at a minimum follow-up of 1 year were included. The Newcastle-Ottawa Scale and Cochrane Collaboration Risk of Bias Tool were utilized to assess the methodological quality. Pooled analysis was performed for continuous and binomial variables where appropriate. Inter-rater reliability of mSASSS status and change scores were assessed with intra-class coefficients (ICC). Twenty-one studies were identified with a total of 4460 patients (mean age: 40.4 years [range 25.3-50 years]; 76% male; mean baseline mSASSS: 12.7 units [range 5.5-19.8 units]). All studies (3 randomized and 18 observational studies) were considered to have moderate-to-high methodological quality. The inter-rater reliability of mSASSS status and change scores from 14 of the 21 studies were excellent (ICC ranges, 0.91-0.99) and moderate-to-excellent (ICC ranges, 0.58-0.90), respectively. From the 21 studies, 11/21 (50%) demonstrated a delayed effect in mSASSS in AS patient administered TNFi. When stratifying these studies into those with ≤4 years of follow-up and >4 years follow-up, 3/11 (27%) and 8/10 (80%) studies respectively indicated a delayed effect of mSASSS with TNFi in AS patients. Pooling for meta-analysis from 3 studies (1159 patients) with study durations ranging 4-8 years, indicated that TNFi-treated patients had reduced odds of structural progression (odds ratio 0.81; 95% CI 0.68-0.96; P = .01; I²  = 0%). Mean rate of mSASSS change from 16 studies ranged from -0.15 to 7.3 mSASSS units for all AS patients. Meta-analysis indicated a numerical, but statistically non-significant, reduction in the rate of mSASSS change with TNFi treatment (7 studies [1438 patients]; mean difference, -0.24; 95% CI, -0.49-0.01; P = .06; I²  = 0%). This systematic review and meta-analysis indicated that >4 years of TNFi usage was associated with delayed structural progression by mSASSS. The narrative analysis of the data from 21 studies further confirmed that studies with >4 years of follow-up had delayed structural progression with TNFi use in AS patients. The systematic review also confirmed that mSASSS has good-to-excellent inter-rater reliability in AS.

Effectiveness of Subcutaneous Tumor Necrosis Factor Inhibitors in Patients With Ankylosing Spondylitis: A Real-World Prospective Observational Cohort Study in China

Objective: This prospective observational study investigated the efficacy of tumor necrosis factor inhibitors (TNFis) on disease activity, physical functionality, and mobility in patients with ankylosing spondylitis (AS) in a real-world setting.

Methods: The Chinese Ankylosing Spondylitis Prospective Imaging Cohort (CASPIC) is an ongoing cohort study. Patients with AS were included to one of two groups: the TNFi user group included those who received TNFi at any time point; the non-TNFi user group included those who did not receive TNFi. Disease activity, physical functionality, and mobility were assessed by AS Disease Activity Scores (ASDAS), Bath AS Functional Index (BASFI), and Bath AS Metrology Index (BASMI), respectively.

Results: A total of 804 patients with AS (241 TNFi users and 563 non-TNFi users) were recruited. For TNFi users, 83% received an etanercept biosimilar and 17.0% received adalimumab. Seventy-three TNFi users (30.3%) discontinued TNFis during the follow-up period; the mean duration of TNFi treatment was 6.9 ± 3.2 months. Reductions in ASDAS were significantly greater in TNFi users than in nonusers at 3, 6, and 12 months (differences in ASDAS reduction were 0.61, 0.56, and 0.46 units, respectively, all P < 0.05). Similarly, the improvement in BASFI was significantly greater in users than in nonusers at 3, 6, and 12 months (differences in BASFI improvement: 0.31, 0.75, and 0.74 units, respectively, all P < 0.05). BASMI increased in nonusers at 6 and 12 months (0.27, P = 0.47; 0.66, P < 0.001, respectively), but did not change in users (−0.16 and −0.13, respectively, both P > 0.05). At 12 months, changes in BASMI were significantly greater in nonusers than in users (−0.60, P = 0.47).

Conclusion: TNFis are effective against disease activity and improve the physical functionality of patients with AS, even in those who taper or discontinue TNFis. Thus, TNFis may retard the progression of spinal mobility dysfunction in AS patients. TNF may maintain spinal mobility as indicated by the BASMI.

Nonendocrine mechanisms of sex bias in rheumatic diseases

Rheumatic diseases affect a wide range of individuals of all ages, but the most common diseases occur more frequently in women than in men, at ratios of up to ten women to one man. Despite a growing number of studies on sex bias in rheumatic diseases, sex-specific health care is limited and sex specificity is not systematically integrated into treatment regimens. Women and men differ in three major biological points: the number of X chromosomes per cell, the type and quantities of sex hormones present and the ability to be pregnant, all of which have immunological consequences. Could a greater understanding of these differences lead to a new era of personalized sex-specific medicine? This Review focuses on the main genetic and epigenetic mechanisms that have been put forward to explain sex bias in rheumatic diseases, including X chromosome inactivation, sex chromosome aneuploidy and microchimerism. The influence of sex hormones is not discussed in detail in this Review, as it has been well described elsewhere. Understanding the sex-specific factors that contribute to the initiation and progression of rheumatic diseases will enable progress to be made in the diagnosis, treatment and management of all patients with these conditions.

Disease Activity and Patient-Reported Health Measures in Relation to Cytokine Levels in Ankylosing Spondylitis

INTRODUCTION

Ankylosing spondylitis (AS) is a lifelong condition where spinal inflammation causes chronic back pain and restriction of spinal function. While proinflammatory cytokines participate in the disease process, their relation with disease activity, spinal function, and quality of life is less well understood.

METHODS

Cross-sectional study of serum levels of four inflammatory cytokines (IL-6, TNF, IL-23, and IL-17A) in AS patients not on biologics. Disease characteristics and simultaneous spinal function tests and patient-reported health measures (Bath Functional Index (BASFI), Dougados Functional Index (DFI), Modified Health Assessment Questionnaire (MHAQ), and routine laboratory parameters were recorded. The composite ASDAS-CRP score was used to classify disease activity as absent, low, or high.

RESULTS

In 164 AS patients (age 46 years, 70.1% males, 90.9% HLAB27 positive, ASDAS-CRP 1.8), disease activity was classified as inactive in 14%, low in 54%, and high in 31%. ASDAS-CRP correlated well with MHAQ, DFI, BASFI, and spinal mobility across patients with low and high disease activity (all p < 0.05). Cytokine levels did not correlate with ASDAS-CRP, ESR, BASFI, or spinal mobility scores and were comparable between patients with no, low, or high disease activity regardless of gender or disease duration (all p > 0.2).

CONCLUSIONS

A large proportion of AS not on biologics have active disease far into the disease course. This impacts negatively on quality of life, work ability, and spinal mobility. Serum cytokine levels are poor markers for these central disease features in AS management.

FUNDING

Abbott Norway AS and Arthritis Foundation of Western Australia.