Radiographic Damage In Ankylosing Spondylitis Research Articles

Clinical and genetic factors associated with radiographic damage in patients with ankylosing spondylitis

ObjectivesTo identify clinical and genetic factors associated with severe radiographic damage in patients with ankylosing spondylitis (AS).MethodsWe newly generated genome-wide single nucleotide polymorphism data (833K) for 444 patients with AS....

A latent class based imputation method under Bayesian quantile regression framework using asymmetric Laplace distribution for longitudinal medication usage data with intermittent missing values

ABSTRACTEvaluating the association between diseases and the longitudinal pattern of pharmacological therapy has become increasingly important. However, in many longitudinal studies, self-reported medication usage data collected at patients’ follow-up visits could be missing for various reasons. These pieces of missing or inaccurate/untenable information complicate determining the trajectory of medication use and its complete effects for patients. Although longitudinal models can deal with specific types of missing data, inappropriate handling of this issue can lead to a biased estimation of regression parameters especially when missing data mechanisms are complex and depend upon multiple sources of variation. We propose a latent class-based multiple imputation (MI) approach using a Bayesian quantile regression (BQR) that incorporates cluster of unobserved heterogeneity for medication usage data with intermittent missing values. Findings from our simulation study indicate that the proposed method performs better than traditional MI methods under certain scenarios of data distribution. We also demonstrate applications of the proposed method to data from the Prospective Study of Outcomes in Ankylosing Spondylitis (AS) cohort when assessing an association between longitudinal nonsteroidal anti-inflammatory drugs (NSAIDs) usage and radiographic damage in AS, while the longitudinal NSAID index data are intermittently missing.

Morphometric Vertebral Assessments via the Use of Dual X-ray Absorptiometry for the Evaluation of Radiographic Damage in Ankylosing Spondylitis: A Pilot Study

We performed a pilot study to compare vertebral fracture assessments (VFA) and lateral X-rays in terms of inter- and intraobserver reliability and degree of correlation for the detection of syndesmophytes in ankylosing spondylitis (AS). We recruited 19 patients with AS and recent lumbar or cervical lateral X-rays with at least one syndesmophyte. Each patient underwent dual-energy X-ray absorptiometry with measurement of bone mineral density and dorso-lumbar VFA. Intra- and interreader reliability for VFA and X-rays were measured using 2 independent, blinded observers and Cohen's kappa values. An adapted modified Stoke Ankylosing Spondylitis Spinal Score (amSASSS) was generated with each method, and these 2 values correlated. For X-rays, intraobserver and interobserver agreement were 94.3% (κ = 0.83) and 98.6% (κ = 0.96), respectively; for VFA, corresponding values were 92.8% (κ = 0.79) and 93.8% (κ = 0.82). Overall agreement between the 2 techniques was 88.6% (κ = 0.72). The Pearson correlation coefficient for the 2 methods was 0.95 for the modified Stoke Ankylosing Spondylitis Spinal Score . Per dual-energy X-ray absorptiometry−generated bone mineral density, >50% of patients were osteopenic and 10% osteoporotic. In terms of reproducibility and correlation with X-rays, performing a VFA appears to be a candidate for assessing radiographic damage in AS, thought further research is necessary to justify this indication.

FRI0294 Feasibility of radiographic damage scores in ankylosing spondylitis

BackgroundRadiographic damage is one of the core outcomes in Ankylosing Spondylitis (AS) and it is usually assessed with the modified Stoke AS Spine Score (mSASSS). Another score has recently been...

Principal Bid vs. Agency Trading

<h3>Background</h3> Bone formation and bone loss are both present in ankylosing spondylitis (AS). New bone formation can lead to the formation of syndesmophytes, ankylosis of the spine and sacroiliac joints, and bone formations on enthesal sites. <h3>Objectives</h3> To investigate the relation between the presence of syndesmophytes and bone turnover markers (BTM) in AS patients with active disease. <h3>Methods</h3> 55 consecutive outpatients with AS based on the modified New York criteria (n=54) or the ASAS criteria for axial spondyloarthritis (n=1) and active disease defined by Bath AS Disease Activity Index (BASDAI) ≥4 (range 0-10) or based on expert opinion were included. Patients with recent fractures, use of bisphosphonates, and/or inflammatory bowel disease were excluded. The lateral view of radiographs of the cervical and lumbar spine were blinded and scored for the presence of syndesmophytes at the anterior corners of the vertebrae by two independent observers. In case of discrepancy between the two observers, there was a consensus meeting afterwards. Markers of bone formation procollagen type 1 N-terminal peptide (PINP) and bone-specific alkaline phosphatase (BALP), and marker of bone resorption serum collagen-telopeptide (sCTX) were measured. Z-scores of BTM were calculated using matched 10-years-cohorts of a Dutch reference group (200 men or 350 women) to correct for the normal influence that age and gender have on bone turnover. <h3>Results</h3> Mean age of the 55 AS patients was 40.4 years (SD ± 11.2), median duration of symptoms was 15 years (range 3-46), median time since diagnosis was 5 years (range 0-27), mean BASDAI was 6.1 (SD ± 1.8), and 58% were male. Syndesmophytes were present in 33 of the 55 (60%) patients. Patients with syndesmophytes had significantly higher levels of PINP (median Z-score: 0.41 vs. -0.17, p=0.005) and sCTX (median Z-score: -0.02 vs. -0.58, p=0.025) than patients without syndesmophytes. No significant differences were found in BALP (median Z-score: 1.56 vs. 0.67, p=0.213) and BASDAI (mean: 6.2 vs. 5.9, p=0.581) between patients with and without syndesmophytes. <h3>Conclusions</h3> This cross-sectional analysis in AS patients with active disease shows that markers of both bone formation (PINP) and bone resorption (sCTX) are significantly higher in patients with syndesmophytes compared to patients without syndesmophytes. Further longitudinal studies are needed to investigate whether BTM can serve as potential biomarkers for radiographic damage in AS. <h3>Disclosure of Interest</h3> None Declared