OP0026 CLINICAL AND IMAGING-BASED CHARACTERIZATION OF A PROSPECTIVE COHORT OF PATIENTS WITH AXIAL PSORIATIC ARTHRITIS (AXIAL PsA). GESPIC-AXIAL PsA: RESULTS OF AN INTERIM ANALYSIS

Background

Psoriatic arthritis (PsA) is a chronic inflammatory disease, which is subsumed together with axial spondyloarthritis (axial SpA) under the umbrella term spondyloarthritis, whose clinical presentations are very heterogeneous. Axial involvement (axial PsA) has been described to be present in 34% of PsA patients [1] and has been systematically investigated only retrospectively or in cross-sectional studies [2]. Although axial PsA seems to have similar characteristics to axial SpA, it is not clear whether axial PsA and axial SpA, are a spectrum of the same disease with different expression patterns or different diseases with great similarities.

Objectives

To prospectively investigate the clinical and imaging morphology patterns in a well-defined cohort of patients with axial PsA from the German SPondyloarthritis Inception Cohort (GESPIC).

Methods

Prospective, longitudinal, observational study of patients with an imaging confirmed diagnosis of axial PsA. In addition to clinical and laboratory characterization, conventional radiographs and magnetic resonance imaging (MRI) - scans of the entire spine and sacroiliac joints (SIJs) are performed at the baseline visit and patients are followed up every 6 months according to a predefined protocol. After 2 years, additional imaging (X-ray and MRI) is performed for follow-up. In this interim analysis baseline data are presented.

Results

Between August 2019 and December 2021, 85 axial PsA patients were included. The mean age was 45.2 ± 12.9 years with a proportion of 55.3% female patients. Peripheral involvement was present in 43 (50.6%) patients, HLA-B27 was positive in 39 (45.9%), and C-reactive protein was elevated (>5mg/l) in 27 (31.8%) patients. Inflammatory back pain (IBP) in the discretion of the treating rheumatologist was present in 64 (75.3%) patients (Table 1). The modified New York criteria were fulfilled in 44.9% (n=35). MRI of the SIJ showed active inflammatory changes in 44 (55%) and structural changes in 59 (73.8%) patients. MRI of the spine showed active inflammation in 60% (n=48). Exclusively active and/or structural changes of the spine without changes in the SIJ were seen in 18.8% (n=15) (Figure 1).

Table 1.

Characteristics of patients with axial PsA

ParametersAxial PsA (n=85)Age in years (mean ± SD)45.2 ± 12.9Female sex, n (%)47 (55.3%)Inflammatory back pain (IBP) present, n (%)64 (75.3%)Peripheral Involvement, n (%)43 (50.6%)Nail Involvement, n (%)39 (45.9%)PASI-Score (mean ± SD)3.3 ± 5.1BASDAI (mean ± SD), 0-104.9 ± 2.0BASFI (mean ± SD), 0-103.8 ± 2.5ASDAS-CRP (mean ± SD)2.8 ± 1.0DAPSA (mean ± SD)14.5 ± 9.2HLA-B 27 positive, n (%)39 (45.9%)CRP >5mg/l, n (%)27 (31.8%)

ASDAS-CRP =Ankylosing Spondylitis Disease Activity Score - CRP, BASDAI = Bath Ankylosing Spondylitis Disease Activity Index, BASFI =Bath Ankylosing Spondylitis Functional Index, CRP = C-reactive protein, DAPSA = Disease Activity in PSoriatic Arthritis-Score, PASI = Psoriasis Area Severity Index, PsA = Psoriatic arthritis, SD = standard deviation.

Figure 1.

MRI-imaging patterns of axial PsA patients (n=80*). MRI= magnetic resonance imaging, SIJs= sacroiliac joints. *Full imaging data available for 80 patients only due to variable reasons.

Conclusion

In the here presented interims analysis of the baseline data of our prospective cohort study of patients with an imaging-based diagnosis of axial PsA, it is shown that these patients are less frequently HLA-B27 positive and more frequently female when compared to previously described cohorts of “classical” axial SpA patients. Noteworthy, nearly 20% of the patients showed an isolated spinal involvement without active or structural changes in the SIJs.

References

[1]Gladman, D.D., et al., Psoriatic arthritis (PSA)--an analysis of 220 patients. Q J Med, 1987. 62(238): p. 127-41.

[2]Feld, J., et al., Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison. Nat Rev Rheumatol, 2018. 14(6): p. 363-371.

Acknowledgements

The GESPIC-axial PsA cohort is partially supported by an independent research grant from Novartis.

We would especially like to thank C. Höppner, C. Lorenz, and all referring rheumatologists for their tireless support.

Disclosure of Interests

Henriette Käding: None declared, Susanne Lüders: None declared, Mikhail Protopopov: None declared, Judith Rademacher: None declared, Valeria Rios Rodriguez: None declared, Laura Spiller: None declared, Murat Torgutalp: None declared, Denis Poddubnyy: None declared, Fabian Proft Speakers bureau: AMGEN, AbbVie, BMS, Celgene, Janssen, MSD, Novartis, Pfizer, Roche, UCB.

Consultant of: AbbVie, Celgene, Janssen, Novartis, UCB.

Grant/research support from: Novartis, Lilly, UCB.

OP0152 A DEEP LEARNING FRAMEWORK FOR MRI DETECTION OF ACTIVE INFLAMMATORY AND STRUCTURAL CHANGES IN THE SACROILIAC JOINT CONSISTENT WITH AXIAL SPONDYLOARTHRITIS: AN INTERNATIONAL COLLABORATIVE STUDY

Background

Magnetic resonance tomography (MRI) plays a key role in the early diagnosis of axial spondyloarthritis (axSpA). However, the detection of changes indicative of axSpA requires specific expertise, which poses a challenge to non-specialized centers. Deep learning (an advanced machine learning method) based on training an artificial neural network may facilitate and support diagnostics in clinical practice.

Objectives

To create a reliable deep learning tool for the detection of active inflammatory and structural changes indicative of axSpA on MRI of sacroiliac joints.

Methods

In this study, MRIs of sacroiliac joints from 477 patients from four cohorts (GESPIC-AS, GESPIC-Crohn, GESPIC-Uveitis and OptiRef comprising 266 patients with and 211 without axSpA) were used to develop a deep learning framework (randomly divided into training, n=404, and validation, n=73, datasets). MRIs from the ASAS cohort (n=116) were used for independent testing (test dataset). Each examination in the training/validation dataset was evaluated for the presence of active inflammatory and structural changes indicative of SpA by six experienced, trained and calibrated readers and by seven expert readers in the test dataset. The presence of the changes was defined as the majority vote amongst readers. Discordant cases in the training/validation dataset underwent consensus reading. In addition, the test dataset was evaluated by three radiologists not specifically trained in SpA. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity.

Results

The prevalence of positive imaging findings for active inflammatory/structural changes indicative of axSpA was 41%/51% in the training/validation dataset and 22%/22% in the test dataset. The model for the detection of active inflammatory changes showed an AUC of 0.91 (0.83 – 0.97) – Figure 1 – and an accuracy of 84% on the validation dataset; the corresponding sensitivity and specificity were 96% and 76%, respectively. Despite a substantially lower prevalence of active inflammatory changes in the test dataset, the model showed good generalization with an AUC of 0.91 (0.84−0.97) and an accuracy of 75%; the sensitivity and specificity were 88% and 71%, respectively. The model demonstrated a similar performance on the validation and test datasets for the detection of active inflammatory changes fulfilling the ASAS definition. The model for the detection of structural changes indicative of axSpA showed good performance on the validation dataset with an AUC of 0.90 (0.82-0.96) for the detection of structural changes and an overall accuracy of 85%. The associated sensitivity and specificity were 95% and 75%, respectively. The model showed reasonable generalization to new data with an AUC of 0.89 (0.81−0.96) and an accuracy of 79%; the sensitivity and specificity were 85% and 78%, respectively. Overall, the model performed close to the individual human experts - Figure 1.

Conclusion

The developed framework allowed the detection of active inflammatory and structural changes indicative of axSpA on MRI. This approach may be used as an assistant tool in the diagnostic workflow.

Acknowledgements

GESPIC-AS has been financially supported by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung - BMBF). GESPIC-Crohn has been supported by the Clinical Research Unit grant from the Berlin Institute of Health (BIH). GESPIC-Uveitis has been supported by a research grant from AbbVie. OptiRef has been supported by a research grant from Novartis. The Assessment of Spondyloarthritis International Society (ASAS) has supported the project with a research grant and provided access to the MRI images of the ASAS calssifiaction cohort.

We want to thank colleagues who performed annotation of the images from the ASAS classification cohort: Pedro Machado, Mikkel Ostergaard, Suzanne Juhl Pedersen, Ulrich Weber. Further, we thank Torsten Karge for the development of the MRI reading interface for GESPIC and OptiRef images, Joel Paschke for development of the scoring interface for ASAS images.

LCA is grateful for her participation in the BIH Charité–Junior Clinician and Clinician Scientist Program and KKB is grateful for his participation in the BIH Charité Digital Clinician Scientist Program all funded by the Charité–Universitätsmedizin Berlin and the Berlin Institute of Health. JR is grateful for her participation in the BIH Charité–Junior Clinician and Clinician Scientist Program.

Disclosure of Interests

None declared

OP0048 DIAGNOSING AXIAL SPONDYLOARTHRITIS: ESTIMATION OF THE DISEASE PROBABILITY IN PATIENTS WITH A PRIORI DIFFERENT LIKELIHOODS OF THE DIAGNOSIS

Background:

The diagnostic approach in axial spondyloarthritis (SpA) relies on a estimation of the post-test disease probability that is based on evaluation of positive and negative results of diagnostic tests in the context of the pre-test disease probability.

Objectives:

To evaluate the diagnostic value of SpA parameters and their combination for the diagnosis of axial SpA in patients with an a priori different probability of the diagnosis.

Methods:

A total of 361 patients with chronic back pain and suspicion of axial SpA (181 referred by primary care physicians or orthopaedists, 180 recruited via an online screening tool) received a structured rheumatologic examination as a part of the OptiRef study [1], which resulted into a diagnosis or exclusion of axial SpA. The prevalence of axial SpA indicating the pre-test probability was 40% in the physician-referred subgroup and 20% in the online screening subgroup. Sensitivities, specificities, and likelihood ratios (LRs) for SpA features were determined in both subgroups and the respective post-test probabilities of axial SpA were calculated.

Results:

The relative diagnostic value of single SpA features varied substantially between the groups with different referral pathways – see the online disease probability calculator http://www.axspa.de/calculator.html. It can be seen that the diagnostic values of the SpA parameters vary substantially between the groups. For instance, HLA-B27 positivity increased the probability of the presence of axial SpA by 35% to 55% in online-screened patients and by 22% to 62% in physician-referred patients. Furthermore, the absence of HLA-B27 resulted in a sharp decrease in the probability of the presence of axial SpA in physician-referred patients (from 40% to 6%). This decrease was less sharp in the online screening group (from 20% to 10%). Furthermore, combinations of parameters performed differently in the studied subgroups. Figure 1 illustrates that the observed differences in the diagnostic values of the SpA parameters in different subgroups were only clinically relevant in the presence of a low number of positive test results. For instance, combining IBP with anterior uveitis increased the post-test probability for axial SpA to 78% in the online screening group and to 87% in the physician-referred group, whereas using HLA-B27 positivity and active sacroiliitis on MRI in combination with IBP resulted in a surge in the post-test probability of the presence of axial SpA to around 95% in both groups.

Conclusion:

The diagnostic value of a single diagnostic test in the clinical practice is not fixed and a number of factors including the referral pathway can affect it. Fluctuation of the diagnostic values is especially relevant when the number of positive parameters is low (1-2).

References:

[1]Proft F, et al. Semin Arthritis Rheum. 2020;50:1015-1021.

Acknowledgements:

The OptiRef study was supported by a research grant from Novartis.

Disclosure of Interests:

None declared

POS1007 OPTIMIZING A REFERRAL STRATEGY FOR PATIENTS WITH A HIGH PROBABILITY OF AXIAL SPONDYLOARTHRITIS: THE ROLE OF AGE AND SYMPTOM DURATION

Background:

One of the most important prerequisites for a timely diagnosis of axial spondyloarthritis (axSpA) is the early referral of a patient with back pain to a rheumatologist. In the past years a number of referral strategies has been proposed, most of them in line with the ASAS referral recommendations [1] and with a similar performance – about 30-40% of the referred patients can be diagnosed with axSpA after examination by a rheumatologist. In addition to physician-based strategies, an online self-referral (OSR) strategy has been recently proposed and evaluated about 20% of the patients being diagnosed with axSpA after rheumatologic evaluation [2].

Objectives:

The objective of the current analysis was to investigate the role of age and symptom duration for the optimization of a physician-based and an OSR strategy for axSpA.

Methods:

In the OptiRef study, patients with chronic back pain and suspicion of axSpA either referred by primary care physicians /orthopedists using the Berlin referral tool (=physician based) or based on a referral recommendation of an OSR were evaluated by rheumatologists in a specialized center [2]. All patients underwent a structured examination including imaging that resulted into the final diagnosis of axSpA or no axSpA. The relationship between age, symptom duration and the likelihood of axSpA diagnosis was evaluated in this analysis.

Results:

A total of 360 patients (180 presented via the OSR and 180 referred by the physician based referral strategy) were included in this analysis. Patient’s characteristics are shown in Table 1. A total of 71 patients (39.4%) in the physician-based group and 35 patients (19.4%) in the OSR group were finally diagnosed with axSpA. The heatmaps depicting the relationship between the proportions of patients diagnosed with axSpA and age plus symptom duration (Figure 1) showed a clear decline of the axSpA probability with increasing age. In the physician-referred group, however, axSpA was diagnosed even in patients who were above 50 years at the time-point of the examination, while there were only few patients with axSpA in the self-referred group aged 40-49 years, and none in the age group ≥50 years. Interestingly, there was no clear relationship between symptom duration and probability of the diagnosis: axSpA was diagnosed in a substantial proportion of patients even with a long history of back pain (>12 years) in both subgroups.

Conclusion:

The probability of axSpA is high in patients suffering from back pain and aged <40 years with a substantial decline thereafter. Therefore, a referral strategy based on self-evaluation of symptoms should be more focused on a younger patient population, while physician-based strategies do not require such a restriction.

References:

[1]Poddubnyy D, et al. Ann Rheum Dis 2015 Aug; 74(8):1483-1487.

[2]Proft F, et al. Semin Arthritis Rheum. 2020; 50(5):1015-1021.

Table 1.

Patient characteristics

TotalN=360Berlin toolN=180Self-referralN=180p-valueDiagnosis of axial SpA, n (%)106 (29.4%)71 (39.4%)35 (19.4%)<0.0001Age, years, mean (SD)36.9 (10.4)37.2 (11.5)36.6 (9.2)>0.99Male sex, n (%)177 (49.2%)100 (55.6%)77 (42.8%)0.02Back pain duration, years, mean (SD)7.9 (7.6)6.5 (6.9)9.2 (8.1)<0.0001HLA-B27 positive, n (%)141 (40.9%)104 (59.8%)37 (21.6%)<0.0001CRP elevation, n (%)52 (14.8%)34 (19.4%)18 (10.2%)0.02Inflammatory back pain, n (%)204 (56.7%)103 (57.2%)101 (56.1%)0.92Figure 1.

Heatmaps depicting the proportions of patients diagnosed with axSpA in relation to age and symptom duration in the physician-based (A) and OSR (B) groups.

Acknowledgements:

We would like to thank all orthopaedists and primary care physicians who referred their patients. Further, we thank Dr. Anne-Katrin Weber and Dr. Susanne Lüders for the data collection support, Annegret Langdon for the data management support and Torsten Karge for set-up and support of the online screening tool.

Funding statement

The OptiRef study was supported by an unrestricted research grant from Novartis.

Disclosure of Interests:

None declared.

Protective regulation of the ACE2/ACE gene expression by estrogen in human atrial tissue from elderly men

Data from animal experiments and clinical investigations suggest that components of the renin-angiotensin system are markedly affected by sex hormones. However, whether estrogen affects human atrial myocardium has not been investigated yet. In this study, we determined the effects of estrogen on key components of atrial renin-angiotensin system: angiotensin-converting enzyme, responsible for generation of angiotensin II and angiotensin-converting enzyme 2, counteracting majority of AngII effects, and different renin-angiotensin system receptors, AT1R, AT2R, and MAS. First, the expression levels of estrogen receptors mRNA were determined in right atrial appendages obtained from patients undergoing heart surgery. The amounts of estrogen receptor α and estrogen receptor β mRNA were similar between women ( n = 14) and men ( n = 10). Atrial tissue slices (350 µm) were prepared from male donors which were exposed to estrogen (1-100 nM; n = 21) or stimulated at 4 Hz for 24 h in the presence or absence of 100 nM estrogen ( n = 16), respectively. The administration of estrogen did not change mRNA levels of estrogen receptors, but activated MAP kinases, Erk1/2. Furthermore, estrogen increased the amounts of angiotensin-converting enzyme 2-mRNA (1.89 ± 0.23; P < 0.05) but reduced that of angiotensin-converting enzyme-mRNA (0.78 ± 0.07, P < 0.05). In addition, the transcript levels of AT2R and MAS were upregulated by estrogen. Pacing of tissue slices significantly increased the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at both the mRNA and protein level. During pacing, administration of estrogen substantially lowered the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at the transcript (0.92 ± 0.21 vs. 2.12 ± 0.27 at 4 Hz) and protein level (0.94 ± 0.20 vs. 2.14 ± 0.3 at 4 Hz). Moreover, estrogen elicited anti-inflammatory and anti-oxidative effects on renin-angiotensin system-associated downstream effectors such as pro-oxidative LOX-1 and pro-inflammatory ICAM-1. An antagonist of estrogen receptor α reversed these anti-inflammatory and anti-oxidative effects of estrogen significantly. Overall, our results demonstrated that estrogen modifies the local renin-angiotensin system homeostasis and achieves protective effects in atrial myocardium from elderly men. Impact statement The present study demonstrates that estrogen affects the human atrial myocardium and mediates protective actions through estrogen receptors-(ER) dependent signaling. Estrogen substantially modulates the local RAS via downregulation of ACE and simultaneous upregulation of ACE2, AT2R and MAS expression levels. This is indicative of a shift of the classical RAS/ACE axis to the alternative, protective RAS/ACE2 axis. In support of this view, estrogen attenuated the expression of RAS-associated downstream effectors, LOX-1, and ICAM-1. A specific antagonist of ERα reversed the anti-inflammatory and anti-oxidative effects of estrogen in paced and non-paced atrial tissue slices. In summary, our data demonstrate the existence of protective effects of estrogen in atrial tissue from elderly men which are at least in part, mediated by the regulation of local RAS homeostasis.

[Dose area product of pediatric VCUG with regard to the strongly lowered German diagnostic reference levels]

PURPOSE

To compare the dose area products of pediatric VCUG in daily practice with the dramatically reduced official German diagnostic reference levels, which are based on selected data.

MATERIALS AND METHODS

413 consecutive pediatric VCUG examinations were analyzed.

RESULTS

The mean dose area product of all examinations was 0.97 dGycm². This is below the lowest reference level that is valid for neonates. In 12 cases (5.6 %) the achieved dose area product was higher than the corresponding reference level.

CONCLUSION

Using the available techniques for radiation protection, it is possible in the daily routine to meet the official diagnostic reference levels for children, which have been reduced by up to 80 %, even though these levels are based on a selected, possibly non-representative data set.

Reducing conduct problems among children of battered women

This study was an experimental evaluation of an intervention designed to reduce conduct problems among children of battered women. Participants were 36 families (mothers and children) in which the mother had sought shelter because of relationship violence and had at least 1 child (4-9 years old) with clinical levels of conduct problems. The intervention consisted of 2 primary components: (a) providing instrumental and emotional support and (b) teaching child management skills to mothers. Families were randomly assigned to either the intervention condition or the existing services comparison condition and were assessed on 5 occasions over 16 months after shelter departure. Compared with families receiving existing services, children in the intervention condition improved at a faster rate, the proportion of children displaying clinical levels of conduct problems was greatly diminished, and mothers displayed greater improvements in child management skills.

[Evaluation of rapid gradient-echo and turbo-spin-echo sequences in MRT of focal liver lesions using 0.5 tesla]

The value of rapid T1- and T2-weighted fast field (T1-FFE, T2-FFE) gradient-echo sequences and T2 weighted turbo-spin echo (TSE) sequences in the diagnosis of focal liver lesions using 0.5 Tesla was compared with conventional spin-echo sequences (SE). Amongst 88 liver lesions T1-SE sequences showed 98%, T2-TSE sequences showed 92%, T2-SE sequence showed 84%, T1-FFE sequence showed 78% and T2-FFE sequence showed 69%. Direct comparison has shown that TSE sequences are able to demonstrate significantly more lesions (p < 0.05) than T2-SE sequences. Quantitative assessment has shown that the tumor/liver contrast/noise ratio in the T1-SE sequence was 118% higher than in the T1-FFE sequence (p < 0.001). Comparison of T2 weighted sequences has shown that the tumour/liver contrast/noise ratio was 45% higher in the TSE sequence than in the T2-SE and 239% higher than in the T2-FFE sequence (p < 0.001). The results indicate that the TSE sequence should be used instead of the conventional T2-SE sequence because of the reduced time (about 40%), due to improved image quality and increased demonstration rate of liver lesions. Neither T1-FFE nor T2-FFE are suitable, when using moderate field strength, to replace T1-SE or TSE sequences.