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

Interferon-alpha 1 expression indicates the disease activity and response of patients with ankylosing spondylitis to anti-TNF-α treatment

OBJECTIVES

This study aimed to investigate whether interferon-alpha 1 (IFNA1) is predictive of Ankylosing spondylitis (AS) progression and treatment response to Tumour necrosis factor inhibitors (TNFis).

METHODS

Data of 50 AS patients receiving TNFi for 24 weeks were retrospectively analysed. AS patients who reached the Assessment of Spondyloarthritis International Society 40 response at the W24 were classified as responders to TNFi treatment; otherwise, they were classified as nonresponders. Human fibroblast-like synoviocytes (HFLS) isolated from AS patients (AS-HFLS) were used for in vitro validation.

RESULTS

When the IFNA1 expression level was used to diagnose AS patients, an area under the curve of 0.895 was yielded (P < .001). Pearson correlation analysis showed negative correlations between IFNA1 expression, C-reactive protein (CRP) level, Bath AS Disease Activity Index scores, AS Disease Activity Score with CRP, and the production of inflammatory cytokines. An increased IFNA1 expression level was found to be associated with a better treatment response to TNFi. IFNA1 overexpression could protect HFLS against inflammatory response in the setting of AS.

CONCLUSIONS

Blood IFNA1 deficiency is correlated with inflammatory cytokine production and disease activity and is indicative of unsatisfied response to TNFi treatment in AS patients.

Costovertebral and costotransverse joint involvement in spondyloarthritis

OBJECTIVES

Costovertebral (CV), costotransverse (CTr), sternoclavicular (SC), and manubriosternal (MS) joints are impacted in spondyloarthritis (SpA) patients; however, clinical aspects of these involvements require additional evaluation.

METHODS

A total of 281 SpA patients who had undergone chest computed tomography (CT) for any reason between 2010 and 2020 were included in the study. SpA patients were divided into three groups, ankylosing spondylitis (AS), non-radiographic axial SpA, and psoriatic arthritis. Thirty age- and sex-matched rheumatoid arthritis (RA) patients and 30 non-rheumatic disease individuals were selected for comparison. An experienced radiologist reviewed 24 CV, 20 CTr, 2 SC, and 1 MS joints from a thorax CT for each patient. All joints were classified as: normal (0); suspicious (1), mild (2), moderate (3), or severe (4).

RESULTS

Total CV and CTr joint scores differed between diseases (p < .001). Male AS patients had higher CV and CTr scores than female AS patients (male CV score: 52 [range 0-96] and CTr score: 22 [range 0-80]; female CV score: 20 [range 0-96] and CTr score: 12 [range 0-79]). Strong negative correlations were detected in AS patients between chest expansion and CV (r = -0.703 p = .007) and CTr (r = -0.763 p = .002) joint involvement; positive correlations between CV and CTr joints, and modified Stoke Ankylosing Spondylitis Spinal Score (p < .05); and no significant association for MS and SC joints.

CONCLUSIONS

CV and CTr joint involvement on thorax CT was more severe in AS and negatively affected chest expansion. The use of thorax CT scans performed for other indications in the examination of these joints may be advantageous for the early beginning of rehabilitation programs targeted at maintaining chest mobility.

Association between changes in serum alkaline phosphatase levels and radiographic progression in ankylosing spondylitis

This retrospective study evaluated the electronic medical records of patients with ankylosing spondylitis (AS) (January 2001-December 2018) to determine the relationship between serum alkaline phosphatase (ALP) levels and radiographic changes over time. Longitudinal data, including serum ALP levels, were imputed by linear interpolation at 3-month intervals. Among the serum ALP levels calculated for 8 years prior to modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) measurement, those having the highest beta coefficient with the mSASSS were selected in the correlation between ALP and longitudinal mSASSS. Linear mixed models with the selected serum ALP levels, mSASSS, and clinical variables were investigated. We included 1122 patients (mean follow-up, 8.20 [standard deviation: 2.85] years). The serum ALP level from 5 years and 3 months prior showed the highest beta coefficient with the mSASSS. In the linear mixed model, the serum ALP level at 5 years and 3 months before radiographic changes was significantly associated with the mSASSS (β = 0.021, 95% confidence interval: 0.017-0.025, p < 0.001). Serum ALP levels measured approximately 5 years before may be a surrogate marker for predicting spinal radiographic changes. Long-term prospective clinical and experimental studies of > 5 years are required for biomarker discovery or therapeutic research on AS radiographic progression.

Syndesmophyte Growth in Ankylosing Spondylitis: from Laboratory to Bedside

PURPOSE OF REVIEW

This study aims to review recent studies on risk factors for syndesmophyte growth in ankylosing spondylitis (AS) and on treatment effects.

RECENT FINDINGS

New genetic studies, including a genome-wide association study, provided only limited evidence of specific genetic associations with radiographic severity. Measures of inflammation, including vertebral osteitis and C-reactive protein level, were strongly associated with radiographic progression, while studies of adipokines had mixed results. Mesenchymal stem cells from HLA-B27 positive AS patients were found to promote vertebral ossification via a pathway of B27 misfolding, retinoic acid receptor-β activation, and increased bone alkaline phosphatase. Low vertebral trabecular bone density is associated with syndesmophyte growth, with reciprocal effects when bridged. Several observational studies suggested radiographic severity was reduced by treatment with tumor necrosis factor inhibitors, particularly when longer than 2 years. Syndesmophyte development in AS is the result of a complex, incompletely understood, interplay of inflammatory and mechanical factors.

The relationship between long-term use of nonsteroidal anti-inflammatory drugs and kidney function in patients with ankylosing spondylitis

Objective

Although nonsteroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for ankylosing spondylitis (AS), their effect on kidney function remains unclear. This longitudinal study investigated the correlation between long-term NSAID use and kidney function in patients with AS using electronic medical records.

Methods

The electronic medical records of 1,280 patients with AS collected from a single center between January 2001 and December 2018 were reviewed. The Assessment of Spondyloarthritis International Society (ASAS) NSAID Intake Score was used to determine the cumulative dose of all NSAIDs prescribed for a different time intervals. Each ASAS NSAID Intake Score was obtained for intervals of 6 months, 1 year, 2 years, 3 years, 5 years, and 10 years. The correlation between the ASAS NSAID Intake Score and final estimated glomerular filtration rate (eGFR) for each interval was investigated.

Results

The mean ASAS Intake Scores for 6-month, 1-year, 2-year, 3-year, 5-year, and 10-year intervals were 55.30, 49.28, 44.84, 44.14, 44.61, and 41.17, respectively. At each interval, the pearson correlation coefficients were -0.018 (95% CI -0.031 to -0.006, p=0.004), -0.021 (95% CI -0.039 to -0.004, p=0.018), -0.045 (95% CI -0.071 to -0.019, p=0.001), -0.069 (95% CI -0.102 to -0.037, p<0.001), -0.070 (95% CI -0.114 to -0.026, p=0.002), -0.019 (95% CI -0.099 to 0.062, p=0.645), respectively. There was a very weak negative relationship between ASAS Intake Score and eGFR at each interval.

Conclusion

Long-term NSAID use did not correlate with kidney function based on real-world data in patients with AS.

Prediction of radiographic progression pattern in patients with ankylosing spondylitis using group-based trajectory modeling and decision trees

Objective

This study aimed to identify trajectories of radiographic progression of the spine over time and use them, along with associated clinical factors, to develop a prediction model for patients with ankylosing spondylitis (AS).

Methods

Data from the medical records of patients diagnosed with AS in a single center were extracted between 2001 and 2018. Modified Stoke Ankylosing Spondylitis Spinal Scores (mSASSS) were estimated from cervical and lumbar radiographs. Group-based trajectory modeling classified patients into trajectory subgroups using longitudinal mSASSS data. In multivariate analysis, significant clinical factors associated with trajectories were selected and used to develop a decision tree for prediction of radiographic progression. The most appropriate group for each patient was then predicted using decision tree analysis.

Results

We identified three trajectory classes: class 1 had a uniformly increasing slope of mSASSS, class 2 showed sustained low mSASSS, and class 3 showed little change in the slope of mSASSS but highest mSASSS from time of diagnosis to after progression. In multivariate analysis for predictive factors, female sex, younger age at diagnosis, lack of eye involvement, presence of peripheral joint involvement, and low baseline erythrocyte sedimentation rate (log) were significantly associated with class 2. Class 3 was significantly associated with male sex, older age at diagnosis, presence of ocular involvement, and lack of peripheral joint involvement when compared with class 1. Six clinical factors from multivariate analysis were used for the decision tree for classifying patients into three trajectories of radiographic progression.

Conclusion

We identified three patterns of radiographic progression over time and developed a decision tree based on clinical factors to classify patients according to their trajectories of radiographic progression. Clinically, this model holds promise for predicting prognosis in patients with AS.

The impact of smoking status on radiographic progression in patients with ankylosing spondylitis on anti-tumor necrosis factor treatment

Background

Ankylosing spondylitis (AS) is characterized by back pain which can lead to spinal ankylosis. Anti-tumor necrosis factor (TNF) dramatically alleviates symptoms, but spinal damage can still be progressive even during anti-TNF treatment. Smoking is a one of well-known risk factors for structural damage in AS. However, it has not been confirmed that smoking can affect radiographic progression even during anti-TNF treatment.

Objective

To investigate factors associated with radiographic progression during anti-TNF treatment with a focus on smoking status which is known as one of poor prognostic factors for AS.

Materials and methods

We conducted a retrospective cohort study of AS patients who began the first-line anti-TNF treatment between 2001 and 2018 according to availability of smoking data. All enrolled patients were observed until the last visit, the first-line anti-TNF discontinuation, or December 2019. Radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). The mSASSS progression rate (units/year) was calculated using the baseline mSASSS, the final mSASSS during observation period, and the duration between them. Univariable and multivariable logistic regression analyses were performed to identify associated factors of mSASSS progression rate > 1 unit/year.

Results

Among 459 AS patients, 185 (40.3%) patients were never smokers, 62 (13.5%) were ex-smokers and 212 (46.2%) were current smokers at baseline. Ex- and current smokers had higher mSASSS progression rates than never smokers [never smoker 0.1 (0.0–0.7), ex-smoker 0.6 (0.0–1.5), and current smoker 0.6 (0.0–1.5) units/year, P < 0.001]. In the multivariable logistic analysis, current smoking [adjusted odds ratio (OR) 1.69, 95% CI 1.01–2.82, P = 0.047] and higher baseline mSASSS [adjusted OR 1.03, 95% CI 1.01–1.04, P < 0.001] were associated with a mSASSS progression rate > 1 unit/year.

Conclusion

Current smoking is a modifiable risk factor for radiographic progression in patients with AS on anti-TNF treatment. Quitting smoking should be strongly recommended.