POS0145 CLINICAL RESPONSE TO RITUXIMAB IS ASSOCIATED WITH PREVENTION OF B-CELL DRIVEN SALIVARY GLAND INFLAMMATION AND EPITHELIAL RESTORATION AS REVEALED BY MOLECULAR PATHOLOGY: RESULTS FROM THE TRACTISS TRIAL IN PRIMARY SJOGREN’S SYNDROME

Background

The TRial for Anti-B-Cell Therapy In patients with pSS (TRACTISS) is the largest multi-centre, placebo-controlled, phase-III trial with the administration of 2 cycles of Rituximab (RTX) or placebo at week 0 and 24, with trial clinical endpoints at week 48. Despite the primary endpoints (30% reduction in fatigue or oral dryness) were not met, RTX treated patients showed an improvement in secondary endpoints, such as unstimulated whole salivary flow (UWSF), and salivary gland (SG) total ultrasound score1,2. Additionally, recent post-hoc analysis of TRACTISS using novel CRESS composite endpoints3, highlighted a significantly increased response rate in the RTX vs placebo arm.

Objectives

To perform the first longitudinal analysis of matched transcriptomic and histological data of SG biopsies of pSS patients treated with RTX vs placebo at 3 time points, over 48 weeks, from the TRACTISS cohort, in order to identify mechanisms of response/resistance to B cell depletion.

Methods

29 pSS patients randomised to RTX or placebo arm consented for labial SG biopsies at week 0, 16 and 48. Patients received two 1000mg cycles of RTX or placebo at week 0 and 24. SG focus score, inflammatory aggregate area fraction, B-cells (CD20+), T-cells (CD3+), follicular dendritic cells (FDCs) (CD21+) and plasma cells (CD138+) density were assessed using quantitative digital image analysis. RNA sequencing with deconvolution and pathway analysis was performed to identify genes signatures and consensus gene modules as biomarkers of disease evolution and response/resistance to therapy.

Results

Placebo-treated SGs showed worsening of SG inflammation highlighted by the increment of aggregate size, B-cell density, development of new FDC networks, and a higher ectopic GC prevalence over 48 weeks, compared to RTX-treated patients. No difference in focus score, total T-cell and plasma cell infiltration was observed. RTX downregulated genes involved in immune cell recruitment and inflammatory aggregate organisation (e.g. CXCL13, CCR7 and PDCD1). Gene signature-based analysis of 35 immune cell types using XCell highlighted how RTX blocked class-switched and memory-B-cells accumulation in SGs over 48 weeks. Pathway analyses confirmed the downregulation of leukocyte migration, MHC-II antigen presentation, and T-cell co-stimulation immunological pathways, such as the CD40 receptor complex pathway. Among RTX-treated patients, only CRESS-responders demonstrated prevention of worsening B cell-driven molecular pathology signatures over time and a significant improvement in UWSF, in parallel with the upregulation of molecular pathways associated to SG restoration of the glandular epithelium. None of the above effects were observed at week 16 after the first RTX cycle.

Conclusion

Two RTX infusions repeated at week 24 exerted beneficial effects on labial SG inflammatory infiltration in pSS by downregulating genes involved in immune cell recruitment, activation and organisation in ectopic GCs. Conversely, all the above parameters showed significant evolution in placebo treated patients over 48 weeks demonstrating progression of SG immunopathology. Clinical responders to RTX based on CRESS response criteria were characterised by preservation of exocrine function which appear driven by SG epithelial restoration.

References

[1]Fisher, B. A. et al. Effect of rituximab on a salivary gland ultrasound score in primary Sjögren’s syndrome: results of the TRACTISS randomised double-blind multicentre substudy. Ann. Rheum. Dis.77, 412–416 (2018).

[2]Bowman, S. J. et al. Randomized Controlled Trial of Rituximab and Cost-Effectiveness Analysis in Treating Fatigue and Oral Dryness in Primary Sjögren’s Syndrome. Arthritis Rheumatol.69, 1440–1450 (2017).

[3]Arends, S. et al. Composite of Relevant Endpoints for Sjögren’s Syndrome (CRESS): development and validation of a novel outcome measure. Lancet Rheumatol.3, e553–e562 (2021).

Disclosure of Interests

None declared

OP0085 CELL LINEAGE-SPECIFIC TRANSCRIPT DECONVOLUTION OF SYNOVIAL BIOPSIES FROM THE R4RA TRIAL IDENTIFIES CELL POPULATIONS ASSOCIATED WITH RESPONSE TO RITUXIMAB AND TOCILIZUMAB

Background

The R4RA trial, the first biopsy-based randomised trial in TNF-i inadequate responder patients with Rheumatoid Arthritis, showed that molecular stratification of RA synovial tissue was associated with clinical response, demonstrating that, in patients with low/absent B-cell lineage signature in synovial-tissue, tocilizumab is superior to rituximab1.

Objectives

Here, we aimed to perform cell-transcript deconvolution of pre-and post-treatment synovial biopsies from the R4RA trial.

Methods

A total of 164 patients underwent pre-treatment synovial biopsy (US-guided or arthroscopic) prior to randomization 1:1 to rituximab (83) or tocilizumab (81). 65 patients had a repeat biopsy at 16 weeks when clinical response was assessed using Clinical Disease Activity Index (CDAI) 50% improvement. RNA extracted from a minimum of 6 synovial samples/patient underwent RNA-sequencing and the abundance of tissue-infiltrating immune and stromal cell populations was estimated using the Microenvironment Cell Populations-counter (MCP-counter) method (Figure 1a).

Results

At baseline, while synovial semiquantitative immunohistochemistry scores did not differ between CDAI50% responders and non-responders, both for rituximab and tocilizumab, MCP-counter analysis showed significantly higher CD8 T-cells in responders to rituximab and higher macrophage-monocytes and myeloid dendritic cells (mDC) in responders to tocilizumab (Figure 1b). Moreover, when patients were classified according to MCP-counter scores, B-cell poor patients (MCP-counter B cell score <median value) showed significantly higher response rates to tocilizumab, while no difference was found in B-cell rich patients (Figure 1c). In contrast, macrophage and myeloid dendritic cell (mDC) rich individuals showed higher responses to tocilizumab (Figure 1d). Combined scores for lymphoid and myeloid cells demonstrated that patients poor in B-cells but rich in macrophages/mDC had a significantly higher response to tocilizumab (77% responders to tocilizumab vs 14% responders to rituximab, p=0.017, OR 16.48, 95%CI 1.29-1000.5) (Figure 1e). By analysing disease activity over time from baseline to week 16, we found a statistically significant interaction effect between treatments and time in B-cell poor (p=0.003), T-cell poor (p=0.022), mDC rich (p=0.029) and B-cell poor/Macrophages-mDC rich patients (p=0.006) (Figure 1f-g-h). Finally, by applying MCP-counter on matched pre-and post-treatment biopsies, rituximab-treated patients showed a significant reduction of B-cells, T-cells and monocyte/macrophages, while tocilizumab-treated patients showed a significant reduction of monocyte/macrophages, T-cells, but also neutrophils, myeloid dendritic cells and, interestingly, an increase in fibroblast signature (Figure 1i).

Conclusion

In silico deconvolution of the synovial tissue identify pre-treatment lymphoid cell lineages associated with response to rituximab and myeloid cells for tocilizumab. The longitudinal analysis of matched pre- and post-treatment synovial biopsies indicated that both medications have an effect on synovial immune cells, but tocilizumab can also affect stromal cells.

References

[1]Humby et al. Rituximab versus tocilizumab in anti-TNF inadequate responder patients with rheumatoid arthritis (R4RA): 16-week outcomes of a stratified, biopsy-driven, multicentre, open-label, phase 4 randomised controlled trial Lancet. 2021 Jan 23;397(10271):305-317. doi: 10.1016/S0140-6736(20)32341-2.

Acknowledgements

We would like to thank all patients and the R4RA recruiting centres and principal investigators http://www.r4ra-nihr.whri.qmul.ac.uk/recruiting_centres.php We would also like to acknowledge the UK National Institute of Health Research for funding the R4RA trial (grant reference: 11/100/76) and Versus Arthritis for providing infrastructure support through the Experimental Arthritis Treatment Centre (grant number: 20022).

Disclosure of Interests

None declared.

OP0077 SYNOVIAL RNA-SEQ ANALYSIS OF THE R4RA TRIAL IDENTIFIES SIGNATURES OF TREATMENT RESISTANCE AND REFRACTORY STATE IN RHEUMATOID ARTHRITIS

Background

Although up to 5-20% of rheumatoid arthritis (RA) patients do not respond to all current medications including biologic therapies, relatively little is known about the underlying pathogenic mechanisms driving non-response. In the first biopsy-driven randomized clinical trial in RA (R4RA)1, patients, in whom synthetic-DMARDs and at least one anti-TNF drug were not effective, were randomised 1:1 to rituximab (RTX) or tocilizumab (TOC) with a balanced stratification based on their synovial B-cell rich/poor signature, and response was assessed at 16 weeks. Non-responders were subsequently allowed to switch to the alternative drug with 48-week follow-up.

Objectives

Investigate mechanisms of response and non-response to RTX and TOC through deep molecular (RNA-Sequencing) profiling of synovial tissue.

Methods

RNA-Seq from baseline synovial tissue biopsies of patients who received RTX (n=88) or TOC (n=94) at any point in the trial was analysed for differentially expressed genes and associated modules between responders and non-responders. Response was defined as 50% improvement in clinical disease activity index (CDAI) score. Patients who had received both drugs during the trial were subdivided into RTX only responders (pro-RTX, n=9), TOC only responders (pro-TOC, n=12) and refractory patients (no response to both RTX & TOC, n=32) and analysed for differential gene expression and performed gene module analysis.

Results

6625 genes were significantly differentially expressed between RTX responders compared to non-responders, with a predominance of antigen presentation as well as T- and B-cell genes being associated with response, while non-response was linked to fibroblast associated genes. Comparison between TOC responders and non-responders identified fewer (85) differentially expressed genes, however lymphocyte and immunoglobulin genes were also high in the synovial tissue of TOC responders similar to RTX responders, while non-responder genes and modules also included a fibroblast signature.

The cross-over study design enabled comparison of rituximab-specific responders (pro-RTX), tocilizumab-specific responders (pro-TOC) and refractory patients (non-responders to both RTX & TOC, n=32) in a 3-way analysis (see Figure 1). This identified 1980 genes upregulated both in pro-RTX and pro-TOC patients, 175 genes exclusive to the pro-RTX group and 306 to the pro-TOC group, while 1277 genes were exclusive to the refractory group. While leukocyte modules and genes dominated RTX & TOC response, the refractory state was strongly associated with fibroblast genes and modules. We confirmed the observed expansion of fibroblasts from the RNA-Seq data by immunohistochemistry showing the presence of DKK3+ sublining fibroblasts in refractory rather than responder patients.

Conclusion

We provide novel insights into the cellular and molecular pathways underpinning multi-biologic resistance that define a refractory RA phenotype, characterised by a stromal/fibroblast signature.

References

[1]Humby, F., et al. Lancet (2021)

Acknowledgements

We would like to thank all patients and the R4RA recruiting centres and principal investigators http://www.r4ra-nihr.whri.qmul.ac.uk/recruiting_centres.php We would also like to acknowledge the UK National Institute of Health Research for funding the R4RA trial (grant reference: 11/100/76) and Versus Arthritis for providing infrastructure support through the Experimental Arthritis Treatment Centre (grant number: 20022).

Disclosure of Interests

None declared.

POS0439 STROMAL B-CELL CROSSTALK PROMOTES THE ESTABLISHMENT OF SYNOVIAL B CELL NICHES THROUGH THE SELECTION, ACTIVATION OF NATURALLY OCCURRING EBV+ B CELLS

Background

Rheumatoid Arthritis (RA) is characterized by the formation of ectopic lymphoid structures (ELS) in the synovial tissue, which can promote B cells activation and local production of autoantibodies. B cells exert an essential role in RA immunopathogenesis, as demonstrated by therapeutical effects of Rituximab (1). We previously showed that ELS in the RA joints frequently accumulate Epstein Barr virus (EBV)-infected B cells displaying evidence of both latent (LMP2A) and early lytic viral reactivation in locally differentiated plasma cells (PCs)(2). RA synovial fibroblasts (SFs) can sustain B cells activation, proliferation and maturation into high affinity antibodies producing cells, mimicking B cells physiological differentiation in germinal centres (3). Whether RASFs can also promote preferential selection of naturally-occurring EBV+ B cells is currently unknown.

Objectives

Here, we aim to a) demonstrate SFs role in EBV+ B cells selection b) phenotypically characterize B cells after co-culture with SFs c) dissect the molecular mechanisms behind the B cells SFs crosstalk.

Methods

Long-term in vitro B cells SFs co-cultures have been established, followed by phenotypical characterization of B cells in flowcytometry. Supernatant were then screened by ELISA at different timepoints, to measure IgG, IgM and IgA production. EBV infection status on B cells were analysed by qRT-PCR after gDNA extraction. Single cells RNA sequencing was finally performed at 28 days of co-culture.

Results

Preliminary results confirmed RASFs role in sustaining B cells activation and maturation, showing B cells survival up to 90 days, production of IgG and an increased IgG/IgM ratio overtime. Interestingly, we identified a particular B cells phenotype occurring in long term in vitro co-cultures, characterized by CD38 expression and the subdivision into two functional subsets, CD58+/CD23high and CD58+/CD23low. These two subpopulations - previously described by Megyola et al. in in vitro EBV infected B cells - are characterized by two different functional states: an highly proliferating (CD58+/CD23high) population and an IL-6 producers (CD58+/CD23low) one(4). We also observed that RASFs preferentially support EBV+ clones expansion, showing a preferential expression of EBV markers in CD58+/CD23high cells. The high proliferation rate of these B cells allowed – on a specific experiment - the establishment of a cell line, named “Carejavi”, that we are currently employing as tool for functional investigation of RASFs primed EBV+ B-cells. Finally, the transcriptomic analysis revealed the selection of a relatively small number of clonotype at the VDJ analysis at the end of co-culture. In addition, we observed the upregulation of genes related to GC formation (such as EBI3, LTA and LTB), B cells proliferation (mki67) and viral oncogenic transformation (MYC).

Conclusion

Here, we demonstrated that RA SFs not only support B cells maturation and activation in local autoantibodies producing cells, but they are also able to preferentially induce selection and proliferation of EBV+ clones, characterized by a peculiar expression of CD58 and CD23. The molecular mechanisms behind this phenomenon are currently under investigation.

References

[1]Cohen SB et al. Rituximab for rheumatoid arthritis refractory to anti-tumor necrosis factor therapy: Results of a multicenter, randomized, double-blind, placebo-controlled, phase III trial evaluating primary efficacy and safety at twenty-four weeks. Arthritis Rheum 2006

[2]Croia C, et al. Epstein-Barr virus persistence and infection of autoreactive plasma cells in synovial lymphoid structures in rheumatoid arthritis. Ann Rheum Dis 2013.

[3]Bombardieri M, et al. A BAFF/APRIL-dependent TLR3-stimulated pathway enhances the capacity of rheumatoid synovial fibroblasts to induce AID expression and Ig class-switching in B cells. Ann Rheum Dis 2011.

[4]Megyola C et al. Identification of a sub-population of B cells that proliferates after infection with epstein-barr virus. Virol J 2011

Disclosure of Interests

None declared.

POS0399 CHARACTERIZATION OF HSP60, A STROMAL-DERIVED AUTOANTIGEN, RECOGNIZED BY RA SYNOVIAL RECOMBINANT MONOCLONAL ANTIBODIES

Background

Up to 50% of rheumatoid arthritis (RA) patients display synovial ectopic lymphoid structures (ELS) supporting B-cell autoreactivity toward locally generated citrullinated and other translationally modified antigens. Recently, screening a large number of recombinant monoclonal antibodies (rmAbs, n=71) which we derived from locally differentiated B-cells from RA ELS+ synovium [1], we identified a subset of antibodies which specifically recognise fibroblast-like-synoviocytes (FLS) (10 out of 71), suggesting FLS as a cellular source of autoantigens fuelling the local autoimmune response. We reported that calreticulin is one of the antigenic targets of these anti-FLS rmAbs, while the nature of other FLS-derived autoantigens is still unclear [2].

Objectives

Here we aimed to define other stromal-derived autoantigens from RA-FLS targeted by RA-rmAbs.

Methods

Western blotting/mass-spectrometry were used to identify potential autoantigens from RA-FLS protein extracts. Putative candidates were validated using colocalization immunofluorescence confocal microscopy/ELISA/immunoprecipitation assay. Finally, both serum and synovial fluid (SF) from RA patients (OA patients used as control) were tested for immunoreactivity towards the putative antigen.

Results

Following immunoprecipitation and mass-spectrometry analysis, among the anti-FLS antibodies we identified a subset of RA-rmAbs which display strong reactivity towards heat shock protein 60 (HSP60). Three RA-rmAbs confirmed a clear immunoreactivity towards HSP60 in ELISA assay in a dose-dependent manner. Confocal microscopy did not show co-localization between anti-HSP60 RA-rmAbs and HSP60, suggesting that HSP60 act as autoantigen when released from the RA-FLS in stress condition. Finally, anti-HSP60 Abs were preferentially detected in RA-SF versus OA-SF, with an accumulation of HSP60 in RA-SF versus RA sera.

Conclusion

Here, we identified synovial B cell-derived RA-rmAbs locally differentiated within the ELS+ RA synovium reacting toward HSP60, suggesting that FLS-derived HSP60 may contribute to fuel the local autoimmune response. Elucidating the mechanisms involved in RA-FLS activation in vitro/in vivo will be important to clarify the anti-FLS rmAbs functional role in modulating inflammation.

References

[1]Corsiero et al, ARD 2016; [2] Corsiero et al, JI 2018.

Acknowledgements

This work was supported by a research grant from Versus Arthritis (Grant 22440 to E. Corsiero).

Disclosure of Interests

None declared.

POS0138 RHEUMATOID SYNOVIAL FIBROBLASTS DISPLAY IMPRINTED MEMORY OF THEIR SYNOVIAL ENDOTYPE WHICH CAN BE PLASTICALLY MODULATED BY B-CELLS CROSSTALK

Background

Despite advances in the treatment of Rheumatoid Arthritis (RA), synthetics and biologicals drugs are ineffective in ~40% of patients. The origin of this refractoriness is unclear, but several clues point at the synovial microenvironment (SE) and the relative cellular heterogeneity between patients. We previously described the existence of different RA endotypes such as the lympho-myeloid, LM, which is B-cell rich and the fibroid-paucimmune, FPI, which is devoid of B-cells. While there is clear evidence that the crosstalk between stromal and immune cells in rheumatoid joints is critical for the perpetuation of chronic inflammation and autoimmunity, it is currently unknown whether transcriptional signatures identified in synovial fibroblasts (SFs) derived from different RA endotypes are driven by “imprinted” properties of the SFs or are shaped by the interaction with infiltrating immune cells in the RA joints.

Objectives

I) to identify “imprinted” vs “inducible” RASFs signatures trough the comparison of freshly isolated SFs and primary established SFs cultures obtained from LM vs FPI RA synovial biopsies and ii) to investigate the identified RASF signature as predictive biomarkers of disease evolution and of response to conventional and biological DMARDs.

Methods

We performed flowcytometry and single cell RNA sequencing (sc-RNAseq) on SFs obtained from LM and FPI biopsies, in isolation or in co-culture with RA B cells. Next, supernatant has been screened trough Multiplex and ELISA. Furthermore, we compared our results to publicly available sc-RNAseq datasets on freshly isolated SFs and to our bulk-RNAseq data from clinical trials patients.

Results

Hierarchical clustering from sc-RNAseq transcriptional profiling of LM vs FPI RASF - after several cell passages - identified profoundly different gene signatures: whereby LM-RASF were characterised by genes involved in inflammation, proteoglycan formation and integrin binding, FPI-RASF were defined by genes related to collagen biosynthesis. Comparing the above signatures with those of freshly isolated RASF we identified both imprinted (i.e. maintained through several in vitro passages) and inducible (i.e. loss after long term culture) gene signatures. Notably, RA B-cells co-cultured with FPI-RASF profoundly altered the FPI-RASF transcriptional profile including the ex-novo expression of gene signatures typical of LM-RASF. Consensus gene modules constructed on LM vs FPI RASF imprinted gene signatures could be tracked in longitudinal whole tissue bulk RNA-seq data obtained from both early arthritis and established RA and were associated with synovial pathotype-specific histological and clinical features. Finally, modulation of FPI-RASF related genes following B-cell depletion identified poor responders to Rituximab in the R4RA randomised clinical trial.

Conclusion

Our work demonstrates that RASFs from different endotypes display imprinted memory of their original synovial tissue when maintained in culture over several months. We also demonstrated that imprinted memory typical of RASF isolated from B-cell rich LM synovial tissues can be dynamically modulated in FPI RASF following crosstalk with RA B cells. Finally, consensus gene modules based on FPI vs LM RASF-gene signatures were able inform on response/resistance to targeted biologic therapies.

References

[1]Lewis, M. J. et al. Molecular Portraits of Early Rheumatoid Arthritis Identify Clinical and Treatment Response Phenotypes. Cell Rep (2019)

[2]Humby, F. et al. Synovial cellular and molecular signatures stratify clinical response to csDMARD therapy and predict radiographic progression in early rheumatoid arthritis patients. Ann Rheum Dis (2019)

[3]Zhang, F. et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol (2019)

[4]Humby, F. et al. Rituximab versus tocilizumab in anti-TNF inadequate responder patients with rheumatoid arthritis (R4RA). Lancet (2021)

Disclosure of Interests

None declared

OP0286 DEVELOPMENT AND PRELIMINARY VALIDATION OF THE SJÖGREN’S TOOL FOR ASSESSING RESPONSE (STAR): A CONSENSUAL COMPOSITE SCORE FOR ASSESSING TREATMENT EFFECT IN PRIMARY SJÖGREN’S SYNDROME

Background

Today, there are still no DMARDs licensed for primary Sjögren Syndrome (pSS) patients. Among the explanations, are the limitations of current outcome measures used as primary endpoints: e.g; high placebo response rate, evaluation of either symptoms or systemic activity, and important features not being assessed. The NECESSITY consortium (https://www.necessity-h2020.eu/), including pSS experts from academia, pharmaceutical industry and patient groups formed to develop a new composite responder index, the Sjögren’s Tool for Assessing Response (STAR) that solve the issues of current outcome measures in pSS and is intended for use in clinical trials as an efficacy endpoint.

Objectives

To develop a composite responder index in primary Sjögren’s syndrome (pSS): the STAR.

Methods

To develop the STAR, the NECESSITY consortium used data-driven methods, based on 9 randomized controlled trials (RCTs), and consensus techniques, involving 78 experts and 20 patients. Based on reanalysis of rituximab trials (TRACTISS and TEARS) and literature review, the Delphi panel identified a core set of domains to include in the STAR, with their respective outcome measures. STAR options combining these domains were designed and proposed to the panel to select and improve them. For each STAR option, sensitivity to change was estimated by the C-index (derived from Effect size) in all 9 RCTs. Delphi rounds were run for selecting STAR among these options. The Delphi panel also voted to classify trials as positive, negative or “in between” in regards to primary but also key secondary endpoints. For the options remaining before the final vote, meta-analyses of the RCTs were performed separately for positive and “in between” trials together, and for negative trials.

Results

The Delphi panel identified 5 core domains (systemic activity, patient symptoms, lachrymal gland function, salivary gland function and biological parameters), and 227 STAR options, combining these domains, were selected to be tested for sensitivity to change. After two Delphi rounds, meta-analyses of the 20 remaining options were performed. The candidate STAR was selected by a final vote based on metrological properties and clinical relevance. In positive/in between trials, candidate STAR detected a difference between arms (OR 3.29, 95%-CI [2.07;5.22], whereas it did not in negative trials (OR 1.53, 95%-CI [0.81;2.91]).

Conclusion

The candidate STAR is a composite responder index, including in a single tool all main disease features, and is designed for use as a primary endpoint in pSS RCTs. Its rigorous and consensual development process ensures its face and content validity. The candidate STAR showed good sensitivity and specificity to change. The candidate STAR will be prospectively validated in a dedicated three arms RCT of the NECESSITY consortium that will evaluate combination of synthetic DMARDs (hydroxychloroquine + lefunomide or hydroxychloroquine + mycophenolate vs placebo). We encourage the use of STAR in any ongoing and future trials.

Table 1.

Candidate STAR

DomainPointDefinition of responseSystemic activity3Decrease of clinESSDAI ≥ 3Patient reported outcome3Decrease of ESSPRI ≥ 1 point or ≥ 15%Lachrymal gland function1Schirmer:If abnormal score at baseline: increase ≥ 5 mm from baselineIf normal score at baseline: no change to abnormalOrOcular Staining Score:If abnormal score at baseline: decrease ≥ 2 points from baselineIf normal score at baseline: no change to abnormalSalivary gland function1Unstimulated Whole Salivary Flow:If score > 0 at baseline: increase ≥ 25% from baselineIf score is 0 at baseline: any increase from baselineorUltrasound:Decrease ≥ 25% in total Hocevar score from baselineBiological1Serum IgG levels: decrease ≥ 10%orRheumatoid Factor levels: decrease ≥ 25%Candidate STAR responder≥ 5 points

ESSDAI: EULAR Sjögren syndrome disease activity index; ESSPRI: EULAR Sjögren syndrome patient reported index; IgG: Immunoglobulin G;

Acknowledgements

NECESSITY WP5 STAR development participants: Suzanne Arends (University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen 9700 RB, Netherlands), Francesca Barone (Centre for Translational Inflammation Research, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK), Albin Björk (Division of Rheumatology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden), Coralie Bouillot (Association Française du Gougerot Sjögren et des Syndromes Secs, France), Guillermo Carvajal Alegria (University of Brest, Inserm, CHU de Brest, LBAI, UMR1227, Brest, France; Service de Rhumatologie, Centre de Référence Maladies Autoimmunes Rares CERAINO, CHU Cavale Blanche, Brest, France), Wen-Hung Chen (GlaxoSmithKline, Research Triangle Park, North Carolina, USA), Kenneth Clark (GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom), Konstantina Delli (Department of Oral and Maxillofacial Surgery, University Medical Center Groningen (UMCG), University of Groningen, The Netherlands), Salvatore de Vita (Rheumatology Clinic, University Hospital of Udine, Italy), Liseth de Wolff (University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen 9700 RB, Netherlands), Jennifer Evans (Novartis Pharmaceuticals corporation USA), Stéphanie Galtier (Institut de Recherches Internationales Servier (IRIS), Suresnes Cedex, France), Saviana Gandolfo (Rheumatology Clinic, Department of Medical area, University of Udine, ASUFC, 33100 Udine, Italy), Mickael Guedj (Institut de Recherches Internationales Servier (IRIS), Suresnes Cedex, France), Dewi Guellec (CHU de Brest, Service de Rhumatologie, Inserm, CIC 1412, Brest, France), Safae Hamkour (Center of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht 3584 GA, Netherlands), Dominik Hartl (Novartis Institutes for BioMedical Research, Basel, Switzerland), Malin Jonsson (Section for Oral and Maxillofacial Radiology, Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Norway), Roland Jonsson (Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Department of Rheumatology, Haukeland University Hospital, Bergen, Norway), Frans Kroese (University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen 9700 RB, Netherlands), Aike Albert Kruize (University Medical Center Utrecht, Department Rheumatology and Clinical Immunology, Utrecht, Netherlands), Laurence Laigle (Institut de Recherches Internationales Servier (IRIS), Suresnes Cedex, France), Véronique Le Guern (AP-HP, Hôpital Cochin, Centre de référence maladies auto-immunes et systémiques rares, service de médecine interne, Paris, France), Wen-Lin Luo (Department of Biometrics and Statistical Science, Novartis Pharmaceuticals, East Hanover, New Jersey), Esther Mossel (University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen 9700 RB, Netherlands), Wan-Fai Ng (Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE2 4HH, UK), Gaëtane Nocturne (Department of Rheumatology, Université Paris-Saclay, INSERM U1184: Centre for Immunology of Viral Infections and Autoimmune Diseases, Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Le Kremlin Bicêtre, Paris, France), Marleen Nys (Global Biometric Sciences, Bristol Myers Squibb, Braine L’Alleud, Belgium), Roald Omdal (Clinical Immunology Unit, Department of Internal Medicine, Stavanger University Hospital, PO Box 8100, 4068, Stavanger, Norway), Jacques-Olivier Pers (LBAI, UMR1227, University of Brest, Inserm, Brest, France and CHU de Brest, Brest, France), Maggy Pincemin (Association Française du Gougerot Sjögren et des Syndromes Secs, France), Manel Ramos-Casals (Department of Autoimmune Diseases, Hospital Clinic de Barcelona Institut Clinic de Medicinai Dermatologia, Barcelona, Catalunya, Spain), Philippe Ravaud (Centre d’Epidémiologie Clinique, Hôpital Hôtel-Dieu, Assistance Publique-Hôpitaux de Paris, Paris, France), Neelanjana Ray (Global Drug Development - Immunology, Bristol Myers Squibb Company, Princeton, New Jersey, USA), Alain Saraux (HU de Brest, Service de Rhumatologie, Univ Brest, Inserm, UMR1227, Lymphocytes B et Autoimmunité, Univ Brest, Inserm, LabEx IGO, Brest, France), Athanasios Tzioufas (Rheumatology Clinic, Department of Medical area, University of Udine, ASUFC, 33100 Udine, Italy), Gwenny Verstappen (University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen 9700 RB, Netherlands), Arjan Vissink, Marie Wahren-Herlenius (Division of Rheumatology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden). We thank the following experts: Esen Karamursel Akpek, Alan Baer, Chiara Baldini, Elena Bartoloni, Marí-Alfonso Begona, Johan Brun, Vatinee Bunya, Laurent Chiche, Troy Daniels, Paul Emery, Robert Fox, Roberto Giacomelli, John Gonzales, John Greenspan, Robert Moots, Susumu Nishiyama, Elizabeth Price, Christophe Richez, Caroline Shiboski, Roser Solans Laque, Muthiah Srinivasan, Peter Olsson, Tsutomu Takeuchi, Frederick Vivino, Paraskevi Voulgari, Daniel Wallace, Ava Wu, Wen Zhang. We thank the anonymous patients from the NECESSITY Patient Advisory Group and the Sjögren Foundation for their valuable contribution to the Delphi process. We thank EW StClair and AN Baer who generated the baminercept data and made them publicly available.

Disclosure of Interests

Raphaèle Seror Consultant of: GlaxoSmithKline, Boehringer, Janssen and Novartis, Grant/research support from: GlaxoSmithKline and Amgen, Gabriel Baron: None declared, Marine Camus: None declared, Divi Cornec Consultant of: GlaxoSmithKline, Bristol Myers Squibb, Janssen, Amgen, Pfizer and Roche, Elodie Perrodeau: None declared, Simon J. Bowman Consultant of: Abbvie, Astra Zeneca, Galapagos and Novartis Pharmaceuticals, Michele Bombardieri Consultant of: UCB, Amgen/Medimmune, Janssen, and GlaxoSmithKline, Grant/research support from: Amgen/Medimmune, Janssen, and GlaxoSmithKline, Hendrika Bootsma: None declared, Jacques-Eric Gottenberg Consultant of: AbbVie, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, Pfizer, Roche, Sanofi, Novartis, MSD, CSL-Behring and Genzyme, Grant/research support from: Bristol Myers Squibb, Benjamin Fisher Speakers bureau: Bristol Myers Squibb and Novartis, Consultant of: Novartis, Bristol Myers Squibb, Janssen and Servier, Grant/research support from: Servier, Galapagos and Janssen, Wolfgang Hueber Shareholder of: Novartis Pharma, Employee of: Novartis Pharma, Joel van Roon: None declared, Valerie Devauchelle-Pensec: None declared, Peter Gergely Shareholder of: Novartis Pharma, Employee of: Novartis Pharma, Xavier Mariette Consultant of: Bristol Myers Squibb, Galapagos, GlaxoSmithKline, Janssen, Novartis, Pfizer and UCB, Grant/research support from: Ose Pharmaceuticals, Raphaël Porcher: None declared

POS0441 IN-DEPTH ANALYSIS OF Axl AND MerTK EXPRESSION PATTERNS AND REGULATION BY BIOLOGIC TREATMENTS IN RHEUMATOID ARTHRITIS

Background

Tyrosine kinases receptors MerTK and Axl have been implicated in the pathogenesis of several autoimmune diseases. Despite sharing significant structural homology and having common ligands, Axl and MerTK have distinct features and biological functions [1]. A growing body of evidence suggests that both Axl and MerTK play a crucial role in Rheumatoid Arthritis (RA) pathogenesis and progression and may be exploited as novel therapeutic targets [2]. However, numerous unanswered questions remain to be addressed.

Objectives:

i.To define common and distinct gene-partners of Axl/MerTK and quantify their expression in RA synovial tissue.

ii.To assess the co-expression of Axl/MerTK by synovial cells.

iii.To outline the longitudinal variation in Axl/MerTK expression upon treatment intervention.

Methods

Synovial tissue samples were collected by US-guided synovial biopsy from: i. Patients with early (<12 months) RA DMARDs/steroid-naïve [n=87]; and ii. RA patients who failed the first-line biologic with TNF-inhibitors (TNFi) before and 16 weeks after receiving either Rituximab (RTX) or Tocilizumab (TOC) [n=164] [3]. Gene expression was obtained by bulk RNAseq performed on an Illumina HiSeq2500 platform. Axl-/MerTK-modules were defined using STRING networks and the module expression determined by the mean z-score of regularized log transformed expression for all genes in the set. Axl, MerTK, CD55, CD90, CD68 protein expression was analysed by multiplex immunofluorescence staining.

Results

Using STRING network analysis, we defined an Axl- and a MerTK-module composed of 31 predicted gene-partners of either Axl or MerTK. Thirteen genes were common to both modules and included the ligands Gas6 and ProteinS, and EGFR. Conversely, eighteen genes were uniquely present in the Axl-module (e.g., PIK3-family, IGF1R, IFNAR1 and STAT3) or the MerTK-module (e.g., Galectin3 and TULP, recently discovered MerTK ligands, FCGR1A/CD64, PTPN1and MEGF10). Axl/MerTK-modules quantified in the early-arthritis treatment-naïve RNAseq dataset showed a significant negative correlation with the synovitis score (Axl r=−0.33, p=0.0032; MerTK r=-0.33, p=0.003). At protein level, CD68+macrophages of the Lining showed notable heterogeneity between patients: they could express either Axl or MerTK alone, or co-express both. Axl was also present in most CD55+ Lining Fibroblast-Like-Cells (FLS) but not by CD90+ Sublining FLS while MerTK, as expected, was restricted to macrophages, including intra-aggregate tingible-body-macrophages.

To define how Axl and MerTK vary depending on disease stage and treatment exposure, we quantified their gene expression in active RA patients inadequately responding to TNFi, prior and 16 weeks after starting second-line biologic (RTX or TOC) [3]. Differently from the early-arthritis cohort, MerTK was significantly up-regulated in synovia characterised by higher degree of tissue inflammation (lympho-myeloid > diffuse-myeloid > pauci-immune, p<0.0001) and significantly positively correlated with several cytokines’ genes such as TNF, IL-6, CCL8 and IL-10. MerTK expression was dependent on clinical response to RTX but not TOC as assessed by EULAR response (DAS28CRP, good vs none/mod, FDRresp 0.048). Conversely, Axl expression significantly increased upon IL-6 blockade by TOC independently of the clinical response (FDRtime 0.016).

Conclusion

Our data further corroborate that Axl and MerTK constitute a dynamic axis influenced by the synovial tissue inflammatory features, the disease stage, the exposure and the response to targeted treatment and the blockade of critical inflammatory pathways over time. A better understanding of the individual features of these tyrosine kinases as well as their interaction would be beneficial to define novel treatment approaches.

References

[1]Zagórska A, et al. Nat Immunol. 2014 Oct;15(10):920-8

[2]Kemble S, Croft AP. Front Immunol. 2021 Sep 3;12:715894

[3]Humby F et al. Lancet. 2021 Jan 23;397(10271):305-317

Acknowledgements

Versus Arthritis.

Disclosure of Interests

None declared.

POS0431 PDGF-BB, TNF-α, AND LT-β REGULATE FOLLICULAR DENDRITIC CELL DEVELOPMENT IN THE RHEUMATOID SYNOVIUM

Background

Follicular dendritic cells (FDCs) fundamentally contribute to the formation of synovial ectopic lymphoid-like structures in rheumatoid arthritis (RA) which is associated with poor clinical prognosis. Despite this critical role in RA pathogenesis, FDC development in the RA synovium has not been fully elucidated.

Objectives

To investigate the role of TNF-α/LT-β and PDGF-BB in the ontogeny of RA synovial FDCs and the differentiation of lymphoid and fibroid RA synovitis.

Methods

RA Synovial tissues were obtained from the Pathobiology of Early Arthritis Cohort (PEAC) of the Centre for Experimental Medicine and Rheumatology of Queen Mary University of London. RNA-Seq analysis and confocal imaging of early and late FDC differentiation markers were carried out and the stromal cell subsets were sorted by flow cytometry. The stromal cell subsets were treated with TNF-α/LT-β and/or PDGF-BB and the expression of FDC differentiation genes was assessed by qPCR. Germinal centre reactions were setup in vitro using TNF-α/LT-β activated stromal cells, and antibody production by naive human B cells stimulated with anti IgM was measured by ELISA.

Results

Our results indicate that PDGF-BB induces the FDC marker CNA.42+ on NG2+/αSMA+ type-1 pericytes, stimulates THY-1 and αSMA gene expression, and strongly correlates with fibroid synovitis using RNA-Seq analysis. On the other hand, TNF-α/LT-β downregulate PDGFR-β, THY-1, αSMA; induce CD21, FcɣRIIB expression, and significantly correlate with lymphoid synovial pathotype. Ultrastructural examination of antigen trapping on TNF-α/LT-β-activated RA synovial fibroblasts (RASFs) showed periodically retained surface antigens and these fibroblasts were able to induce T cell independent B cell activation in in vitro germinal centre reactions. The transition from an early PDGFR-β+ pre FDCs to a late TNF-α/LT-β-responsive mature FDCs is promoted by PDGF-BB. PDGF-BB induces TNF-αR expression in RASFs and facilitates B cell recruitment via pericyte CXCL13 expression and stromal cell migration.

Conclusion

To the best of our knowledge, this is the first report describing the crosstalks between PDGF-BB and TNF-α/LT-β in FDC development in the rheumatoid synovium and its association with the evolution of lymphoid and fibroid synovitis. Selective targeting of this interplay could inhibit FDC differentiation and potentially ameliorate RA in clinically severe and drug-resistant patients.

Disclosure of Interests

None declared.

Tofacitinib Decreases Autophagy of Fibroblast-Like Synoviocytes From Rheumatoid Arthritis Patients

The pathway of Janus tyrosine kinases (JAKs) has a central role in the pathogenesis of Rheumatoid Arthritis (RA) by regulating multiple immune functions and cytokine production. The JAK inhibitor tofacitinib is effective in RA patients not responding to methotrexate or TNF-inhibitors. Since hyperactive autophagy has been associated with impaired apoptosis of RA fibroblast-like synoviocytes (FLS), we aimed to investigate the role of tofacitinib in modulating autophagy and apoptosis in these cells. FLS isolated from RA biopsies were cultured with tofacitinib in presence of autophagy inducer rapamycin and in serum deprivation condition. Levels of autophagy, apoptosis, and citrullinated proteins were analyzed by western blot, flow cytometry, immunocytofluorescence, and Real-Time PCR. Rapamycin induced an increase in RA-FLS autophagy while the levels of autophagy marker LC3-II were reduced after in vitro treatment with tofacitinib. The analysis of autophagic flux by specific fluorescence dye confirmed the reduction of autophagy in RA FLS. The treatment with tofacitinib did not influence apoptosis of RA FLS. Modulation of the autophagic process by tofacitinib did not significantly change citrullination. The results of this study demonstrate that tofacitinib is able to modulate autophagy of FLS contributing to its effectiveness in RA patients.

OP0136 RITUXIMAB PREVENTS THE PROGRESSION OF B-CELL DRIVEN INFLAMMATORY INFILTRATE IN THE MINOR SALIVARY GLANDS OF PRIMARY SJOGREN’S SYNDROME BY DOWNREGULATING IMMUNOLOGICAL PATHWAYS KEY IN ECTOPIC GERMINAL CENTRE ORGANIZATION: RESULTS FROM THE TRACTISS TRIAL

Background:

The pathogenic role of B-cells in primary Sjögren’s Syndrome (pSS) is well established and B cell abnormalities. Because of the substantial role of B-cells, rituximab (RTX), a chimeric anti-CD20 monoclonal antibody, has been considered as a potential biologic disease modifying drug to reduce disease activity in pSS. To date, the TRial for Anti-B-Cell Therapy In patients with pSS (TRACTISS) is the largest multi-centre, placebo-controlled trial with RTX. Despite the unmet primary endpoints (30% reduction in fatigue or oral dryness, measured by visual analogue scale), RTX treated patients showed an improvement in unstimulated whole salivary flow (Bowman et al. Arthritis Rheumatol 2017;69:1440–1450).

Objectives:

To provide the first longitudinal transcriptomic and histological analysis at 3 time points over 48 weeks of labial SGs of pSS patients treated with RTX, in comparison to placebo, from the TRACTISS cohort.

Methods:

26 pSS patients randomised to RTX or placebo arm consented for labial SG biopsies at baseline, weeks 16 and 48. Patients received two 1000mg cycles of RTX or placebo at baseline and week 24. SG focus score, inflammatory aggregate area fraction, B-cells (CD20+), T-cells (CD3+), follicular dendritic cells (FDCs) (CD21+) and plasma cells (CD138+) density were assessed by H&E and immunofluorescence staining. The histological analysis was performed by digital imaging using QuPath software. RNA was extracted from matched labial SG lobules and sequenced with Illumina platform. A Principal Component Analysis (PCA) and features driving the PCA were investigated along with the most influential gene loadings. The limma-voom R pipeline was used to extract Differential Expressed Genes (DEGs) between placebo and RTX group at week 48, and gene ontology (GO) enrichment analysis performed through EnrichR to derive GO terms and pathways associated with DEGs.

Results:

Placebo-treated labial SGs showed a worsening of inflammation highlighted by the increment of B-cell density, development of new FDC networks, and a higher ectopic GC prevalence at week 48, compared to RTX-treated patients. No difference in total T-cells and plasma cell infiltration was observed. RTX downregulated genes involved in immune cell recruitment and inflammatory aggregate organisation (e.g. CCR7, CCL19, CD52, and PDCD1) and gene signature-based analysis of 64 immune cell types highlighted how RTX preferentially blocked class-switched- and memory-B-cells infiltration in SGs at week 48. Pathway analyses confirmed the downregulation of leukocyte migration, MHC class II antigen presentation, and T-cell co-stimulation immunological pathways, such as the CD40 receptor complex pathway. The analysis of placebo SGs transcriptomic at week 48 showed a higher expression of genes linked to ectopic GC organisation, such as CXCL13, CCL19, LTβ, in female compared to male subjects. Gender was confirmed as a key co-variate responsible for most of the variation in the PCA, together with the SG focus score and the foci area fraction.

Conclusion:

Treatment with RTX showed beneficial effects on labial SG inflammatory infiltration in pSS, by downregulating genes involved in immune cell recruitment, activation and organisation in ectopic GCs. Class-switched-B-cells, memory-B-cells and FDC network development were primarily affected appearing to be responsible for the lack of progression in SG B cell infiltration in the RTX compared to the placebo arm in which clear worsening of SG immunopathology over 48 weeks was detected in female patients. Although a clear association with the clinical improvement in unstimulated salivary flow observed at week 48 in RTX-treated patients could not be established given the low number of patients consenting to 3 longitudinal biopsies it is conceivable that RTX is responsible for preserving exocrine function.

Acknowledgements:

SJB receives a salary contribution from the NIHR Birmingham Biomedical Research Centre.

Disclosure of Interests:

Elena Pontarini: None declared, Farzana Chowdhury: None declared, Elisabetta Sciacca: None declared, Sofia Grigoriadou: None declared, Felice Rivellese: None declared, Davide Lucchesi: None declared, Katriona Goldmann: None declared, Liliane Fossati-Jimack: None declared, Paul Emery: None declared, Wan Fai Ng: None declared, Nurhan Sutcliffe: None declared, Colin Everett: None declared, Catherine Fernandez: None declared, Anwar Tappuni: None declared, Myles Lewis: None declared, Costantino Pitzalis: None declared, Simon J. Bowman Consultant of: SJB In 2020 I have received consultancy fees from Novartis, Abbvie and Galapagos., Michele Bombardieri: None declared

OP0130 COMPOSITE OF RELEVANT ENDPOINTS IN SJÖGREN’S SYNDROME (CRESS): A COMPREHENSIVE TOOL FOR CLINICAL TRIALS

Background:

Several large randomised controlled trials (RCTs) in primary Sjögren’s syndrome (pSS) failed to demonstrate drug efficacy.1-4 Many of these trials used ESSDAI as primary endpoint, showing large but similar response rates in active treatment and placebo groups.1,3,4 Given the heterogeneous nature of pSS, there is need for a composite endpoint including multiple clinically relevant parameters.

Objectives:

To develop and validate the Composite of Relevant Endpoints in Sjögren’s Syndrome (CRESS).

Methods:

A multidisciplinary team of pSS experts selected clinically relevant items and measurements to include in the CRESS. Definition of response of CRESS items was based on clinical relevance, previously defined minimal clinically important improvement (MCII) and data of the single-centre ASAP-III (abatacept) trial.1 CRESS was validated in three independent RCTs: TRACTISS (rituximab) trial2, multi-centre abatacept trial3 and ETAP (tocilizumab) trial4. CRESS response rates were assessed at the primary endpoint visit of all four trials.

Results:

Five complementary items were selected to form CRESS: systemic disease activity, patient-reported symptoms, tear gland, salivary gland and serological item. Definition of response per item is presented in Table 1. Total CRESS response was defined as response on ≥3 of 5 items. Since not all trials have ocular staining score or salivary gland ultrasonography (SGUS) available, the concise CRESS (cCRESS) was developed simultaneously, leaving Schirmer’s test and unstimulated whole saliva flow for the tear and salivary gland items, respectively. In the ASAP-III trial, CRESS response rates were 24/40 (60%) for abatacept vs. 7/39 (18%) for placebo at week 24 (p<0.001).

Table 1.

CRESS items and definition of response

ItemsMeasurementsDefinition of responseSystemic disease activityClinESSDAIScore<5 (low disease activity)Patient-reported symptomsESSPRIDecrease of ≥1 point or ≥15%Tear gland*Schirmer/OSS**-If abnormal Schirmer (≤5 mm) at baseline: increase of ≥5 mm in Schirmer-Or if abnormal OSS (≥3 points) at baseline: decrease ≥2 points in OSS-Or if both Schirmer/OSS normal scores at baseline: no change to abnormal in bothSalivary gland*UWS/SGUSIncrease of ≥25% in UWS (or if score is 0 at baseline, any increase)Or decrease of ≥25% in total Hocevar score (SGUS)SerologicalRF/IgGDecrease of ≥25% in RFOr decrease of ≥10% in IgGCRESS responderResponder on ≥3 of 5 items

Ocular Staining Score (OSS), Unstimulated whole salivary flow (UWS), Salivary gland ultrasonography (SGUS), Rheumatoid factor (RF), Immunoglobuline G (IgG)

*Concise CRESS (cCRESS): CRESS without OSS and SGUS, leaving Schirmer and UWS for tear and salivary gland items, respectively

**Mean of both eyes

In the external validation trials, cCRESS response rates for TRACTISS were: 33/67 (49%) rituximab vs. 20/66 (30%) placebo at week 48 (p=0.026). CRESS response rates (without SGUS) for the multi-centre abatacept trial were: 41/92 (45%) abatacept vs. 30/95 (32%) placebo at week 24 (p=0.067). cCRESS response rates (without rheumatoid factor) for ETAP were: 10/55 (18%) tocilizumab vs. 13/55 (24%) placebo at week 24 (p=0.482) (Figure 1A-D). Compared to ESSDAI MCII of ≥3 points decrease, CRESS was able to approximately halve placebo response rates in RCTs with high baseline ESSDAI scores (>5) (Figures 1E-H).

Conclusion:

CRESS shows lower placebo response rates compared to ESSDAI MCII, which is crucial for demonstrating treatment efficacy. With the CRESS, higher response rates in abatacept and rituximab treated patients compared to placebo were found in RCTs which previously showed negative primary endpoint results. CRESS confirmed that no differences were found for almost all outcome measures between tocilizumab and placebo,4 with low response rates. The CRESS is a well-balanced, feasible, composite endpoint for use in clinical trials in pSS patients.

References:

[1]Van Nimwegen 2020;9913(19):1–11

[2]Bowman 2017;69(7):1440–50

[3]Baer (doi:218599)

[4]Felten (doi:21846)

Acknowledgements:

The authors would like to acknowledge all contributors of the included trials.

Disclosure of Interests:

Suzanne Arends: None declared, Liseth de Wolff: None declared, Jolien F. van Nimwegen Speakers bureau: Bristol Myers Squibb, Consultant of: Bristol Myers Squibb, Gwenny M. Verstappen: None declared, Jelle Vehof: None declared, Michele Bombardieri Consultant of: MedImmune, GlaxoSmithKline, Grant/research support from: MedImmune, Simon J. Bowman Consultant of: AstraZenecea/MedImmune, Bristol Myers Squibb, Celgene, Eli Lilly, Glenmark, GlaxoSmithKline, MTPharma, Novartis, Ono, Pfizer, Takeda, UCB, XTLBio, Elena Pontarini: None declared, Alan Baer Consultant of: Bristol Myers Squibb, Sanofi, VielaBio, Novartis, Marleen Nys Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Jacques-Eric Gottenberg Grant/research support from: Bristol Myers Squibb, Pfizer, Renaud FELTEN: None declared, Neelanjana Ray Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Arjan Vissink: None declared, Frans G.M. Kroese Speakers bureau: Bristol Myers Squibb, Roche and Janssen-Cilag, Consultant of: Bristol Myers Squibb, Grant/research support from: Unrestricted grants from Bristol Myers Squibb, Hendrika Bootsma Speakers bureau: Bristol Myers Squibb and Novartis, Consultant of: Bristol Myers Squibb, Roche, Novartis, Medimmune, Union Chimique Belge, Grant/research support from: Unrestricted grants from Bristol Myers Squibb and Roche

OP0011 INTEGRATION OF FLOW AND DIGITAL CYTOMETRY IN EARLY TREATMENT-NAÏVE RHEUMATOID ARTHRITIS IDENTIFIES DISTINCT IMMUNOPHENOTYPES IN PERIPHERAL BLOOD AND DISEASE TISSUE

Background:

The study of synovial tissue in patients with Rheumatoid Arthritis (RA) has led to the identification of synovial patterns of immune cell infiltration and specific cellular subsets associated that have been disease activity and clinical outcomes(1–3). However, the relationship of circulating and synovial immune cell sub-sets with histopathological features and clinical outcomes remains to be defined.

Objectives:

To assess the relationship of peripheral blood and synovial immune cells with RA histopathology and clinical outcomes, by performing flow and digital cytometry in matched peripheral blood and synovial samples from patients with early RA.

Methods:

70 patients with early (<12 months) untreated RA (2010 criteria) recruited in the pathobiology of early Arthritis Cohort (PEAC) at the Barts Health NHS Trust were included(1). Peripheral blood mononuclear cells (n=70) were analysed by flow cytometry. Matched synovial tissues (n=70) obtained by minimally invasive ultrasound-guided synovial biopsy underwent semi-quantitative scoring (0-4) of immune cell infiltration and classification into lympho-myeloid (LM), diffuse-myeloid (DM) and pauci-immune (PI) pathotypes, as previously described(1). 49 synovial and 36 matched peripheral blood samples underwent RNA-sequencing and were analysed by digital cytometry (Xcell) (4) and Singular Value Decomposition (SVD).

Results:

Circulating B cells and their subsets showed significant inverse correlations with inflammatory markers (ESR, CRP), disease activity (swollen joints, four components and two components(5) DAS28) and ultrasound scores (Fig 1A). Among T cell subsets, CXCR5-PD1hiICOS+CD4+ T cells (T peripheral helper cells, Tph) had strong positive correlations with inflammatory markers (ESR and CRP), disease activity (DAS28) and ultrasound scores (Fig 1B). Tph in the peripheral blood also correlated with immune cell infiltration in synovia (Fig 1C) and were significantly higher in patients with a LM pathotype (Fig 1D). Accordingly, circulating Tph were associated with synovial LM pathotype independently of clinical features such as DAS28, ACPA positivity, Body Mass Index (BMI) and age (AUC 0.821). By applying digital cytometry in matched synovial and peripheral blood samples, synovial B and T cells were significantly higher in patients with a LM pathotype, in line with the histological definition of the LM pathotype – rich in B and T cells. On the contrary, circulating B cells and total CD4 and CD8 T cells were significantly lower in patients with a synovial LM pathotype (Fig 1E). The Tph signature in synovia derived by Singular Value Decomposition (SVD) correlated with baseline ESR (R 0.38, p<0.0001) and DAS28 (R 0.35, p <0.0001) and with delta-DAS28 after 6 months of treatment with conventional synthetic DMARDs (R 0.27, p 0.026). Finally, the baseline synovial Tph signature was significantly higher in patients who progressed to the use of biologics and was predictive of future biologic DMARDs use, independently of baseline DAS28, ACPA positivity, BMI and age (AUC 0.703).

Conclusion:

By combining conventional flow cytometry in the peripheral blood and digital cytometry on matched synovial and peripheral blood samples, we highlight diverging associations of circulating immune cell subsets with synovial inflammation and pathotypes. Tph cells, in particular, emerge as predictors of lympho-myeloid synovial inflammation and disease progression.

References:

[1]F. Humby et al., Ann. Rheum. Dis. 78, 761–772 (2019), doi:10.1136/annrheumdis-2018-214539. [2]M. J. Lewis et al., Cell Rep. 28, 2455-2470.e5 (2019), doi:10.1016/j.celrep.2019.07.091.[3]D. a Rao et al., Nat. Publ. Gr. 542, 110–114 (2017), doi:10.1038/nature20810.[4]D. Aran et al., Genome Biol. 18, 220 (2017), doi:10.1186/s13059-017-1349-1.[5]E. M. A. Hensor et al., Rheumatology. 58, 1400–1409 (2019), doi:10.1093/rheumatology/kez049.

Figure 1.

Acknowledgements:

The Pathobiology of Early Arthritis Cohort (PEAC) was supported by the MRC (grant 36661). Versus Arthritis provided funding infrastructure support (grant 20022). F. Rivellese is funded by an NIHR Transitional Research Fellowship (TRF-2018-11-ST2-002). We would like to thank the patients and the clinical and laboratory team (core team) at Queen Mary University of London.

Disclosure of Interests:

None declared

THU0082 MERTK SYNOVIAL EXPRESSION CORRELATES WITH TREATMENT RESPONSE IN RHEUMATOID ARTHRITIS

Background:

Despite substantial improvements in long-term clinical outcomes, a significant proportion of rheumatoid arthritis (RA) patients still fail to respond to treatment adequately, and early prognostic biomarkers of response are missing. Single-cell transcriptomic studies on RA synovial tissue (ST) have shown that MerTK is highly expressed in “anti-inflammatory” macrophages [1]. It has also been suggested that synovial macrophages isolated from RA patients in remission are characterised by a CD206+/MerTK+ signature [2]. Finally, monocyte-derived macrophages from RA patients treated with TNF-inhibitors (TNF-i) up-regulate MerTK.

Objectives:

To assess i) the modulation of synovial tissue MerTK+ macrophages upon treatment with conventional synthetic (cs) disease-modifying anti-rheumatic drugs (DMARDs) and ii) the relationship between baselineMerTKgene expression and response to TNFi.

Methods:

ST was obtained by US-guided synovial biopsies of an inflamed peripheral joint in patients with early (<12 months) treatment-naïve RA (as per ACR/EULAR 2010 criteria). A second biopsy of the same joint was repeated six months after starting treatment with single or multiple csDMARDs. ST (n=15) was stained for CD68, MerTK and CD206 by immunofluorescence using a tyramide amplification signal system. Quantification of the percentage of single- (MerTK+ or CD206+) and double-positive (CD206+MerTK+) CD68+ macrophages was obtained by digital image analysis (Image J). Gene expression analysis was performed on RNA sequences of 22 baseline ST samples (treatment-naïve).

Results:

Before any treatment intervention, the percentage of MerTK+CD206+ macrophages was significantly higher in RA patients with low (DAS28<3.2) versus high (DAS28>5.1) disease activity (24.5±20.1 versus 4.8±4.8, p<0.05). There were no differences in the relative number of MerTK+ or CD206+ or MerTK+CD206+ macrophages at baseline in relationship with the clinical response to csDMARDs at 6-months. On the other hand, patients (n=5) achieving remission (DAS<2.6) upon receiving csDMARDs significantly increased the number of MerTK+ macrophages from pre- to six-months post-treatment (23.6±23.8 to 55.5±15.4, p<0.05) in comparison with patients (n=5) who were still active after treatment (18±15.6 to 30.4±11.17, p=ns). MerTK synovial gene expression at baseline (i.e., in newly diagnosed treatment-naïve RA patients) was significantly higher in patients subsequently treated with TNFi and achieving a good/moderate EULAR response at 12 months in comparison with those who did not respond (n=14, n=8, p adjusted 0.003).

Conclusion:

Our whole-tissue protein expression data further support the hypothesis that a selective expansion of the MerTK+ macrophage subset characterise patients achieving remission. Moreover, the pre-treatment up-regulation of the MerTK gene in future responders to TNFi suggest that MerTK is implicated in modulating synovial inflammatory responses and may be exploited as a therapeutic target in RA.

References:

[1]F. Zhang et al, Nature Immunology, vol. 20, no. 7, pp. 928–942, 2019.

[2]S. R. Finlay at al, Annals of the Rheumatic Diseases, vol. 77, Supplement 2, pp. 183–183, 2018.

[3]Y. Degboé et al, Frontiers in Immunology, vol. 10, p. 3, 2019.

Acknowledgments:

Versus Arthritis

Disclosure of Interests:

None declared

B Cell Synovitis and Clinical Phenotypes in Rheumatoid Arthritis: Relationship to Disease Stages and Drug Exposure

OBJECTIVE

To define the relationship of synovial B cells to clinical phenotypes at different stages of disease evolution and drug exposure in rheumatoid arthritis (RA).

METHODS

Synovial biopsy specimens and demographic and clinical data were collected from 2 RA cohorts (n = 329), one of patients with untreated early RA (n = 165) and one of patients with established RA with an inadequate response to tumor necrosis factor inhibitors (TNFi-IR; n = 164). Synovial tissue was subjected to hematoxylin and eosin and immunohistochemical staining and semiquantitative assessment for the degree of synovitis (on a scale of 0-9) and of CD20+ B cell infiltrate (on a scale of 0-4). B cell scores were validated by digital image analysis and B cell lineage-specific transcript analysis (RNA-Seq) in the early RA (n = 91) and TNFi-IR (n = 127) cohorts. Semiquantitative CD20 scores were used to classify patients as B cell rich (≥2) or B cell poor (<2).

RESULTS

Semiquantitative B cell scores correlated with digital image analysis quantitative measurements and B cell lineage-specific transcripts. B cell-rich synovitis was present in 35% of patients in the early RA cohort and 47.7% of patients in the TNFi-IR cohort (P = 0.025). B cell-rich patients showed higher levels of disease activity and seropositivity for rheumatoid factor and anti-citrullinated protein antibody in early RA but not in established RA, while significantly higher histologic synovitis scores in B cell-rich patients were demonstrated in both cohorts.

CONCLUSION

We describe a robust semiquantitative histologic B cell score that closely replicates the quantification of B cells by digital or molecular analyses. Our findings indicate an ongoing B cell-rich synovitis, which does not seem to be captured by standard clinimetric assessment, in a larger proportion of patients with established RA than early RA.

Reduction of autophagy and increase in apoptosis correlates with a favorable clinical outcome in patients with rheumatoid arthritis treated with anti-TNF drugs

Background

Autophagy has emerged as a key mechanism in the survival and function of T and B lymphocytes, and its activation was involved in apoptosis resistance in rheumatoid arthritis (RA). To investigate whether the relationship between autophagy and apoptosis may impact the response to the therapy, we analyzed ex vivo spontaneous autophagy and apoptosis in patients with RA subjected to treatment with anti-tumor necrosis factor (TNF) drugs and in vitro the effects of TNFα and anti-TNF drugs on cell fate.

Methods

Peripheral blood mononuclear cells (PBMCs) from 25 RA patients treated with anti-TNF drugs were analyzed for levels of autophagy marker LC3-II by western blot and for the percentage of annexin V-positive apoptotic cells by flow cytometry. The same techniques were used to assess autophagy and apoptosis after in vitro treatment with TNFα and etanercept in both PBMCs and fibroblast-like synoviocytes (FLS) from patients with RA.

Results

PBMCs from patients with RA responsive to treatment showed a significant reduction in LC3-II levels, associated with an increased apoptotic activation after 4 months of therapy with anti-TNF drugs. Additionally, the expression of LC3-II correlated with DAS28. TNFα was able to induce autophagy in a dose-dependent manner after 24 h of culture in RA PBMCs and FLS. Moreover, etanercept caused a significant reduction of autophagy and of levels of citrullinated proteins.

Conclusions

Our results show how the crosstalk between autophagy and apoptosis can sustain the survival of immune cells, thus influencing RA progression. This suggests that inhibition of autophagy represents a possible therapeutic target in RA.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1818-x) contains supplementary material, which is available to authorized users.

Interleukin (IL)-22 receptor 1 is over-expressed in primary Sjogren's syndrome and Sjögren-associated non-Hodgkin lymphomas and is regulated by IL-18

The aim of this study was to elucidate more clearly the role of interleukin (IL)-18 in modulating the IL-22 pathway in primary Sjögren's syndrome (pSS) patients and in pSS-associated lymphomas. Minor salivary glands (MSGs) from patients with pSS and non-specific chronic sialoadenitis (nSCS), parotid glands biopsies from non-Hodgkin lymphomas (NHL) developed in pSS patients, were evaluated for IL-18, IL-22, IL-22 receptor 1 (IL-22R1), IL-22 binding protein (IL-22BP) and signal transducer and activator of transcription-3 (STAT-3) expression. MSGs IL-22R1-expressing cells were characterized by confocal microscopy and flow cytometry in pSS, nSCS and healthy controls . The effect of recombinant IL-18 and IL-22 on peripheral blood mononuclear cells (PBMCs) from pSS and nSCS was studied by flow cytometry and reverse transcription-polymerase chain reaction (RT-PCR). MSGs of pSS and NHL were characterized by an imbalance between IL-22 and IL-22BP protein expression, with IL-18 and IL-22BP being expressed in a mutually exclusive manner and IL-18 and IL-22R1 being correlated directly. Aberrant expression of IL-22R1, induced by IL-18, was observed only among tissue and circulating myeloid cells of pSS patients and macrophages of NHL tissues of pSS patients, but not nSCS. IL-22R1 expression on PBMC of pSS was functional, as its stimulation with recombinant IL-22 significantly up-regulated the expression of STAT-3, IL-17 and IL-22. An IL-18-dependent aberrant expression of IL-22R1 on cells of haematopoietic origin seems to be a specific immunological signature of patients with pSS and pSS-associated lymphomas.

Dysregulation of the suppressor of cytokine signalling 3-signal transducer and activator of transcription-3 pathway in the aetiopathogenesis of Sjögren's syndrome

The suppressor of cytokine signalling 3 (SOCS3) negatively regulates the Janus kinase (JAK)/signal transducer and activator of transcription-3 (STAT-3)/interleukin (IL)-17 pathway. The proinflammatory cytokine IL-17 is over-expressed in Sjögren's syndrome (SS) and is a key factor in its pathogenesis. We hypothesized that IL-17 over-expression in SS results from ineffective regulation by SOCS3. The expression of SOCS3 was analysed in peripheral blood mononuclear cells (PBMC) from SS cases, sicca controls (SC) and healthy controls (HC) and tissue samples from SS, SC and healthy salivary glands (HSG). PBMC and salivary gland tissue from SS and controls were dual-immunostained for SOCS3 and IL-17. IL-6-stimulated PBMC from SS and controls were evaluated for time-dependent STAT-3 activation and SOCS3 induction, and for IL-17 expression. Immunoblotting revealed greater levels of SOCS3 in PBMC from SS than SC (P = 0·017) or HC (P < 0·001). Similarly, the proportion of salivary-gland tissue cells staining for SOCS3 was significantly higher in SS than SC (P = 0·029) or HSG (P = 0·021). The cells in PBMC/salivary gland samples from controls predominantly expressed either SOCS3 or IL-17. However, there was a high frequency of SOCS3/IL-17 co-expression within cells of SS samples. IL-6-stimulation of PBMC from SS cases revealed prolonged activation of STAT-3 with reduced negative regulation by SOCS3, and enhanced expression of IL-17. This study showed that SOCS3 expression is up-regulated in SS. However, the absence in SS of the normal inverse relationship between SOCS3 and pSTAT-3/IL-17 indicates a functional disturbance in this signalling cascade. Consequently, a reduction in function, rather than a reduction in expression of SOCS3 accounts for the unregulated expression of IL-17 in SS, and may play a crucial role in aetiopathogenesis.

Cardiovascular risk factors in women with primary Sjögren's syndrome: United Kingdom primary Sjögren's syndrome registry results

Objective

To determine the prevalence of traditional cardiovascular risk factors using established definitions in a large cohort of clinically well-characterized primary Sjögren's syndrome (SS) patients and to compare them to healthy controls.

Methods

Data on cardiovascular risk factors in primary SS patients and controls were collected prospectively using a standardized pro forma. Cardiovascular risk factors were defined according to established definitions. The prevalence of cardiovascular risk factors in the primary SS group was determined and compared to that in the control group.

Results

Primary SS patients had a higher prevalence of hypertension (28–50% versus 15.5–25.6%; P < 0.01) and hypertriglyceridemia (21% versus 9.5%; P = 0.002) than age- and sex-matched healthy controls. Furthermore, a significant percentage (56%) of hypertensive patients expected to be on antihypertensive treatment according to best practice was not receiving it.

Conclusion

Primary SS patients are more than 2 times more likely to experience hypertension and hypertriglyceridemia than age- and sex-matched healthy controls. Additionally, hypertension is underdiagnosed and suboptimally treated in primary SS.

Ultrasound-guided synovial biopsy: a safe, well-tolerated and reliable technique for obtaining high-quality synovial tissue from both large and small joints in early arthritis patients

OBJECTIVE

To determine the tolerability, safety and yield of synovial tissue in an early arthritis cohort using a minimally invasive, ultrasound (US)-guided, synovial biopsy technique in small, medium and large joints.

METHODS

93 sequential biopsy procedures were assessed from a total of 57 patients (baseline and 36 repeat biopsies at 6 months) recruited as part of the 'Pathobiology of Early Arthritis Cohort' study. Patients completed a tolerability questionnaire prior to and following the synovial biopsy procedure. The synovial biopsy was performed under US guidance with US images of the joint recorded prior to each procedure. Synovial tissue was harvested for immunohistochemistry and RNA extraction.

RESULTS

Five different joint sites were biopsied (knee, elbow, wrist, metacarpal phalangeal and proximal interphalangeal). No significant complications were reported following the procedure. No difference in pain, swelling and stiffness of the biopsied joint from before and after the procedure was demonstrated. A median of 14 biopsy samples was retrieved from each procedure with 93% of biopsy procedures yielding good quality tissue. RNA yield was good in all joints and in repeat biopsies. Multivariant analysis demonstrated a significantly greater yield of RNA and graded tissue in relation to a high prebiopsy, grey-scale synovitis score (0-3, semiquantitative).

CONCLUSIONS

A minimally invasive approach to synovial tissue harvesting, using US guidance, is both safe and well-tolerated by patients. Tissue quality/RNA yield is preserved in subsequent biopsies following therapeutic intervention. A high US grey-scale synovitis score is a predictor of good quality/quantity of tissue and RNA.