M van de Sande

Features of the Synovium of Individuals at Risk of Developing Rheumatoid Arthritis: Implications for Understanding Preclinical Rheumatoid Arthritis

Findings from previous studies have suggested that subclinical inflammation of the synovium does not coincide with the appearance of rheumatoid arthritis (RA)–specific autoantibodies. This study was undertaken to examine the relationship between the presence of autoantibodies, changes in the synovium, and development of arthritis over time in a markedly larger, prospective study.

The role of chemokines in rheumatoid arthritis and osteoarthritis

The directed movement of immune cells is highly dependent on the chemokine network. Chemokines are key molecules early in the embryogenesis of lymph nodes and throughout adult life, where they regulate immune responses against pathogens. Although immune cells are best known for expressing chemokine receptors, through which they can respond to matching chemokines, endothelial cells also express chemokine receptors. The directed movement of endothelial cells facilitates angiogenesis. In chronic inflammatory conditions, such as rheumatoid arthritis (RA), chemokines are abundantly present at the site of inflammation and form a group of potential therapeutic targets. Some agents that block chemokine–chemokine receptor interaction are already under clinical investigation. The expression of chemokine receptors has also been found in cell types other than immune cells and endothelial cells. Chondrocytes, for instance, express several chemokine receptors. Elucidating their function may provide new insights into joint degradation in RA as well as in other conditions, including osteoarthritis (OA).

Inflamed target tissue provides a specific niche for highly expanded T-cell clones in early human autoimmune disease

Objective To profile quantitatively the T-cell repertoire in multiple joints and peripheral blood of patients with recent onset (early) or established rheumatoid arthritis (RA) using a novel next-generation sequencing protocol to identify potential autoreactive clones. Methods Synovium of patients with recent onset (early) RA (<6 months) (n=6) or established RA (>18 months) (n=6) was screened for T-cell clones by sequencing over 10 000 T-cell receptors (TCR) per sample. T cells from paired blood samples were analysed for comparison. From two patients synovial T cells were obtained from multiple inflamed joints. The degree of expansion of each individual clone was based on its unique CDR3 sequence frequency within a sample. Clones with a frequency of over 0.5% were considered to be highly expanded clones (HEC). Results In early RA synovium, the T-cell repertoire was dominated by 35 HEC (median, range 2–70) accounting for 56% of the TCR sequenced. The clonal dominance in the synovium was patient specific and significantly greater than in established RA (median of 11 HEC (range 5–24) in established RA synovium accounting for 9.8% of T cells; p<0.01). 34% (range 28–40%) of the most expanded T-cell clones were shared between different joints in the same patients, compared with only 4% (range 0–8%) between synovium and blood (p=0.01). Conclusions In RA, a systemic autoimmune disease, the inflamed synovium forms a niche for specific expanded T-cell clones, especially in early disease. This suggests that, at least in RA, autoreactive T cells should be addressed specifically in the inflamed tissue, preferably in the early phase of the disease.

The clinical picture of rheumatoid arthritis according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria: Is this still the same disease?

OBJECTIVE To examine the implications of using the new classification criteria for rheumatoid arthritis (RA) in clinical practice in a cohort of patients with very early arthritis. METHODS The study group comprised 301 disease-modifying antirheumatic drug-naive patients with early arthritis. The baseline diagnosis was assessed by applying the 1987 American College of Rheumatology (ACR) and 2010 ACR/European League Against Rheumatism (EULAR) criteria for RA as well as established diagnostic criteria for other rheumatic diseases. Diagnostic and prognostic data were collected after 2 years of followup. Fulfillment of the 2010 ACR/EULAR criteria was evaluated in the subset of patients in whom undifferentiated arthritis (UA) was diagnosed when the 1987 ACR criteria were applied, and fulfillment of RA criteria over time was tested by applying the 2 different criteria sets. RESULTS The median arthritis duration at baseline was 4 months (range 0-12 months). At baseline, 28% of the patients fulfilled the 1987 ACR criteria, and 45% fulfilled the 2010 ACR/EULAR criteria for RA. Among the patients classified as having UA at baseline according to the 1987 ACR criteria, 36% had fulfilled the 2010 ACR/EULAR criteria already at baseline. Among the patients classified as having UA at baseline but who fulfilled the 1987 ACR criteria after 2 years of followup, 85% had fulfilled the 2010 ACR/EULAR criteria at baseline. Patients with early disease who fulfilled the 2010 ACR/EULAR criteria were less likely to be autoantibody positive and more likely to have monarthritis at presentation than those fulfilling the 1987 ACR criteria. CONCLUSION Use of the 2010 ACR/EULAR criteria clearly allows earlier diagnosis of RA, although the clinical picture is slightly different on the group level, and RA may be falsely diagnosed in some patients with self-limiting disease.

Investigating the cellular composition of lymph nodes in preclinical and early inflammatory arthritis: a feasibility study

Backgroundand objectives Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease of unknown aetiology. To ultimately cure or prevent this chronic disease, it is critical to understand the earliest changes in the immune system that cause RA. Recent work has shown that systemic autoimmunity precedes inflammation in the synovium of RA patients. Animal models have suggested that changes in the lymph nodes may precede those in the synovial tissue. To provide insight into the immunological mechanisms involved in the pathogenesis of RA, the authors developed a method to obtain lymph node biopsies under local anaesthesia and investigated the lymph node cellular composition and distribution in individuals at risk of developing RA, early arthritis patients and healthy controls. Materials and methods Six individuals without any evidence of arthritis upon physical examination who were positive for IgM rheumatoid factor and/or anticitrullinated protein antibodies were included. For comparison 12 early arthritis patients (1× systemic lupus erythematosus, 1× psoriatic arthritis, 1× gout, 5× undifferentiated arthritis and 4× RA; disease duration <1 year, disease-modifying antirheumatic drug naïve), and four autoantibody negative healthy controls without joint complaints were included in the study. All study subjects underwent ultrasound-guided inguinal lymph node biopsy. Different T lymphocyte subsets were analysed by multi-colour flow cytometry using labelled antibodies specific for CD3, CD4, CD8, CD45 and CD69. Results The procedure was well tolerated; no complications occurred. Different T cell subsets could be distinguished and differences between autoantibody positive individuals at risk of developing RA, early arthritis patients and healthy controls could be observed. Interim analysis indicate an increase of activated CD69+ T cells in the early arthritis as well as in the at risk group compared to the control group. Interestingly, the CD4/CD8 distribution within the activated T cells was significantly changed in the early arthritis patients compared to healthy controls and the same trend was observed for the at risk group. Conclusions Flow cytometry analysis of ultrasound-guided inguinal lymph node biopsies is a feasible method for investigating the cellular composition of lymph nodes in the earliest phases of inflammatory arthritis. These preliminary results suggest increased CD8+ T cell activation within lymph nodes of early arthritis patients as well as in autoantibody positive individuals at risk of developing RA. This method provides a unique tool to investigate the immunological changes in the lymph node compartment in the earliest phases of inflammatory arthritis. These data support the rationale for larger studies using more extensive panels of cellular markers.

FRI0150 Mtor blockade by rapamycin decreases arthritis and spondylitis development and severity in hla-b27 transgenic rats

Background HLA-B27 misfolding is thought to play an important role in the pathogenesis of spondyloarthritis (SpA), possibly through triggering of ER stress and the unfolded protein response. One of the mechanisms that regulates the unfolded protein response is autophagy. Autophagy is a process that degrades proteins, cytoplasmic particles and organelles in lysosomes and is regulated by protein kinases, mechanistic target of rapamycin (mTOR) and AMP activated protein kinase. Objectives To study whether blockade of mTOR will affect spondyloarthritis development and/or severity in the Mycobacterium tuberculosis (M. tub) induced disease HLA-B27 tg rat model. Methods 6 weeks old, female or orchiectomized male HLA-B27/Huβ2m transgenic rats were immunised with 60–90 µg heat-inactivated M. tub in IFA. Rats were prophylactically or therapeutically treated three times a week intra-peritoneally with 1.5 mg/kg rapamycin or vehicle. Clinical measurements included weight, clinical scores for spondylitis and arthritis, and hind paw swelling measured by plethysmometry. After 5 weeks of treatment rats were sacrificed; axial and peripheral joints were isolated for histology and metacarpophalangeal joints, spleen and lymph nodes were isolated for RNA isolation. Results In the prophylactic experiment 72.7% (8/11) and 18.2% (2/11) rapamycin treated rats developed arthritis and spondylitis compared to respectively 100% (13/13; p=0.0225) and 92.3% (12/13; p<0.0001) control animals. Also severity of arthritis and spondylitis was significantly decreased in rapamycin treated animals compared to control treated animals; mean arthritis severity of diseased rats was respectively 0.45 versus 7.15 on a scale from 0–12 (p<0.0001) and mean spondylitis severity was respectively 0.18 versus 2.07 on a scale from 0–3 (p<0.0001). Clinical findings were confirmed by histology with a significant decrease of inflammation (p<0.0001), bone- and cartilage destruction (p=0.0021) and new bone formation (p=0.0010) in peripheral joints of rapamycin treated rats compared to vehicle treated rats and a similar trend was observed in spinal joints. Also in a therapeutic setting rapamycin treatment decreased arthritis severity (mean score of 6 compared to 8.8 in controls; p=0.0317) and spondylitis severity (mean score of 1.23 compared to 2.8 in controls; p=0.0159). Histology for the therapeutic experiment is currently being performed as well as RNA analyses for autophagy genes and pro-inflammatory cytokines, like IL-17A and TNF. Conclusions mTOR blockade significantly suppressed arthritis and spondylitis in the M. tub induced disease HLA-B27 transgenic rat model of SpA. Disclosure of Interest S. Chen: None declared, M. van Tok: None declared, D. Pots: None declared, J. Taurog: None declared, M. van de Sande: None declared, D. Baeten Employee of: UCB Pharma, L. van Duivenvoorde: None declared

THU0317 Creating a european database of psoriatic arthritis patients treated in routine care – first, preliminary results from the eurospa research network collaboration

Background A research network collaboration of 15 European registries collecting data on patients with spondyloarthitis (SpA), “EuroSpA”, has recently been created to strengthen research capabilities in the real world setting1. Here we present initial findings from the collaboration. Objectives To investigate the feasibility of creating a common database within the EuroSpA collaboration and to conduct proof-of-concept analyses by investigation of baseline characteristics, disease activity at baseline and after 6 months and 12 months’ TNFi retention rate in patients with psoriatic arthritis (PsA) initiating Tumour Necrosis Factor inhibitors (TNFi). Methods A common data model for PsA was agreed upon by the EuroSpA Scientific Committee. Virtual meetings between the EuroSpA and registry data managers clarified data availability and structure. This was followed by upload of anonymized data through the secure Virtual Private Network pipelines to the EuroSpA server. Baseline characteristics and disease activity at baseline and after 6 months were investigated with non-parametric descriptive statistics. Kaplan-Meier estimation was used to investigate TNFi retention rates. Results : By January 8th 2018, four of the 15 registries participating in EuroSpA had completed data upload to the EuroSpA database resulting in 3172 patients with PsA in a pooled dataset. Baseline characteristics of the participating registry populations at initiation of first TNFi are shown in table 1. Crude 12 month TNFi retention rates varied from 65%–80% for 1st TNFi and 57%–82% for 2nd TNFi (see figure 1). For the pooled dataset crude 12 months TNFi retention rates were 68% and 60% for the 1st and 2nd TNFi, respectively.Abstract THU0317 – Table 1 Baseline demographic and disease characteristics of patients with PsA registered in four EuroSpA registries Conclusions Preliminary analyses showed differences across European registries regarding baseline characteristics and crude retention rates in PsA patients initiating TNFi. These initial, preliminary analyses demonstrate that the creation of a large European database of PsA patients treated in routine care based on a common data model is feasible, offering important opportunities for future research. Reference [1] Ann Rheum Dis2017;2:65. Acknowledgements The authors acknowledge Novartis Pharmaceuticals AG for financial support and Natasha Pillai and Carol Lines from QuintilesIMS and Craig Richardson from Novartis Pharmaceuticals AG for their assistance in setting up the EuroSpA collaboration. Disclosure of Interest L. Ørnbjerg: None declared, M. Østergaard: None declared, F. Onen: None declared, M. Birlik: None declared, Z. Rotar: None declared, M. Tomsic Consultant for: AbbVie, Eli Lilly, Johnson and Johnson, Medis, MSD, Novartis, Pfizer and Roche, B. Gudbjornsson: None declared, T. Love: None declared, M. J. Nissen: None declared, A. Ciurea: None declared, D. Nordström Consultant for: AbbVie, Celgene, BMS, Lilly, MSD, Novartis, Pfizer, UCB, N. Trokovic: None declared, M. Santos: None declared, A. Barcelos: None declared, E. Kristianslund: None declared, T. Kvien Grant/research support from: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Epirus, Hospira, Merck-Serono, MSD, Mundipharma, Novartis, Orion Pharma, Hospira/Pfizer, Sandoz, UCB, C. Codreanu: None declared, E.-M. Hauge: None declared, J. Askling: None declared, F. Iannone: None declared, H. Mann: None declared, M. V. Hernandez: None declared, G. Macfarlane: None declared, M. van de Sande: None declared, L. H. Hyldstrup: None declared, N. S. Krogh: None declared, M. Hetland Grant/research support from: AbbVie, Biogen, BMS, CellTrion, MSD, Orion, Pfizer, Samsung, UCB

OP0172 Expanded t-cell clones present in synovium at onset of rheumatoid arthritis are already present in the synovium in the seropositive “at risk” stage

Background T-cells are thought to be key players in the initiation and progression of rheumatoid arthritis (RA). Earlier we showed that already at the seropositive “at risk” stage uninflamed synovial tissue contains T-cell infiltrates1. In another study we showed that inflamed synovium selectively harbours expanded T-cell clones that are hardly present in paired blood samples2. Objectives Following up on these observations, we longitudinally investigated whether the same expanded T-cell clones found in the inflamed synovial tissue at onset of RA are already present in the synovium in the seropositive “at risk” stage. Methods Fifty-five individuals without arthritis but seropositive for IgM rheumatoid factor and/or anti-citrullinated protein antibody (ACPA) were prospectively followed. In five aCCP+ individuals synovial biopsies and paired blood samples at inclusion (“at risk” stage) and after development of RA (ACR2010 criteria; mean time to arthritis 27 months (range 11.7–47.3)) were available for analysis. T-cell clones were identified by their unique TCRβ sequence using RNA-based next generation sequencing3. For each sample, 3570 TCRβ sequences were analysed. Clones with a frequency of ≥0.5% were arbitrarily considered as highly expanded clones (HECs). ANOVA and t-test were used for statistical analysis. Results T-cell repertoires in “at risk” and RA synovium were similar (mean (± SD) number of clones 488±70 vs 567±204 respectively, p=0.46), number of HECs (37±7 vs 31±18, p=0.41) and the impact of HECs collectively on the TCR repertoire (mean 48% ± 13% vs 50% ± 20%, p=0.84). Interestingly, of the HECs present in the synovium at onset of arthritis 23% (±9%) were already present as HECs in the synovium at the seropositive “at risk” stage. This overlap was significantly higher than that with paired blood samples taken at the arthritis (3% ± 3%; p=0.01) or at the seropositive “at risk” stage (5% ± 7%; p=0.01; Figure 1a-c patient example; Figure 1d summary of results). Further characterization of the synovial CDR3 sequences (length, total charge, polar, aromatic and aliphatic side chains) showed no significant differences between RA HECs that were and those that were not expanded in the seropositive “at risk” stage. Conclusions Many T-cell clones found in early RA synovial tissue are already present in the pre-clinical “at risk” phase. The resemblance in TCR repertoires indicates that the process leading to disease – at least at the T-cell level – constitutes a smooth development. These clones, being already present in the very early stage of this disease and persisting as dominant clones during contraction of active arthritis, form attractive candidates for further characterization. References de Hair MJ et al. Arthritis Rheum. 2014. Klarenbeek PL et al. Ann Rheum Dis. 2012. Klarenbeek PL et al. Immunol Lett. 2010. Disclosure of Interest None declared

AB0114 Effects of ANTI-IL17A blockade with secukinumab on systemic and local immune responses: a mechanism-of-action study in peripheral spondyloarthritis

Background IL-17A blockade is an effective therapy for ankylosing spondylitis (AS) and psoriatic arthritis (PsA), the two prototypical forms of spondyloarthritis (SpA). How IL-17A blockade affects the systemic and local immune responses in SpA remains incompletely understood. Objectives To assess the effect of anti-IL17A treatment with secukinumab on the systemic cytokine responses and the synovial immunopathology in SpA patients with peripheral disease (pSpA). Methods 20 active SpA patients were included in a 12wk open-label trial followed by 2yrs non-investigational extension. All patients received secukinumab 300mg/wk from baseline to wk4 and then every 4wks. Clinical response was measured 4wkly. TruCulture tubes with SEB and zymosan were drawn at baseline, day3, and wk12. Synovial biopsies were obtained by needle arthroscopy at baseline and wk12, analyzed by immunohistochemistry (IHC) and qPCR. Results The 20 pSpA patients consisted of 13 PsA, 3 undifferentiated SpA, 2 AS with peripheral arthritis, 1 reactive arthritis and 1 IBD associated pSpA. There were no SAEs in the 12wk core study. However, two SAEs occurred in the extension of the study: tonsillitis (suspected to be related to study drug) and myocardial infarction (non related), both fully recovered. Secukinumab induced a rapid and highly significant improvement in SJC (Baseline: 2,5 [IQR1–4] vs wk12: 0,5 [IQR0–1]p=0.001), TJC (6 [2–8] vs 0,5 [0–3]p<0.001); VASptglobal (46 [28–65] vs 13 [6–24]p<0.001). 18/20patients reached EULAR DAS response at wk 12 (10 good and 8 moderate responders). This was paralleled by significant improvements in other activity outcomes such as BASDAI (53 [25–63] vs 20 [9–40]p=0.001) and PASI (5,7 [4,5–7,1] vs 0,6 [0,1–1,8]p=0.001). Systemic inflammatory response revealed a decrease in CRP (3,85 [1,35–16,6] vs 2 [1,15–6,3]p=0,001) and ESR (16 [6–35] vs 6 [2,8–16,3]p=0,001), which was associated with decreased production of MMP-3, a validated biomarker of inflammation in pSpA,1 by peripheral blood cells in the TruCulture system (see figure). With exception of a decrease in IL-17A, the TruCulture system did not reveal any impact of secukinumab on the capacity of peripheral blood cells to produce a broad panel of cytokines and chemokines upon stimulation. In contrast with this preserved systemic immune response, IHC confirmed the positive impact of 12wks of secukinumab on peripheral joint immunopathology as reflected by a significant decrease of infiltration of the synovial sublining with macrophages (2 [1–3] vs 1,5 [1–2]p=0.028) and neutrophils (1 [0,5–3,5] vs 0 [0–1]p=0.004), sensitive synovial biomarkers of treatment response in pSpA.2 mRNA analysis of synovial biopsies before and after 12wks of secukimumab shows a decrease in IL-17A but not TNF expression. Conclusions This mechanism-of-action study indicates that IL-17A blockade with secukinumab has a profound beneficial clinical and biological impact on pSpA without compromising systemic immune responses. Further gene expression analysis will delineate which inflammatory pathways are blocked by secukinumab in the diseased target tissue. References van Dooren, Arthritis & Rheumatism, 2004. Kruithof, Arthritis & Rheumatism, 2005. Disclosure of Interest L. Van Mens: None declared, M. van de Sande Speakers bureau: Benecke, Takeda, Tillots, MSD, Cellgene, S. Menegatti: None declared, I. Blijdorp: None declared, H. de Jong: None declared, I. Fluri: None declared, T. Latuhihin: None declared, A. van Kuijk Grant/research support from: UCB, Pfizer, MSD, Janssen, Consultant for: Novartis, Celgene, N. Yeremenko: None declared, D. Baeten Grant/research support from: Pfizer, MSD, AbbVie, UCB, Novartis, Janssen, Boehringer Ingelheim, Consultant for: Pfizer, MSD, AbbVie, UCB, Novartis, Janssen, Boehringer Ingelheim, Eli Lilly, Roche, BMS, Glenmark, This study was funded by an unrestricted grant from Novartis, Employee of: UCB

FRI0475 ANTI-CD74 antibodies as diagnostic biomarker for early axial spondyloarthritis: data from the spondyloarthritis caught early (SPACE) cohort study

Background Diagnosis of axSpA is often delayed with 5–10 years. A robust biological disease marker is lacking and could decrease the current diagnostic delay. Two studies showed that serum anti-CD74 IgG antibodies are increased in SpA1,2. Objectives To explore the value of anti-CD74 antibodies as diagnostic biomarker for axSpA in patients with early, chronic back pain. Methods We tested the prevalence of anti-CD74 IgG and IgA antibodies in patients from the SPondyloArthritis Caught Early (SPACE) cohort by enzyme-linked immunosorbent assay (ELISA). Patients from the SPACE cohort have chronic back pain for >3 months and ≤2 years with an onset <45 years. Results We included 560 patients of the SPACE cohort, of whom 274 patients were diagnosed with axSpA by a rheumatologist at baseline. Anti-CD74 IgG levels did not differ between patients with and without axSpA (p=0.152, Table 1). Median anti-CD74 IgA levels (tested with either casein or BSA as a blocking buffer) were higher in patients with axSpA (both p<0.0001). Despite these differences at the group level, the diagnostic value of the anti-CD74 IgA antibodies was limited as shown by ROC analysis. The optimal cut off according to ROC analysis was an optical density (OD) of 0.875, providing a sensitivity of 38.3% and a specificity of 77.6%. In line with previous reports, further analysis revealed that total IgA levels were elevated in early axSpA patients vs. non-SpA early back pain patients (p=0.008). When correcting the level of anti-CD74 IgA for the level of total IgA, the differentiating capacity of anti-CD74 disappeared for casein but remained intact for BSA (casein: p=0.731, BSA: p=0.038). Additional analyses using the ASAS classification criteria rather than a clinical diagnosis of axSpA, a strict combination of clinical diagnosis and ASAS classification criteria (excluding patients fulfilling the ASAS axSpA criteria without a clinical diagnosis and vice versa) (Table 1) and using the clinical diagnosis at 1 year of follow-up yielded similar results. Conclusions Serum anti-CD74 IgA antibody levels, but not serum anti-CD74 IgG levels, are elevated in patients with axSpA versus non-SpA with back pain of <2 years duration. However, ROC analyses revealed that these numerical differences are of limited diagnostic value in these patients with early back pain. References Baraliakos, X. et al. High prevalence of anti-CD74 antibodies specific for the HLA class II-associated invariant chain peptide (CLIP) in patients with axial spondyloarthritis. Ann. Rheum. Dis. 1–5 (2013). Baerlecken, N. T. et al. Autoantibodies against CD74 in spondyloarthritis. Ann. Rheum. Dis. 73, 1211–4 (2014). Disclosure of Interest J. de Winter: None declared, M. van de Sande Grant/research support from: Novartis, Eli Lilly, Boehringer Ingelheim, Benecke, Takeda, Tillotts, MSD, Cellgene, N. Baerlecken: None declared, I. Berg: None declared, R. Ramonda: None declared, D. van der Heijde: None declared, F. van Gaalen: None declared, T. Witte: None declared, D. Baeten Grant/research support from: Pfizer, MSD, AbbVie, UCB, Novartis, Janssen, Boehringer Ingelheim., Consultant for: Pfizer, MSD, AbbVie, UCB, Novartis, Janssen, Boehringer Ingelheim, Eli Lilly, Roche, BMS, Glenmark, Employee of: UCB