Development and preliminary validation of the spondyloarthritis research consortium of Canada magnetic resonance imaging sacroiliac joint structural score

Infectious sacroiliitis: MRI- and CT-based assessment of disease extent, complications, and anatomic correlation

OBJECTIVE

To describe the frequency of MR and CT features of infectious sacroiliitis (ISI) and assess its extent and complications MATERIALS AND METHODS: This retrospective study included patients with ISI who were evaluated between 2008 and 2021 in a single center. Two radiologists reviewed MRI and CT images to determine the anatomical distribution (unilateral/bilateral, iliac/sacral bone, proximal/middle/distal), severity (bone marrow edema [BME]/periostitis/erosions), concurrent infection (vertebral/nonvertebral), and complications (abscess/probable adjacent osteomyelitis/cavitation/devitalized areas/sequestrum/pelvic venous thrombosis) of ISI. Interobserver reproducibility was assessed. Correlation analysis evaluated the effect of the causative microorganism on severity. Two human bodies were dissected to outline possible ways that ISI can spread.

RESULTS

Forty patients with ISI (40 years ± 22; 26 women) were evaluated. Ten patients had bilateral ISI. Concurrent vertebral infection was associated in 15% of cases. Reproducibility of sacral BME, periostitis, and reactive locoregional abnormalities was perfect (κ = 1). Reproducibility was low for erosion count (κ = 0.52[0.52-0.82]) and periarticular osteopenia (κ = 0.50[0.18-0.82]). Inflammatory changes were BME (42/42 joints), muscle edema (38/42), and severe periostitis along the ilium (33/37). Destructive structural changes occurred with confluent erosions (iliac, 20/48; sacral, 13/48), sequestrum (20/48), and cavitation (12/48). Complications occurred in 75% of cases, including periarticular abscesses (n = 30/47), probable adjacent osteomyelitis (n = 16/37), and pelvic thrombophlebitis (n = 3). Tuberculous ISI (6/40) correlated with sclerosis (rs = 0.45[0.16; 0.67]; p < 10-2) and bone devitalization (rs = 0.38[0.16; 0.67]; p = .02). The anatomical study highlighted the shared venous vascularization of sacroiliac joints, pelvic organs, and mobile spine.

CONCLUSION

Complications of ISI are frequent, including abscesses, adjacent osteomyelitis, and periostitis. ISI had bilateral involvement nonrarely and is commonly associated with another spinal infection.

T2* cartilage mapping in early axial spondyloarthritis: diagnostic accuracy and correlation with clinical characteristics, sacroiliitis MRI scorings, and diffusion metrics

PURPOSE

To determine the performance of T2* cartilage mapping in diagnosing and assessing disease activity in early axial spondyloarthritis (axSpA), and to investigate the interaction of cartilage damage with clinical characteristics, sacroiliitis MRI scorings, and diffusion metrics.

MATERIALS AND METHODS

This prospective study included 83 axSpA patients and 37 no-axSpA patients. Clinical characteristics, the Assessment of SpondyloArthritis International Society-defined active sacroiliitis on MRI, and T2* SIJs values were recorded. In axSpA, disease activity was evaluated using the ankylosing spondylitis disease activity score-C-reactive protein; active sacroiliitis was evaluated using Spondyloarthritis Research Consortium of Canada, intravoxel incoherent motion, and diffusion kurtosis imaging; chronic sacroiliitis was assessed using composite structural damage score (CSDS) and structural score fat. Mann-Whitney U-test, Kruskal-Wallis test with false discovery rate (FDR), ROC curve, and linear regression were used for statistical analysis.

RESULTS

AxSpA patients had significantly higher T2*SIJs values than no-axSpA patients. (22.86 ± 2.42 ms vs 20.36 ± 1.30 ms, p < 0.001). The combination of T2*SIJs values and active sacroiliitis on MRI had the highest AUC for identifying axSpA. T2*SIJs values were significantly different between the inactive and very high, moderate and very high, high and very high, as well as inactive and high disease activity groups (all pFDR < 0.05). Dk (β = 0.48) and CSDS (β = 0.48) were independently associated with T2*SIJs values.

CONCLUSION

T2* values may be a promising biomarker for diagnosing and differentiating disease activity in early axSpA. Both acute and chronic sacroiliitis influence cartilage properties.

CLINICAL RELEVANCE STATEMENT

Sacroiliac joint cartilage abnormalities can be quantified with T2* relaxation time and allow better characterization of early axSpA.

KEY POINTS

T2* mapping may have value in evaluating axSpA. The combination of T2* values and active sacroiliitis on MRI enhances diagnostic performance for axSpA. Abnormalities measured with T2* values correlate with disease activity, acute sacroiliitis, and degree of structural damage.

Effective diagnosis of sacroiliitis in children: evaluating magnetic resonance imaging with the Canadian scoring system

OBJECTIVES

To reveal the differences by comparing the magnetic resonance imaging (MRI) findings of patients with clinically symptomatic sacroiliitis with those undergoing sacroiliac imaging for other reasons using the Canadian Spondyloarthritis Research Consortium-Sacroiliac Inflammatory Scoring System (SPARCC-SIS).

METHODS

In this retrospective single-center study, sacroiliac MRIs performed between 2017 and 2023 were evaluated from the database. The SPARCC-SIS scoring system is used to evaluate and grade the inflammation of the sacroiliac joints. Mild inflammation is indicated by a score below 24, moderate by a score of 24-48, and severe by a score above 49. Additionally, structural defects of the sacroiliac joint, such as erosion, sclerosis, and ankylosis, were observed. After MRI evaluation, clinically symptomatic (group 1) and non-symptomatic (group 2) patients were divided into two groups. The clinical and laboratory findings of the patients and MRI findings were compared. The patient's age, gender, clinical information from hospital records, acute phase reactants (APRs), and the presence of the Human Leukocyte Antigen (HLA-B27) gene (if applicable) were thoroughly recorded.

RESULTS

One hundred thirty-six children who performed sacroiliac MRI for any indication were included in the study. The APRs positivity, presence of HLA-B27, and SPARCC scoring system were significantly higher in 24 patients with clinical sacroiliitis (group 1) than in 112 patients without sacroiliitis (group 2). In our study, the most common MRI findings in children were bone marrow edema, capsulitis, synovitis, and erosion, while chronic structural changes such as sclerosis and ankylosing were rare.

CONCLUSION

In this study, the SPARCC scoring method, which shows the severity of sacroiliac joint inflammation, correlates with the clinical diagnosis of sacroiliitis. In cases with suspected sacroiliitis, except for extraordinary reasons, it can be evaluated with MRI without contrast material and can be graded to guide the clinician in treatment and approach.

Erosions on T1-Weighted Magnetic Resonance Imaging Versus Radiography of Sacroiliac Joints in Recent-Onset Axial Spondyloarthritis: 2-Year Data (EMBARK Trial and DESIR Cohort)

OBJECTIVE

(1) To compare the capacity to detect sacroiliac joint (SIJ) erosions and baseline-to-week 104 change in erosions between magnetic resonance imaging (MRI) and radiographs in recent-onset axial spondyloarthritis (axSpA); and (2) to compare treatment-discriminatory capacities of MRI and radiographic scores for erosion detection in patients receiving etanercept in the Effect of Etanercept on Symptoms and Objective Inflammation in Nonradiographic axSpA (EMBARK) trial vs controls in the DESIR (Devenir des Spondylarthropathies Indifférenciées Récentes) cohort.

METHODS

Anonymized SIJ MRI and radiographs were assessed at patient and joint surface levels. Three readers evaluated MRI; 3 different readers evaluated radiographs. Final scores for comparison of radiographs and MRI for detection of erosions were assigned based on agreement of ≥ 2 of 3 readers' assessments.

RESULTS

At baseline, discordance in erosion detection between imaging methods was more frequent for MRI erosions in the absence of radiographic erosions (48/224 [21.4%] patients) than for radiographic erosions in the absence of MRI erosions (14/224 [6.3%] patients; P < 0.001). After 104 weeks, a decrease in erosions was observed on MRI but not radiographs in 49/221 (22.2%) patients, and on radiographs but not MRI in 6/221 (2.7%) patients (P < 0.001). In the treatment-discriminant capacity analysis, the largest standardized differences between etanercept and control cohorts at week 104 were changes in Spondyloarthritis Research Consortium of Canada MRI erosion discrete score, changes in erosion average score, and meeting the modified New York criteria on radiographs, with unadjusted/adjusted Hedges G effect sizes of 0.40/0.50, 0.40/0.56, and 0.40/0.43, respectively.

CONCLUSION

In recent-onset axSpA, SIJ erosions and erosion change were observed more frequently on MRI than radiography. The significance of interval improvement of MRI erosions warrants further research. [ClinicalTrials.gov: NCT01258738, NCT01648907].

Automatic segmentation of fat metaplasia on sacroiliac joint MRI using deep learning

OBJECTIVE

To develop a deep learning (DL) model for segmenting fat metaplasia (FM) on sacroiliac joint (SIJ) MRI and further develop a DL model for classifying axial spondyloarthritis (axSpA) and non-axSpA.

MATERIALS AND METHODS

This study retrospectively collected 706 patients with FM who underwent SIJ MRI from center 1 (462 axSpA and 186 non-axSpA) and center 2 (37 axSpA and 21 non-axSpA). Patients from center 1 were divided into the training, validation, and internal test sets (n = 455, 64, and 129). Patients from center 2 were used as the external test set. We developed a UNet-based model to segment FM. Based on segmentation results, a classification model was built to distinguish axSpA and non-axSpA. Dice Similarity Coefficients (DSC) and area under the curve (AUC) were used for model evaluation. Radiologists' performance without and with model assistance was compared to assess the clinical utility of the models.

RESULTS

Our segmentation model achieved satisfactory DSC of 81.86% ± 1.55% and 85.44% ± 6.09% on the internal cross-validation and external test sets. The classification model yielded AUCs of 0.876 (95% CI: 0.811-0.942) and 0.799 (95% CI: 0.696-0.902) on the internal and external test sets, respectively. With model assistance, segmentation performance was improved for the radiological resident (DSC, 75.70% vs. 82.87%, p < 0.05) and expert radiologist (DSC, 85.03% vs. 85.74%, p > 0.05).

CONCLUSIONS

DL is a novel method for automatic and accurate segmentation of FM on SIJ MRI and can effectively increase radiologist's performance, which might assist in improving diagnosis and progression of axSpA.

CRITICAL RELEVANCE STATEMENT

DL models allowed automatic and accurate segmentation of FM on sacroiliac joint MRI, which might facilitate quantitative analysis of FM and have the potential to improve diagnosis and prognosis of axSpA.

KEY POINTS

• Deep learning was used for automatic segmentation of fat metaplasia on MRI. • UNet-based models achieved automatic and accurate segmentation of fat metaplasia. • Automatic segmentation facilitates quantitative analysis of fat metaplasia to improve diagnosis and prognosis of axial spondyloarthritis.

Validation of SPARCC MRI-RETIC e-tools for increasing scoring proficiency of MRI sacroiliac joint lesions in axial spondyloarthritis

BACKGROUND

The Spondyloarthritis Research Consortium of Canada (SPARCC) developers have created web-based calibration modules for the SPARCC MRI sacroiliac joint (SIJ) scoring methods. We aimed to test the impact of applying these e-modules on the feasibility and reliability of these methods.

METHODS

The SPARCC-SIJ RETIC e-modules contain cases with baseline and follow-up scans and an online scoring interface. Visual real-time feedback regarding concordance/discordance of scoring with expert readers is provided by a colour-coding scheme. Reliability is assessed in real time by intraclass correlation coefficient (ICC), cases being scored until ICC targets are attained. Participating readers (n=17) from the EuroSpA Imaging project were randomised to one of two reader calibration strategies that each comprised three stages. Baseline and follow-up scans from 25 cases were scored after each stage was completed. Reliability was compared with a SPARCC developer, and the System Usability Scale (SUS) assessed feasibility.

RESULTS

The reliability of readers for scoring bone marrow oedema was high after the first stage of calibration, and only minor improvement was noted following the use of the inflammation module. Greater enhancement of reader reliability was evident after the use of the structural module and was most consistently evident for the scoring of erosion (ICC status/change: stage 1 (0.42/0.20) to stage 3 (0.50/0.38)) and backfill (ICC status/change: stage 1 (0.51/0.19) to stage 3 (0.69/0.41)). The feasibility of both e-modules was evident by high SUS scores.

CONCLUSION

The SPARCC-SIJ RETIC e-modules are feasible, effective knowledge transfer tools, and their use is recommended before using the SPARCC methods for clinical research and tria.

Measuring response to treatment in axial spondyloarthritis using quantitative imaging biomarkers: a prospective observational cohort study

OBJECTIVE

Objective assessments of disease activity and response to treatment in axial spondyloarthritis (axSpA) remain a challenge; quantitative imaging biomarkers (QIBs) of inflammation could enhance assessments of disease activity and therapeutic response. We aimed to determine the responsiveness of QIBs obtained from diffusion-weighted imaging (DW-MRI) and chemical shift-encoded MRI (CSE-MRI) using the partially automated Bone Edema and Adiposity Characterisation with Histograms (BEACH) software tool in axSpA patients undergoing biologic therapy.

METHODS

We conducted a prospective longitudinal cohort study, including 30 patients with axSpA undergoing biologic therapy. Patients were scanned before and after biologic therapy using conventional MRI, DWI and CSE-MRI at 3T. Apparent diffusion coefficient (ADC) and proton density fat fraction (PDFF) were assessed using the BEACH tool (https://github.com/TJPBray/BEACH), and conventional MR images were assessed using established visual scoring methods by expert radiologists. Responsiveness - the ability of the MRI measurements to capture changes in disease occurring as a result of biologic therapy - was assessed using the standardized response mean (SRM). Inter-reader reliability of the ADC and PDFF maps was assessed using Bland-Altman limits of agreement analysis and the intraclass correlation coefficient.

RESULTS

Responsiveness to therapy was moderate for ADC-based parameters (SRM 0.50) and comparable to established visual scoring methods for bone marrow oedema (SRM 0.53). Interobserver variability was lower for QIBs compared with conventional visual scores methods.

CONCLUSIONS

QIBs measured using the BEACH tool are sensitive to changes in inflammation in axSpA following biologic therapy, with similar responsiveness and lower interobserver variability to visual scoring by expert radiologists.

ADVANCES IN KNOWLEDGE

QIBs measured using the partially automated BEACH tool offer an objective measure of response to biologic therapy in axSpA.

Extracellular matrix turnover biomarkers reflect pharmacodynamic effects and treatment response of adalimumab in patients with axial spondyloarthritis-results from two randomized controlled trials

OBJECTIVE

To investigate if extracellular matrix (ECM) blood-based biomarkers reflect the pharmacodynamic effect and response to TNF-α inhibitor therapy (adalimumab, ADA), in patients with axial spondyloarthritis (axSpA).

METHODS

We investigated ECM biomarkers in two randomized, double-blind, placebo-controlled trials of axSpA patients (DANISH and ASIM, n = 52 and n = 49, respectively) receiving ADA 40 mg or placebo every other week for 12 and 6 weeks, respectively, and thereafter ADA to week 48. Serum concentrations of degraded type I (C1M), II (C2M, T2CM), III (C3M), IV (C4M), VI (C6M), type X (C10C) collagen; metabolite of C-reactive protein (CRPM), prolargin (PROM), citrullinated vimentin (VICM), calprotectin (CPa9-HNE); and formation of type II (PRO‑C2), III (PRO‑C3), and VI (PRO‑C6) turnover of type IV collagen (PRO-C4) were measured at baseline and weeks 6 or 12, 24, and 48. The pharmacodynamic effect and treatment response to ADA was evaluated by linear mixed models, and correlations between biomarkers and clinical scores were assessed by Spearman's correlation.

RESULTS

C1M, C3M, C4M, C6M, CRP, PRO-C4, and CPa9-HNE levels declined after 6 or 12 weeks in patients receiving ADA compared to placebo (all p < 0.05). Patients with AS Disease Activity Score C-reactive protein (ASDAS CRP) major improvement and/or clinically important improvement had significantly higher C1M, C3M, C4M, C6M, and PRO-C4 levels than patients with no/low improvement at baseline (all p < 0.05). Baseline levels of biomarkers showed weak to moderate correlations with ASDAS and structural damage scores.

CONCLUSION

ECM metabolites showed a pharmacodynamic effect and were associated with ASDAS response during TNF-α inhibitor treatment in patients with axSpA.

MRI in pediatric sacroiliitis, what radiologists should know

MRI is used for early detection of inflammation of sacroiliac joints as it shows active lesions of sacroiliitis long before radiographs show damage to the sacroiliac joints. Early diagnosis of arthritis allows early treatment of inflammation and can help delay disease progression and prevent irreversible damage. Also, early identification of axial involvement in juvenile spondyloarthropathy is crucial, as treatment options are different than for peripheral juvenile spondyloarthropathy. In general, standard sequences used in adults are also applied to children. However, interpreting MR images of pediatric sacroiliac joints is more challenging than in adults, because of normal physiological changes during skeletal maturation, which can simulate disease on MR images. Furthermore, classical definitions of sacroiliitis used in adults, for both active inflammatory and structural lesions, can be difficult to extrapolate to children. The development of reliable pediatric-specific definitions for sacroiliitis is still in active study. Understanding both normal and pathological signal changes in children is important to distinguish physiologic findings from disease and to make a correct diagnosis. In this review, the main imaging characteristics of sacroiliitis on MRI in children and its frequent pitfalls will be illustrated, while also citing some discussion points regarding the scan protocol.

Data-Driven Magnetic Resonance Imaging Definitions for Active and Structural Sacroiliac Joint Lesions in Juvenile Spondyloarthritis Typical of Axial Disease: A Cross-Sectional International Study

OBJECTIVE

We aimed to determine quantitative sacroiliac (SI) joint magnetic resonance imaging (MRI) cutoffs for active and structural lesions that will be incorporated as imaging domains in classification criteria of axial disease in juvenile spondyloarthritis (SpA).

METHODS

MRI scans from an international cross-section of juvenile SpA patients were reviewed by 6 musculoskeletal imaging experts blinded to clinical details. Raters globally assessed the presence/absence of lesions typical of axial SpA and performed SI joint quadrant- or joint-based scoring. Sensitivity and specificity of lesion cutoffs were calculated using a rater majority (≥4 of 6 raters) on a global assessment of the presence/absence of active or structural lesions typical of axial SpA with high confidence as the reference standard. Cutoffs were validated in an independent cohort.

RESULTS

Imaging from 243 subjects, 61% male, median age 14.9 years, had sequences available for detailed MRI scoring. Optimal cutoffs for defining lesions typical of axial disease in juvenile SpA were: 1) inflammatory lesion: bone marrow edema in ≥3 SI joint quadrants across all SI joint MRI slices (sensitivity 98.6%, specificity 96.5%); 2) structural lesions: erosion in ≥3 quadrants or sclerosis or fat lesion in ≥2 SI joint quadrants or backfill or ankylosis in ≥2 joint halves across all SI joint MRI slices (sensitivity 98.6%, specificity 95.5%). Sensitivity and specificity of the optimal cutoffs in the validation cohort were excellent.

CONCLUSION

We propose data-driven cutoffs for active inflammatory and structural lesions on MRI typical of axial disease in juvenile SpA that have high specificity and sensitivity using central imaging global assessment as the reference standard and excellent reliability.

Data-Driven Magnetic Resonance Imaging Definitions for Active and Structural Sacroiliac Joint Lesions in Juvenile Spondyloarthritis Typical of Axial Disease: A Cross-Sectional International Study

OBJECTIVE

We aimed to determine quantitative sacroiliac (SI) joint magnetic resonance imaging (MRI) cutoffs for active and structural lesions that will be incorporated as imaging domains in classification criteria of axial disease in juvenile spondyloarthritis (SpA).

METHODS

MRI scans from an international cross-section of juvenile SpA patients were reviewed by 6 musculoskeletal imaging experts blinded to clinical details. Raters globally assessed the presence/absence of lesions typical of axial SpA and performed SI joint quadrant- or joint-based scoring. Sensitivity and specificity of lesion cutoffs were calculated using a rater majority (≥4 of 6 raters) on a global assessment of the presence/absence of active or structural lesions typical of axial SpA with high confidence as the reference standard. Cutoffs were validated in an independent cohort.

RESULTS

Imaging from 243 subjects, 61% male, median age 14.9 years, had sequences available for detailed MRI scoring. Optimal cutoffs for defining lesions typical of axial disease in juvenile SpA were: 1) inflammatory lesion: bone marrow edema in ≥3 SI joint quadrants across all SI joint MRI slices (sensitivity 98.6%, specificity 96.5%); 2) structural lesions: erosion in ≥3 quadrants or sclerosis or fat lesion in ≥2 SI joint quadrants or backfill or ankylosis in ≥2 joint halves across all SI joint MRI slices (sensitivity 98.6%, specificity 95.5%). Sensitivity and specificity of the optimal cutoffs in the validation cohort were excellent.

CONCLUSION

We propose data-driven cutoffs for active inflammatory and structural lesions on MRI typical of axial disease in juvenile SpA that have high specificity and sensitivity using central imaging global assessment as the reference standard and excellent reliability.

Intermediate-weighted MRI with fat suppression (IW-FS): diagnostic performance for bone marrow edema and erosion detection in axial spondyloarthritis

BACKGROUND

Bone marrow edema (BME) and erosion of the sacroiliac joint are both key lesions for diagnosing axial spondyloarthritis (axSpA) on magnetic resonance imaging (MRI).

PURPOSE

To qualitatively and quantitatively compare intermediate-weighted MRI with fat suppression (IW-FS) with T2-weighted short tau inversion recovery (T2-STIR) in assessment of sacroiliac BME and erosion in axSpA.

MATERIAL AND METHODS

Patients aged 18-60 years with axSpA were prospectively enrolled. All patients underwent a 3.0-T MRI examination of the sacroiliac joints. Para-coronal IW-FS, T2-STIR, and T1-weighted (T1W) images were acquired. BME and erosion were scored by two readers in consensus on IW-FS and STIR using a modified Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system. Consensus scores on T1WI were used as the reference for erosion. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for BME.

RESULTS

In total, 49 patients (mean age=33.4 ± 7.6 years) were included. More patients were scored as having BME on T2-STIR (36 vs. 29, P = 0.016). SPARCC-BME score on IW-FS was lower than that acquired on T2-STIR (mean, 11.5 vs. 14.7, P = 0.002). SNR and CNR of BME were both lower on IW-FS than on T2-STIR (mean SNR, 118 vs. 218, P < 0.001; mean CNR, 44 vs. 137, P < 0.001). The sensitivity of erosion detection was higher on IW-FS (83%) than on T2-STIR (54%, P = 0.006).

CONCLUSION

IW-FS is not sufficient for BME detection using T2-STIR as the reference standard in patients with axSpA. IW-FS has a much higher sensitivity than T2-STIR for erosion detection in the sacroiliac joint.

[Chronic back pain in axial spondylarthritis : Current diagnostic challenges and treatment possibilities]

BACKGROUND

Among chronic back diseases, axial spondylarthritis (axSpA) is the entity with the largest spectrum of specific anti-inflammatory treatment modalities; however, from a general medical perspective axSpA is only ranked as another etiology of back pain to be considered after spinal cord or cauda equina compression, bone metastases, epidural abscess or osteomyelitis of the vertebrae, radiculopathy or spinal stenosis. Due to its relatively low prevalence and mostly later occurring sequelae, there is a danger that axSpA will be a relatively neglected entity for specialists.

RESULTS

This article recapitulates the recommendations of the Assessment of Ankylosing Spondyloarthritis International Society (ASAS). This review addresses the practical aspects of the detailed evaluation of treatment attempts carried out so far with nonsteroidal anti-inflammatory drugs (NSAID) for back pain. Undesired effects on the symptoms of the lower intestinal tract could be of particular interest here. The sex-specific differences in the response to treatment with tumor necrosis factor (TNF) inhibitors in axSpA are mentioned. Further aspects of treatment options with biologics in axSpA are discussed based on a case of maintained remission after a course of interleukin (IL) 17 inhibitors in undifferentiated, HLA-B27 and magnetic resonance imaging (MRI) positive axSpA and long-standing good treatment response to IL-12/23 inhibitor treatment in axial psoriatic arthritis. Furthermore, the literature is discussed with respect to uveitis, carditis and amyloidosis in the context of axSpA.

CONCLUSION

The early diagnosis in the general medical context and the specific consideration of numerous predictive factors play an increasingly more important role in the personalized treatment of axSpA.

Detection of erosions and fat metaplasia of the sacroiliac joints in patients with suspected sacroiliitis using a chemical shift-encoded sequence (IDEAL-IQ)

PURPOSE

To evaluate the performance of a chemical shift-encoded sequence called IDEAL-IQ for detecting sacroiliac joint (SIJ) erosions and fat metaplasia compared to T1-weighted fast spin echo (T1 FSE) using qualitative and quantitative analysis.

METHOD

Thirty-four patients with suspicion of sacroiliitis who underwent both MRI and CT were included. Each SIJ was divided into four quadrants for analysis. For qualitative analysis, the diagnostic performance of IDEAL-IQ and T1 FSE for erosions were compared by the McNemar test, using CT as the gold standard. Cochran's Q and McNemar tests were used to determine differences in structural changes detected by different imaging methods. For quantitative analysis, two-sample t test and receiver operating characteristic (ROC) analysis were used for the analysis of histogram parameters of proton density fat fraction (PDFF).

RESULTS

Diagnostic sensitivity and accuracy of IDEAL-IQ were greater than T1 FSE for erosions (all P < 0.05). IDEAL-IQ and CT detected more erosions than T1 FSE (all P < 0.05). IDEAL-IQ did not statistically significantly differ from T1 FSE for the detection of fat metaplasia (P = 0.678). All histogram parameters were different between groups with and without fat metaplasia (all P < 0.05) and could distinguish the two groups (all P < 0.05). PDFF_75th was the most effective histogram parameter.

CONCLUSION

IDEAL-IQ detects SIJ erosions with better accuracy than T1 FSE and is similar to T1 FSE for detection of fat metaplasia, enabling further quantitative analysis of the latter via histogram analysis.

Blurring and Irregularity of the Subchondral Cortex in Pediatric Sacroiliac Joints on T1 Images: Incidence of Normal Findings That Can Mimic Erosions

OBJECTIVE

To determine prevalence of variations of subchondral bone appearance that may mimic erosions on T1-weighted magnetic resonance imaging (MRI) of pediatric sacroiliac (SI) joints according to age and sex.

METHODS

With ethics committee approval and informed consent, SI joint MRIs of 251 children (132 girls), mean age 12.4 years (range 6.1-18.0 years), were obtained in 2 cohorts: 127 children imaged for nonrheumatic reasons, and 124 children with low back pain but no features of sacroiliitis at initial clinical MRI review. MRIs were reviewed by 3 experienced radiologists, blinded from each other, for 3 features of the cortical black line representing the subchondral bone plate on T1-weighted MRI: visibility, blurring, and irregularity.

RESULTS

Based on agreement from 2 or more readers, the cortical black line was partially absent in 88.4% of the children, blurred in 34.7%, and irregular in 41.4%. All these features were most common on the iliac side of SI joints and at the first sacral vertebra level. Clearly visualized, sharply delineated SI joints with none of these features were seen in only 8.0% of children, or in 35.1% if we conservatively required agreement of all 3 readers to consider a feature present. There was no significant difference between sexes or cohorts; findings were similar across pediatric age groups.

CONCLUSION

Understanding the normal MRI appearance of the developing SI joint is necessary to distinguish physiologic findings from disease. At least two-thirds (65%) of normal pediatric SI joints showed at least 1 feature that is a component of the adult definition of SI joint erosions, risking overdiagnosis of sacroiliitis.

Sacroiliac joint beyond sacroiliitis-further insights and old concepts on magnetic resonance imaging

The sacroiliac joint (SIJ) is an amphiarthrosis composed of a posterior syndesmosis and an anterior cartilaginous portion, with limited yet present mobility. Its main function is to transmit the load from the axial skeleton to the lower limbs and vice-versa; it is susceptible to early mechanical and degenerative changes which are much more common than inflammatory sacroiliitis. Magnetic resonance imaging (MRI) has increasingly been used to evaluate these changes, and while subchondral bone marrow edema (BME) is a common finding related to both, care must be taken when applying the ASAS research MRI definition for sacroiliitis without considering lesion BME topography, size and depth, concomitant structural damage and, of course, the clinical picture. In this review, we will discuss the anatomy and biomechanics of the SIJ, the noninflammatory causes of SIJ subchondral BME, and how these concepts combined can be used to increase our diagnostic confidence.

Evaluation of active inflammation, chronic structural damage, and response to treatment of sacroiliitis in axial spondyloarthritis using the Spondyloarthritis research consortium of Canada scoring system

Background

Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease affecting the spine and sacroiliac joints. To investigate whether there are differences in inflammatory and chronic structural damages, as assessed by a semiquantitative MRI scoring method, between non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) patients with active inflammation at baseline, and to evaluate the treatment response in these patients after 3 months of tumor necrosis factor-alpha (TNF-α) inhibitor treatment.

Methods

Fifty-eight axSpA patients with active inflammation were included in the study. The patients were divided into nr-axSpA group and AS group. MRI examinations of the sacroiliac joints were performed before and after treatment. Inflammatory and structural damages in these patients were assessed using the established Spondyloarthritis Research Consortium of Canada (SPARCC) inflammation and sacroiliac joint structural (SSS) scoring methods, which are two MRI-based scoring methods. The SPARCC score, SSS score, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level were compared between the two groups.

Results

At baseline, SPARCC scores for patients in the nr-axSpA and AS groups did not differ significantly (P > 0.05); however, SSS scores for fat metaplasia, erosion, and backfill for patients in the AS group were significantly higher (P < 0.001). Compared with baseline, SPARCC scores were significantly decreased in both groups after treatment (P < 0.001); however, after treatment, no statistically significant difference was found regarding SPARCC scores between the AS and nr-axSpA groups. Compared with baseline, a significant increase in the SSS scores for fat metaplasia and backfill (P < 0.001) and a significant decrease in the SSS scores for erosion (P < 0.001) were observed in all axSpA patients. Changes in the SPARCC score was inversely correlated with the changes in the SSS score for fat metaplasia (r = − 0.634, P < 0.001). Changes in the SSS score for backfill were positively correlated with the changes in the SSS score for fat metaplasia (r = 0.277, P < 0.05) and inversely correlated with those for erosion (r = − 0.443, P < 0.001).

Conclusion

The SPARCC and SSS scoring systems can be used to assess inflammatory and chronic structural damages as well as treatment responses in patients with axSpA. More severe structural damages were seen in AS patients. TNF-α inhibitor treatment for 3 months could effectively reduce inflammation in axSpA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05609-x.

Baseline Severity of Sacroiliitis and Extensive Fat Metaplasia Predicts the Progression of Backfill at the Sacroiliac Joint in Patients With Axial Spondyloarthritis

Objectives

Fat metaplasia in an erosion cavity, also known as backfill, is an essential intermediary in new bone formation in axial spondyloarthritis (axSpA) patients; however, the predictors of backfill progression are unknown. This longitudinal study aimed to assess the predictors of backfill progression in axSpA patients on magnetic resonance imaging (MRI).

Methods

Clinical and MRI data were collected at baseline and follow-up in 52 axSpA patients. Backfill progression was defined as the new or increased T1 hyperintensity within the SI joint space. Logistic regression analyses were performed to identify the predictors of the backfill progression.

Results

A total of 19 patients had “backfill” at baseline and 30 patients exhibited the backfill progression after follow-up. The mean disease duration and SPARCC scores at baseline were significantly different between patients with and without backfill progression (P&lt;0.001, P=0.003, respectively). Patients with backfill progression had a higher frequency of backfill at baseline, a higher SSS score of fat metaplasia, and a higher SSS score of backfill than those without (P=0.001, P&lt;0.001, and P=0.002, respectively). A higher fat fraction value in the fat metaplasia area at the baseline was more frequent in patients with, than without, backfill progression (P=0.019). In the univariate logistic regression analyses, a higher SPARCC score for inflammation and a higher SSS score for fat metaplasia at baseline were associated with backfill progression.

Conclusions

Severity of sacroiliitis and extensive fat metaplasia at baseline are predictors of the backfill progression in axSpA patients.

Instrument selection for the ASAS core outcome set for axial spondyloarthritis

OBJECTIVES

To define the instruments for the Assessment of SpondyloArthritis international Society-Outcomes Measures in Rheumatology (ASAS-OMERACT) core domain set for axial spondyloarthritis (axSpA).

METHODS

An international working group representing key stakeholders selected the core outcome instruments following a predefined process: (1) identifying candidate instruments using a systematic literature review; (2) reducing the list of candidate instruments by the working group, (3) assessing the instruments' psychometric properties following OMERACT filter 2.2, (4) selection of the core instruments by the working group and (5) voting and endorsement by ASAS.

RESULTS

The updated core set for axSpA includes seven instruments for the domains that are mandatory for all trials: Ankylosing Spondylitis Disease Activity Score and Numerical Rate Scale (NRS) patient global assessment of disease activity, NRS total back pain, average NRS of duration and severity of morning stiffness, NRS fatigue, Bath Ankylosing Spondylitis Function Index and ASAS Health Index. There are 9 additional instruments considered mandatory for disease-modifying antirheumatic drugs (DMARDs) trials: MRI activity Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joints and SPARCC spine, uveitis, inflammatory bowel disease and psoriasis assessed as recommended by ASAS, 44 swollen joint count, Maastricht Ankylosing Spondylitis Enthesitis Score, dactylitis count and modified Stoke Ankylosing Spondylitis Spinal Score. The imaging outcomes are considered mandatory to be included in at least one trial for a drug tested for properties of DMARD. Furthermore, 11 additional instruments were also endorsed by ASAS, which can be used in axSpA trials on top of the core instruments.

CONCLUSIONS

The selection of the instruments for the ASAS-OMERACT core domain set completes the update of the core outcome set for axSpA, which should be used in all trials.

Improving the design of RCTs in non-radiographic axial spondyloarthritis

Concerns have been raised that randomized placebo-controlled trials (RCTs) in non-radiographic axial spondyloarthritis (nr-axSpA) might be failing to identify patients that best show differences in clinical response rates between those receiving active drug and those receiving placebo therapies; in addition, some studies might even be showing spurious differences in responses to TNF and IL-17 inhibitor therapies. In particular, the most recent phase III RCTs in nr-axSpA have reported variable and generally lower response rates than observed in phase III trials of patients with ankylosing spondylitis and in trials conducted a decade ago in patients with early axSpA who were selected on the basis of axial inflammation evident on MRI scans. We argue that these observations at least partly reflect an RCT design that does not take full advantage of MRI to select patients who are responsive to therapy because the current MRI-based inclusion criteria cannot identify patients with axSpA with sufficient specificity. We propose that future studies should be designed using revised patient inclusion criteria based on expanded MRI evaluation and the application of data-driven definitions of a positive MRI for inflammatory and structural lesions typical of axSpA reported in an international multicentre analysis of MRI scans from the Assessment of SpondyloArthritis International Society (ASAS) classification cohort.

Impact of filgotinib on sacroiliac joint magnetic resonance imaging structural lesions at 12 weeks in patients with active ankylosing spondylitis (TORTUGA trial)

OBJECTIVE

To assess the effect of filgotinib, which preferentially inhibits Janus kinase 1 (JAK1), on MRI measures of structural change in the SI joint in patients with active AS in the TORTUGA trial.

METHODS

Adults with active AS and inadequate response/intolerance to two or more NSAIDs were randomized 1:1 to filgotinib 200 mg (n = 58) or placebo (n = 58) once daily for 12 weeks. In this post hoc analysis, T1-weighted MRI scans of the SI joint were evaluated by two independent readers using Spondyloarthritis Research Consortium of Canada (SPARCC) Sacroiliac Joint Structural Score (SSS) definitions for erosion, backfill, fat metaplasia and ankylosis. Correlations between SPARCC SSS and improvement in clinical outcomes were also assessed.

RESULTS

MRI scans from 87 patients (48 filgotinib, 39 placebo) were evaluated. At baseline there were no notable differences between filgotinib and placebo for any MRI structural lesion types. From baseline to week 12, filgotinib was associated with a significant reduction in SI joint erosion score (P = 0.02) and an increase in backfill score (P = 0.005) vs placebo, with no significant between-group differences for ankylosis (P = 0.46) or fat metaplasia (P = 0.17). At week 12, the change in SPARCC MRI SI joint inflammation scores correlated positively with erosion scores but negatively with backfill scores.

CONCLUSION

The significant changes in MRI structural lesions induced by filgotinib in the SI joint by week 12 demonstrate that tissue repair can be observed very soon after starting treatment with a JAK1 preferential inhibitor. This could have prognostic implications for development of ankylosis.

TRIAL REGISTRATION

ClinicalTrials.gov, http://clinicaltrials.gov, NCT03117270.

Treatment Failure in Axial Spondyloarthritis: Insights for a Standardized Definition

Axial spondyloarthritis is a chronic inflammatory rheumatic disease that affects the axial skeleton and causes severe pain and disability. It may be also associated with extra-articular manifestations. Early diagnosis and appropriate treatment can reduce the severity of the disease and the risk of progression. The biological disease-modifying antirheumatic drugs (bDMARDs) tumor necrosis factor alpha (TNFα) inhibitors (TNFi) and the anti-interleukin (IL)-17A antibodies secukinumab and ixekizumab are effective agents to reduce disease activity and minimize the inflammation that damages the joints. New alternatives such as Janus kinase (JAK) inhibitors are also available. Unfortunately, response rates to bDMARDs are far from optimal, and many patients experience so-called treatment failure. The definition of treatment failure definition is often vague and may depend on the rigorousness of the therapeutic goal, the inclusion or not of peripheral symptoms/extra-articular manifestations, or patients' overall health. After an exhaustive bibliographic review, we propose a definition based on loss of the following status: low disease activity assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, absence of extra-articular manifestations, and low disease impact on the patients' general health. Apart from discontinuing the therapy because of safety or intolerance reasons, two types of treatment failure can be differentiated depending on when it occurs: primary failure (no response within 6 months after treatment initiation, or lack of efficacy) and secondary failure (response within 6 months but lost thereafter, or loss of efficacy over time). Physicians should carefully consider the moment and the reason for the treatment failure to decide the next therapeutic step. In the case of primary failure on a first TNFi, it seems reasonable to switch to another class of drugs, i.e., an anti-IL-17 agent, as phase III trials showed that the response to IL-17 blockade was higher than to placebo in patients previously exposed to TNFi. When secondary failure occurs, and loss of efficacy is suspected to be caused by antidrug antibodies (ADAs), it is advisable to analyze serum TNFi and ADAs concentrations, if possible; in the presence of ADAs and low TNFi levels, changing the TNFi is rational as it may restore the TNFα blocking capacity. If ADAs are absent/low with adequate drug therapeutic levels, switching to another target might be the best strategy.

Parallel Line Sign-A New MRI Sign Associated With Chronic Sacroiliitis: Prevalence, Characteristics, and Associations

Purpose: The purpose is to demonstrate the existence of the parallel line sign (PLS), a dark line parallel to the sacroiliac joint (SIJ), and determine its prevalence, characteristics, and associations. Methods: 200 consecutive SIJ MRIs referred by rheumatologists were retrospectively reviewed for the presence of the PLS. Presence and extent of imaging features of sacroiliitis (bone marrow edema, fatty infiltration, erosions, sclerosis, and ankylosis) were evaluated. Results: Prevalence of PLS was 11.5% (23/200), with 9 subjects having bilateral PLS, resulting in 32 SIJs showing a PLS. Every PLS involved the synovial portion of the SIJ, and almost all (31/32, 96.9%) involved the iliac (rather than sacral) side of the SIJ. Every PLS occurred with at least one established imaging feature of sacroiliitis. Presence of a PLS was associated with higher prevalence of erosions (78.3% vs 36.7% in those without PLS, P < .001), greater extent of SIJ involvement by erosions (3.6 ± 1.3 vs 2.3 ± 1.1 quadrants of the SIJ involved, P < .001), and higher density of erosions per centimeter (88.9% vs 46.2% with >2 erosions/cm, P = .001). There was higher prevalence of bone marrow edema, fatty infiltration, and sclerosis in those with PLS compared to those without PLS (P = .001, P < .001, and P = .006, respectively). Extent of involvement by any of these features was not significantly different between the two groups (P = .22, P = .16, and P = .46, respectively). Conclusions: The PLS is associated with imaging features of chronic sacroiliitis, especially erosions. Knowledge of the existence of the PLS may help avoid misdiagnosis of an insufficiency fracture and increase confidence in the diagnosis of sacroiliitis.

MRI Assessment of Sacroiliitis With High-Resolution Protocol

Background: Sacroiliac (SI) joint subchondral resorption on high-resolution magnetic resonance imaging (MRI) may be an early sign of the development of sacroiliitis. At our institution, high-resolution intermediate-weighted (proton density) MRI sequences are used in the workup of suspected spondyloarthritis (SpA). Questions/Purpose: We sought to test the hypothesis that SI joint subchondral resorption might be a useful MRI feature in the diagnosis of sacroiliitis. Methods: We retrospectively reviewed the records of patients with suspected SpA from a single rheumatologist's practice from January 1, 2010, to December 31, 2017. Patients had an MRI of the SI joints, using our institution's specialized protocol, and underwent standard physical examination and laboratory evaluation. The sensitivity and specificity of SI joint subchondral resorption in the identification of sacroiliitis were estimated using the clinical diagnosis as the reference standard and from a Bayesian latent class model with conditional dependence. Results: SI joint subchondral resorption on SI joint MRI was highly correlated with a positive diagnosis in patients worked up for axial SpA. It demonstrated superior sensitivity when compared with other MRI features used in the MRI diagnosis of sacroiliitis, such as bone marrow edema pattern, erosion, and ankylosis. Interobserver reliability was high for subchondral resorption. Conclusion: This retrospective study found that subchondral resorption on MRI evaluation of the SI joints appeared to be a sensitive indicator of SpA, potentially of early disease. This imaging feature warrants evaluation in other cohorts of patients suspected of having axial SpA to validate diagnostic performance in diverse populations.

The value of SPARCC sacroiliac MRI scoring in axial psoriatic arthritis and its association with other disease parameters

OBJECTIVES

This study aimed to assess patients with axial psoriatic arthritis (AxPsA) using the Canadian Spondyloarthritis Research Consortium (SPARCC) sacroiliac joint (SIJ) scores and to seek correlations between magnetic resonance imaging (MRI) scores and disease characteristics.

METHODS

Forty PsA patients (32 females, mean age 46.4 years) who had been documented to have active or structural lesions on SIJ MRI were retrospectively evaluated. Disease duration, medications, and disease activity, including Disease Activity in Psoriatic Arthritis (DAPSA), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), minimal disease activity (MDA), and Ankylosing Spondylitis Disease Activity Score (ASDAS) were recorded. On sacroiliac MRI scans, the SPARCC scores of sacroiliac joint inflammation (SIS) and sacroiliac joint structural damage (SSS) were evaluated.

RESULTS

The mean disease duration was 51.4 ± 70.4 months. MRI showed active inflammation in 30 patients (75%) and at least 1 structural lesion in 32 patients (92.5%). The most prevalent structural lesion was erosion (82.5%), followed by fat metaplasia (65%), backfill (12.5%), and ankylosis (2.5%). Only fat metaplasia scores were significantly higher in men than in women (P = .007). Of clinical and laboratory parameters, only C-reactive protein (CRP) was significantly higher in the presence of active inflammation (P = .01). The SIS score was significantly correlated with disease duration (r = -.35) and CRP levels (r = .42,). The SSS score was inversely correlated with BASDAI (r = -.37), ASDAS-CRP (r = -.39), and ASDAS - erythrocyte sedimentation rate (r = -.32). The overall SPARCC scores did not differ between patients in DAPSA remission and non-remission and between those in MDA and non-MDA.

CONCLUSION

Although radiologic involvement is generally not severe in AxPsA, MRI still provides additional information about inflammatory activity and structural lesions. CRP may be helpful in monitoring the radiologic disease activity in AxPsA.

Distribution of Acute and Chronic Lesions in the Sacroiliac Joints of Patients with Axial Spondyloarthritis

Objective

In this study, we aimed to investigate whether there was a pattern of distribution of acute and chronic lesions in the sacroiliac joints (SIJ) of patients with axial spondyloarthritis (axSpA).

Methods

A total of 96 patients diagnosed as axSpA were retrospectively included in this study. The Spondyloarthritis Research Consortium of Canada sacroiliac joint inflammation score (SIS) and structural score (SSS) were used to evaluate the acute and chronic lesions in the SIJs. Scores representing the distribution of bone marrow edema, fatty lesions and erosions were extracted respectively. By dividing the SIJs into sacral or iliac sections, upper or lower sections, anterior and posterior levels, differences of scores representing acute and chronic lesions were analyzed by Kruskal Wallis’ tests.

Results

SIS scores were not significantly different in sacral or iliac sections, in upper or lower sections, on anterior or posterior levels. SSS scores were also not significantly different in different sections, except for higher occurrence rates of erosions in the iliac sections. Post-hoc analysis showed that there was a higher erosion score in the left ilium than left sacrum, as well as in right ilium than left sacrum.

Conclusion

There was no specific distribution pattern of acute or chronic lesions in the SIJs in patients with axSpA. A bigger study sample was needed to confirm the distribution of erosions in sacral or iliac sections.

Structural Lesion Progression of the Sacroiliac Joint and Clinical Features in axSpA During TNFi Reduction: A Retrospective Cohort Study

Objective: In the clinic, some patients with axial spondyloarthritis (axSpA) have to reduce tumor necrosis factor inhibitor (TNFi) for various reasons. However, there are few studies about how to balance the relapse and TNFi reduction. Here we retrospectively analyzed the structural progression of the sacroiliac joint (SIJ) and clinical features in axSpA during TNFi reduction.

Methods: A total of 108 patients with axSpA who followed up for 2 years and completed at least baseline, 12-month, and 24-month MRI scans of SIJ were divided into the tapering group (n = 63) and withdrawal group (n = 45) according to whether TNFi was stopped. We divided 2 years into five intervals, calculating the average dose quotient (DQ) for each of 540 intervals from 108 patients. By using generalized estimation equations with inverse probability of treatment weighting, we investigated the unbiased effects of average DQ on structural progression and treatment response.

Results: The disease activity (such as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP, and ASDAS-ESR) and relapse rate were lower in the tapering group at 12 and 24 months (p < 0.05). Δerosion (β = −0.0100, p = 0.00026) and Δthe Spondyloarthritis Research Consortium of Canada (SPARCC; β = −0.0959, p < 0.0001) were negatively correlated with average DQ. The average DQ 30 (74.8%, 80.0%) or 41.6 (76.5%, 83%) was best to discriminate the status of treatment response or the status of bone marrow edema, but considering operability, the average DQ 25 (78.0%, 63.3%) was also acceptable especially for patients with HLA-B27 negative and non-severe fat metaplasia.

Conclusion: Complete TNFi withdrawal was not recommended. Our study provided a referable strategy (tapering then maintained the average DQ over 30 or even 25) for patients who need TNFi reduction. Higher dose usage of TNFi was associated with a slower erosion progression of SIJ.

Changes over time in inflammatory and structural lesions at the sacroiliac joint in children with spondyloarthritis exposed and unexposed to tumor necrosis factor inhibitor

BACKGROUND

The objective of this work was to describe magnetic resonance imaging (MRI) changes over time in inflammatory and structural lesions at the sacroiliac joint (SIJ) in children with spondyloarthritis (SpA) exposed and unexposed to tumor necrosis factor inhibitor (TNFi).

METHODS

This was a retrospective, multicenter study of SpA patients with suspected or confirmed sacroiliitis who underwent at ≥2 pelvic MRI scans. Images were reviewed independently by 3 radiologists and scored for inflammatory and structural changes using the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ inflammation score (SIS) and structural score (SSS). Longitudinal, quantitative changes in patient MRI scans were measured using descriptive statistics and stratified by TNFi exposure. We used an average treatment effects (ATE) regression model to explore the average effect of TNFi exposure over time on inflammatory and structural lesions, adjusting for baseline lesion scores.

RESULTS

Forty-six subjects were evaluated using the SIS (n = 45) and SSS (n = 18). Median age at baseline imaging was 13.6 years, 63% were male and 71% were white. Twenty-three subjects (50%) were TNFi exposed between MRI studies. The median change in SIS in TNFi exposed and unexposed subjects with a baseline SIS ≥0 was - 20.7 and - 14.3, respectively (p = 0.09). Eleven (85%) TNFi exposed and 8 (89%) unexposed subjects with a baseline SIS ≥0 met the SIS minimal clinically important difference (MCID; ≥2.5). Using the ATE model adjusted for baseline SIS, the average effect of TNFi on SIS in patients with a baseline SIS ≥2 was - 14.5 (p < 0.01). Unadjusted erosion change score was significantly worse in TNFi unexposed versus exposed subjects (p = 0.03) but in the ATE model the effect of TNFi was not significant.

CONCLUSION

This study quantitatively describes how lesions in the SIJs on MRI change over time in patients exposed to TNFi versus unexposed. Follow-up imaging in TNFi exposed patients showed greater improvement than the unexposed group by most metrics, some of which reached statistical significance. Surprisingly, a majority of TNFi unexposed children with a baseline SIS≥2 met the SIS MCID. Additional studies assessing the short and long-term effects of TNFi on inflammatory and structural changes in juvenile SpA are needed.

Tapering of TNF inhibitors in axial spondyloarthritis in routine care-2-year clinical and MRI outcomes and predictors of successful tapering

OBJECTIVES

In a 2-year follow-up study of patients with axial spondyloarthritis (axSpA) in clinical remission who tapered tumor necrosis factor inhibitor (TNFi) treatment according to a clinical guideline, we aimed to investigate the proportion who successfully tapered/discontinued therapy and baseline predictors thereof. The proportion regaining clinical remission after flare and the progression on MRI/radiography were also assessed.

METHODS

One-hundred-and-nine patients (78(72%)/31(28%) receiving standard respectively reduced dose) in clinical remission (BASDAI < 40, physician global score < 40) and no signs of disease activity the previous year tapered TNFi as follows: to two-thirds of standard dose at baseline, half at week 16, one-third at week 32 and discontinuation at week 48. Patients experiencing clinical, BASDAI or MRI flare (predefined criteria) stopped tapering and escalated to previous dose. Prediction analyses were performed by multivariable regression.

RESULTS

One-hundred-and-six patients(97%) completed 2-years follow-up; 55 patients(52%) had successfully tapered: 23(22%) receiving two-thirds, 15(14%) half, 16(15%) one-third dose and 1(1%) discontinued. In patients at standard dose at baseline(n = 78), lower physician global score was the only independent predictor of successful tapering (Odds ratio(OR)=0.79(95% Confidence Interval = 0.64-0.93); p= 0.003). In the entire patient group lower physician global score(OR = 0.86(0.75-0.98); p= 0.017), lower Spondyloarthritis Research Consortium of Canada(SPARCC) Sacroiliac Joint Erosion score(OR = 0.78(0.57-0.98); p= 0.029) and current smoking(OR = 3.28(1.15-10.57); p= 0.026) were independent predictors of successful tapering. At 2-years, 97% of patients were in clinical remission. Minimal changes in imaging findings were observed.

CONCLUSION

After two years following a clinical guideline, 52% of patients with axSpA in clinical remission had successfully tapered TNFi, only 1% discontinued. Baseline physician global score was an independent predictor of successful tapering.

Reliability of the Preliminary OMERACT Juvenile Idiopathic Arthritis MRI Score (OMERACT JAMRIS-SIJ)

This study reports the reliability of the juvenile idiopathic arthritis magnetic resonance imaging scoring system (JAMRIS-SIJ). The study comprised of eight raters—two rheumatologists and six radiologists—and 30 coronal T1 and Short-Tau Inversion Recovery (STIR) MRI scans of patients with enthesitis-related juvenile spondylarthritis. The median age of patients was 15 years with a mean disease duration of 5 years and 22 (73.3%) of the sample were boys. The inter-rater agreement of scores for each of the JAMRIS-SIJ items was calculated using a two-way random effect, absolute agreement, and single rater intraclass correlation coefficient (ICC 2.1). The ICC was interpreted together with kurtosis, since the ICC is also affected by the distribution of scores in the sample. The eight-rater, single measure inter-rater ICC (and kurtosis) values for JAMRIS-SIJ inflammation and damage components were the following: bone marrow edema (BME), 0.76 (1.2); joint space inflammation, 0.60 (1.8); capsulitis, 0.58 (9.2); enthesitis, 0.20 (0.1); ankylosis, 0.89 (35); sclerosis, 0.53 (4.6); erosion, 0.50 (6.5); fat lesion, 0.40 (21); backfill, 0.38 (38). The inter-rater reliability for BME and ankylosis scores was good and met the a priori set ICC threshold, whereas for the other items it was variable and below the selected threshold. Future directives should focus on refinement of the scores, definitions, and methods of interpretation prior to validation of the JAMRIS-SIJ through the assessment of its measurement properties.

Active Inflammatory and Chronic Structural Damages of Sacroiliac Joint in Patients With Radiographic Axial Spondyloarthritis and Non-Radiographic Axial Spondyloarthritis

Objective

Evaluate the MRI evidence of active inflammatory and chronic structural damages in radiographic axial spondyloarthritis (r-axSpA) and non-radiographic axial spondyloarthritis (nr-axSpA).

Methods

A retrospective review of 253 patients who underwent sacroiliac joint (SIJ) MRI between June 2014 and December 2019 was performed. MRI images including short tau inversion recovery scan and T1-weighted spin echo scans were assessed using the Spondyloarthritis Research Consortium of Canada (SPARCC) score and SPARCC MRI SIJ structural score by two independent readers.

Results

Higher mean score of inflammatory (SPARCC) was seen in r-axSpA patients when compared with nr-axSpA patients (8.08 vs 4.37, P<0.05). Frequencies of MRI structural lesions in r-axSpA patients and nr-axSpA patients were as follows: erosion (65.84 vs 88.23%, P=0.002), backfill (33.17 vs 13.73%, P<0.001), fat metaplasia (79.21 vs 60.78%, P=0.01), and ankylosis (37.13 vs 1.96%, P<0.001). Patients with r-axSpA had a higher mean score for fat metaplasia (8.93 vs 4.06, P=0.0003) and ankylosis (4.49 vs 0.04, P<0.001).

Conclusion

More active inflammatory and chronic structural damages except for erosion were seen in r-axSpA patients than nr-axSpA patients, while higher percentage of nr-axSpA patients presented with erosion in MRI.

Advances in Juvenile Spondyloarthritis

PURPOSE

To provide an overview of recent studies on pathogenesis, diagnosis, and management of juvenile spondyloarthritis (JSpA).

RECENT FINDINGS

Recent studies show differences in gut microbiome in patients with JSpA in comparison to healthy controls. There is increased recognition of the impact of the innate immune system on disease pathology. Normative reference on MRI of sacroiliac (SI) joints in children is now available. However, there is significant variability in interpretation of MRI of SI joints in children and a need for standardization. NSAIDs, physical therapy, and Tumor Necrosis Factor Inhibitors (TNFi) remain the mainstay of management for patients with JIA who have polyarthritis, sacroiliitis, and/or enthesitis as per recent ACR guidelines. Newer therapeutic options beyond TNFi are needed to manage patients who fail TNFi. This review highlights some of the recent advances in our knowledge of JSpA pathophysiology, diagnosis, and treatment. It also identifies areas in need of further research and standardization to improve our understanding and outcomes in JSpA.

Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part II: Structural damage lesions

Magnetic resonance imaging (MRI) is the imaging modality of choice for identifying sacroiliitis in juvenile idiopathic arthritis (JIA). Besides active lesions of sacroiliitis, of which bone marrow edema (BME) is the key feature, structural damage lesions can also be detected. Structural changes include erosion, sclerosis, fat lesion, backfill and ankylosis, and are more common at later stages. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the course of the disease and evaluating treatment options. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of structural damage of sacroiliitis. This atlas can serve as a reference for assessing structural lesions of SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 1, Active Lesions.

Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part I: Active lesions

Magnetic resonance imaging (MRI) is an increasingly important tool for identifying involvement of the sacroiliac joints (SIJ) in juvenile idiopathic arthritis (JIA). The key feature for diagnosing active sacroiliitis is bone marrow edema (BME), but other features of active arthritis such as joint space inflammation, inflammation in an erosion cavity, capsulitis and enthesitis can be seen as well. Structural changes may also be seen. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the disease course, choice of therapeutics and evaluating treatment response. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of SIJ inflammation. This atlas demonstrates fundamental MRI disease features of active inflammation in a format that can serve as a reference for assessing SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 2, Structural Lesions.

Morphological characteristics of sacroiliac joint MRI lesions in axial spondyloarthritis and control subjects

OBJECTIVES

To investigate sacroiliac joint(SIJ) MRI inflammation, structural and degenerative lesion characteristics in patients with axial spondyloarthritis(axSpA) and various control groups.

METHODS

Patients with axSpA(n = 41) and lumbar disc herniation(n = 25), women with(n = 46) and without(n = 14) post-partum(childbirth within 4-16 months) buttock/pelvic pain, cleaning assistants(n = 26), long-distance runners(n = 23) and healthy men(n = 29) had MRI of the SIJs prospectively performed. MRI lesions were assessed on 9 slices covering the cartilaginous compartment by two experienced readers according to the definitions of the Spondyloarthritis Research Consortium of Canada(SPARCC) SIJ inflammation and structural scores, and were evaluated according to depth and extent. Other morphological characteristics were also analysed.

RESULTS

Total depth scores for bone marrow oedema(BME) and fat lesion(FAT) and total extent score for erosion were statistically significantly highest in axSpA, while scores for sclerosis were numerically highest in women with post-partum pain. Maximum BME depth > 10mm was frequently and exclusively found in axSpA and post-partum women(39% vs 14-17%) while FAT depth > 5mm was predominantly found in axSpA(76% vs 0-10%). Erosions were primarily seen in axSpA, especially when extensive(≥4 or confluent; 17% vs 0%). Capsulitis was absent in non-axSpA groups. BME and FAT in the ligamentous compartment were primarily found in axSpA(17/22% vs 0/2% in non-axSpA groups). In non-axSpA, osteophytes(axSpA vs non-axSpA: 0% vs 3-17%) and vacuum phenomenon(7% vs 30-66%) were more frequent, and the joint space was wider(mean(SD) 1.5(0.9)mm vs 2.2(0.5)mm).

CONCLUSIONS

FAT depth > 5mm, but not BME depth > 10mm, could almost differentiate axSpA patients from all other groups. When excluding post-partum women, BME >5mm and erosion were highly specific for axSpA.

Development and Validation of 3 Preliminary MRI Sacroiliac Joint Composite Structural Damage Scores In a 5-year Longitudinal Axial Spondyloarthritis Study

OBJECTIVE

In axial spondyloarthritis (axSpA), sacroiliac joint (SIJ) erosion is often followed by fat metaplasia in an erosion cavity (backfill), and subsequently ankylosis. We aimed to combine the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ structural score for erosion, backfill, and ankylosis into 3 versions of a novel preliminary axSpA magnetic resonance imaging (MRI) SIJ Composite Structural Damage Score (CSDS) and to test these.

METHODS

Thirty-three patients with axSpA, followed for 5 years after initiation of tumor necrosis factor inhibitor, had MRIs of the SIJs at baseline, and yearly thereafter. Three versions of CSDS were calculated based on different weightings of erosion, backfill, and ankylosis: (1) equal weighting: CSDS_equal = (erosion × 0.5) + backfill + ankylosis; (2) advanced stages weighting more: CSDS_stepwise = (erosion × 1) + (backfill × 4 ) + (ankylosis × 6); and (3) advanced stages overruling earlier stages ("hierarchical") with "<" meaning "overruled by": CSDS_hierarchical = (erosion × 1) < (backfill × 4) < (ankylosis × 6).

RESULTS

At baseline, all CSDS correlated positively with SPARCC fat and ankylosis scores and modified New York radiography grading, and negatively with the Bath Ankylosing Spondylitis Disease Index and SPARCC SIJ inflammation scores. CSDS_stepwise and CSDS_hierarchical (not CSDS_equal) correlated positively with symptom duration and the Bath Ankylosing Spondylitis Metrology Index, and closer with SPARCC ankylosis score and modified New York radiography grading than CSDS_equal. The adjusted annual progression rate for CSDS_stepwise and CSDS_hierarchical (not CSDS_equal) was higher the first year compared with fourth year (P = 0.04 and P = 0.01). Standardized response mean (baseline to Week 46) was moderate for CSDS_hierarchical (0.64) and CSDS_stepwise (0.59) and small for CSDS_equal (0.25).

CONCLUSION

Particularly CSDS_stepwise and CSDS_hierarchical showed construct validity and responsiveness, encouraging further validation in larger clinical trials. The potential clinical implication is assessment of SIJ damage progression by 1 composite score.

Utility of magnetic resonance imaging in Crohn's associated sacroiliitis: A cross-sectional study

OBJECTIVE

Prevalence of sacroiliitis in Crohn's disease (CD) is variable depending on defining criteria. This study utilized standardized sacroiliac joint (SIJ) magnetic resonance imaging (MRI) to identify sacroiliitis in CD patients and its association with clinical and serological markers.

METHODS

Consecutive adult subjects with CD prospectively enrolled from an inflammatory bowel disease clinic underwent SIJ MRI. Data collected included CD duration, history of joint/back pain, human leukocyte antigen-B27 status, Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Disease Activity Index, Harvey Bradshaw Index (HBI) for activity of CD, Ankylosing Spondylitis Disease Activity Score, and various serologic markers of inflammation. Three blinded readers reviewed MRIs for active and structural lesions according to the Spondyloarthritis Research Consortium of Canada modules.

RESULTS

Thirty-three CD patients were enrolled: 76% female, 80% White, median age 36.4 years (interquartile range 27.2-49.0), moderate CD activity (mean HBI 8.8 ± SD 4.5). Nineteen subjects (58%) reported any back pain, 13 of whom had inflammatory back pain. Four subjects (12%) showed sacroiliitis using global approach and 6 (18%) met Assessment of SpondyloArthritis international Society MRI criteria of sacroiliitis. Older age (mean 51.2 ± SD 12.5 vs. 37.2 ± 14; P = .04), history of dactylitis (50.0% vs. 3.4%, P = .03) and worse BASMI (4.1 ± 0.7 vs. 2.4 ± 0.8, P ≤ .001) were associated with MRI sacroiliitis; no serologic measure was associated.

CONCLUSION

There were 12%-18% of CD patients who had MRI evidence of sacroiliitis, which was not associated with back pain, CD activity or serologic measures. This data suggests that MRI is a useful modality to identify subclinical sacroiliitis in CD patients.

Data-driven definitions for active and structural MRI lesions in the sacroiliac joint in spondyloarthritis and their predictive utility

Objectives

To determine quantitative SI joint MRI lesion cut-offs that optimally define a positive MRI for inflammatory and structural lesions typical of axial SpA (axSpA) and that predict clinical diagnosis.

Methods

The Assessment of SpondyloArthritis international Society (ASAS) MRI group assessed MRIs from the ASAS Classification Cohort in two reading exercises where (A) 169 cases and 7 central readers; (B) 107 cases and 8 central readers. We calculated sensitivity/specificity for the number of SI joint quadrants or slices with bone marrow oedema (BME), erosion, fat lesion, where a majority of central readers had high confidence there was a definite active or structural lesion. Cut-offs with ≥95% specificity were analysed for their predictive utility for follow-up rheumatologist diagnosis of axSpA by calculating positive/negative predictive values (PPVs/NPVs) and selecting cut-offs with PPV ≥ 95%.

Results

Active or structural lesions typical of axSpA on MRI had PPVs ≥ 95% for clinical diagnosis of axSpA. Cut-offs that best reflected a definite active lesion typical of axSpA were either ≥4 SI joint quadrants with BME at any location or at the same location in ≥3 consecutive slices. For definite structural lesion, the optimal cut-offs were any one of ≥3 SI joint quadrants with erosion or ≥5 with fat lesions, erosion at the same location for ≥2 consecutive slices, fat lesions at the same location for ≥3 consecutive slices, or presence of a deep (i.e. &gt;1 cm depth) fat lesion.

Conclusion

We propose cut-offs for definite active and structural lesions typical of axSpA that have high PPVs for a long-term clinical diagnosis of axSpA for application in disease classification and clinical research.

Structural changes in the sacroiliac joint on MRI and relationship to ASDAS inactive disease in axial spondyloarthritis: a 2-year study comparing treatment with etanercept in EMBARK to a contemporary control cohort in DESIR

Background

Limited information is available on the impact of treatment with a tumor necrosis factor inhibitor (TNFi) on structural lesions in patients with recent-onset axial spondyloarthritis (axSpA). We compared 2-year structural lesion changes on magnetic resonance imaging (MRI) in the sacroiliac joints (SIJ) of patients with recent-onset axSpA receiving etanercept in a clinical trial (EMBARK) to similar patients not receiving biologics in a cohort study (DESIR). We also evaluated the relationship between the Ankylosing Spondylitis Disease Activity Score (ASDAS) and change in MRI structural parameters.

Methods

The difference between etanercept (EMBARK) and control (DESIR) in the net percentage of patients with structural lesion change was determined using the SpondyloArthritis Research Consortium of Canada SIJ Structural Score, with and without adjustment for baseline covariates. The relationship between sustained ASDAS inactive disease, defined as the presence of ASDAS < 1.3 for at least 2 consecutive time points 6 months apart, and structural lesion change was evaluated.

Results

This study included 163 patients from the EMBARK trial and 76 from DESIR. The net percentage of patients with erosion decrease was significantly greater for etanercept vs control: unadjusted: 23.9% vs 5.3%; P = 0.01, adjusted: 23.1% vs 2.9%; P = 0.01. For the patients attaining sustained ASDAS inactive disease on etanercept, erosion decrease was evident in significantly more than erosion increase: 34/104 (32.7%) vs 5/104 (4.8%); P < 0.001. A higher proportion had erosion decrease and backfill increase than patients in other ASDAS status categories. However, the trend across ASDAS categories was not significant and decrease in erosion was observed even in patients without a sustained ASDAS response.

Conclusions

These data show that a greater proportion of patients achieved regression of erosion with versus without etanercept. However, the link between achieving sustained ASDAS inactive disease and structural lesion change on MRI could not be clearly established.

Trial registration

EMBARK: ClinicalTrials.gov identifier: NCT01258738, Registered 13 December 2010; DESIR: ClinicalTrials.gov identifier: NCT01648907, Registered 24 July 2012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02428-8.

The utility of magnetic resonance imaging lesion combinations in the sacroiliac joints for diagnosing patients with axial spondyloarthritis. A prospective study of 204 participants including post-partum women, patients with disc herniation, cleaning staff, runners and healthy persons

OBJECTIVES

To investigate the diagnostic utility of different combinations of SI joint MRI lesions for differentiating patients with axial SpA (axSpA) from other conditions with and without buttock/pelvic pain.

METHODS

A prospective cross-sectional study included patients with axSpA (n = 41), patients with lumbar disc herniation (n = 25), women with (n = 46) and without (n = 14) post-partum (birth within 4-16 months) buttock/pelvic pain and cleaning assistants (n = 26), long-distance runners (n = 23) and healthy men (n = 29) without pain. Two independent readers assessed SI joint MRI lesions according to the Spondyloarthritis Research Consortium of Canada MRI definitions and pre-defined MRI lesion combinations with bone marrow oedema (BME) and fat lesions (FAT), respectively. Statistical analyses included the proportion of participants with scores above certain thresholds, sensitivity, specificity, positive and negative predictive values and likelihood ratios.

RESULTS

BME adjacent to the joint space (BME@joint space) was most frequent in axSpA (63.4%), followed by women with post-partum pain (43.5%), but was present in nearly all groups. BME adjacent to fat lesions (BME@FAT) and BME adjacent to erosions (BME@erosion) were only present in axSpA patients and in women with post-partum pain, but scores ≥3 and ≥4, respectively, were only seen in axSpA patients. FAT@erosion was exclusively recorded in axSpA patients. FAT@joint space and FAT@sclerosis were present in most groups, but with higher scores in the axSpA group.

CONCLUSION

BME@joint space and FAT@joint space were frequent in axSpA but also in other conditions, reducing the diagnostic utility. FAT@erosion, and BME@FAT, BME@erosion and FAT@sclerosis above certain thresholds, were exclusively seen in axSpA patients and may thus have diagnostic utility in the differentiation of axSpA from other conditions.

Repeatability and reproducibility of MRI apparent diffusion coefficient applied on four different regions of interest for patients with axial spondyloarthritis and healthy volunteers scanned twice within a week

Objectives:

The apparent diffusion coefficient (ADC) may be used as a biomarker for diagnosis and/or monitoring treatment response in patients with axial spondyloarthritis (axSpA), but this requires reliable ADC measurements. This study assessed test–retest repeatability and reproducibility of ADC measurements using four different region of interest (ROI) settings.

Methods:

In this prospective study, the sacroiliac joints (SIJs) of 25 patients with axSpA and 24 age- and sex-matched healthy volunteers were imaged twice at a mean interval of 6.8 days in a 1.5 T scanner using, multishot echoplanar diffusion-weighted sequences. ADCs at four ROI settings were assessed: 5 mm and 10 mm anatomic band-shaped, 15 mm linear, and 40 mm² circular.

Results:

Intraclass correlation coefficient (ICC) assessments showed that the interstudy repeatability was good for median ADC (ADC_med) and 95th-percentile ADC (ADC₉₅) measurements in patients with axSpA (0.77–0.83 and 0.75–0.83, respectively), but poor-to-moderate in healthy subjects (0.27–0.55 and 0.13–0.37, respectively). For all ROI settings, intrareader reproducibility was excellent for ADC_med-measurements (ICC:0.85–0.99) and moderate-to-excellent for ADC₉₅ measurements (ICC:0.68–0.96). The 5 mm ROI had the least estimated bias and highest level of agreement on Bland–Altman plots. The interreader reproducibility was moderate (ICC:0.71). The 15 mm linear ROI produced significantly greater ADC_med and ADC₉₅ measurements than all other ROI settings (p < 0.01–0.02), except for the circular ROI ADC₉₅ measurements.

Conclusion:

ROI settings influence ADC measurements. Interstudy repeatability of SIJ ADC measurements is independent of ROI settings. However, the 5 mm ROI showed the least bias and random error and seems preferable.

Advances in knowledge:

ADC measurements are affected by ROI settings, and this should be taken into account when assessing ADC maps.

Plasma heat shock protein 90 levels in patients with spondyloarthritis and their relation to structural changes: a cross-sectional study

Aim: Heat shock protein 90 (Hsp90) is a molecular chaperone regulating immune response. We aimed to assess systemic Hsp90 as a biomarker for spondyloarthritis (SpA). Materials & methods: Total of 80 axial SpA (axSpA) and 22 psoriatic arthritis patients and a corresponding number of age- and sex-matched healthy controls (HC) were included. Plasma Hsp90 levels were measured by ELISA. Results: Hsp90 was significantly increased in axSpA patients compared with HC (median interquartile range: 15.7 [10.5-19.8] vs 8.3 [6.6-11.8] ng/ml, p < 0.001). Moreover, Hsp90 was superior to C-reactive protein in differentiating axSpA (and both radiographic axSpA [r-axSpA] and nonradiographic-axSpA) from HC. Hsp90 levels correlated with bone marrow edema of sacroiliac joints in r-axSpA patients (r = 0.594, p = 0.019). Conclusion: Hsp90 could become a biomarker for active inflammation in r-axSpA, and can better distinguish axSpA patients from healthy subjects than C-reactive protein.

Recommendations of the Mexican College of Rheumatology for the Management of Spondyloarthritis

OBJECTIVES

To update the recommendations for the management of patients with Spondyloarthritis (SpA) in the Mexican population, and identify which variables could influence patient management.

MATERIAL AND METHODS

A group of 15 experts in SpA translated, analyzed and modified the recommendations of the Mexican College of Rheumatology (CMR) and the International Society for the Assessment of Spondyloarthritis (ASAS)/European League Against Rheumatism (EULAR) 2016 group through a systematic review of the literature by two external reviewers during the period from 2015 to 2018 using the grade of recommendation, Oxford levels of evidence, percentage of concordance (Delphi).

RESULTS

Compared to previous recommendations, there were no significant changes from the year 2015. However, we modified the five fundamental principles and reduced the number of recommendations to ten by incorporating the first item in the text and combining five recommendations into two and adding a further recommendation. We confirmed the tendency to use glucocorticoids for patients with inflammatory activity and scarce access to biologicals. We identified the sociodemographic and clinical characteristics of patients with SpA and their influence on the application of the recommendations.

CONCLUSIONS

The ten recommendations of the CMR and the analysis of the characteristics of the Mexican patients with SpA focussed on step therapy, including pharmacological and non-pharmacological therapies, in a spectrum from easily accessible to high-tech substances available to a small percentage of the population.

Impact of tumor necrosis factor α inhibitors on MRI inflammation in axial spondyloarthritis assessed by Spondyloarthritis Research Consortium Canada score: A meta-analysis

Spondyloarthritis Research Consortium Canada (SPARCC) score is an effective magnetic resonance imaging (MRI) evaluation method for inflammation in axial spondyloarthritis. Previously published meta-analyses have shown tumor necrosis factor α inhibitors (TNFi) had great effectiveness on improving disease activity and function in axial spondyloarthritis. However, there still has no one that concentrates on the impact of TNFi on MRI inflammation. We conduct a meta-analysis to summarize the impact of TNFi on MRI inflammation in axial spondyloarthritis using SPARCC score. Comprehensive search was conducted in the databases of OVID Medline, OVID EMBASE, and Cochrane library on November 14, 2020. We investigated the differences in SPARCC score of sacroiliac joint and spine, before and after TNFi treatment in patients with axial spondyloarthritis. SPARCC score was further compared in the subgroup by diagnostic category and TNFi types. In addition, clinical assessment indicators including ankylosing spondylitis disease activity score, bath ankylosing spondylitis disease activity index, bath ankylosing spondylitis functional index, c-reactive protein were also analyzed. Data were pooled by mean differences (MD) with 95% confidence intervals (CI) and publication bias was assessed by Egger's test. Jadad scale was applied to assess the quality of included trials. Compared with control group, TNFi significantly improved SPARCC score of sacroiliac joints (n = 11, MD = 2.86, 95% CI 2.50, 3.23) and spine (n = 5, MD = 1.87,95%CI 1.27, 2.46). This effect was consistent among subgroups by different diagnostic category (ankylosing spondylitis, non-radiographic axial spondyloarthritis) and TNFi types (adalimumab, certolizumab pegol). Analysis of clinical assessment indicators also confirmed the therapeutic effect on axial spondyloarthritis. Egger's test suggested no possibility of publication bias. This meta-analysis shows that TNFi are effective to improve MRI inflammation in patients with axial spondyloarthritis and the treatment effectiveness is not affected by diagnostic category and TNFi types.

Update of imaging in the diagnosis and management of axial spondyloarthritis

Imaging of the spine and sacroiliac joints has acquired a central role in the diagnosis and classification of axial spondyloarthritis (axSpA) in the earliest phases of the disease. New definitions of specific imaging lesions, particularly in magnetic resonance imaging (MRI), have been recently updated and revised by the ASAS MRI working group to reach a standardized understanding and diagnosis of axSpA among rheumatologists. Recognizing the misleading pitfalls of MRI lesions and differential diagnosis also represents an essential issue in clinical practice to avoid false-positive findings and establish the diagnosis of axSpA with careful regard to the clinical context, clinical signs, and biological tests. This review summarizes the current evidence on the different imaging modalities of the sacroiliac joints and the spine with their application in the clinical setting of SpA and their main pitfalls; it also highlights the newest emerging imaging techniques.