Evolution of radiographic damage in ankylosing spondylitis: a 12 year prospective follow-up of the OASIS study

OBJECTIVES

To describe the evolution of radiographic abnormalities of the spine in patients with ankylosing spondylitis (AS).

METHODS

Patients with AS were followed prospectively with 2 yearly radiographs for 12 years. The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) was scored by two readers (R1 and R2). New syndesmophytes at uninvolved vertebral corners were computed. Radiographic progression was investigated using generalised estimating equations.

RESULTS

809 radiographs (presenting 520 at 2 yearly intervals) from 186 patients (70% men, mean age 43 (SD 12) years, mean 20 (SD 12) years since symptom onset and 83% HLA-B27 positive) were included. Mean mSASSS at baseline was 11.6 (16.2). While the course of progression in individual patients was highly variable, and still occurred in patients with decades of symptom duration, mean 2 year progression was 2.0 (3.5) mSASSS units. Over the entire follow-up, at least one new syndesmophyte was found in 55% (R1) and 63% (R2) of patients (38% (R1) and 39% (R2) of all intervals). In 24% of patients (39% of intervals), there was no progression. A progression ≥5 mSASSS units occurred in 22% of patients (or in 12% of intervals). At the group level, a linear time course model fitted the data best, with a constant rate over the entire 12 year interval of 0.98 mSASSS units/year. Radiographic progression occurred significantly faster in men, in HLA-B27 positive patients and in patients with a baseline mSASSS≥10.

CONCLUSIONS

Long term radiographic progression in AS is highly variable in the individual patient, more severe in HLA-B27 positive men and still occurs after decades of disease. At the group level, however, progression in AS follows an approximately linear course.

Modified stoke ankylosing spondylitis spinal score as an outcome measure to assess the impact of treatment on structural progression in ankylosing spondylitis

In ankylosing spondylitis (AS), structural damage that occurs as a result of syndesmophyte formation and ankylosis of the vertebral column is irreversible. Structural damage is currently assessed by conventional radiography and scoring systems that reliably assess radiographic structural damage are needed to capture the differential effects of drugs on structural damage progression. The validity of the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) as a primary outcome measure in evaluating the effect of AS treatments on radiographic progression rates was assessed in this review. The mSASSS has not been used, to date, as a primary outcome measure in a prospective randomized controlled clinical trial of biologic therapy in AS. This review of the medical literature confirmed that the mSASSS is the most validated and widely used method for assessing radiographic progression in AS, correlating with worsening measures of disease signs and symptoms, spinal mobility and physical function, with a 2-year interval being required to ensure sufficient sensitivity to change.

Serum levels of Dkk-1, sclerostin and VEGF in patients with ankylosing spondylitis and their association with smoking, and clinical, inflammatory and radiographic parameters

OBJECTIVE

To evaluate serum Dickkopf-1 (Dkk-1), sclerostin and vascular endothelial growth factor (VEGF) levels in patients with ankylosing spondylitis (AS) compared to healthy controls as well as their association with smoking, and clinical, inflammatory and radiographic parameters.

METHODS

Serum samples for total Dkk-1, sclerostin and VEGF were obtained from 57 tumour necrosis factor (TNF) inhibitor naïve patients with AS and 34 sex-, age- and body mass index (BMI)-matched controls. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), modified Stroke AS Spine Score (mSASSS) and smoking status were assessed for each patient.

RESULTS

There was no significant difference in serum bone metabolism markers between AS patients and controls. Dkk-1 levels were significantly (P<0.05) higher in AS patients with elevated ESR and CRP and no syndesmophytes, and were significantly (P<0.001) correlated with sclerostin levels (r=0.592). VEGF levels were significantly (P<0.05) higher in AS patients with current and ever smoking, elevated ESR and CRP, and high BASDAI and BASFI, and were significantly (P<0.05) correlated with ESR (r=0.284), CRP (r=0.285), BASDAI (r=0.349) and BASFI (r=0.275). In multivariate regression analyses, high Dkk-1 levels were significantly (P≤0.001) associated with elevated ESR and CRP, no syndesmophytes and high sclerostin levels, and high VEGF levels significantly (P<0.05) with ever smoking, and elevated ESR and CRP.

CONCLUSION

In AS, serum Dkk-1 concentrations appear to be related not only to syndesmophyte formation but also to systemic inflammation. Furthermore, high VEGF levels may be associated with smoking exposure.

Predictors of Assessment of Spondyloarthritis International Society (ASAS) Health Index in Axial Spondyloarthritis and Comparison of ASAS Health Index between Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis: Data from the Catholic Axial Spondyloarthritis COhort (CASCO)

The Assessment of Spondyloarthritis International Society (ASAS) health index (HI) is a novel tool for approaching disability, health, and functioning in spondyloarthritis (SpA). In the present study we compared ASAS HI between patients with ankylosing spondylitis (AS) and those with nonradiographic axial SpA (nr-axSpA). In addition, we identified predictors of ASAS HI. We designed this cross-sectional study using data from the Catholic Axial Spondyloarthritis COhort (CASCO), a prospective cohort from a single tertiary hospital. We compared baseline characteristics, including ASAS HI, between AS and nr-axSpA, and determined the frequency of each item constituting the ASAS HI. We used linear regression analysis to identify factors associated with ASAS HI. Total of 357 patients with axSpA-261 with AS and 96 with nr-axSpA-were included in analysis. AS patients were older and had higher ASAS HI than nr-axSpA. Among ASAS HI items, pain (item No. 1) and energy/drive (item No. 5) were the most common areas for which axSpA patients experienced discomfort. ASAS HI correlated with other SpA-related parameters such as BASDAI, ASDAS, and BASFI. Multivariable regression analysis of the axSpA group showed that high NSAID intake and mSASSS were positively associated with ASAS HI, whereas higher economic status and alcohol consumption were negatively associated with ASAS HI. Results were consistent in the AS group on subgroup analysis, whereas alcohol consumption was the only factor significantly associated with ASAS HI in the nr-axSpA group. In the present cohort study, patients with AS had poorer health status (higher ASAS HI) than those with nr-axSpA. Items proposed by AS patients (items No. 1 and 5) were the most frequently checked areas as axSpA patients feel discomfort, and this support that ASAS HI could practically assess actual discomfort of axSpA patient. ASAS HI was well correlated with known disease parameters, including activity, function, and quality of life; therefore, ASAS HI could be used in the future to represent the health status of SpA in a systematic way. Spinal structural damage (higher mSASSS), high NSAID intake, alcohol consumption, and economic status were predictors of ASAS HI in patients with axSpA, especially those with AS.

Alcohol consumption as a predictor of the progression of spinal structural damage in axial spondyloarthritis: data from the Catholic Axial Spondyloarthritis COhort (CASCO)

BACKGROUND

The purpose of the present study was to demonstrate whether alcohol consumption could predict spinal structural damage in axial spondyloarthritis (axSpA) in a prospective cohort study.

METHODS

AxSpA patients were enrolled from a single tertiary hospital in a prospective cohort. Baseline data were collected, and 2-year follow-up radiographic data were collected. We analyzed the progression of spinal structural damage in 278 axSpA patients and grouped them into alcohol drinkers and non-drinkers. Baseline and follow-up characteristics were compared between the two groups. Univariable and multivariable logistic regression analyses were performed to reveal predictors of spinal structural damage.

RESULTS

Changes in modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) and syndesmophyte count over the 2-year period were more prominent in the alcohol drinker group than in the non-drinker group (2.7 ± 3.6 vs 1.5 ± 2.8, P = 0.007, 0.9 ± 1.3 vs 0.4 ± 1.2, P = 0.003). The alcohol drinker group showed more frequent significant mSASSS changes (≥ 2 units for 2 years follow-up) and new syndesmophyte/progression of pre-existing syndesmophytes than the non-drinker group (60.7% vs 29.2%, P < 0.001, 51.5% vs 26.4%, P < 0.001, respectively). On univariable and multivariable regression analyses, drinking alcohol showed a significant relationship with the progression of spinal structural damage for both mSASSS and syndesmophyte progression.

CONCLUSION

The present study showed the association between alcohol consumption and spinal structural progression in axSpA patients for the first time.

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.

Analysis of risk factors for sagittal translation after pedicle subtraction osteotomy in patients with ankylosing spondylitis

BACKGROUND CONTEXT

Sagittal translation, a potential complication of pedicle subtraction osteotomy (PSO), can result in neurologic damage. However, few studies have been conducted on sagittal translation and its risk factors after PSO in patients with ankylosing spondylitis (AS).

PURPOSE

We aimed to report cases of sagittal translation that developed after PSO in patients with AS with kyphotic deformity and to analyze risk factors for sagittal translation.

STUDY DESIGN

A retrospective case-control study was carried out.

PATIENT SAMPLE

This study included 53 patients (58 cases) with AS who underwent PSO to correct their kyphotic deformity.

OUTCOME MEASURES

The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) was measured before the surgery. Radiological pelvic and sagittal parameters were also measured before and after surgery. Developments of sagittal translation were confirmed with intraoperative radiograph.

METHODS

The subjects were grouped according to the presence (ST group) and absence (non-ST group) of sagittal translation. The demographic and radiological parameters were compared between two groups. Through multivariate logistic regression analysis, the correlations between sagittal translation and relevant parameters were analyzed for risk factor evaluation.

RESULTS

Sagittal translation developed in 16 patients (30.2%) [16 cases (27.6%)]. The mean lumbar lordosis angle and sagittal vertical axis of both ST group and non-ST group were successfully corrected. In a comparison of two groups, the ST group (58.2±13.3) showed a significantly higher mSASSS than the non-ST group (33.9±11.9) (p<.001). The ST group (50.4°±7.8°, 16.9°±6.8°) also showed a significantly higher preoperative pelvic incidence and sacral slope than the non-ST group (45.3°±7.2°, 11.0°±7.7°) (p=.026, p=.011). No significant differences were observed between the two groups for the rest of radiological parameters. In multivariate analysis, only mSASSS was positively correlated with sagittal translation (odds ratio 1.16, p=.001).

CONCLUSION

The incidence of sagittal translation after PSO was closely related with severity of ankylosis in patients with AS. Therefore, surgeons must consider sagittal translation, which could induce neurologic complications, when PSO is performed for patients with AS with severe ankylosis.

Association of neuropathic-like pain characteristics with clinical and radiographic features in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic, progressive, and inflammatory disorder and causes chronic back pain. It is not unusual for patients with AS to have symptoms similar to neuropathic pain. We aimed to investigate the neuropathic pain (NeP) component in patients with AS using the painDETECT questionnaire (PD-Q) and to assess the relation between NeP and the disease characteristics of AS. A single-center prospective study was performed, including 105 patients. Patients with AS completed three questionnaires: PD-Q, Beck Depression Inventory (BDI), and Euro Quality of Life (EQ-5D) questionnaires. Patients were classified into three groups according to the PD-Q scores: nociceptive pain (NoP) (score ≤ 12), mixed pain (MP) (score 13-18), and NeP pain (score ≥ 19). Fifteen patients (14.2%) were classified into the NeP group, 22 (21.0%) in the MP group, and 68 (64.8%) in the NoP group. The questionnaires and clinical and radiographic findings were analyzed. Patients with NeP and MP scored worse on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI); BDI; modified Stoke Ankylosing Spondylitis Spine Score; pain-visual analog scale (VAS); and EQ-5L index and showed an increased prevalence of enthesitis and peripheral arthritis. There were no differences in objective inflammatory markers. PD-Q scores were positively correlated with pain-VAS, BASDAI, BDI, and inversely correlated with EQ-5D index. Age, BASDAI, presence of current enthesitis, and BDI score were independently associated with PD-Q scores. The findings showed that NeP component in AS was associated with age, high disease activity, presence of current enthesitis, and depression.

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.

A pilot study on deep learning-based grading of corners of vertebral bodies for assessment of radiographic progression in patients with ankylosing spondylitis

Background

Radiographs are widely used to evaluate radiographic progression with modified stoke ankylosing spondylitis spinal score (mSASSS).

Objective

This pilot study aimed to develop a deep learning model for grading the corners of the cervical and lumbar vertebral bodies for computer-aided detection of mSASSS in patients with ankylosing spondylitis (AS).

Methods

Digital radiographic examination of the spine was performed using Discovery XR656 (GE Healthcare) and Digital Diagnost (Philips). The disk points were detected between the bodies using a key-point detection deep learning model from the image obtained in DICOM (digital imaging and communications in medicine) format from the cervical and lumbar spinal radiographs. After cropping the vertebral regions around the disk point, the lower and upper corners of the vertebral bodies were classified as grade 3 (total bony bridges) or grades 0, 1, or 2 (non-bridges). We trained a convolutional neural network model to predict the grades in the lower and upper corners of the vertebral bodies. The performance of the model was evaluated in a validation set, which was separate from the training set.

Results

Among 1280 patients with AS for whom mSASSS data were available, 5,083 cervical and 5245 lumbar lateral radiographs were reviewed. The total number of corners where mSASSS was measured in the cervical and lumbar vertebrae, including the upper and lower corners, was 119,414. Among them, the number of corners in the training and validation sets was 110,088 and 9326, respectively. The mean accuracy, sensitivity, and specificity for mSASSS scoring in one corner of the vertebral body were 0.91604, 0.80288, and 0.94244, respectively.

Conclusion

A high-performance deep learning model for grading the corners of the vertebral bodies was developed for the first time. This model must be improved and further validated to develop a computer-aided tool for assessing mSASSS in the future.

Both structural damage and inflammation of the lumbar spine contribute to the sagittal imbalance in ankylosing spondylitis patients with thoracolumbar kyphosis

Background

The relationship between structural damage and inflammation of the spine and the sagittal imbalance in ankylosing spondylitis (AS) is not well understood. The present study aimed to investigate the correlation between structural damage and inflammation of the lumbar spine and the sagittal imbalance in AS patients with thoracolumbar kyphosis.

Methods

Forty-five AS patients with thoracolumbar kyphosis were retrospectively reviewed. Six sagittal spinal parameters, including the C7 tilt (C7T), spino-sacral angle (SSA), global kyphosis (GK), the sagittal vertical axis (SVA), thoracic kyphosis (TK), and lumbar lordosis (LL), were measured. Structural damage of the lumbar spine was assessed by the modified Stoke AS Spine Score (mSASSS) on radiographs. Lumbar spinal inflammation was evaluated by the AS spinal magnetic resonance imaging (MRI) activity (ASspiMRI-a) on MRI. Correlation analysis was performed using the paired sample t-test. Multivariable linear regression models were constructed to analyze the contributions of mSASSS and ASspiMRI-a to the sagittal parameters.

Results

The average values of the sagittal parameters C7T, SSA, GK, SVA, TK, and LL were 68.1°, 80.1°, 77.3°, 168.7 mm, 47.7°, and -0.7°, respectively. The average mSASSS and ASspiMRI-a scores were 9.8 and 10.8, respectively. Correlation analysis showed that the mSASSS and ASspiMRI-a were correlated with C7T, SSA, SVA, and LL (the Spearman correlation coefficients were -0.439, -0.390, 0.424, and 0.530 for mSASSS; -0.406, -0.402, 0.378, and 0.486 for ASspiMRI-a; P<0.05). The C7T, SSA, and SVA were significantly correlated with LL (r=-0.696, -0.779, and 0.633, respectively; P<0.05). There was a weak correlation between the mSASSS and ASspiMRI-a (β=0.299, P=0.046). The multivariable regression models indicated that the sagittal imbalance was determined to a greater extent by the mSASSS than ASspiMRI-a (the β values were -1.550 vs. -0.649 for C7T, -1.865 vs. -1.231 for SSA, 9.161 vs. 3.823 for SVA, and 3.128 vs. 1.717 for LL).

Conclusions

Both structural damage and inflammation of the lumbar spine contributed to the sagittal imbalance in AS patients with thoracolumbar kyphosis. In the late stages of AS, the sagittal imbalance was more attributable to the structural damage than the inflammation of the lumbar spine.

High melatonin levels are related to spinal ossification in patients with ankylosing spondylitis

Objectives: To investigate associations of serum melatonin with spinal ossification and cytokines in ankylosing spondylitis (AS).Methods: Serum was obtained from 52 AS patients and 25 healthy controls. Melatonin was measured by ELISA kit; bone morphogenetic protein (BMP)-2, dickkopf-related protein (Dkk)-1, IL-1β, IL-6, IL-17 and TNF-α concentrations were assayed using Luminex multiplex bead system. Osteocalcin and β isomer of C-terminal telopeptide of type I collagen (β-CTX) were measured using electrochemiluminescence immunoassay. Spinal damages were assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) on radiographs.Results: Serum melatonin was significantly increased in AS patients. Serum melatonin correlated positively with mSASSS after multivariate adjustment for age and disease duration (r = 0.70, p < .01). Patients with spinal bone bridge have higher levels of melatonin than those without spinal bone bridge [16.69 (4.65, 41.10) pg/ml vs. 7.43 (3.29, 15.30) pg/ml, p = .03]. The multiple linear regression analysis found that melatonin was a risk factor for spinal bone formation (β = 0.35, p < .05). Additionally, melatonin correlated positively with osteocalcin (r = 0.34, p = .04) and IL-1β (r = 0.39, p = .04) in AS.Conclusion: Melatonin is increased in AS patients, especially in patients with spinal bone bridge. It suggests that melatonin may play an important role in the pathological osteogenesis of AS.

Incorporation of the anteroposterior lumbar radiographs in the modified Stoke Ankylosing Spondylitis Spine Score improves detection of radiographic spinal progression in axial spondyloarthritis

Background

To evaluate the performance of the extended modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) incorporating information from anteroposterior (AP) lumbar radiographs as compared to the conventional mSASSS in detection of radiographic spinal progression in patients with axial spondyloarthritis (axSpA)

Methods

A total of 210 patients with axSpA, 115 with radiographic axSpA (r-axSpA), and 95 with non-radiographic axSpA (nr-axSpA), from the GErman SPondyloarthritis Inception Cohort (GESPIC), were included in the analysis based on the availability of spinal radiographs (cervical spine lateral, lumbar spine lateral, and AP views), at baseline and year 2. Two trained readers independently scored lateral cervical and lumbar spine images according to the mSASSS system (0–3 per vertebral corner, 0–72 in total). In addition, all vertebral corners of vertebral bodies visible on lumbar AP radiographs (lower T12 to upper S1) were assessed according to the same scoring system that resulted in a total range for the extended mSASSS from 0 to 144. Reliability and sensitivity to detect radiographic spinal progression of the extended mSASSS as compared to the conventional mSASSS were evaluated.

Results

The reliability of conventional and extended scores was excellent with intraclass correlation coefficients (ICCs) of 0.926 and 0.927 at baseline and 0.920 and 0.933 at year 2, respectively. The mean ± SD score for mSASSS and extended mSASSS at baseline were 4.25 ± 8.32 and 8.59 ± 17.96, respectively. The change score between baseline and year 2 was 0.73 ± 2.34 and 1.19 ± 3.73 for mSASSS and extended mSASSS, respectively. With the extended mSASSS, new syndesmophytes after 2 years were detected in 4 additional patients, new syndesmophytes or growth of existing syndesmophytes in 5 additional patients, and progression by ≥ 2 points in the total score in 14 additional patients meaning a 25%, 28%, and 46% increase in the proportion of patients with progression according to the respective definition as compared to the conventional score.

Conclusions

Incorporation of lumbar AP radiographs in the assessment of structural damage in the spine resulted into detection of additional patients with radiographic spinal progression not captured by the conventional mSASSS score.

Nephrolithiasis in ankylosing spondylitis and its relationship with disease assessment scales

OBJECTIVE:

The aim of this study was to investigate the frequency of renal calculi in patients with ankylosing spondylitis (AS) and to determine its relationship with disease assessment variables.

METHODS:

The study was designed retrospectively, and it included a cohort of 320 patients with AS diagnosed using the Modified New York Criteria. A total of 119 patients who underwent renal ultrasonography (USG), in who the erythrocyte sedimentation rate, C-reactive protein, blood calcium, phosphorus, Vitamin D, parathormone, and urinary calcium excretion were measured, and who also had lateral cervical and lumbar radiography in the same time period were extracted from the cohort. All patients’ demographic characteristics and the results of blood and urine tests were recorded. The Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Mobility Index (BASMI), and Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) were evaluated in all patients.

RESULTS:

Thirteen of the 119 patients had renal calculi confirmed by USG data. The frequency of nephrolithiasis detected by USG was 10.9% in patients with AS. The disease lasted significantly longer in patients with renal calculi ([nephrolithiasis (+): 18.39±8.72 years; nephrolithiasis (−): 12.02±8.43 years, p=0.01]). The BASMI total score was significantly higher in the group of patients with renal calculi. There was not any significant difference in terms of blood samples, HLA-B27, BASDAI, BASFI, and mSASSS between groups.

CONCLUSION:

The frequency of renal stones is increased in patients with AS compared to healthy population. Especially patients who had AS for a long time and higher BASMI values are more susceptible to renal calculi. It is important to point out that the results of this type of studies would be more reliable if the study is conducted on large patient groups and population-based prevalence.

Which Metrological Index-the BASMI or EDASMI-is Best Correlated With Disease-Related Parameters in Spondylarthritis Patients?

OBJECTIVE

To compare the Edmonton Ankylosing Spondylitis Metrology Index (EDASMI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) to determine which of the two is best correlated with disease-related parameters in axial spondyloarthritis (axSpA) patients.

METHODS

A cross-sectional study was made of 86 patients with radiographic axSpA. Sociodemographic data, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Ankylosing Spondylitis Disease Activity Score (ASDAS), the Bath Ankylosing Spondylitis Functional Index (BASFI), and the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire were applied. Spinal mobility was assessed by two indices: the BASMI and the EDASMI. Structural damage of the spine was also evaluated by two indices: the Bath Ankylosing Spondylitis Radiology Index (BASRI) and the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS).

RESULTS

Eighty-six patients with an average age of 43.21 ± 11.43 years (20-79) were included. Impaired spinal mobility, which corresponds to higher BASMI scores, was correlated with prolonged disease duration (p < 0.01, r = 0.310), higher ASDAS-CRP (p < 0.001, r = 0.386), severe functional disability on the BASFI (p < 0.01, r = 0.505) and poorer quality of life according to the ASQoL (p < 0.01, r = 0.369). However, the EDASMI score did not correlate with any disease parameter. The BASMI was correlated with the total BASRI (p < 0.01, r = 0.634) and mSASSS (p < 0.01, r = 0.388). Unlike the BASMI, the EDASMI was neither correlated with the BASRI (p = 0.520, r = 0.245) nor the mSASSS (p = 0.252, r = -0.120).

CONCLUSION

Our results indicate that among the studied metrological indices, the BASMI is more contributory since it is correlated with clinical disease parameters and structural damage, unlike the EDASMI.

The role of LCN2 and LCN2-MMP9 in spondylitis radiographic development: gender and HLA-B27 status differences

Background

Male HLA-B27-positive radiographic-axial spondyloarthritis (r-axSpA) patients are prone to have severe spinal radiographic progression, but the underlying mechanisms are unclear. We recently showed that persistently elevated Lipocalin 2 (LCN2; L) reflects sacroiliac joint (SIJ) inflammation. LCN2 binds to MMP9. Concomitant elevation of L and LCN2-MMP9 (LM) was detected in many inflammatory diseases. We asked whether L and LM play similar roles in r-axSpA pathogenesis.

Methods

We analyzed 190 axSpA patients (123 radiographic and 67 non-radiographic axSpA) who had no detectable circulating Oncostatin M, to avoid complications due to cross-talk between pathways. L and LM levels from a single blood sample of each patient were measured and were correlated with MRI and modified stoke AS (mSASS) scoring. Association of elevated L (L+) or concurrent L+ and elevated LM (LM+) patterns with B27 status and gender were assessed.

Results

In L+LM+ axSpA patients, both L and LM levels correlated with MRI SPARCC SIJ scores, but only LM levels correlated with MRI Berlin Spine Scores, suggesting LM is a biomarker for both SIJ and spinal inflammation. Among patients with minimal spinal ankylosis (mSASSS < 10), 65% of male r-axSpA patients are L+LM+, while 30% and 64% of female patients are L+LM+ and L+, respectively, supporting the role of LM with disease progression. In B27+ L+LM+ male patients, both L and LM (but not CRP) levels correlate with mSASSS. B27 positivity and maleness have additive effects on spondylitis progression, suggesting concurrent high L and LM elevations are associated with B27+ male patients having more significant radiographic damage. L+ B27-negative male patients or L+ female patients are more likely to have milder disease.

Conclusion

L and LM are informative biomarkers for SIJ and spinal inflammation, as well as for ankylosing development in r-axSpA patients. Distinctive L+LM+ or L+ patterns not only could distinguish clinically aggressive vs milder course of disease, respectively, but also provide an explanation for B27-positive male patients being the most susceptible to severe ankylosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02854-2.

Elucidation of factors influencing spinal ankylosis in patients with axial spondyloarthritis

OBJECTIVES

Spondyloarthritis encompasses conditions such as ankylosing spondylitis and psoriatic arthritis. Advanced axial spondyloarthritis causes significant spinal fusion, affecting daily activities. Recent therapeutic agents have enhanced the control of inflammation, yet they do not consistently stop the axial progression. This study aimed to identify factors influencing the progression of axial lesions over a 2-year period in Japanese patients with axial spondyloarthritis.

METHODS

This retrospective and cross-sectional study included 47 axial spondyloarthritis patients. Spinal lesions were assessed using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Patients were categorized into progressive and nonprogressive groups based on changes in their mSASSS scores. Various clinical parameters were analysed for correlation with ankylosis progression.

RESULTS

The study found no significant correlation between ankylosis progression and traditional factors, including the level of inflammation or the use of biologics. However, modified Health Assessment Questionnaire scores were associated with disease progression. The baseline mSASSS was another significant factor, underscoring the importance of early detection and management.

CONCLUSIONS

This study showed that patient-reported outcomes and baseline mSASSS scores are crucial for assessing axial spondyloarthritis progression. This underscores the need for a comprehensive treatment strategy that addresses both clinical indicators and patient-reported outcomes.

An optimal deep learning model for the scoring of radiographic damage in patients with ankylosing spondylitis

Background

Detecting vertebral structural damage in patients with ankylosing spondylitis (AS) is crucial for understanding disease progression and in research settings.

Objectives

This study aimed to use deep learning to score the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) using lateral X-ray images of the cervical and lumbar spine in patients with AS in Asian populations.

Design

A deep learning model was developed to automate the scoring of mSASSS based on X-ray images.

Methods

We enrolled patients with AS at a tertiary medical center in Taiwan from August 1, 2001 to December 30, 2020. A localization module was used to locate the vertebral bodies in the images of the cervical and lumbar spine. Images were then extracted from these localized points and fed into a classification module to determine whether common lesions of AS were present. The scores of each localized point were calculated based on the presence of these lesions and summed to obtain the total mSASSS score. The performance of the model was evaluated on both validation set and testing set.

Results

This study reviewed X-ray image data from 554 patients diagnosed with AS, which were then annotated by 3 medical experts for structural changes. The accuracy for judging various structural changes in the validation set ranged from 0.886 to 0.985, whereas the accuracy for scoring the single vertebral corner in the test set was 0.865.

Conclusion

This study demonstrated a well-trained deep learning model of mSASSS scoring for detecting the vertebral structural damage in patients with AS at an accuracy rate of 86.5%. This artificial intelligence model would provide real-time mSASSS assessment for physicians to help better assist in radiographic status evaluation with minimal human errors. Furthermore, it can assist in a research setting by offering a consistent and objective method of scoring, which could enhance the reproducibility and reliability of clinical studies.

Relationship between spinal structural damage and sagittal balance in axial spondyloarthritis: Is the thoracic spine the starting point?

OBJECTIVES

To assess the relationship between spinal structural damage, sagittal balance parameters and spine curvatures in patients with axial spondyloarthritis (axSpA).

MATERIAL AND METHODS

In this cross-sectional study, the pelvic and sagittal balance parameters were obtained through EOS® (Biospace, Paris, France). Patients were divided into three groups according to the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) tertiles (G1 ≤6, n = 36; G2: 6.1-31, n = 36; G3 >31, n = 35) and pelvic and sagittal parameters were compared across them. Multivariable regression analysis was performed to analyze the impact of spinal structural damage and of other factors on sagittal vertical axis (SVA), an important sagittal balance parameter.

RESULTS

A total of 107 patients was included. G2 and 3 exhibited higher mean values of thoracic kyphosis T1-T12 when compared to G1 (10.5°(12.3) vs. 22.3°(17.3) vs. 35.2°(14.6), p < 0.001), and G3 demonstrated lumbar L1-S1 straightening compared to the other groups (55.7°(9) and 50.7°(19.8), G1 and G2, respectively, vs. 35.7°(13.2), p < 0.001). Mean SVA values showed an increasing gradient from G1 to G3 (21.6(25.1) vs. 41(44.3) vs. 84.3(47.2)mm, p < 0.001). In the multivariable regression, a one-unit increase in total mSASSS was associated with an average 0.8 mm higher SVA.

CONCLUSIONS

Our data showed that more spinal structural damage is associated with a higher SVA, reflecting poorer sagittal balance. Patients with increasing spinal damage have an important increase in thoracic kyphosis suggesting that postural modifications in patients with axSpA might have their origin in the thoracic spine.