The presence of peripheral arthritis delays spinal radiographic progression in ankylosing spondylitis: Observation Study of the Korean Spondyloarthropathy Registry

The Epidemiology and Treatment of Ankylosing Spondylitis in Korea

Ankylosing spondylitis is a chronic inflammatory disorder characterized by inflammation of the axial skeleton and sacroiliac joints and to a lesser extent by peripheral arthritis and the involvement of some extra-articular organs. It is paramount for the provision of effective health care delivery to be familiar with the epidemiologic studies on prevalence, mortality, and disability. Furthermore, there is no systematic arrangement of studies related to the treatment of ankylosing spondylitis in Korea. In this review, we addressed Korean ankylosing spondylitis epidemiological studies related to prevalence, genetic factor especially human leucocyte antigen-B27, extra-articular manifestations, infections, mortality, radiologic progression, child-birth, and quality of life. Furthermore, we reviewed Korean ankylosing spondylitis treatment researches about treatment trend, patients' registration program called The KOrean College of Rheumatology BIOlogics and targeted therapy (KOBIO) registry project, biologics and biosimiliars, complications especially infections, and issues about bony progression. There would be value to further studying the epidemiology and treatment of Korean ankylosing spondylitis.

Age-stratified trends in the progression of spinal radiographic damage in patients with ankylosing spondylitis: a longitudinal study

Objective

The objective of this study was to investigate spinal radiographic progression in specific age ranges of ankylosing spondylitis (AS) patients.

Methods

Longitudinal data for 1125 AS patients at a single hospital from 2000 to 2018 were retrospectively reviewed. Radiographic intervals were obtained from patients with consecutive spinal radiographs. The radiographic progression rate was defined as the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) change per year within each interval. Using generalized estimating equations (GEEs), estimated marginal means were calculated for the mSASSS progression rate across age groups after adjusting for potential confounders.

Results

We obtained 4016 radiographic intervals and stratified them into five groups based on patient age at the interval start: <20 (n = 122); 20-29 (n = 1124); 30-39 (n = 1690); 40-49 (n = 794); and ⩾50 years (n = 286). The mean (SD) mSASSS progression rate for all the intervals was 0.8 (1.9). The GEE-estimated mean mSASSS progression rate increased with age, peaking in the 30-39 age group with a value of 1.15 [95% confidence interval (CI) 1.03, 1.27], and decreased slightly thereafter. In the presence of risk factors, rapid progression occurred at earlier ages: the GEE-estimated mean mSASSS progression rate in those with elevated C-reactive protein levels and preexisting syndesmophytes was 2.82 (95% CI 1.93, 3.71) in the 20-29 age group.

Conclusion

Spinal structural damage in AS seems to progress most rapidly when patients are age 30-39 years. An awareness of the trends in radiographic progression with advancing age could improve understanding of the natural course of AS.

The risk factors and incidence of major infectious diseases in patients with ankylosing spondylitis receiving tumor necrosis factor inhibitors

OBJECTIVES

This study aimed to evaluate the risk factor and incidence of infections in patients receiving tumor necrosis factor inhibitor (TNFi) therapy for ankylosing spondylitis using data from the national health insurance service.

METHODS

This was a retrospective cohort study. Data regarding patients with ankylosing spondylitis prescribed TNFis were obtained from an insurance claims database of the Health Insurance Review & Assessment Service in Korea. Outcomes used were incidence rates of serious infection, pneumonia, tuberculosis, and herpes zoster during the follow-up period as well as the relationship between each TNFi and sex, hazard ratio (HR) of infection-related risk factors, and incidence of infections.

RESULTS

A total of 2515 patients were included. There were no significant differences among the hazard ratios of TNFis for serious infection, pneumonia, and herpes zoster. However, the hazard ratio of tuberculosis was significantly higher for infliximab than for etanercept (adjusted HR 8.40 [95% confidence interval: 1.06-66.91]). In the subgroup analysis by sex, women treated with golimumab had a significantly higher hazard of herpes zoster than those treated with etanercept (adjusted HR 12.40 [95% confidence interval: 1.40-109.58]).

CONCLUSION

We recommend that risk factors for these infectious diseases be identified prior to prescribing TNFis in these patients.

Conventional disease-modifying antirheumatic drugs therapy may not slow spinal radiographic progression in ankylosing spondylitis: results from an 18-year longitudinal dataset

Objectives:

The clinical benefit of conventional disease-modifying antirheumatic drugs (cDMARDs) for treating ankylosing spondylitis (AS) is generally limited to improvements in peripheral arthritis. However, cDMARDs could be conditionally considered as alternatives to established drugs for improving axial manifestations in exceptional circumstances. However, there are few studies of the impact of cDMARDs on radiographic progression outcomes. Therefore, we investigated the effectiveness of cDMARDs on radiographic progression in AS.

Methods:

Among 1280 AS patients at a single hospital from 2000 to 2018, 301 who had been treated with sulfasalazine (SSZ) or methotrexate (MTX) were enrolled. For each patient, the entire follow-up period was split into 1-year intervals. Each interval was classified as either an “on-cDMARD” interval, which was a period of treatment with SSZ alone, MTX alone, or a combination of SSZ and MTX, or an “off-cDMARD” interval, which was a period without cDMARD treatment. Radiographic progression was scored using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). The relationship between cDMARD use and radiographic progression within the intervals, defined as the rate of mSASSS progression, was investigated using linear models with adjustment for potential confounding covariates and for clustering among observations from the same patient.

Results:

The 732 on-cDMARD intervals and 1027 off-cDMARD intervals were obtained from enrolled patients. In multivariable regression analysis, there was no significant association between cDMARDs and the rate of mSASSS progression (β = −0.081, p = 0.418). The mean adjusted mSASSS change per year was 0.610 from on-cDMARD intervals and 0.691 from off-cDMARD intervals.

Conclusion:

Treatment with cDMARDs may not reduce radiographic progression in AS patients.

Baseline extent of damage predicts spinal radiographic progression in Korean patients with ankylosing spondylitis treated with golimumab

BACKGROUND/AIMS

For patients with ankylosing spondylitis (AS), golimumab has consistent efficacy in controlling disease activity over 5 years but its benefit in preventing radiographic progression was less clear at 4 years. To predict radiographic progression, we analyzed the baseline characteristics of AS patients in a Korean population.

METHODS

Sixty-eight Korean patients with AS participated in the phase 3, multicenter, randomized, placebo-controlled, double-blind trial (GO-RAISE) which has previously been described. Baseline modified stoke AS spine score (mSASSS) and change in mSASSS from baseline (ΔmSASSS) until week 208 were analyzed in the Korean patients enrolled in the GO-RAISE study.

RESULTS

Although Korean patients had lower baseline mSASSS compared to non-Korean patients and received active management, radiographic progression was not prevented. Korean patients who did not undergo radiographic progression of spinal lesions of AS were younger and had shorter symptomatic duration, lower Bath AS functional and metrology indices, better chest expansion, and lower baseline mSASSS. The baseline mSASSS and ΔmSASSS were positively correlated in Korean AS patients (p < 0.001). Radiographic progression was more prevalent (80.0%) when baseline mSASSS > 10 and less common (13.0%) with baseline mSASSS = 0.

CONCLUSIONS

In Korean AS patients, radiographic progression of the spine after 4 years was predicted effectively by the initial severity of the spinal lesion(s) in patients treated with golimumab.

TNF blockers inhibit spinal radiographic progression in ankylosing spondylitis by reducing disease activity: results from the Swiss Clinical Quality Management cohort

Objectives

To analyse the impact of tumour necrosis factor inhibitors (TNFis) on spinal radiographic progression in ankylosing spondylitis (AS).

Methods

Patients with AS in the Swiss Clinical Quality Management cohort with up to 10 years of follow-up and radiographic assessments every 2 years were included. Radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with known chronology. The relationship between TNFi use before a 2-year radiographic interval and progression within the interval was investigated using binomial generalised estimating equation models with adjustment for potential confounding and multiple imputation of missing values. Ankylosing Spondylitis Disease Activity Score (ASDAS) was regarded as mediating the effect of TNFi on progression and added to the model in a sensitivity analysis.

Results

A total of 432 patients with AS contributed to data for 616 radiographic intervals. Radiographic progression was defined as an increase in ≥2 mSASSS units in 2 years. Mean (SD) mSASSS increase was 0.9 (2.6) units in 2 years. Prior use of TNFi reduced the odds of progression by 50% (OR 0.50, 95% CI 0.28 to 0.88) in the multivariable analysis. While no direct effect of TNFi on progression was present in an analysis including time-varying ASDAS (OR 0.61, 95% CI 0.34 to 1.08), the indirect effect, via a reduction in ASDAS, was statistically significant (OR 0.75, 95% CI 0.59 to 0.97).

Conclusion

TNFis are associated with a reduction of spinal radiographic progression in patients with AS. This effect seems mediated through the inhibiting effect of TNFi on disease activity.

Clinical importance of inflammatory facet joints of the spine in ankylosing spondylitis: a magnetic resonance imaging study

OBJECTIVES

The aims of this study were to assess the reliability of a novel magnetic resonance imaging (MRI) scoring system for inflammatory lesions of facet joints and to clarify the clinical significance of facet joint inflammation in ankylosing spondylitis (AS).

METHOD

A total of 53 AS patients (45 males, 84.9%) were assessed for active inflammatory lesions involving the facet joints, as indicated by bone marrow oedema, at 23 discovertebral units (DVUs) between C2 and S1 using a novel scale, the AS Activity of the Facet joint (ASAFacet). The reliability of the ASAFacet was evaluated using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

RESULTS

ICC values for the ASAFacet scores were 0.857 [95% confidence interval (CI) 0.741-0.919] for inter-observer and 0.941 (95% CI 0.873-0.969) for intra-observer reliability. Inflammatory activity scores in facet joints were evenly distributed at all spine levels (p = 0.294 for ASAFacet), whereas vertebral body inflammation was more prominent in the thoracic spine than in the cervical and lumbar spine [p < 0.001 for the AS spine MRI activity (ASspiMRI-a) score, p = 0.002 for the Berlin method, and p < 0.001 for the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI index]. ASAFacet scores were closely associated with erythrocyte sediment rate (ESR) and C-reactive protein (CRP) levels (p < 0.05, respectively). Patients with peripheral arthritis had fewer lesions involving the vertebral bodies or facet joints than patients without peripheral arthritis (p < 0.001 for the four different MRI activity indexes).

CONCLUSIONS

This study suggests that recognition of facet joint inflammation has the potential to contribute to our understanding of clinical outcomes in AS.

Radiologic Changes in the Symphysis Pubis of Male Patients with Ankylosing Spondylitis

OBJECTIVE

We aimed to evaluate the involvement of the symphysis pubis in patients with ankylosing spondylitis (AS), and to assess the correlations between symphysis pubis changes and clinical findings.

METHODS

We retrospectively evaluated a total of 222 male patients with AS who underwent pelvic and cervical/lumbar spine radiography at the Hanyang University Hospital for Rheumatic Diseases from August 2004 to February 2014. Radiographs were examined by 2 experienced radiologists, and radiographic damage was scored as follows: 0 (no damage), 1 (subtle irregularity and/or subchondral sclerosis), 2 (erosion), 3 (partial ankylosis), and 4 (total ankylosis). We evaluated the patients' clinical characteristics and analyzed their correlations with radiographic symphysis pubis changes.

RESULTS

The mean patient age was 30.5 ± 8.3 years and mean disease duration was 7.1 ± 4.6 years; 105 patients (47.3%) exhibited radiologic damage in the symphysis pubis. Moreover, 75, 28, 0, and 2 patients had scores of 1, 2, 3, and 4, respectively. When comparing the normal (score 0) and abnormal (score 1-4) symphysis pubis groups, the latter had a longer symptom duration (10.1 ± 7.0 vs 7.6 ± 5.8 yrs, p = 0.004) and higher modified Stoke Ankylosing Spondylitis Spine Score (mSASSS; 18.6 ± 17.0 vs. 14.3 ± 13.4, p = 0.038). Moreover, a significant correlation was noted between the radiographic symphysis pubis damage score and mSASSS (r(2) = 0.147, p = 0.029).

CONCLUSION

Among male patients with AS, 47.3% exhibited symphysis pubis involvement. Moreover, a correlation was observed between the radiographic symphysis pubis and spine changes.

Micro-Ribonucleic Acid Profiles From Microarray in Ankylosing Spondylitis

Objectives

This study aims to detect candidate micro-ribonucleic acids (miRNAs) from microarray within peripheral blood mononuclear cells and synovial fluid mononuclear cells in patients with ankylosing spondylitis (AS).

Patients and methods

Samples from three AS patients (3 males, mean age 37.3±2.5 years; range 35 to 40 years) and three healthy controls (3 males, mean age 39.0±2.6 years; range 37 to 42 years) were obtained for miRNA microarray. The microarray experiment proceeded only when the quality of total RNAs were considered to have "passed", and their integrity was good by total RNA quality control using Agilent Bioanalyzer 2100. Hierarchical clustering was performed to understand the impact of the storage condition on the miRNA expression profiles. MiScript primer assays were used for semiquantitative determination of the expression of human miRNAs to validate results from miRNA microarray.

Results

A total of 887 miRNAs were screened by microarray among groups. After normalization of the raw data, we noted that the expression of five miRNAs was significantly lower (fold change ≤0.5 and p≤0.05) and only hsa-miR-424-5p was significantly higher in AS peripheral blood mononuclear cell (fold change ≥2 and p≤0.05). In AS synovial fluid mononuclear cells, we identified that expressions of 16 miRNAs were significantly down regulated whereas only hsa-miR-424-5p was significantly upregulated (fold change ≥2 and p≤0.05). All above-mentioned miRNAs were reevaluated for further validation. Finally, significantly increased hsa-miR-424-5p and decreased hsa-miR-377 were found in synovial fluid mononuclear cells from AS patients compared with healthy controls. Based on target prediction programs and published papers, potential target genes and its pathways were screened.

Conclusion

miR-424-5p was increased and miR-377 was decreased in synovial fluid mononuclear cells from patients with AS. These two miRs might have functional roles in patients with arthritis via different pathways.

Gender differences in axial spondyloarthritis

Within the concept of axial spondyloarthritis (axSpA), relevant differences between men and women have been described for patients with the radiographic disease form [ankylosing spondylitis (AS)]. The subjective perception of disease activity (spinal and peripheral pain, fatigue, morning stiffness) has been shown to be higher in female than in male patients. Moreover, women experience more functional limitations and a lower quality of life, despite lower degrees of radiographic spinal damage. Peripheral clinical involvement (arthritis and enthesitis) is, additionally, more predominant in women. On the other hand, a higher level of objective signs of inflammation (C-reactive protein, erythrocyte sedimentation rate, magnetic resonance imaging of sacroiliac joints and spine) has been reported in men. Whether these differences might explain the better response to treatment with anti-tumor necrosis factor agents observed in male patients remains unclear. The underlying causes of the discrepancies are still unknown and genetic, environmental, cultural and/or societal factors may be involved. While AS is still more prevalent in men in a ratio of 2-3:1, the prevalence of males and females in patients with axSpA without radiographic sacroiliac damage is similar. Gender differences in this subgroup of patients have not been adequately addressed, and are particularly needed to further validate the Assessment of SpondyloArthritis international Society classification criteria.