Histogram-Based Densitometry Index to Assess the Severity of Interstitial Lung Disease in Systemic Sclerosis in Standard and Low-Dose Computed Tomography

OBJECTIVE

Mean lung attenuation, skewness, and kurtosis are histogram-based densitometry variables that quantify systemic sclerosis-associated interstitial lung disease (SSc-ILD) and were recently merged into a computerized integrated index (CII). Our work tested the CII in low-dose 9-slice (reduced) and standard high-resolution computed tomography (CT) scans to evaluate extensive SSc-ILD and predict mortality.

METHODS

CT scans from patients with SSc-ILD were assessed using the software Horos to compute standard and reduced CIIs. Extensive ILD was determined following the Goh staging system. The association between CIIs and extensive ILD was analyzed with a generalized estimating equation regression model, the predictive ability of CIIs by the area under the receiver-operation characteristic curve (AUC), and the association between CIIs and death by Kaplan-Meier analysis.

RESULTS

Among 243 patients with standard and reduced CT scans available, 157 CT scans from 119 patients with SSc-ILD constituted the derivation cohort. The validation cohort included 116 standard and 175 reduced CT scans. Both CIIs from standard (odds ratio [OR] 0.53, 95% CI 0.37-0.75; AUC 0.77, 95% CI 0.68-0.87) and reduced CT scans (OR 0.54, 95% CI 0.35-0.82; AUC 0.78, 95% CI 0.70-0.87) were significantly associated with extensive ILD. A threshold of CII ≤ -0.96 for standard CT scans and CII ≤ -1.85 for reduced CT scans detected extensive ILD with high sensitivity in both derivation and validation cohorts. Extensive ILD according to Goh staging (OR 2.94, 95% CI 1.10-7.82) and standard CII ≤ -0.96 (OR 1.78, 95% CI 1.24-2.56) significantly predicted mortality; a marginal P value was observed for reduced CII ≤ -1.85 (OR 1.27, 95% CI 0.93-1.75).

CONCLUSION

Thresholds for both standard and reduced CII to identify extensive ILD were developed and validated, with an additional association with mortality. CIIs might help in clinical practice when radiology expertise is missing.

Therapeutic management of fibrosis in systemic sclerosis patients - an analysis from the Swiss EUSTAR cohort

OBJECTIVES

Systemic sclerosis is a chronic autoimmune connective tissue disease leading to microvascular and fibrotic manifestations in multiple organs. Several treatment options and recommendations from different European countries are available. In this study, for which the ambit is Switzerland specifically, we aim to describe the treatment patterns of systemic sclerosis patients with fibrotic manifestations.

METHODS

Systemic sclerosis patients were selected from six Swiss tertiary centres recorded in the multicentre, prospective European Scleroderma Trials and Research (EUSTAR) registry. Patients fulfilling the 2013 ACR/EULAR systemic sclerosis classification criteria at baseline were included. To determine the differences in treatment of varying degrees of fibrosis, four groups were identified: (1) patients with a modified Rodnan skin score (mRSS) >0; (2) those with mRSS ≥7; (3) those with interstitial lung disease (SSc-ILD), diagnosed by either chest X-Ray or high-resolution computed tomography; and (4) patients fulfilling one of the additional criteria for extensive interstitial lung disease, defined as interstitial lung disease involvement of >20% in high-resolution computed tomography, dyspnea NYHA-stage 3/4, or a predicted forced vital capacity (FVC) of <70%.

RESULTS

A total of 590 patients with systemic sclerosis fulfilled the inclusion criteria. In this cohort, 421 (71.4%) had mRSS >0, of whom 195 (33.1%) had mRSS ≥7; interstitial lung disease was diagnosed in 198 of 456 (43.4%), of whom 106 (18.0 %) showed extensive interstitial lung disease. Regarding non-biologic disease-modifying medications (DMARDs), the most frequently prescribed was methotrexate, followed by hydroxychloroquine and mycophenolate mofetil. Rituximab and tocilizumab were most frequently used among the biologic DMARDs. Specifically, 148/372 (39.8%) of treated patients with skin fibrosis received methotrexate, mycophenolate mofetil or rituximab, and 80/177 (45.2%) with interstitial lung disease received cyclophosphamide, mycophenolate mofetil, tocilizumab or rituximab. Most patients received a proton-pump inhibitor, and few patients underwent hematopoietic stem cell transplantation.

CONCLUSION

Overall, in Switzerland, a wide range of medications is prescribed for systemic sclerosis patients. This includes modern, targeted treatments for which randomised controlled clinical trial have been recently reported.

Characteristics and disease course of untreated patients with interstitial lung disease associated with systemic sclerosis in a real-life two-centre cohort

BACKGROUND

Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). According to expert statements, not all SSc-ILD patients require pharmacological therapy.

OBJECTIVES

To describe disease characteristics and disease course in untreated SSc-ILD patients in two well characterised SSc-ILD cohorts.

METHODS

Patients were classified as treated if they had received a potential ILD-modifying drug. ILD progression in untreated patients was defined as (1) decline in forced vital capacity (FVC) from baseline of ≥10% or (2) decline in FVC of 5%-9% associated with a decline in diffusing capacity for carbon monoxide (DLCO)≥15% over 12±3 months or (3) start of any ILD-modifying treatment or (4) increase in the ILD extent during follow-up. Multivariable logistic regression was performed to identify factors associated with non-prescription of ILD-modifying treatment at baseline. Prognostic factors for progression in untreated patients were tested by multivariate Cox regression.

RESULTS

Of 386 SSc-ILD included patients, 287 (74%) were untreated at baseline. Anticentromere antibodies (OR: 6.75 (2.16-21.14), p=0.001), limited extent of ILD (OR: 2.39 (1.19-4.82), p=0.015), longer disease duration (OR: 1.04 (1.00-1.08), p=0.038) and a higher DLCO (OR: 1.02 (1.01-1.04), p=0.005) were independently associated with no ILD-modifying treatment at baseline. Among 234 untreated patients, the 3 year cumulative incidence of progression was 39.9% (32.9-46.2). Diffuse cutaneous SSc and extensive lung fibrosis independently predicted ILD progression in untreated patients.

CONCLUSION

As about 40% of untreated patients show ILD progression after 3 years and effective and safe therapies for SSc-ILD are available, our results support a change in clinical practice in selecting patients for treatment.

The long non-coding RNA HOTAIR contributes to joint-specific gene expression in rheumatoid arthritis

Although patients with rheumatoid arthritis (RA) typically exhibit symmetrical joint involvement, some patients develop alternative disease patterns in response to treatment, suggesting that different molecular mechanism may underlie disease progression depending on joint location. Here, we identify joint-specific changes in RA synovium and synovial fibroblasts (SF) between knee and hand joints. We show that the long non-coding RNA HOTAIR, which is only expressed in knee SF, regulates more than 50% of this site-specific gene expression in SF. HOTAIR is downregulated after stimulation with pro-inflammatory cytokines and is expressed at lower levels in knee samples from patients with RA, compared with osteoarthritis. Knockdown of HOTAIR in knee SF increases PI-Akt signalling and IL-6 production, but reduces Wnt signalling. Silencing HOTAIR inhibits the migratory function of SF, decreases SF-mediated osteoclastogenesis, and increases the recruitment of B cells by SF. We propose that HOTAIR is an important epigenetic factor in joint-specific gene expression in RA.

Involving patients as research partners in research in rheumatology: a literature review in 2023

OBJECTIVE

The inclusion of patient research partners (PRPs) in research projects is increasingly recognised and recommended in rheumatology. The level of involvement of PRPs in translational research in rheumatology remains unknown, while in randomised clinical trials (RCTs), it has been reported to be 2% in 2020. Therefore, we aimed to assess the involvement of PRPs in recent translational studies and RCTs in rheumatology.

METHODS

We conducted a scoping literature review of the 80 most recent articles (40 translational studies and 40 RCTs) from four target diseases: rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus and lower extremity osteoarthritis. We selected 20 papers from each disease, published up until 1 March 2023, in rheumatology and general scientific journals. In each paper, the extent of PRP involvement was assessed. Analyses were descriptive.

RESULTS

Of 40 translational studies, none reported PRP involvement. Of 40 RCTs, eight studies (20%) reported PRP involvement. These trials were mainly from Europe (75%) and North America (25%). Most of them (75%) were non-industry funded. The type of PRP involvement was reported in six of eight studies: six studies reported PRP participation in the study design or design of the intervention and two of them in the interpretation of the results. All the trials reporting the number of PRPs (75%), involved at least two PRPs.

CONCLUSION

Despite a worldwide movement advocating for increased patient involvement in research, PRPs in translational research and RCTs in rheumatology are significantly under-represented. This limited involvement of PRPs in research highlights a persistent gap between the existing recommendations and actual practice.

Retraction Note: Combined effect of genetic background and gender in a mouse model of bleomycin-induced skin fibrosis

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s13075-023-03211-7.

Stratification in systemic sclerosis according to autoantibody status versus skin involvement: a study of the prospective EUSTAR cohort

BACKGROUND

The current subclassification of systemic sclerosis into cutaneous subtypes does not fully capture the heterogeneity of the disease. We aimed to compare the performances of stratification into LeRoy's cutaneous subtypes versus stratification by autoantibody status in systemic sclerosis.

METHODS

For this cohort study, we assessed people with systemic sclerosis in the multicentre international European Scleroderma Trials and Research (EUSTAR) database. Individuals positive for systemic-sclerosis autoantibodies of two specificities were excluded, and remaining individuals were classified by cutaneous subtype, according to their systemic sclerosis-specific autoantibodies, or both. We assessed the performance of each model to predict overall survival, progression-free survival, disease progression, and different organ involvement. The three models were compared by use of the area under the curve (AUC) of the receiver operating characteristic and the net reclassification improvement (NRI). Missing data were imputed.

FINDINGS

We assessed the database on July 26, 2019. Of 16 939 patients assessed for eligibility, 10 711 patients were included: 1647 (15·4%) of 10 709 were male, 9062 (84·6%) were female, mean age was 54·4 (SD 13·8) years, and mean disease duration was 7·9 (SD 8·2) years. Information regarding cutaneous subtype was available for 10 176 participants and antibody data were available for 9643 participants. In the prognostic analysis, there was no difference in AUC for overall survival (0·82, 95% CI 0·81-0·84 for cutaneous only vs 0·84, 0·82-0·85 for antibody only vs 0·84, 0·83-0·86 for combined) or for progression-free survival (0·70, 0·69-0·71 vs 0·71, 0·70-0·72 vs 0·71, 0·70-0·72). However, at 4 years the NRI showed substantial improvement for the antibody-only model compared with the cutaneous-only model in prediction of overall survival (0·57, 0·46-0·71 for antibody only vs 0·29, 0·19-0·39 for cutaneous only) and disease progression (0·36, 0·29-0·46 vs 0·21, 0·14-0·28). The antibody-only model did better than the cutaneous-only model in predicting renal crisis (AUC 0·72, 0·70-0·74 for antibody only vs 0·66, 0·64-0·69 for cutaneous only) and lung fibrosis leading to restrictive lung function (AUC 0·76, 0·75-0·77 vs 0·71, 0·70-0·72). The combined model improved the prediction of digital ulcers and elevated systolic pulmonary artery pressure, but did poorly for cardiac involvement.

INTERPRETATION

The autoantibody-only model outperforms cutaneous-only subsetting for risk stratifying people with systemic sclerosis in the EUSTAR cohort. Physicians should be aware of these findings at the time of decision making for patient management.

FUNDING

World Scleroderma Foundation.

Effectiveness and safety of tocilizumab in patients with systemic sclerosis: a propensity score matched controlled observational study of the EUSTAR cohort

Objectives

Tocilizumab showed trends for improving skin fibrosis and prevented progression of lung fibrosis in systemic sclerosis (SSc) in randomised controlled clinical trials. We aimed to assess safety and effectiveness of tocilizumab in a real-life setting using the European Scleroderma Trial and Research (EUSTAR) database.

Methods

Patients with SSc fulfilling the American College of Rheumatology (ACR)/EULAR 2013 classification criteria, with baseline and follow-up visits at 12±3 months, receiving tocilizumab or standard of care as the control group, were selected. Propensity score matching was applied. Primary endpoints were the modified Rodnan skin score (mRSS) and FVC at 12±3 months compared between the groups. Secondary endpoints were the percentage of progressive/regressive patients for skin and lung at 12±3 months.

Results

Ninety-three patients with SSc treated with tocilizumab and 3180 patients with SSc with standard of care fulfilled the inclusion criteria. Comparison between groups did not show significant differences, but favoured tocilizumab across all predefined primary and secondary endpoints: mRSS was lower in the tocilizumab group (difference −1.0, 95% CI −3.7 to 1.8, p=0.48). Similarly, FVC % predicted was higher in the tocilizumab group (difference 1.5 (−6.1 to 9.1), p=0.70). The percentage of progressive/regressive patients favoured tocilizumab over controls. These results were robust regarding the sensitivity analyses. Safety analysis confirmed previously reported adverse event profiles.

Conclusion

Although this large, observational, controlled, real-life EUSTAR study did not show significant effectiveness of tocilizumab on skin and lung fibrosis, the consistency of direction of all predefined endpoints generates hypothesis for potential effectiveness in a broader SSc population.

OP0095 SINGLE-CELL RNA SEQUENCING REVEALS POTENT ANTI-INFLAMMATORY AND ANTIFIBROTIC ACTIVITIES OF DIMETHYL-ALPHA-KETOGLUTARATE ON EXPLANTED SKIN FROM PATIENTS WITH SYSTEMIC SCLEROSIS

Background

Activated fibroblasts are the main drivers of skin fibrosis in SSc. We have recently identified dimethyl alpha-ketoglutarate (dm-aKG) as a potential repressor of myofibroblast differentiation and profibrotic activity in cultured skin fibroblasts.

Objectives

To further analyse the clinical translation of our findings by investigating the antifibrotic capacity of dm-aKG on explanted skin biopsies from SSc patients.

Methods

We cultured forearm punch skin biopsies from SSc patients (n=10) for 24h ex vivo in the presence/absence of 6 mM dm-aKG. Thereafter, skin biopsies (n=4) were dissociated into single cells using a combined mechanical-enzymatic dissociation protocol, followed by single cell (sc)RNA-seq library preparation (10x Genomics) and sequencing (Illumina, NovaSeq6000, 50,000 reads/cell). We mapped the scRNA-seq reads to the reference genome GRCh38.p13 and analysed the data with R/Bioconductor tools. We deconvoluted cell types in bulk skin transcriptomes from SSc cohorts (GSE: 45485, 59785, 9285, 32413) using human skin scRNA-seq data1. The secretion of IL-6, procollagen-1, PRO-C1 (N-terminal type I collagen pro-peptide), C1M (MMP-degradation fragment of type I collagen), and fibronectin (FBN-C) from cultured skin (n=10) was measured in supernatants by ELISA. We analysed gene and protein expression in TGFβ-activated healthy and SSc dermal fibroblasts (DF, n=10) treated or not with dm-aKG using qPCR, Western blot and ELISA. Contractile properties of DF were assessed by gel contraction assay. Traction forces generated by DF were determined by reference-free traction force microscopy.

Results

Dissociated cultured SSc skin exhibited comparable cell yield and viability in the presence (20,203; 89%) and absence (25,280; 93%) of dm-aKG, respectively. scRNA-seq skin analysis included 20,869 high quality single cell profiles segregating into 10 distinct skin cell populations (Figure 1A). This analysis demonstrated decreased proportion of fibroblasts and increased proportion of keratinocytes in dm-aKG treated skin (p<0.05; Figure 1B). Among skin cell types, skin fibroblasts exhibited the largest amount of differentially expressed genes upon dm-aKG treatment (44%, n=779, x-fold>0.5, FDR<0.05), suggesting that these cells are key targets of dm-aKG therapy in SSc skin. We identified inflammatory/cytokine signalling (hub genes IL6, STAT1) and extracellular matrix (ECM) organization (hub genes MMP1, ITGB3) as top downregulated biological processes in fibroblasts in dm-aKG treated SSc skin (Figure 1C), coinciding with a decreased abundance of proinflammatory skin fibroblast subpopulation. Specifically, these cells were identified as the main source of IL6 (Figure 1D) and were enriched in SSc skin as revealed by deconvolution analysis of skin transcriptomes. Furthermore, dm-aKG reduced the secretion of IL-6, procollagen-1 and C1M, but not pro-C1 and FBN-C, from cultured skin explants. In cultured DF, dm-aKG blocked the inflammatory (IL-6, pSTAT3), profibrotic (aSMA, Fibronectin, Procollagen-1, Pro-C1) and contractile activities, and significantly diminished traction forces exerted by DF on the matrix substrate.

Figure 1.

scRNA-seq – comparison of untreated and dm-aKG treated paired skin biopsies. (A) UMAP plot with annotated skin cells, (B) differential abundance of main skin cell types, (C) volcano plot of DE genes with top downregulated gene ontology (GO) pathways in dm-aKG treated skin fibroblasts, (D) IL6 expression in untreated (blue) and treated (pink) skin fibroblasts.

Conclusion

Dm-aKG broadly interferes with inflammatory and ECM organizational activities of skin fibroblasts in culture and in explanted skin from SSc patients. These results confirm that dm-aKG might represent a potential new therapeutic approach for efficient targeting of skin inflammation and fibrosis in SSc.

References

[1]He H et al. J Allergy Clin Immunol 2020

Acknowledgements

This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology and University Medical Centre Ljubljana.

Disclosure of Interests

Blaž Burja: None declared, Dominique Paul: None declared, Reto Gerber: None declared, Sam G. Edalat: None declared, Muriel Elhai Speakers bureau: BMS, Elena Pachera: None declared, Rahel S. Zingg: None declared, Francesca Michela Pramotton: None declared, Sofie Falkenløve Madsen: None declared, Kristina Buerki: None declared, Giampietro Costanza: None declared, Michael Whitfield: None declared, Anne-Christine Bay-Jensen: None declared, Snežna Sodin-Šemrl: None declared, Matija Tomsic: None declared, Gabriela Kania: None declared, Hubert Rehrauer: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Ziga Rotar: None declared, Mark Robinson: None declared, Katja Lakota: None declared, Mojca Frank Bertoncelj: None declared.

POS0140 PREDICTING OUTCOMES IN SYSTEMIC SCLEROSIS: STRATIFICATION BY AUTO-ANTIBODIES OUTPERFORMS CUTANEOUS SUBSETTING IN THE EUSTAR COHORT

Background

Risk-stratification is key in a heterogeneous disease like systemic sclerosis (SSc). Until now, SSc patients are stratified according to the extent of skin involvement into limited cutaneous, diffuse cutaneous and sine scleroderma subtypes. However, this classification remains inaccurate to capture disease heterogeneity. Autoantibodies are found in more than 90% of the patients and can be detected before onset of the disease. Among them, three predominant and specific antibodies are used: anti-centromere, anti-Scl70 and RNA polymerase III antibodies.

Objectives

To compare the performances of stratification into LeRoy’s cutaneous subtypes versus autoantibody status in SSc versus combination of cutaneous subtypes and autoantibodies status.

Methods

Patients from the EUSTAR database were classified either as (i) limited cutaneous, diffuse cutaneous or sine scleroderma (based on the recording made by the treating physician) or (ii) according to autoantibodies with the following subclassifications: (1) no specific autoantibodies, (2) isolated ANA, (3) anti-centromere antibodies, (4) anti-Scl70 antibodies and (5) anti-RNA polymerase III antibodies or (iii) according to combination of cutaneous subset and auto-antibodies. The respective performance of each model to predict overall survival (OS), progression-free survival (PFS), disease progression and different organ involvements was assessed and the three models were compared by the area under the receiver operating characteristic curve (AUC 95%CI) and the net reclassification improvement (NRI). Missing data were imputed through multiple imputation using chain equations.

Results

In all, 10’711 patients were included: 84.6% females, mean age: 54.4±13.8 years, mean disease duration: 7.9±8.2 years. In the prospective analysis (n= 6’467 to 7’829 according to the outcome), after a mean follow-up of 56 months and a mean of three visits per patient, we did not identify any difference in AUC between the cutaneous-based model and the antibody-based model for prediction of OS and disease progression. However, the NRI showed a significant improvement in prediction of OS (0.57 [0.46-0.71] vs. 0.29 [0.19-0.39]) and disease progression (0.36 [0.29-0.46] vs. 0.21 [0.14-0.28]) at 4 years using the antibody-based model. Regarding prediction of each organ involvement in longitudinal analyses, the antibody-based model showed better performance than the cutaneous-one for renal crisis (AUC: 0.719 [0.696-0.742] vs. 0.664 [0.643-0.685]), with the highest association observed with anti-RNA polymerase III (OR: 7.47 [1.63-34.24], p= 0.010). Similarly, the antibody-based model was better than the cutaneous model in predicting lung fibrosis (AUC 0.719 [0.715-724] vs. 0.653 [0.647-0.659]) and restrictive lung fibrosis (AUC 0.759 [0.749-0.766] vs. 0.711 [0.701-0.721]) which were both associated with anti-Scl70 antibodies (OR: 9.29 [8.17-10.55] and 7.92 [5.37-11.69], respectively, p<0.0001 for both). Although there was no difference in the AUC to predict digital ulcers, NRI showed an improvement using the antibody-based model (0.31 [0.29-0.33] vs. 0.24 [0.22-0.26]) with the highest association with anti-Scl70 antibodies (OR: 3.57 [2.68-4.75], p<0.0001). The two models had similar performances in assessing occurrence of intestinal involvement, heart dysfunction or elevated sPAP. Combining both antibody status and cutaneous subtype did not improve the performance of our models. In the exploratory analysis, there was no change using modified Rodnan skin score to define cutaneous form.

Conclusion

Auto-antibody status outperforms the common cutaneous subsetting to risk-stratify SSc patients in the EUSTAR cohort. This easily performed subclassification using autoantibodies specific status can be used by the clinicians to risk-stratify their patients and to adapt disease monitoring in routine practice.

Disclosure of Interests

Muriel Elhai Speakers bureau: BMS outside of the submitted work, Marouane Boubaya: None declared, Nanthara Sritharan: None declared, Alexandra Balbir-Gurman: None declared, Elise Siegert: None declared, Eric Hachulla: None declared, Jeska de Vries-Bouwstra: None declared, Gabriela Riemekasten: None declared, Jörg H.W. Distler: None declared, Douglas Veale: None declared, Edoardo Rosato: None declared, Francesco Del Galdo: None declared, Fabian A Mendoza: None declared, Daniel Furst Consultant of: Abbvie, Novartis, Pfizer, R-Pharm, Grant/research support from: Emerald, Kadmon, PICORI, Pfizer,Prometheus, Talaris, Mitsubishi, Carlos De la Puente Bujidos: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Consultant of: Actelion, ARXX, Bayer, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Grant/research support from: Boehringer Ingelheim, Armando Gabrielli: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Coralie Bloch-Queyrat: None declared, Yannick Allanore Consultant of: Actelion, Bayer, BMS, Boehringer-Ingelheim, Inventiva, Roche, Sanofi-Aventis, Grant/research support from: Actelion, Bayer, BMS, Boehringer-Ingelheim, Inventiva, Roche, Sanofi-Aventis

POS0878 ASSOCIATION OF A LOWER BODY-MASS INDEX WITH THE PRESENCE OF ILD IN SSc PATIENTS – A DERIVATION PREDICTION STUDY USING DECISION TREE-BASED ALGORITHMS

Background

Upper-gastrointestinal involvement (GI) is associated with more severe interstitial lung disease in patients with systemic sclerosis (SSc-ILD). However, there are many unexplored GI risk factors for the presence of SSc-ILD which could be potentially revealed by machine learning algorithms.

Objectives

The aim of our study was to identify GI related risk factors for the presence of SSc-ILD using machine learning algorithms based on decision trees (DT).

Methods

Data of the last follow-up visit from consecutive patients fulfilling the 2013 ACR/EULAR SSc classification criteria recorded in our local EUSTAR registry were used for this study.

The study outcome was the presence of SSc-ILD on high-resolution computed tomography.

Two sets of predictors were identified based on their potential association with GI. The first set contains the following variables available in the EUSTAR registry: esophageal symptoms (dysphagia and reflux), stomach symptoms (early satiety, vomiting), intestinal symptoms (diarrhea, bloating and constipation), malabsorption syndrome, body-mass-index (BMI) and proton pump inhibitor therapy, calcium channel blocker therapy and immunosuppressive therapy. In the second set, we replaced the first three EUSTAR variables of the first set with the scales of the UCLA Gastrointestinal Tract Questionnaire 2.0 (UCLA-GIT).

Of these two sets, the most important variable was selected using three different DT-based algorithms: (1) recursive partitioning and regression trees (RPART) –which uses trees to build decision rules, (2) random forest (RF) - an ensemble of DT built in parallel, and (3) gradient boosting machines (GBM) - an ensemble of DT built sequentially. The selected variables were eventually integrated with established predictors for presence of SSc-ILD (diffuse cutaneous subset, anti-Scl-70 positivity, male gender, forced vital capacity [FVC] and diffusion capacity of the lung for carbon monoxide-single breath [DLCO-SB]) into final prediction models for SSc-ILD presence using RPART, RF and GBM respectively. Their performance was evaluated by C-statistics. The importance of the newly detected predictor was assessed by variable importance plots (VIPs).

Results

We included in our study 334 patients. The median age was 61 [IQR: 50-69] years, 59 (17.7%) were males and 266 (79.6%) had limited cutaneous SSc. Median BMI was 23 [IQR: 21-26] kg/m2, 133 (39.8%) of the patients had SSc-ILD, median FVC% 93 [IQR: 81-105], DLCO 72.5 [56-84] and. Of the UCLA-GIT scales the highest score was for the distension/bloating with a value of 0.50 [IQR: 0-1.24]. Regarding medications, 167 (50%) patients were exposed to PPI, 39 (11.7%) to CCB and 105 (31.4%) to immunosuppressive therapy.

The BMI was deemed by all three algorithms as the most important predictor of SSc-ILD among both sets of GI related variables (Figure 1A-F). The final model, which included established risk factors for presence of ILD and the BMI, supported the importance of BMI in predicting the SSc-ILD. The VIPs obtained by GBM also ranked the BMI as the most important predictor.

Figure 1.

Tree-based algorithms revealing the importance of BMI for prediction of SSc-ILD. Panels A, B and C are variable importance plots (VIPs), which reveals the most important GI-predictor for occurrence of SSc-ILD in the EUSTAR set– the predictor with the highest relative importance is the most important predictor. Panels D, E and F are VIPs reveals the most important GI-predictor for occurrence of SSc-ILD in the UCLA-GIT set.

A lower BMI was associated with presence of SSc-ILD (C-statistics for the RPART, RF and GBM models were 0.79, 0.70 and 0.76, respectively, corresponding to a fair accuracy). As expected, also a lower FVC, and DLCO-SB, and a positivity for Scl-70 ab were associated with presence of ILD.

Conclusion

Lower BMI is a novel promising predictor for the presence of ILD, which should be confirmed in additional analyses.

Disclosure of Interests

Alexandru Garaiman: None declared, Carina Mihai Speakers bureau: MEDtalks Switzerland, Mepha, Rucsandra Dobrota Consultant of: Actelion and Boehringer-Ingelheim, Grant/research support from: Articulum Fellowship, Pfizer, Actelion, Cosimo Bruni Speakers bureau: Eli-Lilly, Actelion, Boehringer-Ingelheim, Grant/research support from: Gruppo Italiano Lotta alla Sclerodermia (GILS), European,, Scleroderma Trials and Research Group (EUSTAR), Scleroderma Clinical Trials Consortium (SCTC), AbbVie, Muriel Elhai: None declared, Suzana Jordan: None declared, Lea Stamm: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Roche, Merck Sharp & Dohme, ARXX Therapeutics, Lilly and Medscape, Consultant of: Actelion, Boehringer Ingelheim, Jansen, Roche, Merck Sharp & Dohme, ARXX Therapeutics, Lilly and Medscape, Grant/research support from: Boehringer Ingelheim, Bayer, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Medscape, Novartis, Roche, Pfizer, Roche, Sanofi, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon, Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Prometheus Biosences, Roche, Roivant, Topadur and UBC, Lilly, Pfizer, Grant/research support from: Kymera, Mitsubishi Tanabe, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor

POS0880 CHARACTERISTICS AND DISEASE COURSE OF UNTREATED PATIENTS WITH INTERSTITIAL LUNG DISEASE ASSOCIATED WITH SYSTEMIC SCLEROSIS

Background

Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). European consensus guidelines consider that some patients with mild disease might not need pharmacological treatment (1). Up to now, the disease characteristics and the disease course of non-treated SSc-ILD patients remain unknown.

Objectives

To describe disease characteristics and the disease course of non-treated SSc patients with ILD.

Methods

We included patients from our local EUSTAR center registered since 2008, who had a diagnosis of ILD on high-resolution computed tomography (HRCT) and available data on pulmonary function tests and treatment. Longitudinal study included patients with at least one follow-up visit. Patients were classified as treated if they received a potential ILD modifying drug (immunosuppressive therapy or nintedanib). Treated and untreated patients were compared at baseline. Progression in the untreated group was defined as (i) forced vital capacity (FVC) decline from baseline of ≥10% or (ii) an FVC decline of 5-9% in association with a decline in diffusing capacity for carbon monoxide (DLCO) of ≥15%, or (iii) start of a ILD modifying treatment during follow-up. In the untreated group, patients who progressed at any time were compared with patients with stable disease during follow-up. Multivariable logistic regression was performed to identify (i) factors associated with non-prescription of a treatment in ILD patients at baseline and (ii) factors associated with progression in the untreated patients. Covariates were selected according to clinical experience and literature evidence.

Results

Among 496 patients included in our cohort, 209 (42%) patients had ILD on baseline HRCT: 48/209 (23%) were males, median disease duration 8 [IQR: 4-12] years, 67/209 (32%) of diffuse cutaneous subset and 86/209 (41%) had anti-Scl70 antibodies.

Among them, 142/209 (68%) did not receive any potentially ILD modifying treatments at baseline. Untreated patients were older (59 vs. 54 years), had a longer disease duration, were less frequently smokers, had more frequently anticentromere antibodies and lower levels of CRP. They had more frequently a limited extent (<20%) of lung fibrosis on HRCT, higher FVC (97.02 (±19.76) % vs. 78.29 (±19.23) %) and DLCO (72.10 (±18.97) % vs. 57.57 (±20.81) %), better performances in the 6 minute walking test and were less frequently treated with low dose of glucocorticoids.

In multivariable logistic regression, older age (OR: 1.04 [1.01-1.08], p=0.021), a less extensive disease on HRCT (OR: 0.29 [0.09-0.90], p=0.037) and less frequent prescription of glucocorticoids (OR: 0.036 [0.12-0.92], p=0.037) were independently associated with absence of ILD modifying treatment prescription in our cohort.

From the 142 untreated patients, 96 were followed-up for 64 [39-96] months. Of these, 56 (58%) patients showed progression of ILD, of whom 43 progressed by lung function parameters. Of these 56 patients, 31 (56%) progressed in the first 18 months. Diffuse cutaneous subtype (OR: 5.26 [1.26-27.62], p=0.031), shorter disease duration (OR: 0.95 [0.90-0.99], p=0.035) and oesophageal symptoms (reflux, dysphagia) (OR: 3.51 [1.12-12.18], p=0.036) at baseline were independent predictors of progression during follow-up in untreated patients.

Conclusion

A considerable number of SSc patients with ILD are not treated in clinical practice, in particular patients with limited cutaneous SSc, older age and an overall less extensive ILD. However, during a follow-up of 5 years, contrary to the common belief, about 60% of the untreated patients showed ILD-progression. The diffuse cutaneous subtype, shorter disease duration and oesophageal symptoms at baseline characterized these patients. With the development of effective and safe therapies for SSc-ILD, our results support a change in practice for selecting patients for treatment.

References

[1]Hoffmann-Vold A-M, et al. The Lancet Rheumatology. 2020;2(2):e71-e83.

Disclosure of Interests

Moritz Scheidegger: None declared, Alexandru Garaiman: None declared, Carina Mihai Speakers bureau: Boehringer-Ingelheim, MED Talks Switzerland, Consultant of: Boehringer-Ingelheim (advisory board), Janssen (advisory board), Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Consultant of: Mepha, MSD, Novartis, GSK, Bayer and Vifor (advisory board fees), Rucsandra Dobrota Consultant of: Boehringer-Ingelheim (Advisory Board), Cosimo Bruni Speakers bureau: Eli-Lilly2018-2021, Actelion2019, Boehringer-Ingelheim2020-2021, Grant/research support from: AbbVie (educational grant 2021), Suzana Jordan: None declared, Håvard Fretheim Speakers bureau: Personal fees form Bayer and non-financial support from GSK and Actelion, outside the submitted work., Øyvind Midtvedt: None declared, Hilde Jenssen Bjørkekjær: None declared, Imon Barua: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Consultant of: Actelion, ARXX, Bayer, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Grant/research support from: Boehringer Ingelheim, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Muriel Elhai Speakers bureau: Speaker fees: BMS outside the submitted work

OP0003 DOES IMMUNOSUPPRESSIVE THERAPY IMPROVE GASTROINTESTINAL SYMPTOMS IN PATIENTS WITH SYSTEMIC SCLEROSIS?

Background

The gastrointestinal (GI) tract is frequently affected in systemic sclerosis (SSc), leading to considerable morbidity and even mortality. While important progress has been made in the last years regarding treatment of SSc, there is no disease-modifying treatment available for SSc-related GI involvement.

Objectives

We aimed to identify, in an observational cohort study of real-life patients with SSc, an association between immunosuppressive therapy and the severity of GI symptoms, measured by the University of California at Los Angeles / Scleroderma Clinical Trial Consortium Gastro-Intestinal Tract instrument 2.0 (UCLA GIT 2.0).

Methods

We selected patients from our EUSTAR centre who met the 2013 ACR/EULAR classification criteria for SSc and had at least two visits with completed UCLA GIT 2.0 questionnaires, with an interval of 12±3 months between visits. We defined the first visit with a completed UCLA GIT 2.0 questionnaire as baseline visit. Immunosuppressive therapy was defined as exposure for at least 6 months between the two visits to at least one of the following drugs, regardless of indication: mycophenolate mofetil (MMF), cyclophosphamide, methotrexate, azathioprine, leflunomide, glucocorticoids (>10mg/d prednisone-equivalent), rituximab, tocilizumab, and abatacept. The study outcome was the UCLA GIT 2.0 score at the follow-up visit. We performed multivariable linear regression with this outcome as dependent variable and immunosuppressive therapy during follow-up, immunosuppressive therapy before baseline, baseline UCLA GIT 2.0 score and several baseline parameters selected by clinical judgment as potentially influencing GI symptoms, as independent variables. Multiple imputation was implemented to handle missing values.

Results

We included 209 patients. Baseline characteristics were: 82.3% female, median (IQR) age 59.0 (48.6, 68.2) years, median disease duration 6.0 (2.7, 12.5) years, 40 (19.1%) diffuse cutaneous SSc, median baseline UCLA GIT 2.0 score 0.19 (0.06, 0.43). Of these, 71 patients were exposed to immunosuppressive therapy during the observation period: 27/71 methotrexate, 1/71 cyclophosphamide, 17/71 MMF, 3/71 leflunomide, 3/71 azathioprine, 6/71 glucocorticoids >10mg/d, 16/34 rituximab, 18/34 tocilizumab. Patients on immunosuppressive therapy during the observation period had, compared to patients without such treatment, overall more severe SSc, higher prevalence of treatment with proton pump inhibitors, similar UCLA GIT 2.0 scores at baseline and at follow up and tendentially less severe GI symptoms at baseline and follow-up by medical history. In multivariable linear regression, immunosuppressive therapy, lower body mass index, longer disease duration and lower baseline UCLA GIT 2.0 score were significantly associated with lower (better) UCLA GIT 2.0 scores at follow-up (Table 1).

Table 1.Predictors of UCLA GIT 2.0 score at follow-upEstimates95% CIpAge0.002-0.001 – 0.0060.136Sex [male]-0.056-0.172 – 0.0610.347Disease duration-0.005-0.009 – -0.0000.030Body mass index0.0140.002 – 0.0250.017UCLA GIT 2.0 total score baseline0.6900.571 – 0.809<0.001Immunosuppressive therapy during observation period-0.119-0.228 – -0.0100.032Immunosuppressive therapy before baseline0.080-0.032 – 0.1920.160Modified Rodnan Skin Score-0.001-0.008 – 0.0070.860Forced vital capacity-0.001-0.004 – 0.0010.302Erythrocyte sedimentation rate0.003-0.001 – 0.0060.116Proton pump inhibitors-0.034-0.120 – 0.0520.435(Intercept)-0.120-0.531 – 0.2910.566

Baseline factors associated with the total UCLA GIT 2.0 score at the end of the observation period. Multiple linear regression model with imputation for missing variables. N=209 patients

Conclusion

Immunosuppressive treatment was associated with lower UCLA GIT 2.0 scores, which suggests potential effects of immunosuppressants on GI manifestations in patients with SSc. These results need verification in additional studies and randomised controlled clinical trials.

References

[1]Khanna D et al. Arthritis Rheum, 2009; 61: 1257-63.

Disclosure of Interests

Lea Stamm: None declared, Alexandru Garaiman: None declared, Norina Zampatti: None declared, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Consultant of: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Grant/research support from: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Cosimo Bruni Speakers bureau: Actelion, Eli-Lilly, Boehringer-Ingelheim, Grant/research support from: Abbvie, EUSTAR, Gruppo Italiano Lotta alla Sclerodermia (GILS), SCTC, Rucsandra Dobrota Consultant of: Boehringer-Ingelheim, Grant/research support from: Iten-Kohaut Foundation, Muriel Elhai: None declared, Sherif Ismail Grant/research support from: EULAR scientific training grant for young fellows 2021, Suzana Jordan: None declared, Aurora Tatu: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Carina Mihai Speakers bureau: Boehringer-Ingelheim, Mepha, MED Talks Switzerland, Consultant of: Boehringer-Ingelheim, Janssen, Grant/research support from: Boehringer-Ingelheim, Janssen, Roche.

OP0092 DECIPHERING THE SYNOVIAL TISSUE AND FIBROBLAST SUBSETS IN SYSTEMIC SCLEROSIS

Background

Articular involvement is underestimated in systemic sclerosis (SSc), but represents a major cause of disability and is a marker of disease severity. There is no approved effective therapy for arthritis in SSc and immunosuppressive treatments are given to SSc patients by analogy with rheumatoid arthritis (RA), but with limited effect. The last few years have revolutionized the understanding of the pathogenesis of RA by deciphering the heterogeneity of synovium at both the cellular and molecular levels. Nevertheless, the pathogenesis of joint involvement in SSc remains largely unknown.

Objectives

To characterize the synovium in SSc at tissue and cellular levels and to compare it with RA synovium.

Methods

Nine consecutive patients fulfilling SSc classification criteria and having joint synovitis were included. Patients with overlap with other autoimmune rheumatic diseases were excluded. Synovial tissues (8 wrists, 1 knee) were obtained by ultrasound-guided biopsy and were compared to those obtained from five RF and CCP positive RA patients (3 wrists, 3 knees). Tolerance of the procedure was assessed after 3-5 days. Histological analysis of the synovium determined the Krenn synovitis score (0-9) and stratified the synovial tissue according to previously published histological features1. One biopsy, without synovial tissue, was not processed further. ScRNA-seq libraries were prepared with 10X Genomics technology and sequenced on NovaSeq 6000. Integrated bioinformatics analysis used Cell Ranger and Seurat software. Overexpressed genes were selected using log2 ratio (>0.25) and false discovery rate adjusted p value (< 0.05). For pathway enrichment analysis, Enrichr software was used.

Results

Of the nine SSc-patients, 6 were women, median age was 65 [IQR: 58-67] years, median disease duration was 2 [0.5-5] years and 2 had diffuse cutaneous subtype. The antibody status was as follows: anti-Scl70 (2), anti-centromere (2), anti-RNA polymerase III (3), anti-Ku (1) and isolated ANA (1). In the RA cohort, 4/5 were women, median age was 56 [54-59] years and median disease duration 6.5 [5-7.5] years. Synovial biopsy was well-tolerated by all the patients. Krenn synovitis score was lower in SSc as compared to RA across the three components of the synovitis score (lining layer, stroma and inflammatory infiltrate). In SSc, 7/8 (87.5%) biopsies were characterized by a pauci-immune pathotype, whereas in RA 3/6 (50%) were pauci-immune. Due to the low inflammatory pauci-immune pathotype in all but one SSc patients, we focused the scRNA sequencing analysis on synovial fibroblasts (SF) (number of SF studied: 4876 in SSc and 5885 in RA). We identified four clusters of SF with respective marker genes: SF1 (CXCL12, APOE, RARRES2, CCL2), SF2 (PRG4, MMP1, MMP3, CD55), SF3 (POSTN, ASPN, COMP, COL1A1) and SF4 (FN1, TIMP1, SERPIN2, PRELP). Comparison between SSc and RA SF subtypes showed differences in the proportion of the clusters between both diseases with higher enrichment of SF2 corresponding to the lining SF in SSc. 741 genes were differentially expressed between SSc and RA SF with 414 genes overexpressed in SSc SF. Pathway enrichment analysis of these 414 genes identified TGF-β (p.adj: 3.708e-18) and interferon (p.adj: 1.071e-8) signaling pathways. TGF-β signaling was enriched across all the clusters of SF, whereas interferon signaling mostly in sublining SF. The most overexpressed genes in SSc included PLCG2 (encoding the signaling enzyme PLCγ2, which plays a regulatory role in various immune pathways), PCOLCE2 (encoding a procollagen C-endopeptidase enhancer) and the transcription factor AHR (negative regulator of TGF-β).

Conclusion

Synovitis in SSc differs from RA synovitis both at histological and molecular levels. By highlighting the low inflammatory nature of the synovium and the enrichment in TGF-β and interferon signaling pathways in SSc SF, our study questions the use of the same immunosuppressive therapies in RA and SSc. These results are the basis for the development of specific targeted therapies for arthritis in SSc.

References

[1]Humby F, et al. Ann Rheum Dis 2019;78:761–72.

Disclosure of Interests

Miranda Houtman: None declared, Raphael Micheroli: None declared, Kristina Bürki: None declared, Chantal Pauli: None declared, Sam G. Edalat: None declared, Mojca Frank Bertoncelj: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur.

Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Caroline Ospelt: None declared, Muriel Elhai Speakers bureau: BMS.

An Optimized Tissue Dissociation Protocol for Single-Cell RNA Sequencing Analysis of Fresh and Cultured Human Skin Biopsies

We present an optimized dissociation protocol for preparing high-quality skin cell suspensions for in-depth single-cell RNA-sequencing (scRNA-seq) analysis of fresh and cultured human skin. Our protocol enabled the isolation of a consistently high number of highly viable skin cells from small freshly dissociated punch skin biopsies, which we use for scRNA-seq studies. We recapitulated not only the main cell populations of existing single-cell skin atlases, but also identified rare cell populations, such as mast cells. Furthermore, we effectively isolated highly viable single cells from ex vivo cultured skin biopsy fragments and generated a global single-cell map of the explanted human skin. The quality metrics of the generated scRNA-seq datasets were comparable between freshly dissociated and cultured skin. Overall, by enabling efficient cell isolation and comprehensive cell mapping, our skin dissociation-scRNA-seq workflow can greatly facilitate scRNA-seq discoveries across diverse human skin pathologies and ex vivo skin explant experimentations.

Role of synovial fibroblast subsets across synovial pathotypes in rheumatoid arthritis: a deconvolution analysis

OBJECTIVES

To integrate published single-cell RNA sequencing (scRNA-seq) data and assess the contribution of synovial fibroblast (SF) subsets to synovial pathotypes and respective clinical characteristics in treatment-naïve early arthritis.

METHODS

In this in silico study, we integrated scRNA-seq data from published studies with additional unpublished in-house data. Standard Seurat, Harmony and Liger workflow was performed for integration and differential gene expression analysis. We estimated single cell type proportions in bulk RNA-seq data (deconvolution) from synovial tissue from 87 treatment-naïve early arthritis patients in the Pathobiology of Early Arthritis Cohort using MuSiC. SF proportions across synovial pathotypes (fibroid, lymphoid and myeloid) and relationship of disease activity measurements across different synovial pathotypes were assessed.

RESULTS

We identified four SF clusters with respective marker genes: PRG4+ SF (CD55, MMP3, PRG4, THY1neg ); CXCL12+ SF (CXCL12, CCL2, ADAMTS1, THY1low ); POSTN+ SF (POSTN, collagen genes, THY1); CXCL14+ SF (CXCL14, C3, CD34, ASPN, THY1) that correspond to lining (PRG4+ SF) and sublining (CXCL12+ SF, POSTN+ + and CXCL14+ SF) SF subsets. CXCL12+ SF and POSTN+ + were most prominent in the fibroid while PRG4+ SF appeared highest in the myeloid pathotype. Corresponding, lining assessed by histology (assessed by Krenn-Score) was thicker in the myeloid, but also in the lymphoid pathotype + the fibroid pathotype. PRG4+ SF correlated positively with disease severity parameters in the fibroid, POSTN+ SF in the lymphoid pathotype whereas CXCL14+ SF showed negative association with disease severity in all pathotypes.

CONCLUSION

This study shows a so far unexplored association between distinct synovial pathologies and SF subtypes defined by scRNA-seq. The knowledge of the diverse interplay of SF with immune cells will advance opportunities for tailored targeted treatments.

Influence of inflammatory and non-inflammatory rheumatic disorders on the clinical and biological profile of type-2 diabetes

OBJECTIVE

To study the profile of type-2 diabetes (T2D) in patients with RA or OA.

METHODS

This observational, multicentre, cross-sectional study included, over a 24-month period, consecutive patients with adult-onset diabetes and RA or OA. We collected demographics, disease activity and severity indices, current treatments for RA and diabetes, history and complications of diabetes. A systematic blood test was performed, assessing inflammatory, immunological and metabolic parameters. The homoeostasis model assessment (HOMA)2-S was used to assess insulin resistance.

RESULTS

We included 167 patients with T2D, 118 with RA and 49 with OA. RA and OA patients had severe T2D with suboptimal metabolic control and a biological profile of insulin resistance. Insulin resistance was significantly higher in RA than in OA patients after stratification on age, BMI and CS use [HOMA2-S: 63.5 (35.6) vs 98.4 (69.2), P < 0.001]. HOMA2-S was independently associated with DAS28 [odds ratio (OR): 4.46, 95% CI: 1.17, 17.08]. T2D metabolic control was not related to disease activity and functional impairment, but HbA1c levels were independently associated with bone erosions (OR: 4.43, 95% CI: 1.18, 16.61). Treatment with low-dose CSs was not associated with decreased insulin sensitivity or increased HbA1c levels. Treatment with TNF-α inhibitors was associated with increased insulin sensitivity compared with patients not receiving biologics [101.3 (58.71) vs 60.0 (32.5), P = 0.001].

CONCLUSION

RA patients display severe T2D with inflammation-associated insulin resistance. These findings may have therapeutic implications, with the potential targeting of insulin resistance through the treatment of joint and systemic inflammation.

FRI0052 INFLUENCE OF RHEUMATOID ARTHRITIS ON THE CLINICAL AND BIOLOGICAL PROFILE OF TYPE-2 DIABETES MELLITUS

Background:

Type-2 diabetes and rheumatoid arthritis (RA) are two chronic diseases characterized by tissue inflammation and insulin resistance. To date, no data have evaluated the influence of RA-induced joint and systemic inflammation on the course of type-2 diabetes.

Objectives:

To study the impact of RA on type-2 diabetes

Methods:

Observational, multicenter, cross-sectional usual-care study, including 7 rheumatology centers. This study included over a 24-month period consecutive patients with type-2 diabetes and RA, fulfilling the 2010 ACR / EULAR criteria, and diabetic controls with osteoarthritis (OA). The following data were collected: demographics, disease activity and severity indices, current treatment for RA and diabetes, history and complications of diabetes. A systematic blood test was performed, assessing inflammatory (CRP levels) and metabolic (fasting glycemia and insulin levels, HbA1c) parameters. The HOMA2%B (insulin secretion) and HOMA2%S (tissue insulin sensitivity) indices (HOMA calculator, © Diabetes Trials Unit, University of Oxford) were used to assess insulin resistance. Ra and OA patients were compared using parametric tests after adjusting for age and BMI. A multivariate logistic regression was performed ti identify factors independently associated with insulin resistance.

Results:

We included 122 RA patients (74% women, mean age 64+/-11 years, mean disease duration 15+/-11 11 years, 75% with positive ACPA antibodies and 64% with erosive disease) and 54 controls with OA. 64% of RA patients were treated with oral corticosteroids <10 mg/day, 65% received methotrexate and 53% received targeted biological therapies.

The characteristics of type-2 diabetes in the 54 OA patients corresponded to severe insulin-resistant diabetes: age> 65 years, high BMI> 30 kg/m2, mean HbA1c 7.3%+/-11 1.3%, 30% of insulin requirement, high frequency of other cardiovascular risk factors, macroangiopathy found in almost half of patients and biological criteria of insulin resistance (elevation of HOMA2%B and decrease of HOMA2%S).

RA patients with type-2 diabetes had a younger age (64+/-11 years vs. 68+/-12 years, p=0.031) and lower BMI (27.7+/-11 5.5 vs. 31.5+/-11 6.3, p<0.001). These patients also had severe diabetes (HbA1c 7.0%+/-11 1.2%, 29% of insulin requirement, 43% of macroangiopathy) with an insulin resistance profile identical to OA controls. After adjusting for age and BMI, RA patients had a significantly increased insulin secretion compared to OA patients (HOMA2%B: 83.1+/-11 65.2 vs. 49.3+/-11 25.7, p=0.023) as well as a significant reduction of insulin sensitivity (HOMA2%S: 61.1+/-11 31.6 vs. 92.9+/-11 68.1, p=0.016). This insulin resistance was associated with the inflammatory activity of RA, with a negative correlation between the HOMA2%S and the DAS28 (r=-0.28, p=0.027). The multivariate logistic regression confirmed the independent association between the HOMA2%S index and DAS28 (OR: 3.93, 95% CI 1.02-15.06), as well as high blood pressure (OR: 1.29, 95% CI 0.33-1.99 CI).

Conclusion:

RA patients with type-2 diabetes displayed severe, poorly controlled diabetes, highlighting the burden of comorbidities associated with RA. The clinical-biological profile of diabetic RA patients was severe insulin-resistant diabetes, with a biological profile of insulin resistance linked to the inflammatory activity of the disease. These findings may have therapeutic implications, with the potential targeting of insulin resistance through the treatment of joint and systemic inflammation.

Acknowledgments:

Société Française de Rhumatologie (research grant)

Bristol Myers Squibb (research grant)

Disclosure of Interests:

Jérôme Avouac Grant/research support from: Pfizer, Bristol Myers Squibb, Consultant of: Sanofi, Bristol Myers Squibb, Abbvie, Boerhinger, Nordic Pharma, Speakers bureau: Sanofi, Bristol Myers Squibb Abbvie, MSD, Pfizer, Nordic Pharma, Muriel ELHAI: None declared, Marine Forien: None declared, Jérémie SELLAM: None declared, Florent Eymard Consultant of: Regenlab, Anna Moltó Grant/research support from: Pfizer, UCB, Consultant of: Abbvie, BMS, MSD, Novartis, Pfizer, UCB, Laure Gossec Grant/research support from: Lilly, Mylan, Pfizer, Sandoz, Consultant of: AbbVie, Amgen, Biogen, Celgene, Janssen, Lilly, Novartis, Pfizer, Sandoz, Sanofi-Aventis, UCB, Frédéric Banal: None declared, Joel Daminano: None declared, Philippe Dieudé: None declared, Yannick Allanore Shareholder of: Sanofi, Roche, Consultant of: Actelion, Bayer, BMS, Boehringer Ingelheim, Inventiva, Sanofi

Safety and effectiveness of abatacept in systemic sclerosis: The EUSTAR experience

OBJECTIVE

To analyze the safety and effectiveness of abatacept (ABA) given in routine care to patients with systemic sclerosis (SSc).

METHODS

Retrospective multicenter observational study that enrolled patients with SSc treated with ABA. We collected epidemiological data and clinical outcomes. First, we analyzed the frequency of adverse effects. Secondly, we compared the evolution of different organ manifestations during ABA treatment. We collected data from 6 months before start of therapy to the last follow-up the following parameters: modified Rodnan Skin Score (mRSS), joints, lung and gastrointestinal involvement, concomitant medications, and laboratory tests.

RESULTS

Data on twenty-seven patients with SSc were collected (93% females; 67% limited SSc). Rheumatoid arthritis was the most frequent concomitant autoimmune disease. ILD was present in 15 patients. Anti-Scl 70 antibodies were present in 13 patients and rheumatoid factor and ACPA antibodies were present in eight and seven patients respectively. The main indication to use abatacept was joint involvement (59%) followed by myositis (26%). A total of 16 adverse effects were reported in 28 months of abatacept treatment including five that required hospitalization. Most of them occurred in the first 3 months after starting abatacept. After 12 months, the number of tender and swollen joints decreased compared to baseline (p<0.03 and p<0.02 respectively). Moreover, a beneficial effect of abatacept on HAQ-DI at 3 and 6 months (p<0.05) and on morning stiffness at 6 and 12 months (p<0.03) was observed. We also observed a decrease in the modified Rodnan skin score (p<0.05). No changes in lung or gastrointestinal involvement were found.

CONCLUSIONS

ABA demonstrated a good safety profile and seems to have some effectiveness on joint involvement and related disability in SSc patients treated in routine care.

Circulating lung biomarkers in idiopathic lung fibrosis and interstitial lung diseases associated with connective tissue diseases: Where do we stand?

Interstitial lung diseases (ILDs) are complex diseases with various courses where personalized medicine is highly expected. Biomarkers are indicators of physiological, pathological processes or of pharmacological response to therapeutic interventions. They can be used for diagnosis, risk-stratification, prediction and monitoring of treatment response. To better delineate the input and pitfalls of biomarkers in ILDs, we performed a systematic review and meta-analysis of literature in MEDLINE and Embase databases from January 1960 to February 2019. We focused on circulating biomarkers as having the highest generalizability. Overall, 70 studies were included in the review and 20 studies could be included in the meta-analysis. This review highlights that ILD associated with connective tissue diseases (CTD-ILD) and idiopathic pulmonary fibrosis (IPF) share common biomarkers, suggesting common pathophysiological pathways. KL-6 and SP-D, could diagnose lung fibrosis in both IPF and CTD-ILD, with KL-6 having the strongest value (OR: 520.95[110.07-2465.58], p<0.001 in IPF and OR:26.43[7.15-97.68], p<0.001 in CTD-ILD), followed by SPD (OR: 33.81[3.20-357.52], p = 0.003 in IPF and 13.24 [3.84-45.71] in SSc-ILD), MMP7 appeared as interesting for IPF diagnosis (p<0.001), whereas in SSc, CCL18 was associated with ILD diagnosis. Both CCL18 and KL-6 were predictive for the outcomes of ILDs, with higher predictive values for CCL18 in both IPF (OR:10.22[4.72-22.16], p<0.001 and in SSc [2.62[1.71-4.03], p<0.001). However, disease specific biomarkers are lacking and large longitudinal studies are needed before the translational use of the potential biomarkers in clinical practice. With the recent availability of new effective therapies in ILDs, further studies should assess response to treatment.

Outcomes of patients with systemic sclerosis treated with rituximab in contemporary practice: a prospective cohort study

OBJECTIVE

To assess the safety and efficacy of rituximab in systemic sclerosis (SSc) in clinical practice.

METHODS

We performed a prospective study including patients with SSc from the European Scleroderma Trials and Research (EUSTAR) network treated with rituximab and matched with untreated patients with SSc. The main outcomes measures were adverse events, skin fibrosis improvement, lung fibrosis worsening and steroids use among propensity score-matched patients treated or not with rituximab.

RESULTS

254 patients were treated with rituximab, in 58% for lung and in 32% for skin involvement. After a median follow-up of 2 years, about 70% of the patients had no side effect. Comparison of treated patients with 9575 propensity-score matched patients showed that patients treated with rituximab were more likely to have skin fibrosis improvement (22.7 vs 14.03 events per 100 person-years; OR: 2.79 [1.47-5.32]; p=0.002). Treated patients did not have significantly different rates of decrease in forced vital capacity (FVC)>10% (OR: 1.03 [0.55-1.94]; p=0.93) nor in carbon monoxide diffusing capacity (DLCO) decrease. Patients having received rituximab were more prone to stop or decrease steroids (OR: 2.34 [1.56-3.53], p<0.0001). Patients treated concomitantly with mycophenolate mofetil had a trend for better outcomes as compared with patients receiving rituximab alone (delta FVC: 5.22 [0.83-9.62]; p=0.019 as compared with controls vs 3 [0.66-5.35]; p=0.012).

CONCLUSION

Rituximab use was associated with a good safety profile in this large SSc-cohort. Significant change was observed on skin fibrosis, but not on lung. However, the limitation is the observational design. The potential stabilisation of lung fibrosis by rituximab has to be addressed by a randomised trial.

Acute anterior uveitis in spondyloarthritis: a monocentric study of 301 patients

OBJECTIVES

To assess the cumulative incidence of uveitis in spondyloarthritis (SpA) and its associated factors and to evaluate the effect of DMARD treatment on uveitis in a real-life setting.

METHODS

A cross-sectional monocentric observational study (COSPA) was conducted. Patients with definite SpA underwent a face-to-face interview. General data and specific data concerning uveitis were collected. Cumulative incidence of uveitis flares was estimated by Kaplan-Meier survival curves. Factors associated with uveitis were determined by Cox analysis. Treatment effectiveness was evaluated by comparing the number of uveitis flares before/after treatment using Wilcoxon test.

RESULTS

In total, 301 patients were included, 186 (61.8%) were men, with mean age and disease duration of 44.8 (±13.6) and 16.8 (±11.9) years, respectively. Among them, 82 (27.2%) had at least one uveitis flare. Prevalence of uveitis at the time of SpA diagnosis was 11.5 % (±1.9%) and increased over time to reach 39.3% (±4.1%) 20 years after diagnosis. HLA B27 positivity and heel pain were independently associated with uveitis (HR [IC 95%] = 4.5 [1.3-15.2] and 1.8 [1.1-2.9], respectively). A significant reduction in the number of uveitis before/after treatment was observed in patients treated with anti TNF monoclonal antibodies (n=27), (1.83 (±4.03) vs. 0.41 (±1.22), p=0.002), whereas it was not with etanercept (n=19), (0.44 (±0.70) and 0.79 (±1.36), p=NS).

CONCLUSIONS

Prevalence of uveitis in SpA seems to increase with disease duration and seems more likely to appear with HLA B27 positivity and heel pain. Anti-TNF monoclonal antibodies seemed to be more effective in the reduction of uveitis flares.

Linking systemic angiogenic markers to synovial vascularization in rheumatoid arthritis

Background

Neoangiogenesis is a crucial event to promote the development of the hyperplasic proliferative pathologic synovium in Rheumatoid arthritis (RA). Ultrasound (US) is sensitive for detection of power Doppler (PD) vascularization.

Objective

To explore the associations between a set of complementary circulating angiogenic markers and a comprehensive US assessment in patients with RA.

Patients and methods

Serum levels of eight angiogenic markers were measured by quantitative ELISAs in a total of 125 patients with RA, who were all systematically assessed in parallel by PDUS, performed on 32 joints.

Results

Serum levels of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) and Tie-2 were more likely to be increased in patients with synovial hyperemia detected on at least one joint (Power Doppler grade ≥1). sVCAM-1, Tie-2 and Angiostatin concentrations gradually increased together with the grade of the semiquantitative PDUS scale and concentrations of these three markers were markedly increased in patients with moderate to marked hyperemia (Power Doppler grade 2 and 3). Levels of sVCAM-1, Tie-2, and Angiostatin correlated with a global arthritis sum score, defined by the sum of the semiquantitative PDUS scores for all joints examined. Levels of Tie-2 and Placenta Growth Factor (PlGF) were associated with PDUS features indicating residual disease activity.

Conclusion

Our results support the relevance of measuring serum levels of vascular markers to evaluate the intensity and extent of synovial vascularization. Angiogenic markers, and particularly Tie-2, could be a valuable surrogate of active synovitis and their place in relation to PDUS in clinical practice deserve further investigation.

Mapping and predicting mortality from systemic sclerosis

OBJECTIVES

To determine the causes of death and risk factors in systemic sclerosis (SSc).

METHODS

Between 2000 and 2011, we examined the death certificates of all French patients with SSc to determine causes of death. Then we examined causes of death and developed a score associated with all-cause mortality from the international European Scleroderma Trials and Research (EUSTAR) database. Candidate prognostic factors were tested by Cox proportional hazards regression model by single variable analysis, followed by a multiple variable model stratified by centres. The bootstrapping technique was used for internal validation.

RESULTS

We identified 2719 French certificates of deaths related to SSc, mainly from cardiac (31%) and respiratory (18%) causes, and an increase in SSc-specific mortality over time. Over a median follow-up of 2.3 years, 1072 (9.6%) of 11 193 patients from the EUSTAR sample died, from cardiac disease in 27% and respiratory causes in 17%. By multiple variable analysis, a risk score was developed, which accurately predicted the 3-year mortality, with an area under the curve of 0.82. The 3-year survival of patients in the upper quartile was 53%, in contrast with 98% in the first quartile.

CONCLUSION

Combining two complementary and detailed databases enabled the collection of an unprecedented 3700 deaths, revealing the major contribution of the cardiopulmonary system to SSc mortality. We also developed a robust score to risk-stratify these patients and estimate their 3-year survival. With the emergence of new therapies, these important observations should help caregivers plan and refine the monitoring and management to prolong these patients' survival.

Treatment with abatacept prevents experimental dermal fibrosis and induces regression of established inflammation-driven fibrosis

OBJECTIVE

Activated T cells are the main component of the inflammatory skin infiltrates that characterise systemic sclerosis (SSc). Our aim was to investigate the efficacy of abatacept, which tempers T-cell activation, in reducing skin fibrosis in complementary mouse models of SSc.

METHODS

The antifibrotic properties of abatacept were evaluated in the mouse models of bleomycin-induced dermal fibrosis and sclerodermatous chronic graft-versus-host disease, reflecting early and inflammatory stages of SSc. Thereafter, we studied the efficacy of abatacept in tight skin (Tsk-1) mice, an inflammation-independent mouse model of skin fibrosis.

RESULTS

Abatacept efficiently prevented bleomycin-induced skin fibrosis and was also effective in the treatment of established fibrosis. In this model, abatacept decreased total and activated T-cell, B-cell and monocyte infiltration in the lesional skin. Abatacept did not protect CB17-SCID mice from the development of bleomycin-induced dermal fibrosis, which supports that T cells are necessary to drive the antifibrotic effects of abatacept. Upon bleomycin injections, skin interleukin (IL) 6 and IL-10 levels were significantly reduced upon abatacept treatment. Moreover, treatment with abatacept ameliorated fibrosis in the chronic graft-versus-host disease model, but demonstrated no efficacy in Tsk-1 mice. The tolerance of abatacept was excellent in the three mouse models.

CONCLUSIONS

Using complementary models, we demonstrate that inhibition of T-cell activation by abatacept can prevent and induce the regression of inflammation-driven dermal fibrosis. Translation to human disease is now required, and targeting early and inflammatory stages of SSc sounds the most appropriate for positioning abatacept in SSc.

Prevalence and clinical characteristics of psoriasis in spondyloarthritis: a descriptive analysis of 275 patients

OBJECTIVES

To assess the prevalence of psoriasis among a cohort of patients with spondyloarthritis (SpA), to describe the clinical characteristics of psoriasis and associations with other manifestations.

METHODS

This is a retrospective single-centre observational study. The patients were diagnosed with definite SpA (expert opinion), either axial or peripheral. Each patient underwent a direct interview by a physician. The data regarding history of psoriasis and its clinical characteristics were collected. Univariate and multivariate analyses of patients with versus without psoriasis were carried out.

RESULTS

In all, 275 SpA patients were assessed: mean disease duration 16.7±11.8 years, 61.4% were men, 69.1% were diagnosed as axial SpA and 17.8% as peripheral SpA. In all, 84 patients (30.5%) had present or past psoriasis. The prevalence of psoriasis was high whatever the clinical presentation. Psoriasis was present before or concomitantly to diagnosis of SpA in 59/84 patients (70.2%). The most common types of psoriasis were plaque (66.7% of patients with psoriasis) and scalp psoriasis (65.5%). Other localisations were not rare, including palmoplantar pustulosis (20.2%) or nail psoriasis (19.1%). Patients with versus without psoriasis differed only through a lower proportion of radiological sacroiliitis (57.5% vs. 81.3 %, p<0.001).

CONCLUSIONS

With a prevalence of 30.5%, i.e. ten times higher than in the general population, this study confirms that psoriasis is a frequent and early manifestation in SpA and that a systematic search for psoriasis (e.g. scalp) is relevant in SpA for clinical practice, whatever the clinical presentation of SpA.

Combined effect of genetic background and gender in a mouse model of bleomycin-induced skin fibrosis

INTRODUCTION

Systemic sclerosis (SSc) is a connective tissue disorder characterised by the development of skin fibrosis. Our current understanding of the disease pathogenesis is incomplete and the study of SSc is hindered, at least partially, by a lack of animal models that fully replicate the complex state of human disease. Murine model of bleomycin-induced dermal fibrosis encapsulates important events that take place early in the disease course.

METHODS

To characterise the optimum in vivo parameters required for the successful induction of dermal fibrosis we subjected three commonly used mouse strains to repeated subcutaneous bleomycin injections. We aimed to identify the effects of genetic background and gender on the severity of skin fibrosis. We used male and female Balb/C, C57BL/6, and DBA/2 strains and assessed their susceptibility to bleomycin-induced fibrosis by measuring dermal thickness, hydroxyproline/collagen content and number of resident myofibroblasts, all of which are important indicators of the severity of skin fibrosis. All data are expressed as mean values ± SEM. The Mann-Whitney U test was used for statistical analysis with GraphPad Prism 6.04 software.

RESULTS

Dermal fibrosis was most severe in Balb/C mice compared to C57BL/6 and DBA/2 suggesting that Balb/C mice are more susceptible to bleomycin-induced fibrosis. Analysis of the effect of gender on the severity of fibrosis showed that male Balb/C, C57BL/6, DBA/2 mice had a tendency to develop more pronounced fibrosis phenotype than female mice. Of potential importance, male Balb/C mice developed the most severe fibrosis phenotype compared to male C57BL/6 and male DBA/2 as indicated by significantly increased number of dermal myofibroblasts.

CONCLUSION

Our study highlights the importance of genetic background and gender in the induction of murine dermal fibrosis. Robust and reproducible animal models of fibrosis are important research tools used in pharmacological studies which may lead to better understanding of the pathogenesis of fibrotic diseases and assist in identification of new drugs.

Targeting CD226/DNAX accessory molecule-1 (DNAM-1) in collagen-induced arthritis mouse models

Background

Genetic studies have pointed out that CD226 variants, encoding DNAM-1, could be associated with susceptibility to rheumatoid arthritis. Therefore, we aimed to determine the influence of DNAM-1 on the development of arthritis using the collagen-induced arthritis (CIA) mouse model.

Methods

CIA was induced in mice on a DBA/1 background, treated in parallel with a DNAM-1 neutralizing monoclonal antibody, a control IgG and PBS, respectively. CIA was also induced in mice deficient for DNAM-1(dnam1−/−) and control dnam-1+/+ mice on a C57/BL6 background. Mice were monitored for clinical and ultrasound signs of arthritis. Histological analysis was performed to search for inflammatory infiltrates and erosions. The Mann–Whitney U test for non-related samples was used for statistical analysis.

Results

There was a non-significant trend for a less arthritic phenotype in mice receiving anti-DNAM-1 mAb at both clinical, ultrasound and histological assessments. But, we did not observe any difference between dnam1+/+ and dnam1−/− mice for incidence nor severity of clinical arthritis. Histological analysis revealed inflammatory scores similar in both groups, without evidence of erosion. Collagen antibodies levels were similar in all mice, confirming immunization with collagen.

Conclusion

Despite some clues suggesting a role of DNAM-1 in arthritis, these complementary approaches demonstrate no contribution of CD226/DNAM-1 in the arthritic phenotype. These results contrast with previous studies showing a role in vivo of DNAM-1 in some autoimmune disorders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12950-015-0056-5) contains supplementary material, which is available to authorized users.

A gender gap in primary and secondary heart dysfunctions in systemic sclerosis: a EUSTAR prospective study

OBJECTIVES

In agreement with other autoimmune diseases, systemic sclerosis (SSc) is associated with a strong sex bias. However, unlike lupus, the effects of sex on disease phenotype and prognosis are poorly known. Therefore, we aimed to determine sex effects on outcomes.

METHOD

We performed a prospective observational study using the latest 2013 data extract from the EULAR scleroderma trials and research (EUSTAR) cohort. We looked at (i) sex influence on disease characteristics at baseline and (ii) then focused on patients with at least 2 years of follow-up to estimate the effects of sex on disease progression and survival.

RESULTS

9182 patients with SSc were available (1321 men) for the baseline analyses. In multivariate analysis, male sex was independently associated with a higher risk of diffuse cutaneous subtype (OR: 1.68, (1.45 to 1.94); p<0.001), a higher frequency of digital ulcers (OR: 1.28 (1.11 to 1.47); p<0.001) and pulmonary hypertension (OR: 3.01 (1.47 to 6.20); p<0.003). In the longitudinal analysis (n=4499), after a mean follow-up of 4.9 (±2.7) years, male sex was predictive of new onset of pulmonary hypertension (HR: 2.66 (1.32 to 5.36); p=0.006) and heart failure (HR: 2.22 (1.06 to 4.63); p=0.035). 908 deaths were recorded, male sex predicted deaths of all origins (HR: 1.48 (1.19 to 1.84); p<0.001), but did not significantly account for SSc-related deaths.

CONCLUSIONS

Although more common in women, SSc appears as strikingly more severe in men. Our results obtained through the largest worldwide database demonstrate a higher risk of severe cardiovascular involvement in men. These results raise the point of including sex in the management and the decision-making process.

Targeting IL-6 by both passive or active immunization strategies prevents bleomycin-induced skin fibrosis

Introduction

Interleukin-6 (IL-6) is a pleiotropic cytokine for which preliminary data have suggested that it might contribute to systemic sclerosis (SSc). Our aims were to investigate, firstly, IL-6 expression in patients with SSc and, secondly, the efficacy of both passive and active immunization against IL-6 to reduce skin fibrosis in complementary mouse models of SSc.

Methods

Human serum levels and skin expression of IL-6 were determined by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. We first evaluated the antifibrotic properties of the monoclonal anti-IL-6R antibody, MR16-1, in the bleomycin-induced dermal fibrosis mouse model, reflecting early and inflammatory stages of SSc. Then, we assessed the efficacy of MR16-1 in tight skin-1 (Tsk-1) mice, an inflammation-independent model of skin fibrosis. Additionally, we have developed an innovative strategy using an anti-IL-6 peptide-based active immunization. Infiltrating leukocytes, T cells, and B cells were quantified, and IL-6 levels were measured in the serum and lesional skin of mice after passive or active immunization.

Results

Serum and skin levels of IL-6 were significantly increased in patients with early SSc. Treatment with MR16-1 led in the bleomycin mouse model to a 25% (P = 0.02) and 30% (P = 0.007) reduction of dermal thickness and hydroxyproline content, respectively. MR16-1 demonstrated no efficacy in Tsk-1 mice. Thereafter, mice were immunized against a small peptide derived from murine IL-6 and this strategy led in the bleomycin model to a 20% (P = 0.02) and 25% (P = 0.005) decrease of dermal thickness and hydroxyproline content, respectively. Passive and active immunization led to decreased T-cell infiltration in the lesional skin of mice challenged with bleomycin. Upon bleomycin injections, serum and skin IL-6 levels were increased after treatment with MR16-1 and were significantly reduced after anti-IL-6 active immunization.

Conclusions

Our results support the relevance of targeting IL-6 in patients with early SSc since IL-6 is overexpressed in early stages of the disease. Targeting IL-6 by both passive and active immunization strategies prevented the development of bleomycin-induced dermal fibrosis in mice. Our results highlight the therapeutic potential of active immunization against IL-6, which is a seductive alternative to passive immunization.

Performance of skin ultrasound to measure skin involvement in different animal models of systemic sclerosis

Animal models are widely used in systemic sclerosis (SSc) research. We set out to determine whether ultrasonography (US) could be used to assess skin fibrosis in two complementary SSc-models: the bleomycin-induced dermal fibrosis model and the tight-skin 1 mouse model. Back skin thickness was measured using a high-frequency ultrasound dedicated to the small animal. There was no significant difference in dermal thickness measured by US between mice injected with bleomycin and those treated with NaCl. These results were inconsistent with histological analyses. Mean US hypodermal thickness was significantly higher in tight-skin 1 mice as compared with Pa/Pa control subgroup (p = 0.02). Histologic and US measures of dermal and hypodermal thicknesses in this model were well correlated (r = 0.79). The intra-observer concordance was 0.96 for hypodermal thickness. US is reliable and sensitive in detecting hypodermal thickening in the tight-skin 1 mouse model. Further larger studies are warranted to better determine the place of US in SSc-research.

Radiological peripheral involvement in a cohort of patients with polyarticular juvenile idiopathic arthritis at adulthood

OBJECTIVE

Radiographic damage was recently identified as a feature of poor prognosis in polyarticular juvenile idiopathic arthritis (pJIA). However, most radiographic studies did not differentiate pJIA from other subtypes of JIA and little is known about pJIA persisting into adulthood. We describe radiological peripheral involvement in young adults with pJIA compared to patients with rheumatoid arthritis (RA).

METHODS

All consecutive patients with pJIA followed in a transition program were included. Age, sex, disease duration, and medical or surgical treatment information was collected. Laboratory tests and standard radiographs of the hands and wrists, feet, and hips were analyzed by 2 independent radiologists blinded to the diagnosis. One RA control group (age < 55 yrs), matched for sex and disease duration, was recruited.

RESULTS

Forty-three patients with pJIA and 59 with RA were included. Radiographs showed hand lesions in 79% of pJIA and 86% of patients with RA, feet lesions in 74% of pJIA and 80% of patients with RA, and hip damage in 35% of pJIA and 17% of patients with RA (p = nonsignificant). Specific to the juvenile forms were lower frequency of proximal interphalangeal joint involvement (51% vs 76%; p = 0.03) and higher risk of bilateral hip damage (86% vs 25%; p < 0.01) than in adult RA.

CONCLUSION

Structural peripheral damage is as common and as severe in young adults with pJIA as in adults with RA. The main specific feature of pJIA seems to be a high risk of bilateral hip damage. This requires a particular monitoring of pJIA patients with unilateral hip involvement to detect bilateralization.