Thresholds for unacceptable work state in radiographic axial Spondyloarthritis of four presenteeism and two clinical outcome measurement instruments.

OBJECTIVES: To a) identify threshold values of presenteeism measurement instruments that reflect unacceptable work state in employed r-axSpA patients; b) determine whether those thresholds accurately predict future adverse work outcomes (AWO) (sick leave or short/long-term disability); c) evaluate the performance of traditional health-outcomes for r-axSpA; d) explore whether thresholds are stable across contextual factors. METHODS: Data from the multinational AS-PROSE study was used. Thresholds to determine whether patients consider themselves in an 'unacceptable work state' were calculated at baseline for four instruments assessing presenteeism and two health-outcomes specific for r-axSpA. Different approaches derived from the receiver operating characteristic methodology were used. Validity of the optimal thresholds was tested across contextual factors and for predicting future AWO over 12 months. RESULTS: Of 366 working patients, 15% reported an unacceptable work state; 6% experienced at least one AWO in 12 months. Optimal thresholds were: WPAI-presenteeism ≥40 (AUC 0.85), QQ-method <97 (0.76), WALS ≥0.75 (AUC 0.87), WLQ-25 ≥ 29 (AUC 0.85). BASDAI and BASFI performed similarly to the presenteeism instruments: ≥4.7 (AUC 0.82) and ≥3.5 (AUC 0.79), respectively. Thresholds for WALS and WLQ-25 were stable across contextual factors, while for all other instruments they overestimated unacceptable work state in lower educated persons. Proposed thresholds could also predict future AWO, although with lower performance, especially for QQ-method, BASDAI and BASFI. CONCLUSIONS: Thresholds of measurement instruments for presenteeism and health status to identify unacceptable work state have been established. These thresholds can help in daily clinical practice to provide work related support to r-axSpA patients at risk for AWO.

Efficacy of TNF-α Inhibitors in the Treatment of nr-axSpA: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials.

INTRODUCTION: A growing number of randomized controlled trials (RCTs) have demonstrated the effectiveness of tumor necrosis factor-α (TNF-α) inhibitors in treating non-radiographic axial spondyloarthritis (nr-axSpA). This study aimed to evaluate the efficacy of TNF-α inhibitors in the treatment of nr-axSpA. METHODS: PubMed, EMBASE, Web of Science, and the Cochrane Library databases were systematically searched for relevant RCTs using specific keywords up to June 2023. The primary outcome was the proportion of patients who achieved Assessment in SpondyloArthritis international Society 40% (ASAS40). Secondary outcomes included ASAS20, Bath Ankylosing Spondylitis Disease Activity Index 50% (BASDAI50), ASAS partial remission, and ASAS5/6. RESULTS: A total of eight RCTs involving 1,376 patients were included. Patients receiving anti-TNF therapy exhibited a higher rate of ASAS40 (pooled RR = 2.36; 95% CI: 1.63-3.42; p < 0.001). In addition, the TNF-α inhibitor group showed higher BASDAI50 rates (pooled RR = 2.06; 95% CI: 1.48-2.89), ASAS20 rates (pooled RR = 1.48; 95% CI: 1.31-1.67), ASAS partial remission rates (pooled RR = 2.33; 95% CI: 1.58-3.43), and ASAS5/6 rates (RR = 3.46; 95% CI: 2.05-5.83) than the placebo group. CONCLUSION: The TNF-α inhibitors were effective in treating nr-axSpA.

Immunological biomarkers in patients with radiographic axial spondyloarthritis, an exploratory longitudinal Swedish study.

Objectives There is a need for more specific biomarkers to diagnose and predict disease course in patients with axial spondyloarthritis (axSpA). This study aimed to study immunological plasma biomarkers, at different time-points in radiographic (r)-axSpA patients overall and stratified by sex and compare these biomarker pattern in r-axSpA patients concerning disease phenotypes and disease activity. Methods Plasma samples were analysed from r-axSpA patients at and prior (Pre-Backbone) inclusion in the Backbone study. Interferon gamma, interleukin-10, -17A, -17F, -22, -23, -6, MCP-1, TNF-α, VEGF-A, MIF, IgA anti-CD74, zonulin, ESR, hsCRP, white blood cell count, and blood lipids were measured. Results Biomarker pattern discriminated significantly between r-axSpA patients in Backbone and Pre-Backbone compared with controls. When stratifying by sex, it was possible to discriminate between male and female r-axSpA patients in Backbone vs controls and between male r-axSpA patients in pre-Backbone and controls. In Backbone, markers with high discriminative capacity were MIF, IgA anti-CD74, and MCP-1. In Pre-Backbone, IL-6, TNF-α, MIF, triglycerides, cholesterol, IL-10, and zonulin displayed high discriminative capacity. Conclusion Based on their temporal pattern and mutual relationship, we suggest studying MIF, IgA anti-CD74, and MCP-1 in depth, at more time points, to further elucidate disease-driving mechanisms in this complex disease.

Brodalumab, an anti-interleukin-17 receptor A monoclonal antibody, in axial spondyloarthritis: 68-week results from a phase 3 study.

OBJECTIVE: To evaluate the long-term efficacy and safety of brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, in patients with axial spondyloarthritis (axSpA). METHODS: Patients receiving subcutaneous brodalumab 210 mg during the 16-week double-blind period of this multicentre, phase 3 study conducted across Japan, Korea and Taiwan continued the same during the 52-week open-label extension, whereas patients receiving placebo switched to brodalumab 210 mg at week 16. Efficacy [Assessment of SpondyloArthritis International Society (ASAS) 40 and ASAS 20 response rates; change from baseline in AS Disease Activity Score using CRP (ASDAS-CRP)] and safety were evaluated. RESULTS: Overall, 145 patients (brodalumab, n = 77; placebo, n = 68) received brodalumab during the open-label extension. ASAS 40 response rates (95% CI) of 56.3% (44.7%, 67.3%) and 57.4% (44.1%, 70.0%) were achieved in the brodalumab and placebo groups, respectively, at week 68. ASAS 20 response rates (95% CI) achieved at week 68 in both treatment groups were similar [brodalumab, 71.3% (60.0%, 80.8%); placebo, 78.7% (66.3%, 88.1%)]. The least squares mean change (95% CI) in ASDAS-CRP at week 68 suggested a clinically important improvement (change, ≥1.1) in both treatment groups [brodalumab, -1.528 (-1.737, -1.319); placebo, -1.586 (-1.815, -1.357)]. The exposure-adjusted event rates (per 100 patient-years) for treatment-emergent adverse events (TEAEs) and drug-related TEAEs were 255.9 and 147.9, respectively; nasopharyngitis (35.6) and upper respiratory tract infection (14.7) were the most common TEAEs. CONCLUSIONS: Brodalumab demonstrated sustained efficacy and a consistent safety profile in patients with axSpA over 68 weeks. STUDY REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT02985983.

Efficacy and safety of golimumab in patients with non-radiographic axial spondyloarthritis: a withdrawal and retreatment study (GO-BACK).

OBJECTIVES: The GO-BACK study was designed to evaluate the efficacy and safety of golimumab (GLM) treatment withdrawal in adults with non-radiographic axial spondyloarthritis (nr-axSpA) who demonstrate inactive disease during a 10-month open-label (OL) GLM run-in. METHODS: Eligible participants received OL GLM in period 1. In period 2, participants who achieved inactive disease were randomized 1:1:1 to receive double-blind (DB) treatment with monthly placebo (PBO, treatment withdrawal) or continued GLM treatment given monthly (GLM QMT) or every 2 months (GLM Q2MT). Participants who did not have a disease flare continued DB treatment for ∼12 months. Participants with a disease flare discontinued DB treatment and resumed monthly OL GLM. Primary endpoint compared the proportion of participants without a disease flare in the continued GLM treatment groups (QMT or Q2MT) vs PBO in a multiplicity-controlled, step-down fashion. Safety follow-up continued for ∼3 months after last treatment. RESULTS: A total of 188 patients, out of the 323 enrolled, were eligible for participation in period 2. Both GLM QMT and GLM Q2MT were superior to treatment withdrawal (PBO) in preventing disease flare (P < 0.001), with a treatment-difference vs PBO of 50.4% and 34.4% for the GLM QMT and GLM Q2MT groups, respectively. The time-to-first flare was significantly longer (log-rank P < 0.0001) with GLM treatment compared with PBO. Of 53 participants (in Q2MT or PBO) who had a confirmed disease flare, 51 (96.2%) attained a clinical response within 3 months of restarting OL GLM. Adverse events were consistent with the known GLM safety profile. CONCLUSION: Among participants with active nr-axSpA who attained inactive disease after 10 months of GLM treatment, continued GLM treatment is well tolerated and provides superior protection against disease flares compared with GLM withdrawal. (EudraCT: 2015-004020-65, registered on 30 March 2022; NCT: 03253796, registered on 18 August 2017.).

Clinical significance of possible HLA biomarkers in axial spondyloarthritis beyond HLA-B27 positivity.

The aim of this study is to compare four forms of axial spondyloarthritis (axSpA): non-radiographic axial spondyloarthritis (nr-axSpA), ankylosing spondylitis (AS), non-radiographic axial psoriatic arthritis (nr-axPsA) and radiographic axial psoriatic arthritis (r-axPsA). In a cross-sectional retrospective study, gender difference, human leukocyte antigen (HLA) typing, laboratory C-reactive protein (CRP) and erythrocyte sedimentation (SE) values, and radiographic and magnetic resonance scans were analyzed. One hundred and thirty-seven patients were included in the study: 45 AS, 51 nr-axSpA, 32 r-axPsA and 9 nr-axPsA; 74 women and 63 men. Most of the gender, laboratory and radiological findings confirmed the results of previously conducted studies about each group of the investigated axSpA. The key findings of our study are the newly detected findings of HLA typing beyond HLA-27 positivity: HLA-DR16 in AS, HLA-DR11 in nr-axSpA, HLA-B13, HLA-B57, HLA-Cw12 and HLA-DR7 in r-axPsA, and HLA-B18 in nr-axPsA. Our study also confirmed some of the results of previously conducted studies on predominant genes of HLA typing in axSpA: HLA-B27 in AS, HLA-B39 and HLA-Cw6 in r-axPsA, and HLA-Cw7 in nr-axPsA. Important conclusions about the nr-axPsA group cannot be drawn because of the very small number of subjects included in this group of axSpA. Our results suggest that the newly detected HLA typing findings beyond HLA-B27 positivity could be possible biomarkers of early detection of axSpA, but further studies on larger samples are needed.

Long-term tolerability and efficacy of golimumab in active non-radiographic axial spondyloarthritis: results from open-label extension.

OBJECTIVES: We report the open-label extension (OLE) of the GO-AHEAD study evaluating the long-term efficacy and safety of golimumab (GLM) in patients with non-radiographic axial spondyloarthritis (nr-axSpA). METHODS: Patients [both GLM- and placebo (PBO)-treated in the double-blind phase] received GLM 50 mg every 4 weeks during the OLE (36-week treatment; additional 8-week safety follow-up; GLM/GLM and PBO/GLM groups). All patients who entered and received ≥1 dose of study treatment in the OLE were included in the efficacy and safety analyses. The primary efficacy evaluations were the proportions of patients achieving 20% and 40% improvement in the ASAS criteria (ASAS20 and ASAS40, respectively). Responders' analyses were calculated using a non-responder imputation approach. RESULTS: Of 198 patients randomised, 189/198 (95.5%) entered the OLE; 174/198 patients (87.9%) completed all visits. Although the proportion of responders increased from week 16 to week 52 in the OLE in both GLM/GLM and PBO/GLM groups, the GLM/GLM group had a higher proportion of responders than the PBO/GLM group throughout the OLE from week 16 to week 52 (ASAS20: 71.1% to 83.9% vs 40.0% to 75.0%, respectively; ASAS40: 56.7% to 76.3% vs 23.0% to 59.4%, respectively; ASAS partial remission: 33.0% to 53.8% and 18.0% to 45.8%). In the OLE, the overall incidence of AEs was lower in the GLM/GLM vs PBO/GLM groups (41.9% and 54.2%). CONCLUSIONS: Sustained improvement in clinical efficacy was observed at 52 weeks in patients with nr-axSpA following GLM treatment. GLM was well tolerated and provided substantial long-term benefits to patients with nr-axSpA. TRIAL REGISTRATION: NCT01453725; United States National Library of Medicine clinical trials database; www.clinicaltrials.gov.

Associations between syndesmophytes and facet joint ankylosis in radiographic axial spondyloarthritis patients on low-dose CT over 2 years.

OBJECTIVES: In radiographic axial spondyloarthritis (r-axSpA), spinal damage manifests as syndesmophytes and facet joint ankylosis (FJA). We evaluated whether the presence of one lesion increased the risk of the other lesion. METHODS: Patients with r-axSpA underwent low-dose CT (ldCT) and MRI of the whole spine at baseline and 2 years. On ldCT, vertebrae were scored for presence and size of syndesmophytes; facet joints were assessed for ankylosis. MR images were assessed for inflammation. Two hypotheses were tested: (i) presence of FJA is associated with new syndesmophyte(s) on the same vertebral unit (VU) 2 years later, and (ii) presence of bridging syndesmophyte(s) is associated with new FJA on the same VU 2 years later. Two generalized estimating equations models were tested per hypothesis using increase of FJA/syndesmophytes (model A) or presence of FJA/syndesmophytes (model B) as outcome, adjusted for inflammation at baseline. Secondary analyses tested the hypotheses with outcomes on adjacent VUs and dose-response effects. RESULTS: Fifty-one patients were included (mean age 49, 84% male, 82% HLA-B27+). Baseline bridging syndesmophytes occurred more often (range: 10-60% per VU) than FJA (range: 8-36%). Odds ratios (ORs) (95% CI) for presence of bridging syndesmophytes on development of FJA were 3.55 (2.03, 6.21) for model A and 3.30 (2.14, 5.09) for model B. ORs for presence of baseline FJA on new syndesmophytes were 1.87 (1.20, 2.92) for model A and 1.69 (0.88, 3.22) for model B. Secondary analyses yielded positive ORs for both hypotheses. CONCLUSIONS: Bone formation in vertebrae and in facet joints influence each other's occurrence, with the effect of syndesmophytes being larger than that of FJA.

Increased proportions of inflammatory T cells and their correlations with cytokines and clinical parameters in patients with ankylosing spondylitis from northern Sweden.

Ankylosing spondylitis (AS) is an autoimmune disease affecting parts of the skeletal structure in particular. Previously increased levels of the inflammatory cell types Th17, Th22, Tc17 and Tc22 cells have been shown to be associated with AS. Here, we analysed the levels of inflammatory T cell subsets, related cytokines and clinical characteristics of AS patients vs controls from northern Sweden. Peripheral blood mononuclear cells (PBMCs) obtained from 50 AS patients and 50 matched controls were short term stimulated with PMA/Ionomycin, stained and analysed by flow cytometry. Plasma levels of Interleukin (IL)-17, IL-22, IL-10 as well as clinically relevant markers were determined. Compared to male controls, male AS patients showed 1.5- to 2-fold increases of Th17 (P = .013), Th22 (P = .003) and Tc22 (P = .024) among CD45+ CD3+ lymphocytes. Plasma IL-22 levels correlated with the Tc17 proportion in male patients (Rs  = 0.499, P = .003) and plasma IL-10 levels were inversely correlated with Tc17 among all patients (Rs  = -0.276, P = .05). Male patients with syndesmophytes showed significantly higher Th17 proportions (P = .038). In female AS patients, Tc22 was negatively correlated with C-reactive protein (high sensitivity) (hsCRP) (Rs  = -0.573, P = .016). We confirmed increased proportions of inflammatory T cells and correlations with relevant cytokines from male AS patients. The correlation between Th17 and syndesmophytes supports a role of Th17 in the pathogenic process.

Axial Spondyloarthritis in Japan.

PURPOSE OF REVIEW: The differences in the epidemiology and management of patients with axial spondyloarthritis (axSpA) among regions and countries largely depend on the positivity of human leukocyte antigen (HLA)-B27 and the health care system. This review article focused on axSpA in Japan, where the prevalence of HLA-B27 is extremely low (0.3%) and the universal health insurance system typically provides a 70% or more copayment by the government. RECENT FINDINGS: A nationwide survey was conducted in Japan in 2018, which estimated that there were 3200 patients (95% confidence interval [CI]: 2400-3900) with ankylosing spondylitis (AS), a term interchangeable with radiographic axSpA (r-axSpA), and 800 patients (95% CI: 530-1100) had non-radiographic (nr)-axSpA. These data indicate a prevalence of 2.6/100,000 or 0.0026% for AS and 0.6/100,000 or 0.0006% for nr-axSpA. Patients with AS, but not those with nr-axSpA, are designated as suffering from intractable diseases in Japan; thus, their medical expenses are reduced by grant under the Act on Medical Care for Patients with Intractable Diseases. As of February 2022, infliximab, adalimumab, secukinumab, ixekizumab, and brodalumab have been approved for AS, and secukinumab, ixekizumab, and brodalumab have been approved for nr-axSpA. An algorithm for nr-axSpA in Japan has been developed for the proper diagnosis and use of these therapeutic agents. A low prevalence of axSpA, especially that of nr-axSpA, was found in Japan. Early referral and the resultant diagnosis and appropriate treatment of these patients by rheumatologists are crucial issues in Japan, as in other countries.

The validity and reliability of quality of life questionnaires in patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis: a systematic review and meta-analysis.

BACKGROUND: Patients who suffered from ankylosing spondylitis (AS) or non-radiographic axial spondyloarthritis (nr-axSpA) often have poor quality of life (QoL) and there has been a substantial increase in research on acceptable questionnaires for assessment of QoL. This systematic review aims at examining the validity and reliability of QoL questionnaires in patients with AS/nr-axSpA. METHODS: Randomized controlled trials (RCTs), cohort trials, and cross-sectional trails were retrieved by searching seven databases. Primary outcomes included test-retest reliability and construct validity. Secondary outcomes included internal consistency, structural validity, responsiveness and so on. Data extraction and analyses were conducted according to the Cochrane standards. The Agency for Healthcare Research and Quality (AHRQ) checklists was used to assess the risk of bias for each included study. We used the Consensus-based Standards for the Selection of Health Status Measurement Instruments (COSMIN) to assess the methodological quality and measurement property of included instruments. The quality of evidence on pre-specified outcomes were assessed by the Grades of Recommendations, Development and Evaluation (GRADE) approach. RESULTS: 22 publications containing 10 self-rating instruments were included in this study. Most studies were cross-sectional in design and a total of 3,085 participants were enrolled. 19 studies had moderate to high test-retest reliability. Cronbach's alpha (α) Coefficients were generally high (0.79-0.97) for overall scales. The ankylosing spondylitis quality of life (ASQOL) and evaluation of ankylosing spondylitis quality of life (EASi-QoL) questionnaires showed the strongest measurement properties in high-quality studies. The correlation coefficient for test-retest reliability of the ASQOL questionnaire was 0.85 (95% CI 0.80 to 0.89). The pooled Cronbach's α coefficients of the ASQOL questionnaire and the EASi-QoL questionnaire were high. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) were considered as two validity criteria. For the ASQOL and EASi-QoL questionnaire, pooled convergent validity associations with BASDAI and BASFI were low to strong (0.24-0.81). CONCLUSIONS: This study indicated acceptable reliability and stability of included QoL questionnaires. The ASQOL and the EASi-QoL questionnaires are validated and reliable disease-specific questionnaires for the assessment of QoL in patients with AS/nr-axSpA.

Nonsteroidal anti-inflammatory drug-sparing effect of secukinumab in patients with radiographic axial spondyloarthritis: 4-year results from the MEASURE 2, 3 and 4 phase III trials.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to reduce pain and inflammation, and are considered the cornerstone of pharmacological intervention in patients with radiographic axial spondyloarthritis (r-axSpA); however, the long-term use of NSAIDs is debatable due to their restricted therapeutic potential and the risk of side effects and complications. Therefore, reduction in NSAID intake is desirable in r-axSpA patients. Here, we report the long-term NSAID-sparing effect of secukinumab over 4 years in patients with r-axSpA. This post hoc analysis pooled data from 3 secukinumab trials (MEASURE 2-4) for each secukinumab maintenance dose of 150 and 300 mg, regardless of the loading dose regimen being i.v. or s.c. NSAID intake was evaluated prospectively using the Assessment of SpondyloArthritis International Society (ASAS)-NSAID score. Patients with an ASAS-NSAID score > 0 at baseline were analysed. NSAID-sparing endpoints included the mean change in the ASAS-NSAID score, the proportion of patients achieving 50% reduction, and the proportion of patients with an ASAS-NSAID score < 10. Percentages of patients who achieved BASDAI ≤ 2 were also assessed. Overall, 562 patients were included in this pooled analysis (secukinumab: 150 mg, N = 467; 300 mg, N = 95). The mean ASAS-NSAID score decreased with time in both the secukinumab 150 mg and 300 mg dose groups. The proportion of patients who achieved 50% reduction in the ASAS-NSAID score and clinically meaningful reduction of ASAS-NSAID score < 10 increased with time in both dose groups and in both low and high NSAID intake patients. The percentage of patients with a clinically relevant improvement (BASDAI ≤ 2) was consistently higher in patients with an ASAS-NSAID score < 10 than in patients with an ASAS-NSAID score ≥ 10. Secukinumab provided sustained, long-term NSAID-sparing effects in patients with r-axSpA for up to 4 years of treatment, as measured using the ASAS-NSAID score. Trial registered at clinicaltrials.gov: NCT01649375 ( https://clinicaltrials.gov/ct2/show/NCT01649375 ); NCT02008916 ( https://clinicaltrials.gov/ct2/show/NCT02008916 ); NCT02159053 ( https://clinicaltrials.gov/ct2/show/NCT02159053 ).

A nationwide questionnaire survey on the prevalence of ankylosing spondylitis and non-radiographic axial spondyloarthritis in Japan.

OBJECTIVE: This nationwide study aimed to reveal the prevalence of ankylosing spondylitis (AS), non-radiographic axial spondyloarthritis (nr-ax SpA), and the positivity rate of human leukocyte antigen (HLA) among such patients in Japan. METHODS: The first survey was conducted in 2221 randomly selected facilities (26.3%) in September 2018, where the patients with AS/nr-ax SpA were taken care of from January to December 2017. We estimated the total number of these patients using response and extraction rates. A second survey was conducted in 117 facilities (49.8%) to assess for HLA-B27 positivity rate and clinical features. RESULTS: The estimated total numbers of the patients with AS and nr-ax SpA were 3200 (95% confidence interval [CI]: 2400-3900) and 800 (530-1100), suggesting that the prevalence values of AS and nr-ax SpA in general population were 2.6/100,000 (0.0026%) and 0.6/100,000 (0.0006%), respectively. Although 55.5% (76/137) of patients with AS were HLA-B27-positive, those whose age of onset was estimated to be over 50 years tended to undergo less HLA-B27 testing. CONCLUSION: This study revealed the lower prevalence of AS/nr-ax SpA in Japan, compared to those in other countries. Further studies are required to reveal the association of HLA-B27 with the clinical features.

Procollagen I N-terminal peptide correlates with inflammation on sacroiliac joint magnetic resonance imaging in ankylosing spondylitis but not in non-radiographic axial spondyloarthritis: A cross-sectional study.

OBJECTIVES: To identify disease activity scores and biomarkers that reflect magnetic resonance imaging (MRI)-determined sacroiliac joint (SIJ) inflammation in ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). METHODS: Patients who had AS and nr-axSpA were enrolled. All the patients underwent SIJ MRI. SpondyloArthritis Research Consortium of Canada (SPARCC) method was used to score bone marrow edema in the inflammatory lesions on MRI. Radiographic assessment of the spine was performed using modified Stoke Ankylosing Spondylitis Spine Score. Clinical variables, inflammatory markers, serum alkaline phosphatase, osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX-I), and procollagen I N-terminal peptide (PINP) were measured. Correlation analysis between MRI-determined SIJ inflammation scores and disease activity scores and laboratory variables was performed. RESULTS: Thirty-five patients had AS and 36had nr-axSpA. Significant differences were noted between the AS group and the nr-axSpA group in terms of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Ankylosing Spondylitis Disease Activity Score (ASDAS)-ESR, ASDAS-CRP, PINP, and SPARCC (p < .001, p = .004, p < .001, p < .001, p = .030, p < .001, respectively). MRI-determined SIJ inflammatory scores correlated with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), OC, CTX-I, and PINP in AS (p = .036, p = .023, p = .002, p = .041, p = .004, respectively) and correlated with ESR, CRP, ASDAS-ESR, ASDAS-CRP, BASDAI, and BASFI in nr-axSpA (p = .003, p = .002, p < .001, p < .001, p = .010, p = .007, respectively). Multivariate analysis showed that PINP exhibited a positive correlation independent of the MRI inflammatory score and that age exhibited a negative correlation independent of the MRI inflammatory score. CONCLUSIONS: In AS, PINP and age independently correlated with active inflammation on SIJ MRI. PINP may be useful as a marker of objective inflammation in AS.

Anti-CD74 IgA autoantibodies in radiographic axial spondyloarthritis: a longitudinal Swedish study.

OBJECTIVES: Antibodies against anti-CD74 are related to axial spondyloarthritis (axSpA). The objectives were (i) to study IgA anti-CD74 in radiographic (r)-axSpA patients in the Backbone cohort and to calculate the sensitivity and specificity of anti-CD74, (ii) to study the fluctuation of IgA anti-CD74 levels in prospectively collected samples, and (iii) to explore the relation between IgA anti-CD74 and radiographic spinal changes. METHODS: IgA anti-CD74 was analysed by ELISA in 155 patients with r-axSpA and age- and sex-matched controls. BASDAI, ASDAS, BASFI and BASMI were assessed and spinal radiographs were scored for r-axSpA-related changes with mSASSS. Previously donated samples, before inclusion in the Backbone study, were identified in the Medical Biobank of Northern Sweden. RESULTS: A total of 155 patients comprising 69% men and 31% women, age [mean (s.d.)] 55.5 (11.4) years and 152 (98.1%) HLA-B27 positive, were included. The plasma level of IgA anti-CD74 was significantly higher in the patients [median (interquartile range), 12.9 (7.9-17.9) U/ml] compared with controls [10.9 (7.2-14.6) U/ml, P = 0.003]. IgA anti-CD74 was above the cut-off level of 20 U/ml in 36/155 (23.2%) patients and in 15/151 (9.9%) controls (P = 0.002). Multivariable logistic regression analyses revealed ≥1 syndesmophyte associated with IgA anti-CD74 (odds ratio 5.64; 95% CI: 1.02, 35.58; P = 0.048) adjusted for hsCRP, smoking, BMI, sex and age. No distinct pattern of IgA anti-CD74 over time was revealed. CONCLUSION: Plasma levels of IgA anti-CD74 were increased in r-axSpA and independently associated with radiographic spinal changes, which suggests that IgA anti-CD74 could play a role in the pathogenies of r-axSpA.

Validation of the Ankylosing Spondylitis Quality of Life assessment tool in patients with non-radiographic axial spondyloarthritis.

PURPOSE: To evaluate the psychometric performance of the Ankylosing Spondylitis Quality of Life (ASQoL) scale in patients with non-radiographic axial spondyloarthritis (nr-axSpA) to assess its appropriateness as an outcome measure in future clinical studies. METHODS: Patients with active axSpA from a Phase III, randomized, double-blind, placebo-controlled trial (RAPID-axSpA, NCT01087762) were included (N = 325). Modified New York (mNY) classification criteria were used to classify patients as having ankylosing spondylitis or nr-axSpA; those with nr-axSpA were further categorized based on objective signs of inflammation. Psychometric properties of the ASQoL were assessed/documented using a mixture of modern psychometric methods and classical test theory methods. These included exploratory factor analysis and item response theory models to assess the domain structure, test the utility of a single domain relative to subdomains, assess bias, and generate statistics to guide an empirical scoring algorithm. The reliability and validity of scores were evaluated via internal consistency, test-retest reliability, concurrent validity, and known-groups validity. Score responsiveness was assessed via anchor-based clinically meaningful change, supplemented with empirical cumulative distribution function visualizations. RESULTS: The ASQoL data were defined by four domains. However, a four-domain solution was found to be inferior to a bifactor solution in which the four domains were included within a total domain. Scoring statistics supported a unit-weighted total score. Within the nr-axSpA population with objective signs of inflammation, the ASQoL mean score had adequate reliability, validity, and ability to detect clinically meaningful change. CONCLUSIONS: Our findings suggest that the ASQoL is an appropriate outcome measure in interventional clinical trials in patients with nr-axSpA.

The structural, functional and electrophysiological assessment of paraspinal musculature of patients with ankylosing spondylitis and non-radiographic axial spondyloarthropathy.

Paravertebral muscles are affected in spondyloarthritis. Decreased mobility of spine may lead to atrophy and fatty degeneration of these muscles. The objective of this study was to compare the sonographic, electrophysiological and magnetic resonance imaging (MRI) features of paraspinal muscles between patients with ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The patients who were diagnosed as AS with modified New York criteria and those as nr-axSpA with ASAS 2009 criteria were enrolled. Clinical evaluation, electrophysiological examination including nerve conduction studies and needle electromyography (EMG) for lower extremities and paraspinal mapping (PSM) were performed by the first examiner. The second examiner measured lumbar multifidus areas, graded the fatty degeneration of the muscle at different levels in T2 weighted axial MRI and also performed the ultrasonographic evaluation. A total of 19 patients with AS and 14 patients with nr-axSpA were evaluated. MRI of 2 patients with AS could not be obtained. Right lumbar multifidus area/vertebra area (MV ratio) was smaller in AS patients at L3 level (p 0,029); there were no significant differences in other levels. Fatty degeneration was also higher in AS patients in left multifidus at L5-S1 disc level (p 0,015). PSM scores that demonstrate the extent of denervation in paraspinal muscles were significantly higher in AS patients than in nr-axSpA patients (p < 0,001). Patients with AS have more fatty degeneration and denervation in paraspinal muscles. These processes may also contribute the severity of pain and disability. The relationship between paraspinal muscle denervation and progression of fatty degeneration should further be revealed.

Non-radiographic versus radiographic axSpA: what's in a name?

Axial spondyloarthritis is a heterogeneous inflammatory condition with variable clinical presentations and outcomes. The complexity of its diagnosis and absence of biomarkers hamper the development of diagnostic criteria with the risk of misuse of the available classification criteria in clinical practice and its consequences. Axial spondyloarthritis should be regarded as a continuum in which some patients, but not all, will have a more severe phenotype characterized by progression into new bone formation and joint fusion. Growing understanding of the factors that might drive disease progression and treatment response will allow for better characterization of treatment options and outcome for each affected individual. The aim of this review is to update the current evidence of what is axial spondyloarthritis and to highlight the need to focus on the concept rather than its classification.

Enhanced NETosis generation in radiographic axial spondyloarthritis: utility as biomarker for disease activity and anti-TNF-α therapy effectiveness.

BACKGROUND: Radiographic axial spondyloarthritis (r-axSpA) is a chronic inflammatory form of arthritis in which tumor necrosis factor (TNF)-α, a potent inducer of inflammatory response and a key regulator of innate immunity and of Th1 immune responses, plays a central role. NETosis is a mechanism of innate immune defense that is involved in diverse rheumatology diseases. Nevertheless, spontaneous NETosis generation in r-axSpA, its association to disease pathogenesis, and the NETosis involvement on anti-TNF-α therapy's effects has never been explored. METHODS: Thirty r-axSpA patients and 32 healthy donors (HDs) were evaluated. Neutrophil extracellular trap (NET) formation, mediators of signal-transduction cascade required for NETosis induction and cell-free NETosis-derived products were quantified. An additional cohort of 15 r-axSpA patients treated with infliximab (IFX) for six months were further analyzed. In vitro studies were designed to assess the effects of IFX in NETosis generation and the inflammatory profile triggered. RESULTS: Compared to HDs, neutrophils from r-axSpA patients displayed augmented spontaneous NET formation, elevated expression of NET-associated signaling components, nuclear peptidylarginine deiminase 4 translocation and increased citrullinated histone H3. Furthermore, patients exhibited altered circulating levels of cell-free NETosis-derived products (DNA, nucleosomes and elastase). Additional studies revealed that cell-free NETosis-derived products could be suitable biomarkers for distinguish r-axSpA patients from HDs. Correlation studies showed association between cell-free NETosis-derived products and clinical inflammatory parameters. Besides, nucleosomes displayed potential as a biomarker for discriminate patients according to disease activity. IFX therapy promoted a reduction in both NETosis generation and disease activity in r-axSpA patients. Mechanistic in vitro studies further unveiled the relevance of IFX in reducing NET release and normalizing the augmented inflammatory activities promoted by NETs in mononuclear cells. CONCLUSIONS: This study reveals that NETosis is enhanced in r-axSpA patients and identifies the NETosis-derived products as potential disease activity biomarkers. In addition, the data suggests the potential role of NET generation analysis for assessment of therapeutic effectiveness in r-axSpA.

Relationship between disease activity status or clinical response and patient-reported outcomes in patients with non-radiographic axial spondyloarthritis: 104-week results from the randomized controlled EMBARK study.

BACKGROUND: We assessed the external validity of composite indices Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Assessment in SpondyloArthritis international Society (ASAS) 40 response (ASAS40) by evaluating the correlations between the changes in some patient reported outcomes (PROs) for patients with non-radiographic axial spondyloarthritis (nr-axSpA) and the changes in the scores of the composite indices. METHODS: This was a post-hoc analysis of data from the EMBARK study in patients with nr-axSpA treated with etanercept. PROs were grouped according to ASDAS status (inactive [< 1.3], low [≥ 1.3 to < 2.1], high [≥ 2.1 to ≤3.5], and very high [> 3.5]), patient achievement of > 50% improvement in BASDAI (BASDAI50 responders), and > 40% improvement in ASAS (ASAS40 responders) at 104 weeks. Analyses were conducted on observed cases available at Week 104. Changes in PROs from Baseline to Week 104 were assessed using analysis of covariance with adjustment for baseline with linear contrast. RESULTS: Higher ASDAS disease activity at 104 weeks was associated with lower long-term improvement from baseline in PROs (e.g., total back pain [visual analog scale, cm (95% confidence interval): - 4.58 (- 4.95, - 4.21), - 3.86 (- 4.28, - 3.43), - 2.15 (- 2.68, - 1.61), and 1.30 (- 0.51, 3.12) for inactive, low, high, and very high ASDAS disease activity, respectively; Multidimensional Fatigue Inventory (MFI) general fatigue: - 4.77 (- 5.70, - 3.84), - 2.96 (- 4.04, - 1.87), - 1.00 (- 2.32, 0.31), and 2.14 (- 2.10, 6.38); all p < 0.001)]. BASDAI50 non-responders had less improvement in PROs from Baseline to Week 104 vs. responders (e.g., total back pain: - 1.61 (- 2.05, - 1.18) vs. -4.43 (- 4.69, - 4.18); MFI general fatigue: - 0.01 (- 1.12, 1.09) vs. -4.30 (- 4.98, - 3.62); all p < 0.001). ASAS40 non-responders also had less improvement in PROs from Baseline to Week 104 vs. responders (e.g., total back pain: - 1.91 (- 2.30, - 1.52) vs. -4.75 (- 5.05, - 4.46); MFI general fatigue: - 0.63 (- 1.56, 0.30) vs. -4.64 (- 5.37, - 3.91); all p < 0.001). CONCLUSION: Composite indices are valid for monitoring treatment response and adequately reflect treatment-related changes experienced by patients with nr-axSpA. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01258738. Registered 9 December 2010.