Imaging to predict early relapses after treatment discontinuation in patients with large vessel giant cell arteritis - A cohort study

OBJECTIVES

To investigate the value of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in predicting relapse after treatment discontinuation in patients with large-vessel giant cell arteritis (LV-GCA).

METHODS

This study included patients with LV-GCA whose treatment was discontinued between 2018 and 2023. All patients underwent PET/CT and/or MRI at the time of treatment discontinuation in clinical remission. Qualitative and quantitative PET/CT scores, by measuring standardized uptake values (SUV), and semiquantitative MRI scores of the aorta and supraaortic vessels were compared between patients who relapsed within 4 months after treatment discontinuation and those who did not.

RESULTS

Forty patients were included (median age 67.4 years, interquartile range (IQR) 60.8-74.0; 77.5 % females). Eleven patients (27.5 %) relapsed after treatment discontinuation (time to relapse 1.9 months, IQR 1.4-3.3). Patients who relapsed were comparable to those who remained in remission with respect to the presence of active vasculitis on MRI and/or PET/CT (54.5% vs. 58.6 %, p = 1.0), the number of segments with vasculitic findings on MRI (0, IQR 0.0-1.5, vs. 2, IQR 0.0-3.0, p = 0.221) or the highest SUV artery/liver ratio on PET/CT (1.5, IQR 1.4-1.6, vs. 1.3, IQR 1.2-1.6, p = 0.505). The median number of vasculitic segments on PET/CT was 2.5 (IQR 0.5-4.5) in those with vs. 0 (IQR 0.0-1.5, p = 0.085) in those without relapse, and the PET/CT scores 4.5 (IQR 0.75-8.25) vs. 0 (IQR 0.0-3.0, p = 0.172).

CONCLUSION

PET/CT or MRI at treatment stop did not predict relapse and may not be suited to guide treatment decisions in patients with LV-GCA in remission.

Plasma mtDNA as a possible contributor to and biomarker of inflammation in rheumatoid arthritis

OBJECTIVES

Neutrophil extracellular trap formation and cell-free DNA (cfDNA) contribute to the inflammation in rheumatoid arthritis (RA), but it is unknown if mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) is more abundant in the circulation. It is unclear if DNA concentration measurements may assist in clinical decision-making.

METHODS

This single-center prospective observational study collected plasma from consecutive RA patients and healthy blood donors. Platelets were removed, and mtDNA and nDNA copy numbers were quantified by polymerase chain reaction (PCR).

RESULTS

One hundred six RA patients and 85 healthy controls (HC) were recruited. Circulating median mtDNA copy numbers were increased 19.4-fold in the plasma of patients with RA (median 1.1 x108 copies/mL) compared to HC (median 5.4 x106 copies/mL, p<0.0001). Receiver operating characteristics (ROC) curve analysis of mtDNA copy numbers identified RA patients with high sensitivity (92.5%) and specificity (89.4%) with an area under the curve (AUC) of 0.97, p <0.0001 and a positive likelihood ratio of 8.7. Demographic, serological (rheumatoid factor (RF) positivity, anti-citrullinated protein antibodies (ACPA) positivity) and treatment factors were not associated with DNA concentrations. mtDNA plasma concentrations, however, correlated significantly with disease activity score-28- erythrocyte sedimentation rate (DAS28-ESR) and increased numerically with increasing DAS28-ESR and clinical disease activity index (CDAI) activity. MtDNA copy numbers also discriminated RA in remission (DAS28 <2.6) from HC (p<0.0001). Also, a correlation was observed between mtDNA and the ESR (p = 0.006, R= 0.29). Similar analyses showed no significance for nDNA.

CONCLUSION

In contrast to nDNA, mtDNA is significantly elevated in the plasma of RA patients compared with HC. Regardless of RA activity, the abundance of circulating mtDNA is a sensitive discriminator between RA patients and HC. Further validation of the diagnostic value of mtDNA testing is required.

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.

Early axial spondyloarthritis according to the ASAS consensus definition: characterisation of patients and effectiveness of a first TNF inhibitor in a large observational registry

OBJECTIVE

To characterise the population fulfilling the Assessment of SpondyloArthritis international Society (ASAS) consensus definition of early axial spondyloarthritis (axSpA) and to determine the effectiveness of a first tumour necrosis factor inhibitor (TNFi) in early versus established axSpA in a large observational registry.

METHODS

A total of 3064 patients with axSpA in the Swiss Clinical Quality Management registry with data on duration of axial symptoms were included (≤2 years=early axSpA, N=658; >2 years=established axSpA, N=2406). Drug retention was analysed in patients starting a first TNFi in early axSpA (N=250) versus established axSpA (N=874) with multiple-adjusted Cox proportional hazards models. Adjusted logistic regression analyses were used to determine the achievement of the ASAS criteria for 40% improvement (ASAS40) at 1 year.

RESULTS

Sex distribution, disease activity, impairments of function and health-related quality of life were comparable between patients with early and established axSpA. Patients with established disease were older, had more prevalent axial radiographical damage and had a higher impairment of mobility. A comparable TNFi retention was found in early versus established disease after adjustment for age, sex, human leucocyte antigen-B27 status, education, body mass index, smoking, elevated C reactive protein and sacroiliac inflammation on MRI (HR 1.05, 95% CI 0.78 to 1.42). The adjusted ASAS40 response was similar in the two groups (OR 1.09, 95% CI 0.67 to 1.78). Results were confirmed in the population fulfilling the ASAS classification criteria.

CONCLUSION

Considering the recent ASAS definition of early axSpA, TNFi effectiveness seems comparable in early versus established disease.

Serious infection risk of tofacitinib compared to biologics in patients with rheumatoid arthritis treated in routine clinical care

Recently, serious infections related to the use of tofacitinib (TOF) for treatment of rheumatoid arthritis (RA) have raised considerable interest. This study aimed to compare the risk for serious infections in patients with RA upon receiving TOF versus biologic disease-modifying antirheumatic drugs (bDMARDs) by age at treatment initiation. We identified adult RA patients exposed to TOF or bDMARDs using data collected by the Swiss registry for inflammatory rheumatic diseases (SCQM) from 2015 to 2018. The event of interest was the first non-fatal serious infection (SI) during drug exposure. Missing or incomplete SI dates were imputed as either the lower (left) or upper (right) limit of the known occurrence interval. The ratio of SI hazards (HR) of TOF versus bDMARDs was estimated as a function of age using covariate-adjusted Cox regression applied to each type of imputed time-to-SI. A total of 1687 patients provided time at risk for a first SI during study participation and drug exposure for 2238 different treatment courses, 345 for TOF and 1893 for bDMARDs. We identified 44 (left imputation) or 43 (right imputation), respectively, first SIs (12/12 on TOF versus 32/31 on bDMARDs). Left and right imputation produced similar results. For patients aged ≥ 69 years, the treatment HR started to be increased (lower limit of 95% confidence intervals (LLCIs) > 1). By the age of 76, the difference between TOF and bDMARDs started to be clinically relevant (LLCIs > 1.25). For patients aged < 65 years, the data were insufficient to draw conclusions. Our results suggest that we should expect an increased risk for SIs in older patients treated with TOF compared to bDMARDs supporting a cautious use of TOF in these patients.

Anaemia is associated with higher disease activity in axial spondyloarthritis but is not an independent predictor of spinal radiographic progression: data from the Swiss Clinical Quality Management Registry

OBJECTIVE

As anaemia represents a biomarker for increased radiographic damage in rheumatoid arthritis, we aimed to investigate whether it independently predicts spinal radiographic progression in axial spondyloarthritis (axSpA).

METHODS

AxSpA patients with available haemoglobin levels from the prospective Swiss Clinical Quality Management Registry were included for comparison of patients with and without anaemia. Spinal radiographic progression was assessed according to the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) in patients with ankylosing spondylitis (AS) if ≥ 2 sets of spinal radiographs were available every 2 years. The relationship between anaemia and progression (defined as an increase ≥ 2 mSASSS units in 2 years) was analysed with generalized estimating equation models after adjustment for the Ankylosing Spondylitis Disease Activity Score (ASDAS) and potential confounding, as well as after multiple imputations of missing values.

RESULTS

A total of 212/2522 axSpA patients presented with anaemia (9%). Anaemic patients had higher clinical disease activity, higher acute phase reactants and more severe impairments in physical function, mobility and quality of life. In the subgroup of patients with AS (N = 433), a comparable mSASSS progression was found in anaemic and non-anaemic patients (OR 0.69, 95% CI 0.25 to 1.96, p = 0.49). Age, male sex, baseline radiographic damage and ASDAS were associated with enhanced progression. The results were confirmed in complete case analyses and with progression defined as the formation of ≥ 1 syndesmophyte in 2 years.

CONCLUSION

Although anaemia was associated with higher disease activity in axSpA, it did not additionally contribute to the prediction of spinal radiographic progression. Key Points • Anaemia is associated with higher disease activity and more severely impaired physical function, mobility and quality of life in axSpA. • Anaemia does not provide an additional value to ASDAS for prediction of spinal radiographic progression.

Prior polymyalgia rheumatica is associated with sonographic vasculitic changes in newly diagnosed patients with giant cell arteritis

OBJECTIVES

To investigate the hypothesis that a history of polymyalgia rheumatica (PMR) is associated with a more severe and damaging disease course in newly diagnosed giant cell arteritis (GCA) patients.

METHODS

Retrospective analysis of GCA patients diagnosed between 12/2006 and 05/2021. We compared vascular ultrasound findings (presence of vasculitis and vascular stenosis) in GCA patients with and without prior PMR.

RESULTS

49 of 311 GCA patients (15.8%) had prior PMR in median 30.6 (IQR 7.1-67.3) months before GCA diagnosis. Patients with prior PMR had more often large vessel vasculitis (LVV) (51.0% vs 25.0%, p< 0.001) and stenosis within the vasculitic segments (18.4% vs 3.1%, p< 0.001) on ultrasound. In multivariable analysis, prior PMR remained significantly associated with LVV (OR 7.65, 95% CI 2.72-23.97, p< 0.001). Polymyalgic symptoms at GCA diagnosis in the patients without prior PMR were not associated with a higher prevalence of LVV (p= 0.156).

CONCLUSION

Patients with a diagnosis of PMR before GCA diagnosis had two times more often large vessel involvement and significant more vasculitic stenoses on ultrasound examination than patients without prior PMR. Pre-existing PMR is an independent risk factor for more extensive and advanced ultrasound findings at GCA diagnosis. The contribution of subclinical vasculitis to disease associated damage has to be further studied.

Obesity Represents a Persisting Health Issue in Axial Spondyloarthritis, Particularly Affecting Socially Disadvantaged Patients

OBJECTIVE

Obesity is an important comorbidity in axial spondyloarthritis (axSpA); however, the prevalence of obesity in axSpA compared with the general population and associated socioeconomic factors remain unknown.

METHODS

This repeated cross-sectional study compared BMI (kg/m2) groups of patients with axSpA to the Swiss population at 3 timepoints (2007, 2012, and 2017). BMI categories were compared by different age, sex, and education categories using the chi-square goodness of fit test. Unpaired, 1-sided t tests were used to compare the BMI in patients with axSpA between the different timepoints.

RESULTS

Compared to the general population, patients with axSpA had a higher proportion of overweight and obesity: 18.9% of all patients with axSpA were obese, compared to 11.3% of the Swiss population in 2017. Comparison of BMI groups within sex, age, and education groups consistently showed a trend toward higher rates of overweight and obesity in axSpA. Further, patients with axSpA, especially females, showed a trend of increasing BMI over the studied 10 years. At every time point, overweight and obese patients were significantly more likely to be male, were older, and had higher disease activity than patients with normal weight. Obesity was associated with a deprived socioeconomic status as indicated by a higher proportion of patients with manual labor jobs and lower levels of education.

CONCLUSION

The prevalence of obesity was significantly higher among patients with axSpA compared to the Swiss population, with socially disadvantaged individuals being the most affected. There is an urgent need to initiate prevention strategies for obesity in patients with axSpA.

Rapid glucocorticoid tapering regimen in patients with giant cell arteritis: a single centre cohort study

OBJECTIVES

We evaluated the feasibility of a rapid glucocorticoid tapering regimen to reduce glucocorticoid exposure in patients with giant cell arteritis (GCA) treated with glucocorticoids only.

METHODS

Newly diagnosed patients with GCA treated with a planned 26-week glucocorticoid tapering regimen at the University Hospital Basel were included. Data on relapses, cumulative steroid doses (CSD) and therapy-related adverse effects were collected from patients' records.

RESULTS

Of 47 patients (64% women, median age 72 years), 32 patients (68%) had relapsed. Most relapses were minor (28/32) and 2/3 of those were isolated increased inflammatory markers (19/32). Among major relapses, one resulted in permanent vision loss. The median time until relapse was 99 days (IQR 71-127) and median glucocorticoid dose at relapse was 8 mg (IQR 5-16). Nine of 47 patients stopped glucocorticoids after a median duration of 35 weeks and did not relapse within 1 year. Median CSD at 12 months was 4164 mg which is lower compared with published data. Glucocorticoid-associated adverse effects occurred in 40% of patients, most frequently were new onset or worsening hypertension (19%), diabetes (11%) and severe infections (11%).

CONCLUSION

We could demonstrate that 32% of patients remained relapse-free and 19% off glucocorticoids at 1 year after treatment with a rapid glucocorticoid tapering regimen. Most relapses were minor and could be handled with temporarily increased glucocorticoid doses. Consequently, the CSD at 12 months was much lower than reported in published cohorts. Thus, further reducing treatment-associated damage in patients with GCA by decreasing CSD seems to be possible.

Preclinical characterization of the Toll-like receptor 7/8 antagonist MHV370 for lupus therapy

Genetic and in vivo evidence suggests that aberrant recognition of RNA-containing autoantigens by Toll-like receptors (TLRs) 7 and 8 drives autoimmune diseases. Here we report on the preclinical characterization of MHV370, a selective oral TLR7/8 inhibitor. In vitro, MHV370 inhibits TLR7/8-dependent production of cytokines in human and mouse cells, notably interferon-α, a clinically validated driver of autoimmune diseases. Moreover, MHV370 abrogates B cell, plasmacytoid dendritic cell, monocyte, and neutrophil responses downstream of TLR7/8. In vivo, prophylactic or therapeutic administration of MHV370 blocks secretion of TLR7 responses, including cytokine secretion, B cell activation, and gene expression of, e.g., interferon-stimulated genes. In the NZB/W F1 mouse model of lupus, MHV370 halts disease. Unlike hydroxychloroquine, MHV370 potently blocks interferon responses triggered by specific immune complexes from systemic lupus erythematosus patient sera, suggesting differentiation from clinical standard of care. These data support advancement of MHV370 to an ongoing phase 2 clinical trial.

HLA-B27 as a predictor of effectiveness of treatment with TNF inhibitors in axial spondyloarthritis: data from the Swiss Clinical Quality Management Registry

OBJECTIVE

To explore the impact of the human leucocyte antigen (HLA)-B27 on the effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA).

METHODS

A total of 1109 patients with available HLA-B27 status (831 B27+ patients and 278 B27- patients) fulfilling the Assessment of Spondyloarthritis international Society classification criteria for axSpA from the prospective Swiss Clinical Quality Management Registry initiating a first TNFi were included. Drug retention was investigated with multiple adjusted Cox proportional hazard models with imputation of missing values. Multiple-adjusted logistic regression analyses were used to assess the proportion of patients reaching 50% reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50) at 1 year.

RESULTS

B27+ and B27- patients differed with regard to age, sex, BASDAI, C-reactive protein (CRP), body mass index, enthesitis, uveitis, and classification status. After adjustment for potential confounders for the relationship between HLA-B27 and drug effectiveness (sex and family history of spondyloarthritis), a higher risk of drug discontinuation was found in B27- patients (HR 1.53, 95% CI 1.27-1.83). This difference decreased after additional adjustment for parameters which may act as mediators (HR 1.30, 95% CI 1.30-1.55). Male sex and elevated C-reactive protein (CRP) levels were consistently associated with longer retention. Comparable results were obtained for BASDAI50 responses.

CONCLUSION

The HLA-B27 genotype is an important predictor of treatment effectiveness. Male sex and CRP seem, however, to better describe variability of response in individual patients. This data may help avoiding potential discrimination of B27- individuals with regard to TNFi initiation. Key Points • HLA-B27 is a predictor of effectiveness of TNF inhibitors in axial spondyloarthritis. • Variability of response in individual patients is better defined by sex and objective markers of disease activity, such as C-reactive protein.

Mitochondrial DNA: a novel indicator of active inflammation in ANCA-associated vasculitides

OBJECTIVES

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) includes granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). ANCA triggers neutrophil extracellular trap formation, which releases either mitochondrial (mt) DNA or nuclear DNA (n) DNA, contributing to inflammation. Our aim was to prospectively examine the extent and nature of circulating DNA in AAV and the clinical utility of DNA quantification.

METHODS

DNA was isolated from platelet-free plasma of consecutive GPA and MPA patients and healthy controls (HC). mtDNA and nDNA copy numbers were quantified by PCR. Clinical data including the Birmingham Vasculitis Activity Score (BVAS), were collected.

RESULTS

Ninety-two HC (median age 51 years, 58.7% female) and 101 AAV patients (80 GPA, 21 MPA, median age 64 years, 50.5% female, BVAS range: 0-30) were included. Median mtDNA copies were 13-fold higher in AAV than HC; nDNA concentrations did not differ. Patients with active AAV (BVAS > 0) had 4-fold higher median mtDNA copies than patients in remission (P= 0.03). mtDNA, unlike nDNA, correlated with BVAS (r = 0.30, P= 0.002) and was associated with AAV activity at multivariable analysis. Receiver operating characteristic curve analysis indicates that mtDNA quantification differentiates active AAV (BVAS >0) from HC with 96.1% sensitivity and 98.9% specificity (AUC 0.99). In 27 AAV patients with follow-up, mtDNA changes but not CRP or ANCA-titers correlated with BVAS changes (r = 0.56, P= 0.002).

CONCLUSIONS

mtDNA, unlike nDNA, is elevated in the plasma of AAV patients and may contribute to systemic inflammation. mtDNA could be superior to established biomarkers in the laboratory monitoring of AAV activity.

Long delay from symptom onset to first consultation contributes to permanent vision loss in patients with giant cell arteritis: a cohort study

OBJECTIVES

To characterise factors associated with permanent vision loss (PVL) and potential reasons for the therapeutic delay contributing to PVL in giant cell arteritis (GCA).

METHODS

Retrospective analysis of GCA patients diagnosed at the University Hospital Basel between December 2006 and May 2021.

RESULTS

Of 282 patients with GCA (64% females), 49 (17.4%) experienced PVL. In 43/49 (87.8%) PVL occurred before treatment. Of these, 24 (55.8%) patients had first non-ocular symptoms and eventually sought consultation when PVL occurred in a median of 21 (IQR 14.75-31.0) days after the first symptoms. Only five of the 24 patients had consulted a physician before PVL, but GCA diagnosis was missed. Treatment was initiated rapidly after diagnosis (median 1 day (IQR 0.0-7.0)). PVL on therapy occurred in six patients in a median of 40 (IQR 20.5-67.3) days after treatment started. In two of those, glucocorticoids were tapered too quickly.In multivariable analysis, patients with PVL were older (OR 1.17, 95% CI 1.07 to 1.29, p=0.001) and reported more frequently jaw claudication (OR 3.52, 95% CI 1.02 to 13.16, p=0.051). PVL was present in 18 (42.9%) of the 42 patients with vasculitic ultrasound findings in all six temporal artery segments. The incidence of PVL over 15 years did not decline (Spearman rank=0.3, p=0.68).

CONCLUSION

The prevalence of GCA-associated PVL remains high. Associated factors were advanced age, jaw claudication and ultrasound findings consistent with vasculitis in all six temporal artery segments. Despite preceding non-ocular GCA symptoms weeks before the onset of PVL, most patients were not seen by a rheumatologist before PVL occurred.

Comparison of drug retention of TNF inhibitors, other biologics and JAK inhibitors in RA patients who discontinued JAK inhibitor therapy

OBJECTIVES

JAK Inhibitors (JAKi) are recommended DMARDs for patients with moderate-to-severe RA who failed first-line therapy with methotrexate. There is a lack of data allowing an evidence-based choice of subsequent DMARD therapy for patients who had discontinued JAKi treatment. We aimed to compare the effectiveness of TNF inhibitor (TNFi) therapy vs JAKi vs other mode of action (OMA) biologic DMARD (bDMARD) in RA patients who were previously treated with a JAKi.

METHODS

RA patients who discontinued JAKi treatment within the Swiss RA registry SCQM were included for this observational prospective cohort study. The primary outcome was drug retention for either TNFi, OMA bDMARD or JAKi. The hazard ratio for treatment discontinuation was calculated adjusting for potential confounders. A descriptive analysis of the reasons for discontinuation was performed.

RESULTS

Four hundred treatment courses of JAKi were included, with a subsequent switch to either JAKi, TNFi or OMA bDMARD. The crude overall drug retention was higher in patients switching to another JAKi as compared with TNFi and comparable to OMA. A significant difference of JAKi vs TNFi persisted after adjusting for potential confounders.

CONCLUSION

In a real-world population of RA patients who discontinued treatment with a JAKi, switching to another JAKi resulted in a higher drug retention than switching to a TNFi. A switch to a second JAKi seems an effective therapeutic option.

The role of C5a-C5aR1 axis in bone pathophysiology: A mini-review

Bone remodeling is a physiological, dynamic process that mainly depends on the functions of 2 cell types: osteoblasts and osteoclasts. Emerging evidence suggests that complement system is crucially involved in the regulation of functions of these cells, especially during inflammatory states. In this context, complement component 5a (C5a), a powerful pro-inflammatory anaphylatoxin that binds the receptor C5aR1, is known to regulate osteoclast formation and osteoblast inflammatory responses, and has thus been proposed as potential therapeutic target for the treatment of inflammatory bone diseases. In this review, we will analyze the role of C5a-C5aR1 axis in bone physiology and pathophysiology, describing its involvement in the pathogenesis of some of the most frequent inflammatory bone diseases such as rheumatoid arthritis, and also in osteoporosis and bone cancer and metastasis. Moreover, we will examine C5aR1-based pharmacological approaches that are available and have been tested so far for the treatment of these conditions. Given the growing interest of the scientific community on osteoimmunology, and the scarcity of data regarding the role of C5a-C5aR1 axis in bone pathophysiology, we will highlight the importance of this axis in mediating the interactions between skeletal and immune systems and its potential use as a therapeutic target.

Nonhematopoietic IRAK1 drives arthritis via neutrophil chemoattractants

IL-1 receptor-activated kinase 1 (IRAK1) is involved in signal transduction downstream of many TLRs and the IL-1R. Its potential as a drug target for chronic inflammatory diseases is underappreciated. To study its functional role in joint inflammation, we generated a mouse model expressing a functionally inactive IRAK1 (IRAK1 kinase deficient, IRAK1KD), which also displayed reduced IRAK1 protein expression and cell type–specific deficiencies of TLR signaling. The serum transfer model of arthritis revealed a potentially novel role of IRAK1 for disease development and neutrophil chemoattraction exclusively via its activity in nonhematopoietic cells. Consistently, IRAK1KD synovial fibroblasts showed reduced secretion of neutrophil chemoattractant chemokines following stimulation with IL-1β or human synovial fluids from patients with rheumatoid arthritis (RA) and gout. Together with patients with RA showing prominent IRAK1 expression in fibroblasts of the synovial lining, these data suggest that targeting IRAK1 may be therapeutically beneficial. As pharmacological inhibition of IRAK1 kinase activity had only mild effects on synovial fibroblasts from mice and patients with RA, targeted degradation of IRAK1 may be the preferred pharmacologic modality. Collectively, these data position IRAK1 as a central regulator of the IL-1β–dependent local inflammatory milieu of the joints and a potential therapeutic target for inflammatory arthritis.

IgA rheumatoid factor in rheumatoid arthritis

OBJECTIVES

Rheumatoid factor (RF) is a well-established marker for the diagnosis and classification of rheumatoid arthritis (RA). Most studies evaluated IgM RF or isotype-nonspecific total RF assays. We evaluated the added value of IgA RF in this context.

METHODS

An international sample cohort consisting of samples from 398 RA patients and 1073 controls was tested for IgA RF with 3 commercial assays. For all RA patients and 100 controls essential clinical and serological data for ACR/EULAR classification were available.

RESULTS

The sensitivity of IgA RF for diagnosing RA was lower than the sensitivity of IgM RF. Differences in numerical values between IgA RF assays were observed. With all assays, the highest IgA RF values were found in patients with primary Sjögren's syndrome. Double positivity for IgM RF and IgA RF had a higher specificity for RA than either IgM RF or IgA RF. The sensitivity of double positivity was lower than the sensitivity of either IgA RF or IgM RF. Single positivity for IgA RF was at least as prevalent in controls than in RA patients. Adding IgA RF to IgM RF and anti-citrullinated protein antibodies (ACPA) did not affect RA classification. However, combined positivity for IgA RF, IgM RF and IgG ACPA had a higher specificity and lower sensitivity for RA classification than positivity for either of the antibodies.

CONCLUSIONS

IgA RF showed a lower sensitivity than IgM RF. Combining IgA RF with IgM RF and ACPA did not improve sensitivity of RA classification. Combined positivity (IgA-RF/IgM-RF/ACPA) increased specificity.

Skeletal Muscle Disorders: A Noncardiac Source of Cardiac Troponin T

BACKGROUND

Cardiac troponin (cTn) T and cTnI are considered cardiac specific and equivalent in the diagnosis of acute myocardial infarction. Previous studies suggested rare skeletal myopathies as a noncardiac source of cTnT. We aimed to confirm the reliability/cardiac specificity of cTnT in patients with various skeletal muscle disorders (SMDs).

METHODS

We prospectively enrolled patients presenting with muscular complaints (≥2 weeks) for elective evaluation in 4 hospitals in 2 countries. After a cardiac workup, patients were adjudicated into 3 predefined cardiac disease categories. Concentrations of cTnT/I and resulting cTnT/I mismatches were assessed with high-sensitivity (hs-) cTnT (hs-cTnT-Elecsys) and 3 hs-cTnI assays (hs-cTnI-Architect, hs-cTnI-Access, hs-cTnI-Vista) and compared with those of control subjects without SMD presenting with adjudicated noncardiac chest pain to the emergency department (n=3508; mean age, 55 years; 37% female). In patients with available skeletal muscle biopsies, TNNT/I1-3 mRNA differential gene expression was compared with biopsies obtained in control subjects without SMD.

RESULTS

Among 211 patients (mean age, 57 years; 42% female), 108 (51%) were adjudicated to having no cardiac disease, 44 (21%) to having mild disease, and 59 (28%) to having severe cardiac disease. hs-cTnT/I concentrations significantly increased from patients with no to those with mild and severe cardiac disease for all assays (all P<0.001). hs-cTnT-Elecsys concentrations were significantly higher in patients with SMD versus control subjects (median, 16 ng/L [interquartile range (IQR), 7-32.5 ng/L] versus 5 ng/L [IQR, 3-9 ng/L]; P<0.001), whereas hs-cTnI concentrations were mostly similar (hs-cTnI-Architect, 2.5 ng/L [IQR, 1.2-6.2 ng/L] versus 2.9 ng/L [IQR, 1.8-5.0 ng/L]; hs-cTnI-Access, 3.3 ng/L [IQR, 2.4-6.1 ng/L] versus 2.7 ng/L [IQR, 1.6-5.0 ng/L]; and hs-cTnI-Vista, 7.4 ng/L [IQR, 5.2-13.4 ng/L] versus 7.5 ng/L [IQR, 6-10 ng/L]). hs-cTnT-Elecsys concentrations were above the upper limit of normal in 55% of patients with SMD versus 13% of control subjects (P<0.01). mRNA analyses in skeletal muscle biopsies (n=33), mostly (n=24) from individuals with noninflammatory myopathy and myositis, showed 8-fold upregulation of TNNT2, encoding cTnT (but none for TNNI3, encoding cTnI) versus control subjects (n=16, P_Wald<0.001); the expression correlated with pathological disease activity (R=0.59, P_t-statistic<0.001) and circulating hs-cTnT concentrations (R=0.26, P_t-statistic=0.031).

CONCLUSIONS

In patients with active chronic SMD, elevations in cTnT concentrations are common and not attributable to cardiac disease in the majority. This was not observed for cTnI and may be explained in part by re-expression of cTnT in skeletal muscle.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03660969.

Standardisation of ACPA tests: evaluation of a new candidate reference preparation

INTRODUCTION

Commercial assays measuring antibodies to citrullinated protein/peptide (ACPA) show poor quantitative agreement. The diagnostic industry has never adopted the International Union of Immunological Societies-Centers for Disease Control and Prevention (IUIS-CDC) ACPA reference standard. Recently, the National Institute for Biological Standards and Control (NIBSC) prepared a new candidate ACPA standard (18/204). We evaluated both reference materials using different commercially available ACPA assays.

MATERIALS AND METHODS

This is an international study in which the NIBSC candidate ACPA standard and the IUIS-CDC ACPA reference material were analysed together with 398 diagnostic samples from individuals with rheumatoid arthritis (RA) and in 1073 individuals who did not have RA using nine commercial ACPA assays.

RESULTS

For both reference materials and samples from individuals with RA and individuals who did not have RA, there were large differences in quantitative ACPA results between assays. For most assays, values for the IUIS-CDC standard were lower than values for NIBSC 18/204 and the IUIS-CDC/NIBSC ratio was comparable for several, but not all assays. When NIBSC 18/204 was used as a calibrator, an improvement in alignment of ACPA results across several of the evaluated assays was obtained. Moreover, NIBSC 18/204 could align clinical interpretation for some but not all assays.

CONCLUSION

Adoption of an international standard for ACPA determination is highly desirable. The candidate NIBSC 18/204 standard improved the standardisation and alignment of most ACPA assays and might therefore be recommended to be used as reference in commercial assays.

POS0536 REFINING THE SEROLOGICAL SCORES OF THE ACR/EULAR 2010 RHEUMATOID ARTHRITIS CLASSIFICATION CRITERIA: AN INTERNATIONAL STUDY

Background

Rheumatoid factor (RF) and anti-cyclic citrullinated protein/peptide antibodies (ACPA) are included in the ACR/EULAR 2010 classification criteria for rheumatoid arthritis (RA)(1). Both markers are given the same weight in the criteria.

Objectives

As the performance characteristics differ significantly between RF and ACPA(2), we set out to refine the serological scores for RA classification.

Methods

Diagnostic samples from 398 RA patients and from 1073 diseased controls were evaluated with five RF assays (two RF IgM isotype-specific assays and three total RF assays) and five ACPA IgG assays from five different manufacturers.

Results

Firstly, we harmonized thresholds between manufacturers based on predefined specificity for low positive (at 92.5% specificity for RF and at 97.5% specificity ACPA) and high positive results (at 97.5% specificity RF and at 99.0% specificity for ACPA). Next, we determined likelihood ratios (LRs) for RF, ACPA, and combinations of both, for negative, low positive, and high positive results. The LR was higher for ACPA than for RF, for high positive results than for low positive results and for double positivity than for single positivity. Based on these data we refined the weights of serological scores for classification (Table 1).

Table 1.

Refined weights of serological scores for RA classification

RF negativeRF low positiveRF high positiveACPA negative011ACPA low positive233ACPA high positive344

Application of such refined serological weights significantly increased the area under the curve of receiver operating characteristics analysis to distinguish RA from controls, significantly reduced the serological scores in the controls as well as the number of RA misclassifications without affecting the diagnostic sensitivity.

Besides, we showed that combining predefined specificity thresholds with the refined serological scoring, reduced manufacturer-dependent variability in RA classification impacting RA classification for controls from 18.0-29.0% by ACR/EULAR to 11.0-13.0% (significantly increasing specificity) and for RA patients from 67.8-74.0% to 67.6-71.5% (without significantly affecting sensitivity).

Conclusion

Serological weight factors for RA classification can be improved by taking into account the antibody type (RF versus ACPA), the antibody level, and single or combined positivity.

References

[1]Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham COr, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis 2010; 69: 1580-8.

[2]Bossuyt X. Anticitrullinated protein antibodies: taking into account antibody levels improves interpretation. Ann Rheum Dis 2017; 76: e33.

Acknowledgements

We thank all participating diagnostic companies for the in-kind support of assays, their technical training and the constructive discussions. Furthermore, we are very thankful to the laboratory technicians of all participating laboratories for their most appreciated assistance in the performance of the RF/ACPA analyses.

Disclosure of Interests

Lieve Van Hoovels Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Grant/research support from: Thermo Fisher, Bert Vander Cruyssen: None declared, Daniela Sieghart Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Carolien Bonroy: None declared, Eszter Nagy: None declared, Rille Pullerits: None declared, Saša Čučnik: None declared, Charlotte Dahle: None declared, Ingmar Heijnen Speakers bureau: Thermo Fisher, Luca Bernasconi Speakers bureau: Thermo Fisher, Farid Benkhadra: None declared, Laura Bogaert: None declared, Stefanie Van Den Bremt: None declared, Ann Vanliedekerke: None declared, Geert Vanheule: None declared, Johan Robbrecht: None declared, Lucy Studholme: None declared, Wirth Claudine: None declared, Rüdiger Müller: None declared, Diego Kyburz: None declared, Christopher Sjowall: None declared, Alf Kastbom: None declared, Rok Jese: None declared, Boja Jovancevic: None declared, Emese Virag Kiss: None declared, Peggy Jacques: None declared, Günter Steiner Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Patrick Verschueren: None declared, Xavier Bossuyt Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher.

POS0250 PLASMA MITOCHONDRIAL DNA AS A BIOMARKER IN THE DIAGNOSIS AND FOLLOW-UP OF ANCA-ASSOCIATED VASCULITIDES

Background

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) include granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) (1, 2). ANCA recognize the antimicrobial proteins proteinase 3 (PR3) or myeloperoxidase (MPO) (1,2) and trigger the formation of neutrophil extracellular traps (NETs), which release DNA into the extracellular space and systemic circulation. This cell-free (cf)DNA induces endothelial damage, vascular inflammation and necrosis (3).

Objectives

The nature, diagnostic and prognostic value of cfDNA in AAV is still unknown. The aim of the present study was to examine the clinical utility of cfDNA quantification as a biomarker in AAV.

Methods

Total DNA was isolated from platelet-free plasma samples of healthy controls (HC) and consecutive AAV patients. Plasma and clinical data were collected at baseline and follow-up. Copy numbers were quantified by qPCR for mtDNA (ATP-6 gene) and nuclear (n) DNA (GAPDH gene) (4). Patients with eosinophilic GPA (EGPA) were excluded.

Results

Ninety-two HC (median age 51 ± 9, 48.2% female) and 104 AAV patients (median age 64 ± 10, 48% female, mean BVAS: 0; range: 0-40) were available for analysis. Eighty-four (80.8%) of these patients were diagnosed with GPA, and 20 with MPA (19.2%).

mtDNA levels were significantly elevated in AAV plasma (8.7x107 copies/ml plasma, 95% CI: 5.3x107 to 1.3 x108)), compared to HC plasma (6.7x106 copies/ml plasma, 95% CI: 5.4x106 to 9.1x107, p<0.0001). nDNA levels in contrast did not differ between AAV (4.0x106 copies/ml plasma, 95%CI: 2.7x106 to 5.0x106) and HC (3.3x106 copies/ml plasma, 95%CI: 2.4x106 to 4.7x106, p=0.30). ROC analysis showed that a cut-off value of 1.3x107 mtDNA copy numbers differentiated between AAV and HC with 89.4% sensitivity, 82.6% specificity and an AUC of 0.94. For AAV patients with active AAV, a cut-off value of 2.9x107 mtDNA copy numbers differentiated between AAV and HC with 96.1% sensitivity, 98.9% specificity and an AUC of 0.99 (Figure 1a).

Figure 1.

(a.) ROC curve for mtDNA plasma concentrations to discriminate between HC and active AAV patients (BVAS>0). AUC: area under the curve. (b.) Plasma mtDNA levels distinguish between AAV patients with active disease versus patients in a state of remission. Whiskers represent 95% CI. (c.) Plasma mtDNA levels in AAV patients correlate with the evolution of disease activity at follow-up.

With the exception of the peripheral nervous system involvement, there was no association of mtDNA elevation with any particular type of active organ involvement at the time of blood sampling. A positive correlation between all cell-free DNA species and anti-MPO antibody titres was observed, as expected (for cfDNA, nDNA and mtDNA - r=0.25, p=0.01; r=0.21, p=0.02; r=0.22, p=0.02, respectively).

AAV patients with active disease (BVAS>0) had a mean of 2.0x108 copies/ml of mtDNA in plasma which was higher compared to HC (p<0.0001) and AAV patients in remission (BVAS=0) (6.2x107copies/ml, p=0.03). For nDNA on the other hand, there were similar levels in active disease as in remission (5.3x106 and 4.8x106 copies/ml, respectively; p=0.64) (Figure 1b).

Follow-up data were available for 27 AAV patients (median follow-up: 6 ± 6 months, IQR: 12). Longitudinal changes in mtDNA levels robustly correlated with changes in BVAS (r=0.56, p=0.002, Figure 1c).

Conclusion

The quantification of cell free mtDNA - but not nDNA - copy numbers allows a sensitive and specific distinction between healthy individuals and patients with active AAV. mtDNA levels correlate cross sectionally with disease activity in AAV patients. Plasma mtDNA quantification may therefore aid in the diagnosis of AAV and in monitoring AAV activity.

References

[1]Kitching, A.R., et al. Nat Rev Dis Primers6, 71 (2020).

[2]Kallenberg, C. Nat Rev Rheumatol10, 484–493 (2014).

[3]Kessenbrock, K., et al. Nat Med15, 623–625 (2009).

[4]Giaglis S, et al. RMD Open 2021;7:e002010.(2021)

Disclosure of Interests

None declared

Multicentre study to improve clinical interpretation of rheumatoid factor and anti-citrullinated protein/peptide antibodies test results

BACKGROUND

Rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) are important biomarkers for diagnosis of rheumatoid arthritis (RA). However, there is poor harmonisation of RF and ACPA assays. The aim of this study was to refine RF and ACPA interpretation across commercial assays.

MATERIALS AND METHODS

Six total RF isotype-non-specific assays, 3 RF IgM isotype-specific assays and 9 ACPA immunoglobulin G assays of 13 different companies were evaluated using 398 diagnostic samples from patients with RA and 1073 disease controls.

RESULTS

Using cut-offs proposed by the manufacturer, there was a large variability in diagnostic sensitivity and specificity between assays. Thresholds of antibody levels were determined based on predefined specificities and used to define test result intervals. Test result interval-specific likelihood ratios (LRs) were concordant across the different RF and ACPA assays. For all assays, the LR for RA increased with increasing antibody level. Higher LRs were found for ACPA than for RF. ACPA levels associated with LRs >80 were found in a substantial fraction (>22%) of patients with RA.

CONCLUSION

Defining thresholds for antibody levels and assigning test result interval-specific LRs allows alignment of clinical interpretation for all RF and ACPA assays.

Current differentiation between radiographic and non-radiographic axial spondyloarthritis is of limited benefit for prediction of important clinical outcomes: data from a large, prospective, observational cohort

OBJECTIVE

To compare disease characteristics and outcomes between patients with axial spondyloarthritis with non-radiographic disease (nr-axSpA), bilateral grade 2 sacroiliitis (r22axSpA) and unilateral/bilateral grade 3-4 sacroiliitis (r3+axSpA) according to the modified New York criteria.

METHODS

We included patients with axial spondyloarthritis with available pelvic radiographs from the Swiss Clinical Quality Management Cohort. Retention of a first tumour necrosis factor inhibitor (TNFi) was investigated with multiple adjusted Cox proportional hazards models. The proportion of patients reaching 50% reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50) at 1 year was assessed with multiple adjusted logistic regression analyses. Spinal radiographic progression, defined as an increase in ≥2 mSASSS units in 2 years, was assessed in generalised estimating equation models.

RESULTS

From 2080 patients, those with nr-axSpA (n=485) and r22axSpA (n=443) presented with lower C reactive protein levels and less severe clinical spinal involvement compared with patients with r3+axSpA (n=1152). While TNFi retention was similar in r22axSpA and nr-axSpA, the risk of discontinuation was significantly lower in r3+axSpA (HR 0.60, 95% CI 0.44 to 0.82 vs nr-axSpA). BASDAI50 responses at 1 year were comparable in r22axSpA and nr-axSpA, with a better response associated with r3+axSpA (OR 2.05, 95% CI 1.09 to 3.91 vs nr-axSpA). Spinal radiographic progression was similar in r22axSpA and nr-axSpA and significantly higher in r3 +axSpA.

CONCLUSION

Patients with r22axSpA are comparable to nr-axSpA patients but differ from patients with more severe sacroiliac damage with regard to treatment effectiveness and spinal radiographic progression. Therefore, current differentiation between nr-axSpA and radiographic disease seems of limited use for outcome prediction.

[Rheumatoid Arthritis]

Rheumatoid Arthritis Abstract. Rheumatoid Arthritis (RA) is the most frequent chronic inflammatory joint disease with a prevalence of approximately 1% worldwide. The pathogenesis is a complex interplay of genetic, epigenetic, and environmental factors, which are still incompletely understood. The disease is characterized by a polyarticular synovitis with symmetrical involvement of small and large joints. The majority of patients has detectable autoantibodies in the serum, rheumatoid factor and anti-CCP antibodies which are specific for RA. The uncontrolled chronic joint inflammation results in destructive changes of joint cartilage and bone. An early diagnosis and initiation of treatment is therefore of central importance. Disease-modifying anti-rheumatic drugs (DMARD) are able to inhibit joint destruction and should be started as soon as possible. Therapy should be targeted to reach a state of remission. The introduction of highly effective biologic and targeted synthetic DMARD has allowed to reach this goal of therapy in many patients and to prevent disability. However, risks of medication need to be considered, as well as comorbidities.

Circulating mitochondrial DNA copy numbers represent a sensitive marker for diagnosis and monitoring of disease activity in systemic lupus erythematosus

OBJECTIVES

Cell-free DNA is involved in the pathogenesis of systemic lupus erythematosus (SLE) but the clinical value of cell-free DNA measurements in SLE is unknown. Our aim was therefore to examine the utility of mitochondrial (mt) DNA and nuclear (n) DNA quantification in SLE.

METHODS

EDTA plasma was drawn from 103 consecutive patients with SLE and from 56 healthy blood donors. mtDNA and nDNA copy numbers were quantified by PCR from cell-free plasma. Clinical parameters were recorded prospectively.

RESULTS

Circulating mtDNA copy numbers were increased 8.8-fold in the plasma of patients with SLE (median 6.6×10⁷ /mL) compared with controls (median 7.6×10⁶ /mL, p<0.0001). Among all 159 individuals, a cut-off set at 1.8×10⁷ mtDNA copies in a receiver operated curve identified patients with SLE with 87.4% sensitivity and 94.6% specificity; the area under the curve was 0.95 (p<0.0001). mtDNA levels were independent of age or gender, but correlated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) on multivariable analysis (p=0.004). Conversely, SLEDAI was associated with prednisone dose (p<0.001), anti-double stranded DNA-titres (p=0.003) and mtDNA levels (p=0.005), but not nDNA copy numbers. In 33 patients with SLE with available follow-up, the changes of mtDNA, but not those of nDNA concentrations, robustly correlated with the evolution of the SLEDAI (r=0.55, p=0.001).

CONCLUSIONS

Circulating mtDNA unlike nDNA molecules are markedly increased in SLE plasma. Regardless of disease activity, circulating mtDNA levels distinguish patients with SLE from healthy controls with high sensitivity and represent an independent marker of SLE activity.

Prediction of sustained biologic and targeted synthetic DMARD-free remission in rheumatoid arthritis patients

Objectives

The aim was to develop a prediction model of sustained remission after cessation of biologic or targeted synthetic DMARD (b/tsDMARD) in RA.

Methods

We conducted an explorative cohort study among b/tsDMARD RA treatment episode courses stopped owing to remission in the Swiss Clinical Quality Management registry (SCQM; 2008-2019). The outcome was sustained b/tsDMARD-free remission of ≥12 months. We applied logistic regression model selection algorithms using stepwise, forward selection, backward selection and penalized regression to identify patient characteristics predictive of sustained b/tsDMARD-free remission. We compared c-statistics corrected for optimism between models. The three models with the highest c-statistics were validated in new SCQM data until 2020 (validation dataset).

Results

We identified 302 eligible episodes, of which 177 episodes (59%) achieved sustained b/tsDMARD-free remission. Two backward and one forward selection model, with eight, four and seven variables, respectively, obtained the highest c-statistics corrected for optimism of c = 0.72, c = 0.70 and c = 0.69, respectively. In the validation dataset (47 eligible episodes), the models performed with c = 0.99, c = 0.80 and c = 0.74, respectively, and excellent calibration. The best model included the following eight variables (measured at b/tsDMARD stop): RA duration, b/tsDMARD duration, other pain/anti-inflammatory drug use, quality of life (EuroQol), DAS28-ESR score, HAQ score, education, and interactions of RA duration and other pain/anti-inflammatory drug use and of b/tsDMARD duration and HAQ score.

Conclusion

Our results suggest that models with up to eight unique variables may predict sustained b/tsDMARD-free remission with good efficiency. External validation is warranted.

Bilateral proximal hamstring muscle avulsion after treatment with immune checkpoint inhibitors and corticosteroids

A 66-year-old man presented with 4 weeks of bilateral buttock pain without previous trauma or intense exercise. He had been treated with immune checkpoint inhibitors because of metastasising melanoma and experienced immune-related adverse events requiring treatment with corticosteroids. Magnetic resonance imaging of the pelvis revealed bilateral avulsion of the proximal hamstring muscles. Treatment with physical therapy and nonsteroidal anti-inflammatory drugs led to a slow but lasting relief. This is, to our knowledge, the first report of symptomatic non-traumatic bilateral hamstring muscle avulsion following treatment with immune checkpoint inhibitors and corticosteroids.

Cohort profile: SCREEN-RA: design, methods and perspectives of a Swiss cohort study of first-degree relatives of patients with rheumatoid arthritis

PURPOSE

Rheumatoid arthritis (RA) is an insidious autoimmune disease, with an immunological onset years before diagnosis. Early interventions in preclinical stages could prevent or minimise the progression towards irreversible joint damage. The SCREEN-RA cohort (Evaluation of a SCREENing strategy for Rheumatoid Arthritis) aims to characterise the preclinical stages of the disease, to identify environmental risk factors, and to discover or validate novel biomarkers predictive for RA development.

PARTICIPANTS

SCREEN-RA includes an at-risk population for RA, namely first-degree relatives of patients with established RA.

FINDINGS TO DATE

The cohort started in 2009 is composed of mostly asymptomatic healthy individuals (total n=1458, 7262 person-years), with a mean age of 44 years at enrolment, 74% female and 91% Caucasian ethnicity. During the study period, 16 participants have developed RA. All participants provide baseline serum, DNA and RNA samples, and in a subset, stool samples and oral examination are performed for microbiota assessment. At enrolment, 10% of participants had asymptomatic autoimmunity associated with RA (n=147), 10% presented 'clinically suspect arthralgias' (n=143) and 3% reported arthralgias in conjunction with autoimmunity or high genetic risk (n=51). Studies with this cohort have uncovered risk factors for RA development, such as female hormonal factors, poor oral health or intestinal dysbiosis.

FUTURE PLANS

Future directions include immunological and 'multiomics' approaches to discover new biological markers of progression towards RA, as well as testing preventive interventions in 'high-risk' population.

POS0108 PLASMA MITOCHONDRIAL DNA AS A BIOMARKER IN DIAGNOSIS AND FOLLOW-UP OF SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

A fundamental role of mitochondria in systemic lupus erythematosus (SLE) was recently demonstrated (1). In brief, mitochondrial ROS participate in the formation of neutrophil extracellular traps (NETs) (2), while extrusion of cell-free mitochondria and highly oxidized interferogenic mtDNA causes disease in an animal model of SLE (3-5).

Objectives:

The diagnostic and prognostic value of cell-free DNA in SLE is still unknown. The aim of the present study was therefore to examine the clinical utility of cell-free DNA quantification as a non-invasive biomarker in SLE.

Methods:

Total DNA was isolated from platelet-free plasma samples of healthy individuals (HC) and consecutive SLE patients. Plasma and clinical data were collected at baseline and follow-up. Copy numbers were quantified by qPCR for mitochondrial (mt) DNA (ATP-6 gene) and nuclear (n) DNA (GAPDH gene).

Results:

Fifty-six HC (median age 48.3 ± 13.5, 64% female) and 103 SLE patients (median age 46.8 ± 15.8, 99% female, mean SLEDAI: 3 ± 4) were available for analysis.

mtDNA levels were significantly elevated in SLE plasma (1.3x108 copies/ml plasma, 95% CI: 7.3x107 to 1.7 x108)), compared to HC plasma (8.6x106 copies/ml plasma, 95% CI: 6.9x106 to 1.0x107, p<0.0001). nDNA levels in contrast did not differ between SLE (8.3x106 copies/ml plasma, 95%CI: 5.9x106 to 1.4 x107) and HC (1.0x107 copies/ml plasma, 95%CI: 2.0x106 to 1.5 x107, p=0.61). Receiver operating characteristic curve analysis showed that a cut-off value of 1.9x107 mtDNA copy numbers differentiated between SLE and HC with 87.4% sensitivity, 94.6% specificity and an AUC of 0.95 (Figure 1a).

mtDNA levels correlated with the SLE Disease Activity Index 2000 (SLEDAI-2K) (r=0.29, p=0.0026), less so also nDNA copy numbers (r=0.24, p=0.014). There was no association of mtDNA elevation with any particular type of SLE organ involvement and no correlation between mtDNA copy numbers in SLE plasma and dsDNA antibody levels.

Follow-up data were available for 32 SLE patients (median follow-up 4.0 months, IQR: 4.0). delta mtDNA-levels robustly correlated with changes in SLEDAI-2K (r=0.51, p=0.0012, Figure 1b).

Conclusion:

The quantification of cell free mtDNA, but not nDNA copy numbers allows a sensitive and specific distinction between healthy individuals and patients with SLE. mtDNA levels correlate cross sectionally with disease activity in SLE patients and within individual SLE patients longitudinally with the SLEDAI. Plasma mtDNA quantification may therefore aid in the diagnosis of SLE and in monitoring SLE activity.

References:

[1]Riley JS, Tait SW. Mitochondrial DNA in inflammation and immunity. EMBO Rep. 2020;21(4):e49799.

[2]West AP, Shadel GS. Mitochondrial DNA in innate immune responses and inflammatory pathology. Nat Rev Immunol. 2017;17(6):363-75.

[3]Crow MK, Olferiev M, Kirou KA. Type I Interferons in Autoimmune Disease. Annu Rev Pathol. 2019;14:369-93.

[4]Kim J, Gupta R, Blanco LP, Yang S, Shteinfer-Kuzmine A, Wang K, et al. VDAC oligomers form mitochondrial pores to release mtDNA fragments and promote lupus-like disease. Science. 2019;366(6472):1531-6.

[5]Lood C, Blanco LP, Purmalek MM, Carmona-Rivera C, De Ravin SS, Smith CK, et al. Neutrophil extracellular traps enriched in oxidized mitochondrial DNA are interferogenic and contribute to lupus-like disease. Nat Med. 2016;22(2):146-53.

Declaration of conflict of interest:

UW is coinventor of patents owned by Freiburg University; NV is coinventor of patents owned by Freiburg University.

Figure 1.

(a) Receiver operating characteristic curve for mtDNA plasma concentrations to discriminate between HC and SLE patients. AUC: area under the curve. (b) Changes in plasma mtDNA levels in SLE patients correlate with the evolution of disease activity at follow-up.

Disclosure of Interests:

None declared

AB0270 EFFECTIVENESS OF A SWITCH FROM TOFACITINIB TO BARICITINIB IN RHEUMATOID ARTHRITIS: A RETROSPECTIVE ANALYSIS OF REAL-WORLD DATA IN SWITZERLAND

Background:

Janus Kinase Inhibitors (JAKi) have recently been approved for the treatment of rheumatoid arthritis (RA) over the last years. JAKi differ in their specificity for the different JAK family members (JAK1, JAK2, JAK3 and TYK2). All three JAKis that are currently approved in Switzerland seem to have comparable efficacy on different disease stages of RA. Whether a JAKi can be effective after discontinuation of another JAKi is one of the open questions of interest according to the EULAR RA guidelines [1].

Objectives:

To study the effectiveness of baricitinib in patients with RA after discontinuation of tofacitinib.

Methods:

Longitudinal, retrospective chart review conducted between October 2019 and December 2020 of patients with RA at two Swiss centers (Kantonsspital Aarau and Inselspital Bern). Disease activity was assessed by DAS 28.

Results:

12 patients (1 male, 11 female) were treated with 4mg baricitinib/d after tofacitinib was discontinued. Mean age of the patients was 61 years, disease duration 140 months. Patients were previously treated with at least two conventional synthetic DMARDs and 75% with at least one biological DMARD. 58% of patients were positive for ACPA, 42% for rheumatoid factor. 50% of the patients suffered from erosive disease. Tofacitinib was stopped in 92% of the patients because of an insufficient response after a mean of 25.8 months. Moderate EULAR response was achieved in 83.3% of the patients after an average of 8 months treatment with baricitinib, and good EULAR response in 58.3% after an average of 10 months. There were no serious adverse events, neoplasms, opportunistic or serious infections during follow-up.

Conclusion:

The first retrospective analysis of real-world data of baricitinib following tofacitinib shows that there is a good clinical response in 70% of cases. Although limited by the number of patients this study therefore supports the notion that baricitinib after discontinuation of tofacitinib in RA patients may be an effective therapeutic option.

References:

[1]Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Annals of the Rheumatic Diseases. 2020;79(6):685-699. doi:10.1136/annrheumdis-2019-216655, p. 695

Disclosure of Interests:

Simon Kellerhals: None declared, Jennifer Amsler: None declared, Hendrik Schulze-Koops: None declared, Thomas Hügle Consultant of: GSK, Abbvie, Pfizer, Jansen, Novartis, Eli Lilly., Michael J. Nissen Consultant of: Abbvie, Celgene, Eli-Lilly, Janssen, Novartis and Pfizer., Hasler paul Consultant of: Abbvie, Lilly, Diego Kyburz Consultant of: Abbvie, Gilead, Lilly, Novartis and Pfizer, outside of the submitted work, Rudiger Muller Consultant of: Abbvie, Novartis, Grant/research support from: Bebro Pharma

POS0806 FINDINGS CONSISTENT WITH SUBCLINICAL VASCULITIS IN PATIENTS WITH NEW ONSET POLYMYALGIA: A SYSTEMATIC LITERATURE REVIEW AND A META-ANALYSIS OF COHORT DATA

Background:

GCA is characterized by cranial symptoms but imaging techniques show that patients with non-specific symptoms such as systemic inflammation or PMR may have undiagnosed large vessel (LV) GCA1. Although silent GCA in patients with clinically isolated PMR may have consequences for patients’ outcome, little is known about its prevalence and characteristics of affected patients.

Objectives:

To review data on the prevalence of silent GCA in newly diagnosed PMR patients without cranial GCA symptoms and to analyze which characteristics are associated with vascular involvement among PMR patients.

Methods:

We systematically screened PubMed, Embase and Web of Science databases and included studies screening for GCA in steroid naïve PMR patients without cranial symptoms consistent with GCA. Authors of the publications that used PET for vasculitis screening were invited to share their individual patient data (IPD) for a meta-analysis. We sought to define patient characteristics that were associated with vasculitis using univariable mixed effects logistic regression models with vascular involvement as the outcome, missing values were imputed using multilevel joint modeling multiple imputation. To fit a multivariable model with the candidate predictors we excluded variables that were hypothesized to have less medical relevance for the outcome and highly correlated inflammation markers (ESR, Lc).

Results:

Out of the 3047 studies screened independently by 2 authors (DG and TD), 13 fulfilled the inclusion criteria. These studies (published 1963-2019) reported on 543 PMR patients examined by temporal artery biopsy (n=175), ultrasound (n=110), PET or PET-CT (n=258). 115 PMR patients were diagnosed with GCA (21.2%), with prevalence ranging from 0-92%.

We collected IPD for 243 patients from 4 cohorts using PET and 3 using PET/CT for GCA diagnosis. The overall median age of patients was 72.3 years (IQR 66.4-78.0) and vasculitis was found in 65 patients (26.7%) (table 1).

Table 1.OverallPMRPMR+GCAn (%)243178 (73.3)65 (26.7)Female sex (%)146 (60.1)98 (55.1)48 (73.8)Shoulder girdle pain (%)236 (97.1)174 (97.8)62 (95.4)Pelvic girdle pain (%)174 (71.6)127 (71.3)47 (72.3)Inflammatory back pain (%)No107 (44.0)83 (46.6)24 (36.9)Yes106 (43.6)70 (39.3)36 (55.4)Lower limb pain (%)No87 (35.8)61 (34.3)26 (40.0)Yes81 (33.3)68 (38.2)13 (20.0)Weight loss (%)112 (46.1)78 (43.8)34 (52.3)CRP (mg/l) (median [IQR])46.0 [19.0, 77.7]44.0 [16.9, 74.2]52.0 [27.9, 85.0]ESR (mm/h) (mean (SD))65.2 (30.3)62.7 (30.2)72.3 (29.7)Hemoglobin (g/dl) (mean (SD))12.1 (1.5)12.2 (1.5)11.7 (1.6)Thrombocytes (1e+09/ml) (mean (SD))341.9 (106.3)323.9 (103.2)375.8 (104.6)

In the univariable analyses the following factors were most strongly associated with vasculitic PET findings: female sex (OR 2.31, CI 1.17-4.58), inflammatory back pain (OR 2.73, CI 1.32-5.64), temperature >37° (OR 1.83, CI 0.90-3.7), weight loss (OR 1.83, CI 0.96-3.51), thrombocytosis (i.e., patients with a thrombocyte count 1 SD above mean have an OR of 1.51, CI 1.05-2.18), anemia (i.e., 1 g/dl decrease in Hb below mean corresponds to an OR of 1.25, CI 1.00-1.56). Patients with lower limb pain were less likely to have vasculitis (OR 0.43, CI 0.19–0.95). The estimated ORs were very similar in the multivariable model although the 95%CIs became wider.

Conclusion:

Although the prevalence across published studies showed substantial variation, 6 out of 13 studies reported a prevalence of silent GCA in 18-40% of all PMR patients. The exploratory analysis of the collected IPD identified female sex, inflammatory back pain, fever, weight loss, absence of lower leg pain, thrombocytosis and anemia as factors associated with LV-GCA. These findings should be validated in future prospective cohort studies. The presence or absence of these factors may further aid in diagnosing LV-GCA in PMR patients.

References:

[1]Buttgereit F, Dejaco C, Matteson EL, Dasgupta B. Polymyalgia Rheumatica and Giant Cell Arteritis: A Systematic Review. JAMA. 2016 Jun 14;315(22):2442–58.

Acknowledgements:

The study is funded by the “Schweizerische Stiftung für die Erforschung der Muskelkrankheiten (SSEM)”.

Disclosure of Interests:

Daniele Silvio Gozzoli: None declared, Andrea Hemmig: None declared, Lars Hemkens: None declared, Laura Werlen: None declared, Hannah Ewald: None declared, Christoph Berger: None declared, Diego Kyburz Grant/research support from: DK reports personal fees from Abbvie, Gilead, Lilly, Novartis and Pfizer, outside of the submitted work, Stephan Imfeld: None declared, Markus Aschwanden: None declared, Mihaela Stegert: None declared, Dario Camellino: None declared, Marco Amedeo Cimmino: None declared, Corrado Campochiaro Grant/research support from: personal fees from Roche, Alessandro Tomelleri: None declared, Liesbet Henckaerts: None declared, Daniel Blockmans Speakers bureau: Paid speaker for Roche, Consultant of: Paid consultant for Roche, Patricia Moya: None declared, Hector Corominas: None declared, Russell Buchanan: None declared, Claire Owen Speakers bureau: CO has received speaking honoraria from Roche, Janssen, Novartis and Pfizer, and meeting sponsorship from Roche, UCB and Janssen, Yannick van Sleen: None declared, Elisabeth Brouwer Speakers bureau: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Consultant of: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Hiroyuki Ymashita: None declared, Thomas Daikeler: None declared

Comparative effectiveness of antitumour necrosis factor agents, biologics with an alternative mode of action and tofacitinib in an observational cohort of patients with rheumatoid arthritis in Switzerland

Background

Multiple biologic and targeted synthetic disease-modifying rheumatic drugs (b/tsDMARDs) are approved for the management of rheumatoid arthritis (RA), including TNF inhibitors (TNFi), bDMARDs with other modes of action (bDMARD-OMA) and Janus kinase inhibitors (JAKi). Combination of b/tsDMARDs with conventional synthetic DMARDs (csDMARDs) is recommended, yet monotherapy is common in practice.

Objective

To compare drug maintenance and clinical effectiveness of three alternative treatment options for RA management.

Methods

This observational cohort study was nested within the Swiss RA Registry. TNFi, bDMARD-OMA (abatacept or anti-IL6 agents) or the JAKi tofacitinib (Tofa) initiated in adult RA patients were included. The primary outcome was overall drug retention. We further analysed secondary effectiveness outcomes and whether concomitant csDMARDs modified effectiveness, adjusting for potential confounding factors.

Results

4023 treatment courses of 2600 patients were included, 1862 on TNFi, 1355 on bDMARD-OMA and 806 on Tofa. TNFi was more frequently used as a first b/tsDMARDs, at a younger age and with shorter disease duration. Overall drug maintenance was significantly lower with TNFi compared with Tofa [HR 1.29 (95% CI 1.14 to 1.47)], but similar between bDMARD-OMA and Tofa [HR 1.09 (95% CI 0.96 to 1.24)]. TNFi maintenance was decreased when prescribed without concomitant csDMARDs [HR: 1.27 (95% CI 1.08 to 1.49)], while no difference was observed for bDMARD-OMA or Tofa maintenance with respect to concomitant csDMARDs.

Conclusion

Tofa drug maintenance was comparable with bDMARDs-OMA and somewhat higher than TNFi. Concomitant csDMARDs appear to be required for optimal effectiveness of TNFi, but not for bDMARD-OMA or Tofa.

Discontinuation of biologic DMARDs in a real-world population of patients with rheumatoid arthritis in remission: outcome and risk factors

OBJECTIVES

Data from randomized controlled trials have shown the feasibility of discontinuation of bDMARD therapy in patients with RA that have reached remission. Criteria for selecting patients that are likely to remain in remission are still incompletely defined.We aimed to identify predictors of successful discontinuation of bDMARD therapy in the Swiss Clinical Quality Management (SCQM) registry, a real-world cohort of RA patients.

METHODS

RA patients in DAS28-ESR remission who stopped bDMARD/tsDMARD treatment were included. Loss of remission was defined as a DAS28-ESR > 2.6 or restart of a bDMARD/tsDMARD. Time to loss of remission was the main outcome. Kaplan-Meier methods were applied and cox regression was used for multivariable analyses adjusting for confounding factors. Missing data were imputed using multiple imputation.

RESULTS

318 patients in a bDMARD/tsDMARD-free remission were followed between 1997 and 2017. 241 patients (76%) lost remission after a median time of 0.9 years (95%CI 0.7-1.0). The time to loss of remission was shorter in women, in patients with a longer disease duration >4yrs and in patients who did not meet CDAI remission criteria at baseline. Remission was longer in patients with csDMARD therapy during b/tsDMARD free remission (HR 0.8, p= 0.05, 95%CI 0.6-1.0).

CONCLUSION

In a real-world patient population the majority of patients who discontinued b/tsDMARD treatment lost remission within <1 year. Our study confirms that fulfilment of more rigorous remission criteria and csDMARD treatment increases the chance of maintaining b/tsDMARD free remission.

Impact of the COVID-19 pandemic on the disease course of patients with inflammatory rheumatic diseases: results from the Swiss Clinical Quality Management cohort

OBJECTIVES

To investigate whether the transient reduction in rheumatology services imposed by virus containment measures during the COVID-19 pandemic was associated with disease worsening in axial spondyloarthritis (axSpA), rheumatoid arthritis (RA) or psoriatic arthritis (PsA).

METHODS

Patient-reported disease activity assessed during face-to-face visits and/or via a smartphone application were compared between three periods of each 2 months duration (before, during and after the COVID-19-wave) from January to June 2020 in 666 patients with axSpA, RA and PsA in the Swiss Clinical Quality Management cohort.

RESULTS

The number of consultations dropped by 52%, whereas the number of remote assessments increased by 129%. The proportion of patients with drug non-compliance slightly increased during the pandemic, the difference reaching statistical significance in axSpA (19.9% vs 13.2% before the pandemic, p=0.003). The proportion of patients with disease flares remained stable (<15%). There was no increase in mean values of the Bath Ankylosing Disease Activity Index, the Rheumatoid Arthritis Disease Activity Index-5 and the Patient Global Assessment in patients with axSpA, RA and PsA, respectively.

CONCLUSION

A short interruption of in-person patient-rheumatologist interactions had no major detrimental impact on the disease course of axSpA, RA and PsA as assessed by patient-reported outcomes.

[CME Rheumatology 24/Answers: DISH of the Hand and Undifferentiated Polyarthritis]

CME Rheumatology 24/Answers: DISH of the Hand and Undifferentiated Polyarthritis Abstract. We present a case with undifferentiated, unclassified polyarthritis and with peripheral diffuse idiopathic skeletal hyperostosis (DISH). We discuss the differential diagnoses of "seronegative" polyarthritis and explain the radiographic findings of the little-known peripheral aspects of DISH.

[CME Rheumatology 24: DISH of the Hand and Undifferentiated Polyarthritis]

CME Rheumatology 24: DISH of the Hand and Undifferentiated Polyarthritis Abstract. We present a case with undifferentiated, unclassified polyarthritis and with peripheral diffuse idiopathic skeletal hyperostosis (DISH). We discuss the differential diagnoses of "seronegative" polyarthritis and explain the radiographic findings of the little-known peripheral aspects of DISH.

Effectiveness of secukinumab versus an alternative TNF inhibitor in patients with axial spondyloarthritis previously exposed to TNF inhibitors in the Swiss Clinical Quality Management cohort

Objective

To compare effectiveness of treatment with secukinumab (SEC) with that of alternative tumour necrosis factor inhibitors (TNFis) in patients with axial spondyloarthritis (axSpA) after withdrawal from one or more TNFis.

Methods

Patients diagnosed as having axSpA in the Swiss Clinical Quality Management cohort were included if they had initiated SEC (n=106) or an alternative TNFi (n=284) after experiencing TNFi failure. Drug retention was investigated with matching weights propensity score (PS) analyses and multiple adjusted Cox proportional hazards models. Matching weights PS-based analyses and multiple-adjusted logistic regression analyses were used to assess the proportion of patients reaching 50% reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50) at 1 year.

Results

SEC was more often used as third-line or later-line biological drug (76% vs 40% for TNFi). Patients starting SEC had higher BASDAI, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index and C reactive protein levels. A comparable risk of drug discontinuation was found for SEC versus TNFi (HR 1.14, 95% CI 0.78 to 1.68 in the PS-based analysis and HR 1.16, 95% CI 0.79 to 1.71 in the multiple-adjusted analysis). No significant difference in BASDAI50 responses at 1 year was demonstrated between the two modes of biological drug action, with CI of estimates being, however, wide (OR for SEC vs TNFi 0.76, 95% CI 0.26 to 2.18 and 0.78, 95% CI 0.24 to 2.48 in the PS-based and the covariate-adjusted model, respectively).

Conclusion

Our data suggest a comparable effectiveness of SEC versus an alternative TNFi after prior TNFi exposure.

FRI0040 MULTI-VARIATE APPROACH INCLUDING SEROLOGY AND GENETICS FOR AN IMPROVED IDENTIFICATION OF PATIENTS AT RISK OF DEVELOPING RA

Background:

First-degree relatives of rheumatoid arthritis (RA) patients (FDR-RA) have a 3 - 5-fold increased prevalence of the disease [1]. RA development is triggered by an interaction between genetic and environmental factors.

As the field is moving towards prevention in pre-clinical stages of RA, it is key to identify individuals with imminent RA, prior to onset of symptoms, which will presumably rely on both the measurement of autoantibodies and genetic risk markers.

Objectives:

Assemble a pattern of serologic biomarkers in combination with genetics to improve the identification of individuals at high risk to develop RA.

Methods:

The cohort included 827 serum samples from 601 individuals, followed within the Swiss multicenter cohort study SCREEN-RA of FDR [2]. FDR-RA were categorized into four groups according to the presence of symptoms and systemic autoimmunity associated with RA; 1: asymptomatic FDR-RA without anti-CCP or symptoms, 416 (69%); 2: FDR-RA with clinically suspect arthralgia (CSA) [3] or with signs of arthritis, without anti-CCP, 72 (12%); 3: FDR-RAs with no signs of arthritis, positive anti-CCP test, 55 (9%); 4: FDR with signs of arthritis or CSA, positive anti-CCP-test, 58 (10%).

Serum samples were analyzed for the presence of anti-CCP (IgG, IgA), RF (IgM, IgA) and anti-RA33 (IgM, IgA, IgG) using the EliATMinstrument platform (Phadia AB, Uppsala, Sweden).

Genetic measurements were performed using the AmpliSeqTMtechnology on the Ion GeneStudioTMinstruments (Thermo Fisher Scientific, Carlsbad, USA), covered variants were analyzed using an algorithm focusing on the identification of RA patients.

Results:

The overall prevalence of biomarkers, considering results above cutoff values, was 1% for anti-CCP IgG and IgA, 10% and 2% for RF IgM and RF IgA, respectively, and 6-15% for all three anti-RA33 isotypes. Several individuals had multiple positive serology tests (Fig 1): 3.6% (22) were positive for 2 tests and 1% (6) were positive for 3 or more tests. Among the 28 individuals positive for ≥2 tests, 17 (61%) were symptomatic.

Figure 1.

Distribution of positive serology within the different groups. No positivity (none), positive for one (1), equal or more than 2 (2-5) of the serologic tests.

Nine of 604 FDR-RA subsequently developed classifiable RA and were positive for serologic biomarkers before date of RA diagnosis (Table 1). The RA converters had a mean age of 39 years (24-75 yrs) and an average follow-up time within the study of 3.6 years (1-7 yrs).

Table 1.

Biomarker status of subsequent RA converters before date of diagnosis.

RA convertersCCP IgGCCP IgARF IgMRF IgARA33 total1+++++2+−++−3−−+−+4−−+−−5−−+−−6−−−−+7−−−−+8−−−−−9−−−−−

Using an algorithm to analyze the RA-associated genetic SNPs, we could highlight 48 FDR-RA (8%) with an increased genetic risk to develop RA. 15 out of 48 individuals (31%) at high genetic risk reported CSA, and 12 out of 48 individuals (25%) displayed signs of systemic autoimmunity associated with RA.

Conclusion:

When looking at FDR it could help to not only include anti-CCP autoantibody testing but also additional biomarkers like RF and anti-RA33. Furthermore, looking at the genetic risk factors could give additional information. The combination with the multi-variate profile could even improve the early diagnosis of these patients.

References:

[1]Kuo et al. Rheumatology 2017; 56:928933

[2]Finckh et al. Ann Rheum Dis 2011; 70: S3–282

[3]van Steenbergen HW, et al. Ann Rheum Dis 2017; 76:491–496

Disclosure of Interests:

Maresa Grundhuber Grant/research support from: Thermo Fisher Scientific, Employee of: Thermo Fisher Scientific, Isabel Gehring Grant/research support from: Thermo Fisher Scientific, Employee of: Thermo Fisher Scientific, Céline Lamacchia Grant/research support from: Thermo Fisher Scientific partially supported this study, Pascale Roux-Lombard: None declared, Michael Nissen Grant/research support from: Abbvie, Consultant of: Novartis, Lilly, Abbvie, Celgene and Pfizer, Speakers bureau: Novartis, Lilly, Abbvie, Celgene and Pfizer, Ulrich Walker Grant/research support from: Ulrich Walker has received an unrestricted research grant from Abbvie, Consultant of: Ulrich Walker has act as a consultant for Abbvie, Actelion, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, MSD, Novartis, Pfizer, Phadia, Roche, Sandoz, Sanofi, and ThermoFisher, Paid instructor for: Abbvie, Novartis, and Roche, Speakers bureau: Abbvie, Actelion, Bristol-Myers Squibb, Celgene, MSD, Novartis, Pfizer, Phadia, Roche, Sandoz, and ThermoFisher, Burkhard Moeller: None declared, Diego Kyburz Grant/research support from: Abbvie, Roche, Consultant of: Abbvie, BMS, Novartis, Pfizer, Roche, UCB, Gilead, Sanofi, Speakers bureau: Pfizer, BMS, Novartis, Abbvie, Adrian Ciurea Consultant of: Consulting and/or speaking fees from AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Merck Sharp & Dohme, Novartis and Pfizer., Maryam Poorafshar Grant/research support from: Thermo Fisher Scientific, Employee of: Thermo Fisher Scientific, Axel Finckh Grant/research support from: Pfizer: Unrestricted research grant, Eli-Lilly: Unrestricted research grant, Consultant of: Sanofi, AB2BIO, Abbvie, Pfizer, MSD, Speakers bureau: Sanofi, Pfizer, Roche, Thermo Fisher Scientific

Safety and immunogenicity of tetanus/diphtheria vaccination in patients with rheumatic diseases-a prospective multi-centre cohort study

OBJECTIVES

We aimed to assess the safety and immunogenicity of a diphtheria/tetanus vaccine booster dose in three different patient groups with rheumatic diseases on a variety of immunosuppressive/immunomodulatory medications compared with healthy controls (HCs).

METHODS

We conducted a multi-centre prospective cohort study in Switzerland. We enrolled patients with RA, axial SpA/PsA, vasculitis (Behçet's disease, ANCA-associated vasculitis) and HCs. Diphtheria/tetanus vaccination was administered according to the Swiss vaccination recommendations. Blood samples were drawn before vaccination, and 1 month and 3 months afterwards. Antibody concentrations against vaccine antigens were measured by ELISA. Immunogenicity was compared between patient and medication groups. A mixed model was applied for multivariate analysis. Missing data were dealt with using multiple imputation.

RESULTS

Between January 2014 and December 2015, we enrolled 284 patients with rheumatic diseases (131 RA, 114 SpA/PsA, 39 vasculitis) and 253 HCs. Of the patients, 89% were on immunosuppressive/immunomodulatory medication. Three months post-vaccination 100% of HCs vs 98% of patients were protected against tetanus and 84% vs 73% against diphtheria. HCs and SpA/PsA patients had significantly higher responses than RA and vasculitis patients. Assessing underlying diseases and medications in a multivariate model, rituximab was the only factor negatively influencing tetanus immunogenicity, whereas only MTX treatment had a negative influence on diphtheria antibody responses. No vaccine-related serious adverse events were recorded.

CONCLUSION

Diphtheria/tetanus booster vaccination was safe. Tetanus vaccination was immunogenic; the diphtheria component was less immunogenic. Vaccine responses were blunted by rituximab and MTX.

TRIAL REGISTRATION

ClinicalTrials.gov, http://clinicaltrials.gov, Identifier: NCT01947465.

Assessment of the anti-CD40 antibody iscalimab in patients with primary Sjögren's syndrome: a multicentre, randomised, double-blind, placebo-controlled, proof-of-concept study

BACKGROUND

Primary Sjögren's syndrome is an autoimmune disease that presents as dryness of the mouth and eyes due to impairment of the exocrine glands. To our knowledge, no systemic therapies for primary Sjögren's syndrome have shown efficacy. CD40-CD154-mediated T cell-B cell interactions in primary Sjögren's syndrome contribute to aberrant lymphocyte activation in inflamed tissue, leading to sialadenitis and other tissue injury. Therefore, we investigated the safety and preliminary efficacy of iscalimab (CFZ533), a novel anti-CD40 monoclonal antibody, in patients with primary Sjögren's syndrome.

METHODS

This multicentre, randomised, double-blind, placebo-controlled, proof-of-concept study took place at ten investigational sites across Europe (UK, n=4; Germany, Switzerland, and Hungary, n=1 each) and the USA (n=3). Eligible patients were aged 18-75 years and fulfilled the 2002 American European consensus group diagnostic classification criteria for primary Sjögren's syndrome. In the double-blind phase of the trial, patients were randomly assigned (2:1) via computer-generated unique randomisation numbers to receive subcutaneous iscalimab (3 mg/kg) or placebo at weeks 0, 2, 4, and 8 (cohort 1) or intravenous iscalimab (10 mg/kg) or placebo at weeks 0, 2, 4, and 8 (cohort 2). Randomisation was stratified according to baseline intake of oral corticosteroids. At week 12, patients in both cohorts received open-label iscalimab (same dose and route) for 12 weeks. The primary objectives of the study were to assess the safety, tolerability, and efficacy of multiple doses of iscalimab in the two sequential dose cohorts. Safety and tolerability were assessed by adverse events and efficacy of iscalimab versus placebo was assessed by clinical disease activity, as measured by the change in European League Against Rheumatism Sjögren's syndrome disease activity index (ESSDAI) score after 12 weeks of treatment. Analyses were done on a per-protocol basis. The trial was registered with ClinicalTrials.gov, NCT02291029.

FINDINGS

Between Oct 22, 2014, and June 28, 2016, we assessed 82 patients for eligibility (25 for cohort 1 and 57 for cohort 2). 38 patients were excluded because of ineligibility. In cohort 1, 12 patients were randomly assigned to receive either 3 mg/kg doses of iscalimab (n=8) or placebo (n=4), and in cohort 2, 32 patients were randomly assigned to receive either intravenous 10 mg/kg doses of iscalimab (n=21) or placebo (n=11). Adverse events were similar between iscalimab treatment groups and placebo groups, with adverse events occurring in all patients in cohort 1, and in 52% and 64% of the iscalimab and placebo groups, respectively, in cohort 2. Two serious adverse events were reported (one case of bacterial conjunctivitis in cohort 1 and one case of atrial fibrillation in cohort 2), which were unrelated to treatment with iscalimab. Intravenous treatment with iscalimab resulted in a mean reduction of 5·21 points (95% CI 0·96-9·46; one-sided p=0·0090) in ESSDAI score compared with placebo. There was no signficiant difference in ESSDAI score between subcutaneous iscalimab and placebo.

INTERPRETATION

To our knowledge, this is the first randomised, placebo-controlled proof-of-concept study of a new investigational drug for primary Sjögren's syndrome that indicates preliminary efficacy. Our data suggest a role of CD40-CD154 interactions in primary Sjögren's syndrome pathology and the therapeutic potential for CD40 blockade in this disease should be investigated further.

FUNDING

Novartis Pharma.

Rheumatoid cervical pannus: feasibility of volume and perfusion quantification using dynamic contrast enhanced time resolved MRI

Background

Dynamic contrast-enhanced magnetic resonance imaging has the potential to show disease activity of rheumatoid arthritis even in complex anatomic areas as the atlantodental region.

Purpose

To demonstrate the technical feasibility of measuring synovial volume and perfusion characteristics with dynamic contrast-enhanced magnetic resonance imaging of the atlantodental region in patients with rheumatoid arthritis.

Material and Methods

Ten patients with rheumatoid arthritis and cervical spine involvement underwent dynamic contrast-enhanced magnetic resonance imaging of the cervical spine at 1.5 T. For each patient, 80 3D datasets were acquired using the commercialized Time Resolved Imaging of Contrast KineticS (TRICKS) sequence. Volumes of synovia with active synovitis on anatomical and parametric images were segmented. Synovial tissue perfusion parameters, namely plasma flow (Fp), relative plasma volume (vp), and the permeability-surface area product (PS), were calculated using a two-compartment uptake model. Statistical analysis included calculation of intra- and inter-reader agreement and a correlation of perfusion parameters with Outcome Measures in Rheumatology Clinical Trials (OMERACT) criteria.

Results

Dynamic contrast-enhanced magnetic resonance imaging as well as quantification of volume and perfusion characteristics of synovia was successful in most patients (80%). Intra- and inter-reader agreement was excellent (0.89–0.99). There was a positive correlation between OMERACT score and the permeability-surface product.

Conclusion

Dynamic contrast-enhanced magnetic resonance imaging using a 4D angiography sequence for the atlantodental region in patients with rheumatoid arthritis for quantitative and qualitative assessment of synovial volume and perfusion characteristics is technically feasible.

miR-221-3p Drives the Shift of M2-Macrophages to a Pro-Inflammatory Function by Suppressing JAK3/STAT3 Activation

Objectives: Macrophages are conventionally classified as pro-inflammatory (M1) and anti-inflammatory (M2) functional types. There is evidence for a predominance of macrophages with an inflammatory phenotype (M1) in the rheumatoid arthritis (RA) synovium. MicroRNAs (miRs) play a pivotal role in regulating the inflammatory response in innate immune cells and are found at dysregulated levels in RA patients. Here we explored miRs that tune the inflammatory function of M2-macrophages.

Methods: Expression profiles of miR-221-3p and miR-155-5p were analyzed in clinical samples from RA, other inflammatory arthritis (OIA), osteoarthritis (OA), and healthy donors (HD) by qPCR. In vitro generated macrophages were transfected with miR-mimics and inhibitors. Transcriptome profiling through RNA-sequencing was performed on M2-macrophages overexpressing miR-221-3p mimic with or without LPS treatment. Secretion of IL-6, IL-10, IL-12, IL-8, and CXCL13 was measured in M1- and M2-macrophages upon TLR2/TLR3/TLR4-stimulation using ELISA. Inflammatory pathways including NF-κB, IRF3, MAPKs, and JAK3/STAT3 were evaluated by immunoblotting. Direct target interaction of miR-221-3p and predicted target sites in 3'UTR of JAK3 were examined by luciferase reporter gene assay.

Results: miR-221-3p in synovial tissue and fluid was increased in RA vs. OA or OIA. Endogenous expression levels of miR-221-3p and miR-155-5p were higher in M1- than M2-macrophages derived from RA patients or HD. TLR4-stimulation of M1- and M2-macrophages resulted in downregulation of miR-221-3p, but upregulation of miR-155-5p. M2-macrophages transfected with miR-221-3p mimics secreted less IL-10 and CXCL13 but more IL-6 and IL-8, exhibited downregulation of JAK3 protein and decreased pSTAT3 activation. JAK3 was identified as new direct target of miR-221-3p in macrophages. Co-transfection of miR-221-3p/miR-155-5p mimics in M2-macrophages increased M1-specific IL-12 secretion.

Conclusions: miR-221-3p acts as a regulator of TLR4-induced inflammatory M2-macrophage function by directly targeting JAK3. Dysregulated miR-221-3p expression, as seen in synovium of RA patients, leads to a diminished anti-inflammatory response and drives M2-macrophages to exhibit a M1-cytokine profile.

Physical activity may drive healthy microvascular ageing via downregulation of p66Shc

Background

Narrower retinal arterioles and wider venules are linked to adverse cardiovascular outcomes. The mitochondrial adaptor p66Shc is a major source of ageing-induced generation of reactive oxygen species. Promoter DNA methylation inhibits p66Shc gene transcription. This cross-sectional study was designed to investigate the link between physical activity, retinal vessel diameters and p66Shc expression in active and sedentary ageing subjects.

Design/methods

Altogether 158 subjects were included in the study (mean age 59.4 ± 7.0 years). Thirty-eight subjects were healthy active, 36 were healthy sedentary and 84 were sedentary with ≥2 cardiovascular risk factors. Retinal arteriolar and venular diameters were measured by means of a retinal vessel analyser. As a marker of oxidative stress, plasma 3-nitrotyrosine was determined by enzyme-linked immunosorbent assay. Gene expression of p66Shc and DNA methylation were assessed in mononuclear cells by real-time quantitative polymerase chain reaction and methylated-DNA capture (MethylMiner Enrichment kit) coupled with quantitative polymerase chain reaction, respectively.

Results

Wider retinal arterioles (179 ± 14 vs 172 ± 11 and 171 ± 14 µm; p < 0.05 and narrower venules (204 ± 17 vs 209 ± 11 and 218 ± 16 µm; p < 0.001) were observed in healthy active subjects compared with healthy sedentary subjects and sedentary subjects with ≥2 cardiovascular risk factors, respectively. Furthermore, healthy active subjects had blunted p66Shc expression and lower 3-nitrotyrosine plasma levels compared with healthy sedentary and sedentary subjects with ≥2 cardiovascular risk factors. Accordingly, hypomethylation of p66Shc promoter observed in healthy sedentary and sedentary subjects with ≥2 cardiovascular risk factors was not found in healthy active subjects.

Conclusion

Long-term physical activity-induced DNA methylation of p66Shc may represent a putative mechanistic link whereby active lifestyle promotes healthy microvascular ageing.

The target uric acid level in multimorbid patients with gout is difficult to achieve: data from a longitudinal Swiss single-centre cohort

OBJECTIVE

To characterise adherence and treat-to-target (T2T) strategy in gout patients within a Swiss tertiary hospital.

METHODS

Consecutive presenting patients with proven gout were prospectively included in this cohort. Symptoms, comorbidities, medication and laboratory values were assessed (during hospitalisation and at planned 3- and 12-month follow-up assessments).

RESULTS

116 patients (98 men) with a mean age of 67 (range 23&ndash;94 years) were included, 74% of whom had active arthritis. Comorbidities were frequent: hypertension, renal impairment, and obesity were present in 72, 55 and 35% of patients, respectively. Thirty-five percent of patients received urate-lowering treatment at inclusion. Only 62 and 50% attended the 3- and 12-month follow-up. The target serum uric acid level of &lt;360 &mu;mol/l was achieved in 22 and 57% of patients by the 3- and 12-month follow-up visits, respectively. Patients followed up by rheumatologists reached the target serum uric acid at follow-up more often than those that were not (p = 0.033). Median daily allopurinol dose at 12-month follow-up was 300 mg in those achieving T2T and 100 mg in the others (p = 0.033). Flares occurred during the first 3 months in 52% and during the subsequent 9 months in 47% of patients.

CONCLUSION

Only half of patients attended the planned follow-up visits, indicating low awareness for gout. Of those attending follow-up, only approximately 50% had achieved the serum urate target at 12 months. Although new treatments are available, care for gout patients remains insufficient, notably in difficult-to-treat multimorbid patient subsets as described in this cohort.

Differential effects of specific cathepsin S inhibition in biocompartments from patients with primary Sjögren syndrome

OBJECTIVE

Primary Sjögren syndrome (pSS) is characterized by T and B cell infiltration of exocrine glands. The cysteine protease cathepsin S (CatS) is crucially involved in MHCII processing and T cell stimulation, and elevated levels have been found in patients with RA, psoriasis and pSS. However, little is known about the functional characteristics and mechanisms of SS-A- and SS-B-specific T cells in pSS patients. We herein investigated the inhibition of CatS activity in different biocompartments of pSS patients including antigen-specific T cell responses.

METHODS

Ex vivo CatS activity was assessed in tears, plasma and saliva of 15 pSS patients and 13 healthy controls (HC) and in the presence or absence of the specific CatS inhibitor RO5459072. In addition, antigen (SS-A (60kD), SS-B, influenza H3N2, tetanus toxoid and SEB)-specific T cell responses were examined using ex vivo IFN-γ/IL-17 Dual ELISPOT and Bromdesoxyuridin (BrdU) proliferation assays in the presence or absence of RO5459072. Supernatants were analysed for IL-1β, IL-6, IL-10, TNF-α, IL-21, IL-22 and IL-23, using conventional ELISA.

RESULTS

CatS activity was significantly elevated in tear fluid, but not other biocompartments, was inversely associated with exocrinic function in pSS patients and could significantly be suppressed by RO5459072. Moreover, CatS inhibition by RO5459072 led to strong and dose-dependent suppression of SS-A/SS-B-specific T cell effector functions and cytokine secretion by CD14+ monocytes. However, RO5459072 was incapable of suppressing SS-A/SS-B-induced secretion of cytokines in CD14+ monocytes when T cells were absent, confirming a CatS/MHCII-mediated mechanism of suppression.

CONCLUSION

CatS activity in tear fluid seems to be a relevant biomarker for pSS disease activity. Conversely, CatS inhibition diminishes T cell and associated monokine responses towards relevant autoantigens in pSS. Thus, CatS inhibition may represent a promising novel treatment strategy in pSS.

High-intensity interval training modulates retinal microvascular phenotype and DNA methylation of p66Shc gene: a randomized controlled trial (EXAMIN AGE)

Aims

Impairments of retinal vessel diameter are associated with major adverse cardiovascular (CV) events. Promoter DNA methylation is a repressor of the mitochondrial adaptor p66Shc gene transcription, a key driver of ageing-induced reactive oxygen species. The study aimed to investigate whether high-intensity interval training (HIIT) affects retinal microvascular phenotype as well as p66Shc expression and oxidative stress in ageing subjects with increased CV risk from the EXAMIN AGE cohort.

Methods and results

Eighty-four sedentary subjects (mean age 59.4 ± 7.0 years) with ≥2 CV risk factors were randomized into either a 12-week HIIT or standard physical activity recommendations. Retinal arteriolar and venular diameters were measured by use of a retinal vessel analyser. As a marker of oxidative stress plasma 3-nitrotyrosine (3-NT) level was determined by ELISA. Gene expression of p66Shc and DNA methylation were assessed in mononuclear cells by RT-qPCR and methylated-DNA capture (MethylMiner Enrichment Kit) coupled with qPCR, respectively. High-intensity interval training reduced body mass index, fat mass, low-density lipoprotein and increased muscle mass, as well as maximal oxygen uptake (VO2max). Moreover, HIIT restored microvascular phenotype by inducing retinal arteriolar widening (pre: 175 ± 14 µm vs. post: 181 ± 13 µm, P = 0.001) and venular narrowing (pre: 222 ± 14 µm vs. post: 220 ± 14 µm, P = 0.007). After HIIT, restoration of p66Shc promoter methylation (P = 0.034) reduced p66Shc gene expression (P = 0.037) and, in turn, blunted 3-NT plasma levels (P = 0.002).

Conclusion

High-intensity interval training rescues microvascular dysfunction in ageing subjects at increased CV risk. Exercise-induced reprogramming of DNA methylation of p66Shc gene may represent a putative mechanistic link whereby exercise protects against age-related oxidative stress.

Clinical trial registration

 ClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ct2/show/NCT02796976).