AB1346-HPR REAL-WORLD EFFECTIVENESS AND PERCEIVED USEFULNESS OF SYMPTOM CHECKERS IN RHEUMATOLOGY: INTERIM REPORT FROM THE PROSPECTIVE MULTICENTER BETTER STUDY

Background:

Symptom checkers (SC) promise to reduce diagnostic delay, misdiagnosis and effectively guide patients through healthcare systems. They are increasingly used, however little evidence exists about their real-life effectiveness.

Objectives:

The aim of this study was to evaluate the diagnostic accuracy, usage time, usability and perceived usefulness of two promising SC, ADA (www.ada.com) and Rheport (www.rheport.de). Furthermore, symptom duration and previous symptom checking was recorded.

Methods:

Cross-sectional interim clinical data from the first of three recruiting centers from the prospective, real-world, multicenter bETTeR-study (DKRS DRKS00017642) was used. Patients newly presenting to a secondary rheumatology outpatient clinic between September and December 2019 completed the ADA and Rheport SC. The time and answers were recorded and compared to the patient’s actual diagnosis. ADA provides up to 5 disease suggestions, Rheport calculates a risk score for rheumatic musculoskeletal diseases (RMDs) (≥1=RMD). For both SC the sensitivity, specificity was calculated regarding RMDs. Furthermore, patients completed a survey evaluating the SC usability using the system usability scale (SUS), perceived usefulness, previous symptom checking and symptom duration.

Results:

Of the 129 consecutive patients approached, 97 agreed to participate. 38% (37/97) of the presenting patients presented with an RMD (Figure 1). Mean symptom duration was 146 weeks and a mean number of 10 physician contacts occurred previously, to evaluate current symptoms. 56% (54/96) had previously checked their symptoms on the internet using search engines, spending a mean of 6 hours. Rheport showed a sensitivity of 49% (18/37) and specificity of 58% (35/60) concerning RMDs. ADA’s top 1 and top 5 disease suggestions concerning RMD showed a sensitivity of 43% (16/37) and 54% (20/37) and a specificity of 58% (35/60) and 52% (31/60), respectively. ADA listed the correct diagnosis of the patients with RMDs first or within the first 5 disease suggestions in 19% (7/37) and 30% (11/37), respectively. The average perceived usefulness for checking symptoms using ADA, internet search engines and Rheport was 3.0, 3.5 and 3.1 on a visual analog scale from 1-5 (5=very useful). 61% (59/96) and 64% (61/96) would recommend using ADA and Rheport, respectively. The mean SUS score of ADA and Rheport was 72/100 and 73/100. The mean usage time for ADA and Rheport was 8 and 9 minutes, respectively.

Conclusion:

This is the first prospective, real-world, multicenter study evaluating the diagnostic accuracy and other features of two currently used SC in rheumatology. These interim results suggest that diagnostic accuracy is limited, however SC are well accepted among patients and in some cases, correct diagnosis can be provided out of the pocket within few minutes, saving valuable time.

Figure:

Acknowledgments:

This study was supported by an unrestricted research grant from Novartis.

Disclosure of Interests:

Johannes Knitza Grant/research support from: Research Grant: Novartis, Jacob Mohn: None declared, Christina Bergmann: None declared, Eleni Kampylafka Speakers bureau: Novartis, BMS, Janssen, Melanie Hagen: None declared, Daniela Bohr: None declared, Elizabeth Araujo Speakers bureau: Novartis, Lilly, Abbott, Matthias Englbrecht Grant/research support from: Roche Pharma, Chugai Pharma Europe, Consultant of: AbbVie, Roche Pharma, RheumaDatenRhePort GbR, Speakers bureau: AbbVie, Celgene, Chugai Pharma Europe, Lilly, Mundipharma, Novartis, Pfizer, Roche Pharma, UCB, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Timo Meinderink: None declared, Wolfgang Vorbrüggen: None declared, Cay-Benedict von der Decken: None declared, Stefan Kleinert Shareholder of: Morphosys, Grant/research support from: Novartis, Consultant of: Novartis, Speakers bureau: Abbvie, Novartis, Celgene, Roche, Chugai, Janssen, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Peter Bartz-Bazzanella: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, Martin Welcker Grant/research support from: Abbvie, Novartis, UCB, Hexal, BMS, Lilly, Roche, Celgene, Sanofi, Consultant of: Abbvie, Actelion, Aescu, Amgen, Celgene, Hexal, Janssen, Medac, Novartis, Pfizer, Sanofi, UCB, Speakers bureau: Abbvie, Aescu, Amgen, Biogen, Berlin Chemie, Celgene, GSK, Hexal, Mylan, Novartis, Pfizer, UCB

POS0423 NCOA3 AMPLIFIES PROFIBROTIC TRANSCRIPTIONAL PROGRAMS IN SYSTEMIC SCLEROSIS

Background:

Excessive activation of fibroblasts with a TGFβ-biased gene signature and deposition of extracellular matrix are key features of fibrotic diseases. The mechanisms underlying these transcriptional changes remain poorly understood. Deregulation, mutations and malfunctions of transcriptional co-regulators, which can interact with multiple transcription factors and enable a broad-spectrum regulation of transcriptional networks, have been implicated as driving factors in a large number of diseases and pathologies.

Objectives:

In the present study, we aimed to analyze the role of the co-regulator Nuclear Receptor Co-Activator 3 (NCOA3) in fibroblast activation and tissue fibrosis, and to evaluate a potential interaction of NCOA3 with fibrosis-relevant transcription factors.

Methods:

NCOA3 was inhibited genetically by siRNA transfection and pharmacologically by the SRC3 inhibitor-2 (SI-2). We performed bulk RNASeq of human dermal fibroblasts and in silico transcription factor binding site screening of differentially expressed genes (DEGs). The interaction of NCOA3 and TGFβ-SMAD signaling was analyzed by reporter and CoIP assays.

Results:

The expression of NCOA3 in skin biopsies of SSc patients compared to normal controls demonstrated that SSc fibroblasts express modestly, but significantly reduced levels of NCOA3, which persisted in cultured SSc fibroblasts. Stimulation of normal fibroblasts with chronically high levels of TGFβ as they also occur in fibrotic tissue remodeling strongly decreased NCOA3 expression to a similar extent as in SSc fibroblasts. Furthermore, NCOA3 expression is also deregulated in different murine models of skin fibrosis. To investigate the functional effects of decreased NCOA3 levels, we targeted the expression of NCOA3 in normal fibroblasts. SiRNA-mediated knockdown of NCOA3 ameliorated TGFβ-induced gene expression, collagen release, myofibroblast differentiation and cell proliferation. In contrast, knockdown of NCOA3 had no effects on collagen release, expression of contractile proteins or gene expression in unstimulated fibroblasts, suggesting that NCOA3 is not required for cellular homeostasis. To characterize the molecular mechanisms, we performed RNASeq upon NCOA3 knockdown. We identified 343 significant differentially expressed genes (220 downregulated and 123 upregulated with a Benjamini-Hochberg false discovery rate FDR < 0.25 and fold change > 1.5) between TGFβ-stimulated fibroblasts with and without NCOA3 knockdown (NCOA3-DEGs) including the fibrosis-relevant genes EDNRB, COL5A3, HES1, IL11 or IL33. Functional analysis of the NCOA3-DEGs showed enrichment of pathway terms such as collagen binding and extracellular matrix organization. In silico screening of the promoters of the NCOA3-DEGs for potential transcription factor binding motifs revealed binding motifs of core transcription factors of fibroblast activation and tissue fibrosis such as SMAD2/3/4, RBPJ, ZEB1, TCF4, REL, and SNAIL2 amongst the downregulated NCOA3-DEGs. Experimental validation of our biostatistical results using SMAD3 as example demonstrated a higher percentage of NCOA3-pSMAD3 double-positive fibroblasts in skin sections of SSc patients compared to healthy controls. In addition, knockdown of NCOA3 reduced TGFβ-induced SMAD-reporter activity. Furthermore, stimulation with TGFβ increased the interaction of NCOA3 with SMAD3 as analyzed by co-immunoprecipitation. Simultaneous knockdown of NCOA3 and SMAD3 showed no additional reductions compared to the single knockdowns, suggesting that NCOA3 controls SMAD3-dependent gene transcription under fibrotic conditions. Finally, inhibition of NCOA3 showed anti-fibrotic effects in different murine models of experimental skin and lung fibrosis.

Conclusion:

Our findings characterize NCOA3 as regulator of multiple pro-fibrotic transcription programs. Pharmaceutical inhibition of NCOA3 might be a strategy to interfere simultaneously with several core pro-fibrotic mediators in fibrotic diseases such as SSc.

Acknowledgements:

We thank Lena Summa, Vladyslav Fedorchenko, Wolfgang Espach and Regina Kleinlein for excellent technical assistance.

The study was funded by grants DI 1537/7-1, DI 1537/8-1, DI 1537/9-1 and -2, DI 1537/11-1, DI 1537/12-1, DI 1537/13-1, DI 1537/14-1, DI 1537/17-1, DE 2414/2-1, DE 2414/4-1, and RA 2506/3-1 of the German Research Foundation, SFB CRC1181 (project C01) and SFB TR221/ project number 324392634 (B04) of the German Research Foundation, grants J39, J40 and A64 of the IZKF in Erlangen, grant 2013.056.1 of the Wilhelm-Sander-Foundation, grants 2014_A47, 2014_A248 and 2014_A184 of the Else-Kröner-Fresenius-Foundation, grant 14-12-17-1-Bergmann of the ELAN-Foundation Erlangen, BMBF (Era-Net grant 01KT1801), MASCARA program, TP 2 and a Career Support Award of Medicine of the Ernst Jung Foundation.

Disclosure of Interests:

Clara Dees: None declared, Sebastian Poetter: None declared, Maximilian Fuchs: None declared, Christina Bergmann: None declared, Alexandru-Emil Matei: None declared, Andrea-Hermina Györfi: None declared, Alina Soare: None declared, Andreas Ramming: None declared, Paolo Ceppi: None declared, Georg Schett: None declared, Meik Kunz: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

[Cellular therapy in autoimmune disease]

In addition to natural thymus-derived regulatory T-cells (Tregs), peripherally-induced Tregs are of central importance in immune homeostasis. Homotypic interactions between activated effector T-cells and resting memory T-cells induced the generation of IL-10 and IFNgamma producing Tregs in vitro. This mechanism in Treg development allows new insights into T-cell vaccination, which has been employed in pilot trials of multiple sclerosis and rheumatoid arthritis with promising results.

[Th9 cells. Functionally important or just an epiphenomenon?]

Development of the recently described Th9 cells is selectively and dynamically controlled by epigenetic modifications. The selective epigenetic inactivation of the PU.1 promoter associated with diminished Th9 cell differentiation by naive CD4 T cells allows the assumption of a special physiologic role of IL-9. Once deregulated, IL-9 seems to play an important role in the pathogenesis of several autoimmune disorders.

POS0834 LONG-TERM OUTCOME OF SSC ASSOCIATED ILD: IMPROVED SURVIVAL IN PPI TREATED PATIENTS

Background:

Gastroesophageal reflux disease (GERD) occurs frequently in patients with systemic sclerosis (SSc) and SSc-associated interstitial lung disease (SSc-ILD). PPI use has to been shown to improve survival in patients with idiopathic pulmonary fibrosis, whereas to date there are no data on the use of PPI in SSc-ILD.

Objectives:

This study was aimed to assess whether use of PPI is associated with progression of SSc-ILD and survival.

Methods:

We retrospectively analysed 1931 patients with SSc and SSc-ILD from the German Network for Systemic Sclerosis (DNSS) database (2003 onwards). Kaplan–Meier analysis compared overall survival (OS) and progression-free survival (PFS) in patients with vs. without GERD (SSc and SSc-ILD), and PPI vs. no PPI use (SSc-ILD only). Progression was defined as a decrease in either % predicted forced vital capacity ≥10% or single-breath diffusing capacity for carbon monoxide ≥15%, or death.

Results:

GERD was not associated with decreased OS or PFS in patients with either SSc or SSc-ILD. In patients with SSc-ILD, PPI use was associated with improved OS vs. no PPI use after 1 year (98.4% [95% confidence interval: 97.6–99.3]; n=760 vs. 90.8% [87.9–93.8]; n=290) and after 5 years (91.4% [89.2–93.8]; n=357 vs. 70.9% [65.2–77.1]; n=106; p<0.0001). PPI use was also associated with improved PFS vs. no PPI use after 1 year (95.9% [94.6–97.3]; n=745 vs. 86.4% [82.9–90.1]; n=278) and after 5 years (66.8% [63.0–70.8]; n=286 vs. 45.9% [39.6–53.2]; n=69; p<0.0001).

Conclusion:

GERD had no effect on survival in SSc or SSc-ILD. PPIs improved survival in patients with SSc-ILD; however, controlled, prospective trials are needed to confirm this finding.

Disclosure of Interests:

Michael Kreuter Speakers bureau: Boehringer, Consultant of: Boehringer, Grant/research support from: Boehringer, Francesco Bonella Speakers bureau: Boehringer, Roche, GSK, Consultant of: Boehringer, Roche, GSK, Grant/research support from: Boehringer, Kuhr Kathrin: None declared, Jörg Henes Speakers bureau: Abbvie, Boehringer, Chugai, Roche, Janssen, Novartis, SOBI, Pfizer and UCB, Consultant of: Boehringer, Celgene, Chugai, Roche, Janssen, Novartis, SOBI, Grant/research support from: Chugai, Roche, Janssen, Novartis, SOBI, Pfizer, Elise Siegert: None declared, Gabriela Riemekasten Speakers bureau: Novartis, Janssen, Roche, GSK, Boehringer, Consultant of: Janssen, Actelion, Boehringer, Norbert Blank Consultant of: Sobi, Novartis, Roche, UCB, MSD, Pfizer, Actelion, Abbvie, Boehringer, Grant/research support from: Novartis, Sobi, Christiane Pfeiffer: None declared, Ulf Müller-Ladner: None declared, Alexander Kreuter Speakers bureau: MSD, Boehringer, InfectoPharm, Paid instructor for: MSD, PETER KORSTEN Consultant of: Glaxo, Abbvie, Pfizer, BMS, Chugai, Sanofi, Lilly, Boehringer, Novartis, Grant/research support from: Glaxo, Aaron Juche: None declared, Marc Schmalzing Speakers bureau: Chugai Roche, Boehringer, Celgene, Medac, UCB, Paid instructor for: Novartis, Abbvie, Astra Zeneca, Chugai Roche, Janssen, Consultant of: Chugai Roche, Hexal Sandoz, Gilead, Abbvie, Janssen, Boehringer, Margitta Worm Speakers bureau: Boehringer, Ilona Jandova Speakers bureau: Boehringer, Novartis, Abbvie, Laura Susok Speakers bureau: MSD, Novartis, BMS, Sunpharma, Consultant of: MSD, Tim Schmeiser Consultant of: Abbvie, Boehringer, Novartis, UCB, Claudia Guenther Paid instructor for: Advisory Board Boehringer January 2020, Employee of: Novartis 2002-2005, Gernot Keyszer Consultant of: Boehringer, Jan Ehrchen Speakers bureau: Boehringer, Janssen, Chugai, Sobi, Employee of: Pfizer, Actelion (now Janssen), Andreas Ramming Speakers bureau: Boehringer, Gilead, Janssen, Pfizer, Roche, Consultant of: Boehringer, Pfizer, Grant/research support from: Novartis, Pfizer, Ina Kötter Speakers bureau: several companies, Consultant of: several companies, Grant/research support from: several companies, Hanns-Martin Lorenz Speakers bureau: Abbvie, Astra Zeneca, Actelion, Alexion Amgen, Bayer Vital, Baxter, Biogen, Boehringer, BMS, Celgene, Fresenius, Genzyme, GSK, Gilead, Hexal, Janssen, Lilly, Medac, MSD, Mundipharm, Mylan, Novartis, Octapharm, Pfizer, Roche Chugai, Sandoz, Sanofi, Shire SOBI, Thermo Fischer, UCB, Grant/research support from: basic research studies: Pfizer, Novartis, Abbvie, Gilead, Lilly, MSD, Roche Chugai, Pia Moinzadeh Speakers bureau: Boehringer, Actelion, Grant/research support from: Actelion, Nicolas Hunzelmann Speakers bureau: Boehringer Janssen, Roche, Sanofi, Consultant of: Boehringer

OP0201 DYNAMIC CHANGES IN O-GLCNACYLATION REGULATE OSTEOCLAST DIFFERENTIATION AND BONE LOSS IN ARTHRITIS

Background:

Bone remodeling is a constant process maintained by the balance between osteoclast-triggered bone resorption and osteoblast-mediated bone formation. In inflammatory arthritis, such as rheumatoid arthritis (RA), the pro-inflammatory environment favors osteoclast differentiation and skews the balance towards resorption, leading to progressive bone erosion and bone loss. O-GlcNAcylation is a post-translational modification, which transfers a single N-acetylglucosamine molecule to the serine or threonine of the target protein. The modification is accomplished by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Unlike other glycosylation, O-GlcNAcylation occurs in multiple cellular compartments, including the nucleus. Although O-GlcNAcylation is one of the most common modifications, its role in bone homeostasis is still poorly understood.

Objectives:

We aimed to investigate the role of O-GlcNAcylation in osteoclastogenesis under pro-inflammatory milieus. We also focused on dissecting the signaling pathways affected by O-GlcNAcylation during osteoclast differentiation.

Methods:

We examined the levels of O-GlcNAc during in vitro osteoclastogenesis by western blotting. The levels of O-GlcNAc in tissue from RA patients and experimental arthritis were detected by immunofluorescence. Pharmacological inhibition and genetic knockout were used to manipulate O-GlcNAcylaiton during osteoclastogenesis. RNA sequencing was performed to study O-GlcNAc-mediated pathways.

Results:

We demonstrate the dynamic changes in O-GlcNAcylation during osteoclastogenesis. The elevated O-GlcNAcylation was found in the early differentiation stages, whereas its downregulation was detected in the maturation process. TNFα elaborates the dynamic changes in O-GlcNAcylation, which further intensifies osteoclast differentiation.

Targeting OGT by selective inhibitor and genetic knockout restrain O-GlcNAcylation and hinder the expression of the early differentiation marker Nfatc1. Inhibition of OGA, which forces high levels of O-GlcNAcylation throughout the differentiation, reduces the formation of multinucleated mature osteoclasts. Consistent with our in vitro data, suppressing OGT and OGA both ameliorate bone loss in experimental arthritis. We detected a reduced number of TRAP-expressing precursors and mature osteoclasts in the mice subjected to OGT inhibition. While inhibiting OGA only lowers the number of TRAP+F4/80– mature osteoclasts without affecting the number of TRAP+F4/80+ precursors.

Transcriptome profiling reveals that O-GlcNAcylation regulates several biological processes. Increased O-GlcNAcylation promotes cytokine signaling and oxidative phosphorylation. The downregulation of O-GlcNAcylation is essential for cytoskeleton organization and cell fusion.

Conclusion:

We demonstrate that the dynamic changes of O-GlcNAcylation are essential for osteoclast differentiation. These findings reveal the therapeutic potential of targeting O-GlcNAcylation in pathologic bone resorption.

Disclosure of Interests:

Chih-Wei Chen: None declared, Yi-Nan Li: None declared, Thuong Trinh-Minh: None declared, ZHU Honglin: None declared, Alexandru-Emil Matei: None declared, Xiao Ding: None declared, Cuong Tran Manh: None declared, Xiaohan Xu: None declared, Christoph Liebel: None declared, Ruifang Liang: None declared, Min-Chuan Huang: None declared, Neng-Yu Lin: None declared, Andreas Ramming Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Grant/research support from: Pfizer, Novartis, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg H.W. Distler Shareholder of: 4D Science, Speakers bureau: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Employee of: FibroCure

SAT0342 INNATE LYMPHOID CELLS ARE PREDICTORS OF DISEASE PROGRESSION IN SYSTEMIC SCLEROSIS: A 3-YEARS FOLLOW-UP STUDY

Background:

Activation of the immune system is a characteristic feature of SSc. Numerous studies have suggested that type 2 are key drivers of progressive fibrosis. Recently, innate lymphoid cells (ILC) are emerging as an important cellular source of type 2 cytokines triggering fibrotic tissue remodeling independently of the adaptive immune system. Increased levels of ILC2 were found in patients with SSc. However, the contributive role of ILC2 in pathogenesis of SSc is not completely understood.

Objectives:

We aim in our 3 years observational study to evaluate the predictive role of ILC2 in SSc patients.

Methods:

We conducted an observational retrospective study on 52 patients with SSc fulfilling the 2013 ACR/EULAR classification criteria. Yearly clinical, laboratory and investigational data according to EUSTAR recommendations were collected. Blood samples collected between 15.09.2014 and 15.01.2015 were analyzed by flow cytometry and ILC2 counts were measured. The predictive value of ILC2 during a 3-year follow-up was analyzed using SPSS 21.0.

Results:

52 patients were included in the study, 78% female, 63% limited cutaneous SSc with a mean follow-up time of 2.85 ± 1.28 years. At baseline we have shown that circulating ILC2s are significantly increased compared to gender and age-matched healthy controls. Increased numbers of ILC2s significantly correlated with worsening of mRSS calculated by five point increase in mRSS or 25% increase from baseline (p < 0.001; 95% CI 1.39 – 3.26). ILC2 counts also correlated with 5% decrease of diffusion capacity of carbon monoxide (DLCO) during the follow-up time (p < 0.0001; 95% CI 1.83 – 3.49). Worsening of forced vital capacity (FVC) assessed as 5% decrease over 2 years was also significantly correlated with an increased number of ILC2s (p < 0.0001; 95% CI 1.27 – 3.04). In contrast, we did not find any correlation regarding increase in pulmonary arterial pressure assessed by echocardiography. Although new appearance of digital ulcers could not be predicted by ILC2 counts, increased numbers of ILC2s were correlated with digital ulcers at follow-up.

Conclusion:

Here, we provide first evidence for a role of ILC2s as potential prognostic marker of disease progression in SSc.

Disclosure of Interests:

Alina Soare: None declared, Stefanie Weber: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

POS0260 LONG-TERM HUMORAL RESPONSE TO SARS-CoV-2 VACCINATION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASE

Background

The first vaccine against SARS-CoV-2 was approved in December 2020. Immunogenicity of SARS-CoV2 vaccines in patients with immune-mediated inflammatory disease (IMID) have so far been evaluated in the 2-6 weeks following complete vaccination and risk groups for poor early vaccine response have been identified leading to specific vaccination recommendations. However, data on the long-term course and persistence of vaccine response in IMID patients, as well as the outcomes of the specific recommendations are lacking.

Objectives

To evaluate the long-term course of humoral response to SARS-CoV-2 vaccination in a large prospective cohort of IMID patients and non-IMID controls with a follow-up duration of up-to to 10 months after the first vaccine dose.

Methods

We have initiated a prospective dynamic cohort of IMID patients and healthy controls in February 2020 to monitor immune response to SARS-CoV-2 and respiratory infections including COVID-19 (1). Participants who contributed data starting from the 4 weeks before their first vaccination onwards were included in this analysis. Antibodies against SARS-CoV-2 spike protein were quantified with an ELISA from Euroimmun (Lübeck, Germany) with an optical density cutoff of 0.8. We fitted linear mixed-effect models for log-transformed antibody levels using time splines with adjustment for age and sex. Marginal mean antibody levels with 95% confidence intervals (CI) were estimated at selected time points for IMID patients and controls with double vaccination. We descriptively analyzed the observed antibody levels over time in cohort participants receiving two vaccinations vs. three vaccinations.

Results

Among 5076 cohort participants, 3147 IMID patients and healthy controls (mean (SD) age 49 (16)) provided 4756 samples for this analysis between December 2020 and 2021, with a median (IQR) 28 (14-31) weeks of follow-up after the first vaccination (Table 1). 2965 (94%) participants had received at least 2 and 223 (7%) participants had received three vaccine doses by the date of their latest sampling. In IMID patients, age and sex-adjusted estimated marginal mean antibody levels waned after week 16 and were substantially reduced at all time points compared to the controls, finally dropping to the borderline range (1.01, 95%CI 0.86 to 1.19) at week 40 (Figure 1A, Table 1). A third dose was given to 128 (7%) of IMID patients with a poor response to 2 vaccine doses after a median 20 weeks of the second dose (IQR 10 to 26 weeks). After the third dose, antibody levels in IMID patients were comparable to those of healthy controls at 40 weeks who had three vaccine doses. These were also higher than that of IMID patients and controls who did not receive a third dose (Figure 1B).

Table 1.

Participant characteristics and antibody levels

Healthy controlsIMID N11991948 Age, mean (SD)40.8 (13.5)54.3 (14.8) Follow-up, weeks, median (IQR)31.1 (23.8-36.6)19.6 (12.3-26.6) Follow-up range, weeks,1.6-46.11.7-46.3Sex, n(%) Female554 (46.2)1136 (58.3)Vaccine intervals, ´median (IQR) 1st to 2nd dose4.6 (3.0-6.0)6.0 (5.0-6.1) 2nd to 3rd dose29.6 (26.9-36.4)19.9 (10.0-26.1)Diagnosis, n (%) Spondyloarthritis-713 (36.6) Rheumatoid arthritis-489 (25.1) Autoimmune disease, systemic+-420 (21.5) Inflammatory bowel disease-219 (11.2) Psoriasis-107 (5.5)Mean* antibody levels after 1st dose Week-84.16 (3.89 to 4.45)2.97 (2.83 to 3.12) Week-168.39 (7.81 to 9.02)5.04 (4.81 to 5.28) Week-325.02 (4.73 to 5.33)2.52 (2.32 to 2.74) Week-402.14 (1.95 to 2.35)1.01 (0.86 to 1.19)

+ Systemic lupus, systemic sclerosis, Sjögren’s syndrome, vasculitis

* Estimated marginal means adjusted for age and sex.

Figure 1.

Conclusion

Humoral response to vaccination against SARS-CoV-2 was weaker in IMID patients compared to controls at all time points after the first vaccine dose and practically disappeared after 1 year. IMID patients can still achieve a good antibody response with a third dose even after a weak response with two doses.

References

[1]Simon D et al Nat Commun 2020

Disclosure of Interests

None declared

Comparing ensemble methods combined with different aggregating models using micrograph cell segmentation as an initial application example

Strategies such as ensemble learning and averaging techniques try to reduce the variance of single deep neural networks. The focus of this study is on ensemble averaging techniques, fusing the results of differently initialized and trained networks. Thereby, using micrograph cell segmentation as an application example, various ensembles have been initialized and formed during network training, whereby the following methods have been applied: (a) random seeds, (b) L ₁-norm pruning, (c) variable numbers of training examples, and (d) a combination of the latter 2 items. Furthermore, different averaging methods are in common use and were evaluated in this study. As averaging methods, the mean, the median, and the location parameter of an alpha-stable distribution, fit to the histograms of class membership probabilities (CMPs), as well as a majority vote of the members of an ensemble were considered. The performance of these methods is demonstrated and evaluated on a micrograph cell segmentation use case, employing a common state-of-the art deep convolutional neural network (DCNN) architecture exploiting the principle of the common VGG-architecture. The study demonstrates that for this data set, the choice of the ensemble averaging method only has a marginal influence on the evaluation metrics (accuracy and Dice coefficient) used to measure the segmentation performance. Nevertheless, for practical applications, a simple and fast estimate of the mean of the distribution is highly competitive with respect to the most sophisticated representation of the CMP distributions by an alpha-stable distribution, and hence seems the most proper ensemble averaging method to be used for this application.

OP0142 FIBROBLAST GROWTH FACTOR RECEPTOR 3 REGULATES THE ACTIVITY OF PROFIBROTIC CYTOKINE AND GROWTH FACTOR PATHWAYS TO DRIVE FIBROBLAST ACTIVATION AND TISSUE FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Fibroblast growth factor receptor 3 (FGFR3) is a member of the family of different fibroblast growth factor receptors with several ligands called fibroblast growth factors (FGFs) in humans. Each FGFR has different isoforms resulting from natural alternative splice variants. Upon binding FGF ligands, fibroblast growth factor receptors (FGFRs) trigger various intracellular signaling pathways to regulate important biological processes. Systematic evaluation of FGF/FGFR signaling in the context of SSc has not been performed so far.

Objectives:

The aim of this study was to characterize FGFR3/FGF9 signaling in the context of fibroblast activation and to evaluate FGFR3 as a potential molecular target for antifibrotic treatment in SSc.

Methods:

Differential expression profiling of dermal cells from SSc patients and healthy volunteers were performed employing GEArray cDNA microarray. Real-time PCR, Western Blot, immunohistochemistry and immunofluorescence were done in skin tissues and fibroblasts from SSc patients. Selective inhibitors in conjunction with genetic knockdown and knockout strategies were used to target FGFR3 signalingin vitroand in mouse models of SSc: skin fibrosis induced by bleomycin and by overexpression of a constitutively active transforming growth factor receptor 1 (TBR) and tight skin-1 (TSK) mice. Affymetrix gene arrays in dermal fibroblasts from mice with constitutive FGFR3 signaling and mice lacking FGFR3.

Results:

Expression of FGFR3, specifically the isoform FGFR3IIIb and its ligand FGF9, was significantly upregulated in the dermis and dermal fibroblasts of SSc patients as compared to healthy volunteers. Furthermore, an increase of FGFR3 IIIb/FGF9 expression comparable to that in SSc fibroblasts could also be obtained by stimulating normal healthy dermal fibroblasts with transforming growth factor (TGFβ)in vitroand in mice constitutively overexpressing active TGFβ receptor type I.

Transcriptome profiling,in silicoanalysis and functional experiments revealed that FGFR3 synergistigically induces multiple profibrotic pathways including Endothelin-, Interleukin-4- and CTGF-signaling in a CREB-dependent manner. FGFR3 exerts profibrotic effects by modulating phosphorylation of CREB by ERK-, AKT-, CAMK2- and p38-kinases. Activation of FGFR3 in healthy or SSc dermal fibroblasts by stimulation with recombinant FGF9 was sufficient to induce resting fibroblast-to-myofibroblast differentiation along with increased collagen secretion and alpha-SMA production.

Genetic knockout of Fgfr3 abrogates myofibroblast differentiationin vitroand ameliorates skin fibrosis in TSK and TBR mice and in bleomycin-induced fibrosis. Further confirming the translational potential of these findings in the preclinical models of SSc, we demonstrate that pharmacological inactivation of FGFR3 by PD173074 could induce the regression of experimental fibrosis invitroand in bleomycin-challenged, TSK and TBR mice.

Conclusion:

Our findings characterize FGFR3 as an upstream regulator of a network of profibrotic mediators in SSc and thus, we could demonstrate successfully that the targeted inhibition of FGFR3 could inhibit multiple signaling pathwaysin vitroand ameliorated fibrosis in different preclinical models of SSc. These findings may have direct translational implications as FGFR3 inhibitors are currently in development.

Disclosure of Interests:

Debomita Chakraborty: None declared, Honglin Zhu: None declared, Astrid Juengel: None declared, Lena Summa: None declared, Yi-Nan Li: None declared, Christina Bergmann: None declared, Alexandru-Emil Matei: None declared, Thuong Trinh-Minh: None declared, Chih-Wei Chen: None declared, Clara Dees: None declared, Andreas Ramming: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

AB0584 DOES ANTI-ACID TREATMENT INFLUENCE DISEASE PROGRESSION IN SYSTEMIC SCLEROSIS INTERSTITIAL LUNG DISEASE (SSC-ILD)? DATA FROM THE GERMAN SSC-NETWORK

Background:

Gastroesophageal reflux (GER) is common in SSc and thus treatment with anti-acid therapy (AAT) is frequent. An association between GER and the development / progression of SSc-ILD has been hypothesized. However, outcomes of AAT on disease progression in SSc-ILD has only sparsely been studied.

Objectives:

Methods:

The German Network for Systemic Scleroderma (DNSS), which includes SSc pts. prospectively, was analyzed for SSc-ILD. Those without progression at ILD 1stdiagnosis were categorized in AAT vs. no-AAT users and disease outcome was assessed.

Results:

SSc-ILD was reported in 1165 (28.2%) out of 4131 pts. 712 of SSc-ILD pts had no disease progression at ILD 1stdiagnosis. 567 used AAT while 145 did not. Baseline characteristics were similar between groups with regards to age (mean 54.7 years), BMI, time since SSc diagnosis and immunosuppressant use. Significant differences in no-AAT vs. AAT were found for gender (male 18% vs. 25%, p=0.05), SSc subtype (p=0.002, diffuse more common in AAT), lung function (DLCO 66% vs. 58%, p=0.001; FVC 86% vs. 77%, p=0.001), mRSS (8 vs. 11.5, p<0.01), esophageal involvement (32% vs. 56%, p<0.01) and steroid use (30% vs. 43%, p=0.005). While mortality did not differ between groups (3.9%, p= 0.59), disease progression was more common in the AAT group than in no-AAT users (24.5% vs. 13%, p=0.03). Furthermore, there was a significant difference in decline of FVC≥10% with 30% in the AAT compared to 14% in no-AAT (p=0.018); a decline in DLCO≥15% was more common in the AAT group by trend (23% vs. 14%, p=0.087).

Conclusion:

While results may have partially been biased by differences in baseline characteristics, this current analysis disfavors the approach of AAT use for SSc-ILD.

Disclosure of Interests:

Michael Kreuter Grant/research support from: Roche, Boehringer, Consultant of: Roche, Boehringer, Speakers bureau: Boehringer, Roche, Francesco Bonella Grant/research support from: Boehringer, Consultant of: Boehringer, Roche, Bristol MS, Galapagos, Speakers bureau: Boehringer, Roche, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Ulf Müller-Ladner Speakers bureau: Biogen, Jörg Henes Grant/research support from: Novartis, Roche-Chugai, Consultant of: Novartis, Roche, Celgene, Pfizer, Abbvie, Sanofi, Boehringer-Ingelheim,, Elise Siegert Grant/research support from: Actelion, Consultant of: AEC, Speakers bureau: NA, Claudia Guenther: None declared, Ina Koetter Grant/research support from: Novartis, Roche, Speakers bureau: Abbvie, Actelion, Celgene, MSD, UCB, Sanofi, Lilly, Pfizer, Novartis, Chugai, Roche, Boehringer, Norbert Blank Speakers bureau: Actelion, Roche, Boehringer, Pfizer, Chugai, Christiane Pfeiffer: None declared, Marc Schmalzing: None declared, Gabriele Zeidler: None declared, PETER KORSTEN Grant/research support from: Novartis, Juarms GmbH, Consultant of: Abbvie, Pfizer, Lilly, BMS, Speakers bureau: Abbvie, Pfizer, chugai, BMS, Lilly, Sanofi aventis, Laura Susok: None declared, Aaron Juche: None declared, Margitta Worm Consultant of: Mylan Gemany, Bencard Allergie, BBV Technologies S.A., Novartis, Biotest, Sanofi, Aimmune Therapies, Regeneron, Speakers bureau: ALK-Abello, Novartis, Sanofi, Biotest, Mylan, Actelion, HAL Allergie, Aimmune Bencard Allergie, Ilona Jandova: None declared, Jan Ehrchen: None declared, Cord Sunderkoetter: None declared, Gernot Keyszer: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Tim Schmeiser Speakers bureau: Actelion, UCB, Pfizer, Alexander Kreuter Speakers bureau: Sanofi, Abbvie, Merck Sharp&Dohme, Boehringer, Kathrin Kuhr: None declared, Hanns-Martin Lorenz Grant/research support from: Consultancy and/or speaker fees and/or travel reimbursements: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly. Scientific support and/or educational seminars and/or clinical studies: Abbvie, MSD, BMS, Pfizer, Celgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, Astra-Zeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, Thermo Fisher., Consultant of: see above, Pia Moinzadeh: None declared, Nicolas Hunzelmann Speakers bureau: Actelion, Boehringer

OP0132 ALLERGIC ASTHMA INDUCES THE ACCUMULATION OF SYNOVIAL RESIDENT EOSINOPHILS, TRIGGERING THE RESOLUTION OF INFLAMMATORY ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory disorder, involving synovial joints, which affects approximately 1 percent of the world population[1]. Our former work demonstrated that the Th2-eosinophil pathway is a strong anti-inflammatory mediator of inflammatory arthritis[2]. Allergic asthma is an inflammatory disease of the airway, triggered by type 2 immune response. Hitherto, clinical observations on the impact of asthma on RA showed controversial results. Herein, we investigated the action of allergic asthma on inflammatory arthritis.

Objectives:

We aimed to delineate the molecular and cellular responses induced by allergic asthma on inflammatory arthritis, particularly depicting the role of eosinophil subsets in arthritic synovium.

Methods:

Allergic asthma was induced in wild type and genetically modified mice by ovalbumin (OVA) treatment. After the initiation of allergic asthma, K/BxN serum was transferred into the asthmatic mice or control mice to trigger serum induced arthritis (SIA). Then, arthritis severity, circulating cytokines and the cytology of lung and synovium were analyzed. Eosinophil subsets were studied by flow cytometry, single cell RNA sequencing analysis, and were isolated and transferred into the synovial cavity of eosinophil deficient arthritic mice. Clinical data of patients with both RA and asthma were collected and checked for the relapse of RA after asthma treatment with anti-interleukin (IL)-5 antibody.

Results:

Mice induced with allergic asthma exhibited a rapid resolution of SIA. The OVA-triggered resolution disappeared in eosinophil deficient mice (ΔdblGATA), and was partially blocked by IL-5 neutralization. We could detect that IL-5 was mainly produced by type 2 innate lymphoid cell (ILC2) in the lung. Allergic asthma exclusively induced the proliferation (Ki67+) and accumulation of synovial resident eosinophils (rEos, Siglec-Fint), which switched classical macrophages into alternatively activated macrophages. Synovial induced eosinophils (iEos, Siglec-Fhigh) appeared only in the acute phase of SIA. Single cell RNA sequencing analysis showed that rEos played an anti-inflammatory role, while iEos had pro-inflammatory properties in arthritis. The roles of rEos and iEos in arthritis were confirmed by transferring rEos/iEos into the synovial cavity of arthritic mice. Patiens with both RA and asthma showed a remission relapse of RA after using humanized monoclonal IL-5 antibody for treating sever eosinophilic asthma.

Conclusion:

Allergic asthma induced an IL-5 mediated proliferation and accumulation of synovial rEos. The latter triggered the resolution of inflammatory arthritis. In human, eosinophils induced by asthma were essential for the sustaining of RA remission.

References:

[1]Myasoedova, E., et al., Is the incidence of rheumatoid arthritis rising?: results from Olmsted County, Minnesota, 1955-2007. Arthritis Rheum, 2010.62(6): p. 1576-82.

[2]Chen, Z., et al., Th2 and eosinophil responses suppress inflammatory arthritis. Nat Commun, 2016.7: p. 11596.

Acknowledgments:

Mengdan Liu and Darja Andreev contributed equally to this study

Disclosure of Interests:

Mengdan Liu: None declared, Darja Andreev: None declared, Katerina Kachler: None declared, Julia Koelle: None declared, Simon Rauber: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Susetta Finotto: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Aline Bozec: None declared

Number of necessary training examples for Neural Networks with different number of trainable parameters

In this work, the network complexity should be reduced with a concomitant reduction in the number of necessary training examples. The focus thus was on the dependence of proper evaluation metrics on the number of adjustable parameters of the considered deep neural network. The used data set encompassed Hematoxylin and Eosin (H&E) colored cell images provided by various clinics. We used a deep convolutional neural network to get the relation between a model’s complexity, its concomitant set of parameters, and the size of the training sample necessary to achieve a certain classification accuracy. The complexity of the deep neural networks was reduced by pruning a certain amount of filters in the network. As expected, the unpruned neural network showed best performance. The network with the highest number of trainable parameter achieved, within the estimated standard error of the optimized cross-entropy loss, best results up to 30% pruning. Strongly pruned networks are highly viable and the classification accuracy declines quickly with decreasing number of training patterns. However, up to a pruning ratio of 40%, we found a comparable performance of pruned and unpruned deep convolutional neural networks (DCNN) and densely connected convolutional networks (DCCN).

OP0141 HIGH DIMENSIONAL ANALYSIS REVEAL A NETWORK OF CERTAIN TRANSCRIPTION FACTORS THAT LINK VASCULOPATHY AND ORGAN FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Since vascular manifestations such as Raynaud’s phenomenon often precede the onset of other clinical manifestations of systemic sclerosis (SSc), the identification of pathways linking vasculopathy to organ fibrosis might thus provide important insights into early disease mechanisms and allow early targeted intervention for both fibrotic and vascular events.

Objectives:

In this study we performed high dimensional (HD) analyses to identify mediators that link vasculopathy to organ fibrosis.

Methods:

HD techniques including RNA-seq, ChIP-seq, ATAC-seq and FISH-seq have been performed to identify mediators in vessels and fibrotic lesions of human skin samples of SSc patients and healthy volunteers. In addition, murine skin and lung tissue samples were analyzed by multi-channel immunofluorescence (IF) and confocal laser scanning microscopy. Microvascular endothelial cells, smooth muscle cells and fibroblasts have been further processed to address their functional attributes with regard to their proliferative, migratory and chemotactic capacity. In vivo models and ex vivomouse fetal metatarsal assays were performed to study fibrotic and angiogenic processes.

Results:

Bioinformatic HD analyses revealed the ETS transcription factor PU.1 as molecular checkpoint of a network of factors that drive matrix production and fibrotic imprinting in SSc. Within this network ATF3 was significantly upregulated in fibroblasts of skin biopsies of SSc patients and of various organs of fibrosis models. ATF3 deficiency ameliorated fibrosis in various mouse models. Notably, ATF3 was significantly upregulated in vascular cells of fibrotic tissues of SSc patients. Multi-channel IF and confocal laser scanning microscopy of skin and lung biopsies of SSc patients revealed an increased expression of ATF3 especially in microvascular endothelial cells and smooth muscle cells. ATF3 overexpression in smooth muscle cells led to an extensively enhanced proliferation and increased migratory capacity whereas endothelial cells showed a SSc-like phenotype with reduced proliferation and migration. After ATF3 overexpression, tube formation capacity was completely altered as assessed by cumulative tube length, tube numbers and capillary sprouting. To investigate vessel outgrowth from a different perspective, we used theex vivofetal mouse metatarsal assay. ATF3 knockout mice showed a completely altered angiogenic response as assessed by tube length, number of branches and number junctions compared to wildtype controls.

Conclusion:

We identified PU.1 and ATF3 as key factors in disturbed vasculature and endogenous activated fibroblasts suggesting this axis as a potential therapeutic target intervening both fibrotic and vascular manifestations.

Disclosure of Interests:

Charles Gwellem Anchang: None declared, Bettina Matalobos Lawaree: None declared, Stefanie Weber: None declared, Simon Rauber: None declared, Thomas Wohlfahrt: None declared, Markus Luber: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0354 TYPE 3 INNATE LYMPHOID CELLS ARE KEY DRIVERS OF PSORIATIC ARTHRITIS

Background:

Psoriasis (PsO) and psoriatic arthritis (PsA) are two types of chronic inflammatory diseases that share a similar cytokines profile. About 30% of PsO patients also develop a joint involvement, but the underlying mechanism is still unclear. Innate lymphoid cells (ILC) and specifically the type 3 ILCs (ILC3s) have raised increasing interest as possible player in the pathogenesis of both diseases, as they produce the pathological key cytokine IL-17A.

Objectives:

We addressed the contribution of ILC3s to the pathogenesis of PsO and PsA in patients as well as murinein vivomodels.

Methods:

130 patients satisfying the Classification Criteria for Psoriatic Arthritis (CASPAR), 40 patients with PsO and 35 healthy volunteers were enrolled in the study. Information regarding clinical features, laboratory parameters were collected and psoriasis area severity index (PASI), disease activity score 28 (DAS28), disease activity in psoriatic arthritis (DAPSA), minimal disease activity score (MDA) were calculated. Magnetic resonance imaging (MRI) and high-resolution peripheral CT (HR-pQCT) were taken and PsA MRI score (PsAMRIS) was assessed. Flow cytometric analysis was performed and IFNγ-producing ILC1s, IL-4/IL-5-producing ILC2s and IL-17/IL-22-producing ILC3s were identified among ILCs. Multivariate linear regression and Receiver-Operating Characteristic (ROC) Curve analysis was performed using the IBM SPSS Statistics software. Different in vivo models were used to assess functional implications of ILCs at different time points of the disease. Joint inflammation was assessed through MRI and H&E staining of ankle areas. Peripheral blood was obtained from mice of each group and flow cytometry analysis was performed. High dimensional analyses including RNA-seq was performed to identify phenotypic characteristics of ILCs implemented into the pathogenesis of the disease.

Results:

Total number of circulating ILCs were increased in PsA patients compared to PsO and healthy controls (p<0,001). Linear regression analyses of the relationship between disease activity and circulating ILCs counts showed strongest correlation between ILC3s counts and DAPSA score. ILC3s counts also correlated with imaging signs of inflammation such as enthesitis, synovitis, erosions and/or ostoeproliferation as assessed by MRI and HR-pQCT. Musculoskeletal inflammation in mice was predominantly associated with p19 expression and IL-23R-signaling as assessed by RNA-seq. These effects were also accompanied by a strong upregulation of IL-17-producing lymphocytes within the inflamed joint niche with a dominant presence of ILC3s. Multi-channel immunofluorescence and confocal laser scanning microscopy revealed not only upregulation of ILC3 induced IL-17 production within the synovial membrane but also in peri-articular areas of the inflamed joints.

Conclusion:

ILC3s not only correlate with various facets of PsA manifestations but also functionally contribute to synovitis and enthesitis suggesting them as interesting target for upcoming treatment strategies in the near future.

Disclosure of Interests:

Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Simon Rauber: None declared, Markus Luber: None declared, Aleix Rius Rigau: None declared, Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Rahul Agarwal: None declared, Alina Soare: None declared, Michael Sticherling Grant/research support from: Novartis, Consultant of: Advisory boards Abbvie, Celgene, Janssen Cilag, Lilly, Pfizer, MSD, Novartis, Amgen, Leo, Sanofi, UCB, Speakers bureau: Abbvie, Celgene, Janssen Cilag, Leo, MSD, Novartis, Pfizer, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0284 EPIGENETIC DEREGULATION OF AUTOPHAGY PROMOTES FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Autophagy is catabolic process allowing cells to degrade unnecessary or dysfunctional cellular organelles. Failure of appropriate regulation of autophagy, however, can severely perturb tissue homeostasis. Several stimuli present in fibrosis such as pro-fibrotic cytokines are known to activate autophagy.

Objectives:

The objective of this work was to characterize the regulation of autophagy in systemic sclerosis (SSc) and to decipher its role in the pathogenesis of SSc.

Methods:

Activation of autophagy in SSc skin and matched tissue samples from healthy individuals was assessed by immunofluorescence staining for ATG7, BECLIN1 and P62. We generatedAtg7fl/flxCol1a2;CreER mice to selectively disable autophagy in fibroblasts. The role of the autophagy was investigated in the model of bleomycin- and TβRIact-induced dermal and pulmonary fibrosis. Overexpression of Myst1 was achieved by adenovirus encoding forMyst1. Collagen release and protein expression were measure by Western blot. Target genes were analyzed by RT-PCR. Co-immunoprecipitation and reporter assay were performed to study physical and functional interactions between MYST1 and SMAD3. To monitor the autophagic fluxin vitroandin vivowe generated adenoviral vectors encoding for tandem fluorescent-tagged LC3 (mRFP-EGFP-LC3).

Results:

Transforming growth factor-β (TGFβ) activates autophagy by an epigenetic mechanism to amplify its profibrotic effects. TGFβ induces autophagy in fibrotic diseases by SMAD3-dependent downregulation of the H4K16 histone acetyltransferase MYST1, which regulates the expression of core components of the autophagy machinery such as ATG7 and BECLIN1. Activation of autophagy in fibroblasts promotes collagen release and is both, sufficient and required, to induce tissue fibrosis. Forced expression of MYST1 abrogates the stimulatory effects of TGFβ on autophagy and re-establishes the epigenetic control of autophagy in fibrotic conditions. Interference with the aberrant activation of autophagy inhibits TGFβ-induced fibroblast activation and ameliorates experimental dermal and pulmonary fibrosis. These findings link uncontrolled TGFβ signaling to aberrant autophagy, deregulated epigenetics in fibrotic diseases and may open new avenues for therapeutic intervention in fibrotic diseases.

Conclusion:

We demonstrate that the epigenetic control of autophagy is disturbed by a TGFβ-dependent downregulation of the H4K16 histone acetyltransferase MYST1. The increased activation of autophagy induces fibroblast-to-myofibroblast transition and promotes fibrotic tissue remodeling. Re-expression of MYST1 prevents aberrant autophagy, limits the profibrotic effects of TGFβ and ameliorates experimental fibrosis. Restoration of the epigenetic control of autophagy might thus be a novel approach to ameliorate fibrotic tissue remodeling.

References:

[1]Wynn, T.A. Cellular and molecular mechanisms of fibrosis. J Pathol 214, 199-210 (2008).

[2]Distler, J.H., et al. Review: Frontiers of Antifibrotic Therapy in Systemic Sclerosis. Arthritis & rheumatology (Hoboken, N.J.) 69, 257-267 (2017).

[3]Gyorfi, A.H., Matei, A.E. & Distler, J.H.W. Targeting TGF-beta signaling for the treatment of fibrosis. Matrix biology: journal of the International Society for Matrix Biology 68-69, 8-27 (2018).

[4]Wang, C.W. & Klionsky, D.J. The molecular mechanism of autophagy. Mol Med 9, 65-76 (2003).

[5]Hernandez-Gea, V., et al. Autophagy releases lipid that promotes fibrogenesis by activated hepatic stellate cells in mice and in human tissues. Gastroenterology 142, 938-946 (2012).

Disclosure of Interests:

Ariella Zehender: None declared, Neng Yu Lin: None declared, Yi-Nan Li: None declared, Andrea-Hermina Györfi: None declared, Christina Bergmann: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

SAT0302 INNATE LYMPHOID CELLS INDUCE A FIBROTIC PHENOTYPE OF FIBROBLASTS

Background:

Fibrotic diseases are characterized by excessive extracellular matrix production as a result of immune-mediated permanent fibroblast activation. Innate lymphoid cells type II (ILC2) are an only recently discovered cell type involved in barrier integrity and tissue homeostasis. There is upcoming evidence that ILC2s play a central role in mediating fibrotic diseases.

Objectives:

The aim of the study was to further elucidate the role of ILC2s in fibrotic tissue remodeling and fibroblast activation.

Methods:

Skin biopsies of patients with systemic sclerosis (SSc) or sclerodermatous chronic graft versus host disease (scGvHD) as well as lung biopsies of patients with idiopathic pulmonary fibrosis (IPF) were analyzed by immunofluorescence (IF) staining. Single cell RNA-sequencing (scRNA-seq) was performed on ILCs from fibrotic skin and lung of bleomycin-challenged mice. Further characterization of ILC2 phenotypes in fibrosis models was done by flow cytometry.In vitroculture of fibroblasts and ILC2s was used to study cellular interaction and fibrotic activation. Quantitative realtime-PCR, western blot, IF staining and ELISA were used as readouts.

Results:

Two different subtypes of ILC2s were found in skin of SSc and scGvHD patients as well as in lungs of IPF patients with one subpopulation being particularly increased in fibrotic tissue. Single cell RNA-sequencing confirmed the existence of two major populations of ILC2s in experimental fibrosis. One subtype showed features of immature ILC2 progenitors and was actively recruited from the bone marrow during fibrotic tissue remodeling. The other ILC2 subset was highly activated and expressed pro-fibrotic cytokines. These profibrotic ILC2s directly interacted with fibroblasts in a cell contact dependent manner. Semaphorin 4A (SEMA4A) expressed by ILC2s bound to Plexin D1 (PLXND1) on fibroblasts. This interaction resulted into fibrotic imprinting with high expression levels of the transcription factor PU.1 which was recently described as central regulator of the pro-fibrotic gene expression program (Wohlfahrt et al. 2019). Signaling through Jagged 1 (JAG1) and Notch receptor 2 (NOTCH2) was identified as a second mechanism of interaction between fibroblasts and ILC2s. JAG1 expressed by fibroblasts activated NOTCH2 signaling in ILC2s which emphazised the secretion of pro-fibrotic cytokines.

Conclusion:

We identified a bidirectional interaction between ILCs and fibroblasts incorporating a vicious circle of fibrotic tissue remodelling. As ILCs are still not accessible as therapeutic targets these results might contribute to the development of new strategies for anti-fibrotic therapies.

References:

[1]Wohlfahrt, Thomas, Simon Rauber, Steffen Uebe, Markus Luber, Alina Soare, Arif Ekici, Stefanie Weber, Alexandru-Emil Matei, Chih-Wei Chen, Christiane Maier, Emmanuel Karouzakis, Hans P. Kiener, Elena Pachera, Clara Dees, Christian Beyer, Christoph Daniel, Kolja Gelse, Andreas E. Kremer, Elisabeth Naschberger, Michael Stürzl, Falk Butter, Michael Sticherling, Susetta Finotto, Alexander Kreuter, Mark H. Kaplan, Astrid Jüngel, Steffen Gay, Stephen L. Nutt, David W. Boykin, Gregory M. K. Poon, Oliver Distler, Georg Schett, Jörg H. W. Distler, and Andreas Ramming. 2019. ‘PU.1 controls fibroblast polarization and tissue fibrosis’,Nature, 566: 344-49.

Disclosure of Interests:

Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Simon Rauber: None declared, Markus Luber: None declared, Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Yuko Ariza Employee of: Ono Pharmaceutical Co., Ltd., Aleix Rius Rigau: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

OP0272 68GA-FAPI-04 PET/CT STUDY EXTENSION FOR THE ASSESSMENT OF FIBROBLAST ACTIVATION AND RISK EVALUATION IN SYSTEMIC SCLEROSIS-RELATED INTERSTITIAL LUNG DISEASE

Background:

Interstitial lung disease (ILD) is the most common cause of death in systemic sclerosis (SSc). To date, the progression of SSc-ILD is judged by the accrual of lung damage on computed tomography (CT) and functional decline (forced vital capacity). However, this approach does not directly assess the activity of tissue remodeling. Moreover, prediction of the course of ILD in individual SSc patients remains challenging. Fibroblast Activation Protein (FAP) is a specific, ex vivo validated marker for activated fibroblasts.

Objectives:

The aims of this study were: 1. To assess differences in the uptake of 68GA-FAPI 04 in SSc-ILD patients compared to controls, to analyze 2. whether 68GA-FAPI 04 uptake at baseline correlates with other risk factors of disease progression and 3. Whether 68GA-FAPI 04 uptake is associated with the course of SSc-ILD.

Methods:

Between September 2018 and April 2020, 21 patients with SSc-ILD confirmed by HRCT and onset of SSc-ILD within ≤ 5 years or signs of progressive ILD and 21 controls without ILD were consecutively enrolled. All participants underwent 68Ga-FAPI-04 PET/CT imaging and standard-of-care procedures including HRCT and lung function testing (PFT) at baseline. Patients with SSc-ILD patients were followed-up for 6 months with HRCT and PFT. Follow-up 68Ga-FAPI-04 PET/CT scans were obtained in a subset of patients treated with nintedanib. We compared baseline 68Ga-FAPI-04 PET/CT uptake to standard diagnostic tools and currently used predictors of ILD progression. The association of 68Ga-FAPI-04 uptake with changes in FVC was analyzed using mixed-effects models.

Results:

68Ga-FAPI-04 accumulated in fibrotic areas of the lungs in SSc-ILD compared to controls with a median (q1-q3 interval) wlSUVmean of 0.8 (0.6 to 2.1) in the SSc-ILD group and 0.5 (0.4 to 0.5) in the control group (p<0.0001 with Mann-Whitney test) and a median whole lung maximal standardized uptake value (wlSUVmax) of 4.4 (3.05 to 5.2) in the SSc-ILD group compared to 0.7 (0.65 to 0.7) in the control group (p<0.0001). wlFAPI-MAV and wlTL-FAPI were not measurable in control subjects, as no 68Ga-FAPI-04 uptake above background level was observed. In the SSc-ILD group the median wlFAPI-MAV was 254cm3 (163.4 to 442.3) and the median wlTL-FAPI was 183.6 cm3 (98.04 to 960.7). 68Ga-FAPI-04 uptake was higher in patients with extensive disease, with previous ILD progression or high EUSTAR activity scores. Increased 68Ga-FAPI-04 uptake at baseline was associated with progression of ILD independently of extent of involvement on HRCT scan and the forced vital capacity at baseline. In consecutive 68Ga-FAPI-04-PET/CTs, changes in 68Ga-FAPI-04 uptake was concordant with the observed response to the fibroblast-targeting antifibrotic agent nintedanib.

Conclusion:

Our study presents first in human evidence that 68Ga-FAPI-04-fibroblast uptake correlates with fibrotic activity and disease progression in the lungs of SSc-ILD patients and that 68Ga-FAPI-04-PET/CT may be of potential to improve risk assessment of SSc-ILD.

Figure 1.

A and B:68Ga-FAPI-04 PET/CT scan from a patient with SSc-ILD with selective 68Ga-FAPI-04 uptake in fibrotic areas of the left- and right lower lung lobes (red arrows), but not in non-fibrotic areas such as the middle lobe (green arrow). B Corresponding CT component.

Acknowledgements:

We gratefully acknowledge Prof. Uwe Haberkorn (University Hospital Heidelberg and DKFZ, Heidelberg, Germany) and iTheranostics Inc. (Dulles, VA, USA) for providing the precursor FAPI-04.

Disclosure of Interests:

Christina Bergmann: None declared, Jörg H.W. Distler Speakers bureau: Actelion, Anamar, ARXX, Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Christoph Treutlein: None declared, Koray Tascilar Speakers bureau: Gilead sciences GmbH, Pfizer Turkey, UCB Turkey, Anna-Theresa Mueller: None declared, Armin Atzinger: None declared, Alexandru-Emil Matei: None declared, Johannes Knitza: None declared, Andrea-Hermina Györfi: None declared, Anja Lueck: None declared, Clara Dees: None declared, Alina Soare: None declared, Andreas Ramming: None declared, Verena Schönau: None declared, Oliver Distler Speakers bureau: Arxx Therapeutics, Baecon Discovery, Blade Therapeutics,Bayer, Böhringer Ingelheim, Catenion,Competitive Drug Development International Ltd, Corbuspharma, CSL Behring, ChemomAb, Horizon Pharmaceuticals, Ergonex, Galaapagos NV, Glenmark Pharmaceuticals,GSK, Inventiva, Italfarmaco, IQvia, Kymera, Lilly, Medac, Medscape, MSD, Novartis, Pfizer, Roche, Sanofi, Taget Bio Sciencec, UCB, Grant/research support from: Bayer,Böhringer Ingelheim, Mitsubishi Tanabe Pharma, Olaf Prante: None declared, Philipp Ritt: None declared, Theresa Ida Goetz: None declared, Markus Koehner: None declared, Michael Cordes: None declared, Tobias Baeuerle: None declared, Torsten Kuwert Speakers bureau: Honoraria for occasional lectures by Siemens Healthineers, Grant/research support from: Research grant to the Clinic of Nuclear Medicine by this entity covering projects in the field of SPECT/CT, Georg Schett: None declared, Christian Schmidkonz: None declared

OP0256 FIBROBLAST ACTIVATION PROTEIN (FAP) PET-CT IMAGING ALLOWS TO DEPICT INFLAMMATORY JOINT REMODELING IN PATIENTS WITH PSORIATIC ARTHRITIS

Background

Psoriatic arthritis (PsA) is characterized by substantial mesenchymal tissue activation in the context of inflammation leading to structural damage. Measuring mesenchymal tissue activation in humans in vivo is challenging but may represent a possibility to detect regions at risk for structural damage. Recently, theranostic ligands have been developed that selectively bind Fibroblast Activation Protein (FAP) and allow recognition of activated mesenchymal cells in vivo. Accumulation of such FAP-based tracers can be visualized by positron-emission tomography (PET) (1).

Objectives

In this study, we analyzed whether FAP tracer-based PET-CT can detect mesenchymal tissue activation in patients with PsA and whether this signal is associated with joint damage.

Methods

120 consecutive PsA patients fulfilling CASPAR criteria and 100 healthy controls without musculoskeletal disease received full-body PET-CT investigation using a 68Ga-labelled FAP inhibitor (68Ga-FAPI-04) tracer, specifically binding FAP. For all visually identified pathological tracer-positive lesions the mean and maximum standardized uptake value (SUV mean, SUV max) was assessed. Tracer uptake was quantified in peripheral and axial joints and correlated to various composite scores of PsA. Hand MRI scans were performed in parallel to assess inflammation and structural lesions. Follow-up 68Ga-FAPI-04 PET-CT scans were obtained in a subset of patients treated with cytokine inhibitors (follow-up between 3-6 months) to assess joint damage over time. In addition, FAP related tissue responses in synovial biopsy samples were evaluated on a molecular level by high-resolution slide RNA-sequencing in a subset of patients.

Results

68Ga-FAPI-04 accumulated at synovial and enthesial sites in patients with PsA compared to healthy controls (p < 0.0001). Active pain in peripheral as well as axial joints as measured on a visual analogue scale highly correlated with an increased 68Ga-FAPI-04 uptake (peripheral pain: R = 0.718, p < 0.0001; back pain: R = 0.875, p < 0.0001). Disease Activity in PSoriatic Arthritis (DAPSA) score also correlated with the SUV mean and SUV max of FAP expression (R = 0.774; p = 0.0001). Increased 68Ga-FAPI-04 uptake at baseline was associated with progression of joint damage 3-6 months later as assessed by PsAMRIS score (R = 0.778, p < 0.0001). Treatment with cytokine inhibitors partially reduced FAP expression which was associated with arrest of joint damage in MRI. In contrast, persistent FAP expression was associated with a rapid progression of joint damage in MRI. Molecular analysis of synovial biopsy samples from FAP+ lesions revealed interactions between FAP+ fibroblasts and T cells, innate lymphoid cells and macrophages, which was correlated to a strong upregulation of NF-kB related pathways fostering cartilage and bone destruction.

Conclusion

Our study presents the first in-human evidence that fibroblast activation correlates with disease progression and joint damage in patients with PsA. FAP related imaging might therefore improve the risk assessment of rapidly emerging joint damage in PsA and open new options of treat-to-target strategies in PsA.

References

[1]Schmidkonz C, Rauber S, Atzinger A, Agarwal R, Gotz TI, Soare A, Cordes M, Prante O, Bergmann C, Kleyer A, Agaimy A, Kuwert T, Schett G, Ramming A, Disentangling inflammatory from fibrotic disease activity by fibroblast activation protein imaging. Ann. Rheum. Dis. 79 (2020), 1485-1491.

Disclosure of Interests

None declared