Laura Hunt

Autoantibodies to posttranslational modifications in rheumatoid arthritis.

Autoantibodies have been associated with human pathologies for a long time, particularly with autoimmune diseases (AIDs). Rheumatoid factor (RF) is known since the late 1930s to be associated with rheumatoid arthritis (RA). The discovery of anticitrullinated protein antibodies in the last century has changed this and other posttranslational modifications (PTM) relevant to RA have since been described. Such PTM introduce neoepitopes in proteins that can generate novel autoantibody specificities. The recent recognition of these novel specificities in RA provides a unique opportunity to understand human B-cell development in vivo. In this paper, we will review the three of the main classes of PTMs already associated with RA: citrullination, carbamylation, and oxidation. With the advancement of research methodologies it should be expected that other autoantibodies against PTM proteins could be discovered in patients with autoimmune diseases. Many of such autoantibodies may provide significant biomarker potential.

Ultrasound findings predict progression to inflammatory arthritis in anti-CCP antibody-positive patients without clinical synovitis

Objectives To determine whether ultrasound can identify anti-cyclic citrullinated peptide (anti-CCP) antibody-positive patients without clinical synovitis (CS) who progress to inflammatory arthritis (IA). Methods In a prospective study, anti-CCP-positive patients without CS underwent ultrasound imaging of 32 joints (wrists, metacarpophalangeal joints, proximal interphalangeal joints and metatarsophalangeal joints (MTPs)) and were monitored for the development of IA. Associations between baseline ultrasound findings (grey scale (GS), power Doppler (PD) and erosions) and (1) progression to IA and (2) development of CS within an individual joint were measured. Results Consecutive anti-CCP-positive patients (n=136; mean age 51 years, 100 women) were followed up for median of 18.3 months (range 0.1–79.6). At baseline 96% had GS, 30% had PD and 21% had one or more erosions. IA developed in 57 patients (42%) after median of 8.6 months (range 0.1–52.4). Ultrasound abnormalities (GS ≥2, PD ≥1 or erosion ≥1) were found in 86% at baseline compared with 67% of non-progressors (χ2=6.3, p=0.012). Progression to IA was significantly higher in those with ultrasound findings in any joint (excluding MTPs for GS) (GS ≥2: 55% vs 24%, HR (95% CI) 2.3 (1.0 to 4.9), p=0.038; PD ≥2: 75% vs 32%, 3.7 (2.0 to 6.9), p<0.001 and erosion ≥1: 71% vs 34%, 2.9 (1.7 to 5.1), p<0.001). Furthermore, progression occurred earlier with PD ≥2 (median 7.1 vs 52.4 months) and erosion ≥1 (15.4 vs 46.5). At the individual joint level, the trend for progression to CS was more significant for GS and PD (GS ≥2: 26% vs 3%, 9.4 (5.1 to 17.5), p<0.001; PD ≥2: 55% vs 4%, 31.3 (15.6 to 62.9), p<0.001). Conclusion Ultrasound features of joint inflammation may be detected in anti-CCP-positive patients without CS. Ultrasound findings predict progression (and rate of progression) to IA, with the risk of progression highest in those with PD signal. Trial registration number NCT02012764; Results.

Enriching case selection for imminent RA: the use of anti-CCP antibodies in individuals with new non-specific musculoskeletal symptoms – a cohort study

Objectives Around 1% of the population test positive for anti-cyclic citrullinated peptide (anti-CCP) antibodies. This biomarker predicts the progression to rheumatoid arthritis (RA) but over a variable time frame. To increase its clinical relevance, this study sought to determine (1) if the proportion of anti-CCP-positive individuals could be enriched by case selection of people attending primary care with new non-specific musculoskeletal (MSK) symptoms but without clinical synovitis (CS) and (2) whether these individuals progress rapidly to inflammatory arthritis (IA), in particular RA. Methods In this prospective cohort study, individuals aged ≥18 years with new non-specific MSK symptoms, without CS, were recruited from primary care in the UK. Anti-CCP-positive individuals were invited for follow-up in the rheumatology department, Leeds. Those who tested negative were sent questionnaires 12 months later. Results 2028 individuals were recruited. Of these, 2.8% (57/2028) were anti-CCP positive, of whom 47% (27/57) developed IA – 24 RA, 1 undifferentiated IA (UIA), 2 polymyositis; 92.6% (25/27) within 12 months, median 1.8 months (IQR 1.0–4.3, range 0.3–16.1). Of the anti-CCP-negative individuals, 1.3% (20/1559) developed IA (1 UIA, 13 RA, 6 psoriatic arthritis); 75% (15/20) within 12 months. The relative risk for developing RA within 12 months in the anti-CCP-positive group was 66.8 (95% CI 32.2 to 138.4, p<0.001); for IA, it was 45.5 (95% CI 25.4 to 81.6, p<0.001). Conclusions Selecting individuals with new non-specific MSK symptoms without CS enriched the prevalence of anti-CCP positivity to 2.8%. Those who tested positive had a high risk of rapidly developing RA. The cost-effectiveness of this approach will need to be determined. Trial registration number NCT02012764.

T cell subsets: an immunological biomarker to predict progression to clinical arthritis in ACPA-positive individuals

Objectives Anticitrullinated protein antibody (ACPA)+ individuals with non-specific musculoskeletal symptoms are at risk of inflammatory arthritis (IA). This study aims to demonstrate the predictive value of T cell subset quantification for progression towards IA and compare it with previously identified clinical predictors of progression. Methods 103 ACPA+ individuals without clinical synovitis were observed 3-monthly for 12 months and then as clinically indicated. The end point was the development of IA. Naïve, regulatory T cells (Treg) and inflammation related cells (IRCs) were quantified by flow cytometry. Areas under the ROC curve (AUC) were calculated. Adjusted logistic regressions and Cox proportional hazards models for time to progression to IA were constructed. Results Compared with healthy controls (age adjusted where appropriate), ACPA+ individuals demonstrated reduced naïve (22.1% of subjects) and Treg (35.8%) frequencies and elevated IRC (29.5%). Of the 103 subjects, 48(46.6%) progressed. Individually, T cell subsets were weakly predictive (AUC between 0.63 and 0.66), although the presence of 2 T cell abnormalities had high specificity. Three models were compared: model-1 used T cell subsets only, model-2 used previously published clinical parameters, model-3 combined clinical data and T cell data. Model-3 performed the best (AUC 0.79 (95% CI 0.70 to 0.89)) compared with model-1 (0.75 (0.65 to 0.86)) and particularly with model-2 (0.62 (0.54 to 0.76)) demonstrating the added value of T cell subsets. Time to progression differed significantly between high-risk, moderate-risk and low-risk groups from model-3 (p=0.001, median 15.4 months, 25.8 months and 63.4 months, respectively). Conclusions T cell subset dysregulation in ACPA+ individuals predates the onset of IA, predicts the risk and faster progression to IA, with added value over previously published clinical predictors of progression.

Etanercept in the treatment of rheumatoid arthritis

Introduction: Biologic agents have transformed clinical outcomes in rheumatoid arthritis, and there are now several immune-modulating therapies available. Tumour necrosis factor-α (TNF-α) inhibitors were the first biologic drug class licensed for the treatment of rheumatoid arthritis. Etanercept is a fusion protein composed of two TNF receptors bound to the constant portion (Fc) of human immunoglobulin G (IgG). Areas covered: This article will consider the pharmacological properties of etanercept and the clinical efficacy data presented in clinical trials. Its safety in clinical practice will be reviewed. Expert opinion: There is overwhelming evidence to support the use of etanercept in rheumatoid arthritis. Trial data demonstrate etanercepts efficacy in reducing structural damage, improving clinical outcomes and inducing remission. Optimal response to therapy is seen when used in combination with methotrexate and when initiated early. Etanercept is an attractive therapeutic option given the excellent safety profile, reduced immunogenicity and ease of administration.

Emergence of proinflammatory autoreactive T-cell responses in preclinical rheumatoid arthritis

Abstract Background 5 million people suffer from rheumatoid arthritis (RA) and every year 25 000 people will develop this disease in the UK. In an emerging model, the pathogenesis of RA can be understood as a development of sequential phases that precede clinically apparent disease. Autoimmunity with anti-immunoglobulin G rheumatoid factors (RF) and anti-citrullinated protein antibodies (ACPA) can be detected in the blood up to 13 years before onset of clinical synovitis (joint swelling). Regulatory T cells (Tregs) are an important component of the immune system that dampen and limit damage caused by excessive immune activity, and their dysfunction is found in RA. We aimed to identify autoreactive T cells to a known RA-associated antigen and to determine whether the quality of the response (regulatory vs inflammatory) is associated with health, preclinical RA, and RA. Methods 41 patients were recruited from studies in the Division of Rheumatic & Musculoskeletal Disease, University of Leeds. 21 patients had preclinical RA (ACPA-positive with arthralgia but no evidence of clinical synovitis) and 20 had RA (ACPA-positive RA). Healthy volunteers (19 employees of the University of Leeds and Leeds Teaching Hospitals Trust) were controls. We measured T-cell responses to the RA-associated autoantigen, citrullinated vimentin (CitVim): peripheral blood mononuclear cells were incubated with peptide pools covering the entire sequence of CitVim for 72 h. Interleukin (IL) 10 (regulatory) and interferon (IFN) γ (inflammatory) responses were measured by ELISPOT. The study has ethics approval from the Leeds (West) Research Ethics (references 06/Q1205/169 and 04/Q1206/107). Findings Autoreactive T-cell reactivity was detected in healthy controls, preclinical RA, and RA. However, the quality of this response differed between the groups: health was associated with IL-10 responses, whereas in preclinical RA there was an emergence of IFN-γ responses, which were also present in a proportion of RA patients (healthy volunteers, preclinical RA, and RA with IFN-γ responses were 11% [2/19], 32% [7/21], and 45% [9/20] and with IL-10 responses were 89% [17/19], 68% [14/21], and 55% [11/20], respectively; χ 2 7·516, df=2, p=0·0233). Looking at the balance of regulation and inflammatory responses, we found a sequential reduction in the ratio of IL10 to IFNγ from health to preclinical RA to RA. There was a significant effect of disease status on the ratios with significant difference between health and preclinical RA and health and RA. The IL10:IFNγ ratio for healthy controls was significantly different from the preclinical RA and the RA groups (mean 1·255 [SD 1·383] vs 0·3892 [1·548] vs 0·1943 [1·395], ANOVA and Tukey test F =5·275, p=0·0062. We also found that the magnitude of the IFN-γ CitVim response increased after neutralising IL10 in four patients with preclinical RA. Interpretation We report that a distinction can be made between health, preclinical RA, and RA in the context of the quality of autoimmune T-cell responses. We have found a sequential change in the balance of IL-10 and IFN-γ responses from health (which favours a regulatory phenotype) to preclinical RA and then to established RA (which favours a relatively inflammatory phenotype). We have also shown that autoreactive IL-10 Treg responses are actively inhibiting IFN-γ responses in patients with preclinical RA. It is plausible that such a regulatory T-cell response plays an important part in preventing disease in health and also progression to disease in preclinical RA. Perhaps approaches to strengthen this regulatory response in people with preclinical disease could prevent progression to disease. Such immunomodulatory approaches are used in allergy practice and in studies in the prevention of diabetes. Funding None.

OP0180 Risk of Developing Clinical Synovitis in ACPA Positive Patients with Non-Specific Musculoskeletal Symptoms

Background Rheumatoid Arthritis (RA) is associated with autoantibodies including ACPA which may be present years before clinical presentation. In the pre clinical phase, patients usually present with non specific musculoskeletal (MSK) symptoms. Objectives 1- To monitor the progression In ACPA positive patients with non specific MSK symptoms to clinical synovitis (CS). 2- To investigate if demographic, clinical, imaging, and serological measures can identify patients at high risk of developing RA at pre-clinical stage. Methods Patients were recruited from rheumatology clinics and primary care. Clinical assessment and investigations including magnetic resonance imaging (MRI) and ultrasound (US) were undertaken at baseline and 3-6 month intervals or at change of symptoms. The end point was the development of CS, defined as the presence of at least one tender and swollen joint. Healthy controls were recruited as a comparator group. Results A total of 122 patients without a diagnosis of inflammatory arthritis were studied. 22 patients were found to have CS at baseline and hence were excluded from analysis. 100 patients (73% females) with a mean age of 51 years (±11.8) had no CS at baseline and were followed up for a median duration of 38.5 weeks (range 1-234 weeks). 44 patients (44%) developed CS after a median duration of 26.5 weeks (1-170 weeks); 22 patients (22%) within 6 months and 33 (33%) within 12 months. Baseline early morning stiffness (EMS) was the only clinical parameter which demonstrated significant difference between the two groups; 59 minutes in those who progressed and 19 minutes in those who did not (P=0.001). The remaining baseline demographic, clinical, and serological parameters were not significantly different between the two groups. Baseline US of wrist and hands (controls =28, patients=98) showed a mean total power Doppler (PD) of 0.2 (SD 0.5) in the controls. In patients who did not progress, mean total PD score was 0.8 (SD 1.8) compared to 2.0 (SD 3.0) in those who progressed (p=0.003). A sub group of ACPA positive patients underwent MRI of a wrist and hand (n=33). Significant difference in flexor tenosynovitis mean score was demonstrated between groups (1.8 (SD 1.6) in patients who progressed vs. 0.7 (SD 1.1) in those with no progression, p=0.024). Conclusions A significant proportion of patients in this cohort progressed to clinical synovitis, the majority within 12 months of presentation. EMS was the only clinical parameter associated with progression. US and MRI may provide a useful tool in identifying patients who may progress to CS. Disclosure of Interest C. Rakieh: None Declared, J. Nam: None Declared, L. Hunt: None Declared, E. Villeneuve: None Declared, L.-A. Bissell: None Declared, S. Das: None Declared, P. Conaghan: None Declared, D. McGonagle: None Declared, R. Wakefield: None Declared, P. Emery Consultant for: Honoraria/Advisory Board: Abbot, Pfizer, Roche, Chugai, BMS, UCB, MSD

A1.33 Predicting the evolution of inflammatory arthritis in ACPA-positive individuals: can T-cell subsets help?

Background and Objectives ACPA+ individuals with non-specific musculoskeletal symptoms are at high risk of developing rheumatoid arthritis (RA). We previously demonstrated dys-regulation of T-cell subsets with loss of naïve and regulatory T-cells (Treg) in early disease. The aim of the current study is to demonstrate the predictive value of T-cell subset analysis for progression towards symptom onset in ACPA+ individuals. Materials and Methods 84 ACPA+ individuals without clinical synovitis at recruitment were followed. 95 healthy controls (HC) provided a reference group. At baseline T-cell subset analyses were performed using 6-colour flowcytometry for naïve T-cells (CD4+ CD45RB + CD45RA+ CD62L+), Treg (CD4+ CD25highFoxp3 + CD127low) and inflammation related cells (IRC: CD4+ CD45RB + CD45RA+ CD62L-). The relationship between naïve cell frequency and age was established in HC and used to age-correct values in ACPA+ . ROC curve analysis was used to identify 2 T-cell cut-offs predicting progression to IA at any time; one which maximised the Youden index (sensitivity + specificity-1), and one which prioritised specificity over sensitivity. Results 42/84 (50%) of patients developed clinical synovitis within a median follow-up of 6.0 months (range 1 week-46 months). For age-corrected naïve T-cells area under the ROC curve (AUC) was 0.67 (95% CI 0.55, 0.79; n = 84, p = 0.007), for IRC 0.70 (0.59, 0.81; n = 81, p = 0.002) and for Treg 0.67 (0.53, 0.80; n = 65, p = 0.021). For each of the three subsets, the Youden index cut-off correctly classified >65% of patients (Table 1). Cut-offs prioritising specificity were identified which did not greatly reduce overall classification success. The confidence intervals for these estimates remain wide and our sample size may still be limited for running such analysis. Youden index cut-off Specificity priority cut-off Subset Cut-off Sensitivity Specificity % Correct Cut-off Sensitivity Specificity % Correct Naïve ≤-6.4 59.5 (43.3, 74.4) 76.2 (60.5, 87.9) 67.9 ≤-14.0 26.2 (13.9, 42.0) 90.5 (77.4, 97.3) 58.3 IRC ≥2.8 56.4 (39.6, 72.2) 76.2 (60.5, 87.9) 66.7 ≥4.5 30.8 (17.0, 47.6) 90.5 (77.4, 97.3) 61.7 Treg ≤4.15 90.6 (75.0, 98.0) 41.2 (24.6, 98.0) 65.1 ≤1.6 34.4 (18.6, 53.2) 91.2 (76.3, 98.1) 63.7 Abstract A1.33 Table 1 Sensitivity and specificity of T-cell subset frequencies for progression to IA, using two different cut-off values for each subset; one where the Youden index was maximised and another that prioritised specificity over sensitivity. Conclusions T-cell dys-regulation in ACPA+ individuals with non-specific musculoskeletal pain may be useful in predicting progression to inflammatory arthritis. Multivariable modelling in larger cohorts is needed to quantify the utility of T-cell subsets in predicting progression to IA.

Comorbidities in Anti-Cyclic Citrullinated Peptide Positive At-Risk Individuals Do Not Differ from Those Patients with Early Inflammatory Arthritis

Objectives To compare comorbidities in a cohort of cyclic citrullinated peptide (CCP) antibody positive patients without or prior to onset of inflammatory arthritis (IA) to those in patients with early IA. Methods Baseline data from two established cohorts were used. The first recruited people at risk of IA: CCP antibody positive cases without IA (CCP Cohort, n = 296). The second cohort [the Inflammatory Arthritis CONtinuum study (IACON)] recruited patients with early IA (n = 725). Proportions of patients with given comorbidities were compared between cohorts and then logistic regression was used to determine odds ratios (OR) for the CCP cohort having specific comorbidities, compared to IACON patients. Analyses adjusted for gender, age, smoking status, and body mass index. Results Patients from the CCP cohort were younger (mean age 50, compared to 53 years). The proportion of patients with at least one comorbidity was higher in the IACON than the CCP cohort: (40% compared to 24%, respectively). Results of logistic regression analyses suggested the odds of hypertension, taking a lipid-lowering agent, ischemic heart disease, cerebrovascular disease, lung disease, and diabetes were not increased in either cohort. However, patients in the CCP cohort were more likely to be taking an antidepressant (OR = 1.62, 95% CI 1.03, 2.56, p = 0.037). Conclusion There was no significant difference in comorbidities among people with CCP antibodies but without IA, compared to those of patients with established IA.

FRI0047 Mri interosseous tendon inflammation occurs in anti-ccp positive at-risk individuals and may precede the development of synovitis

Background Tenosynovitis (TSV) occurs in individuals at-risk of developing RA and could explain pain and stiffness in the absence of synovitis. TSV of the wrist and finger flexor tendons has been described in at-risk individuals but involvement of other hand tendons has not been well investigated. The hand interossei are crucial to hand function and can become inflamed in RA(.1 Whether the interosseous tendons (IT) are sites of inflammation in at-risk individuals, and how this relates to joint inflammation and clinical features is unknown. Objectives To describe the anatomy, prevalence, pattern and clinical associations of IT inflammation in anti-CCP positive at-risk individuals. Methods Anti-CCP positive individuals with no synovitis (CCP+), healthy controls (HC), DMARD-naïve early RA patients (ERA) and treated ‘late’ RA patients (LRA) were recruited. All subjects underwent clinical and MRI assessment. 1.5T or 3T unilateral hand MRI scans were consensus scored for RAMRIS, TSV and IT inflammation by two radiologists. IT inflammation was defined as enhancing tissue around the tendon evident in two planes. For RAMRIS and tenosynovitis, scores were adjusted for 193 age-matched controls(.2 To understand the anatomical basis for MRI IT inflammation, a cadaveric study was performed on 20 fresh hand specimens; coloured dyes were injected along the first dorsal IT and into the adjacent second MCP joint and specimens were frozen and sectioned. Results 93 CCP+, 20 HC, 47 ERA and 28 LRA were recruited. Frequency of swollen and tender joints, MRI inflammation (synovitis, BME, erosions, TSV) and CRP level increased along the RA continuum with increasing disease duration. The proportion of patients with IT inflammation increased along the RA continuum. No HC, 18/93 (19%) CCP+, 23/47 (49%) ERA and 16/28 (57%) LRA patients had inflammation of ≥1 IT (p<0.001). The number of affected ITs increased along the RA continuum (p<0.001) and tendons associated with MCPJs 2 and 5 were most commonly affected. IT inflammation and MRI synovitis were associated with MCPJ swelling [OR 2.7 (0.9, 8.1) and OR 3.1 (1.0, 9.8) respectively] but IT inflammation was the only feature independently associated with MCPJ tenderness [OR 3.1 (1.4, 6.8) p=0.004]. In CCP+, 99/372 (27%) MCPJs had only one MRI abnormality; in 68% of these the abnormality was extra-capsular (57% TSV and 11% IT inflammation). No IT sheath was identified in the cadaveric specimens suggesting the MRI findings represent peri-tendonitis rather than TSV. Dye studies indicated no clear communication between the IT and the adjacent joint (figure 1).Abstract FRI0047 – Figure 1 Axial MRI showing inflammation of the 3rd palmar interosseous tendon and frozen section showing green dye around the interosseous tendon and blue dye within the MCP joint Conclusions IT inflammation represents a peri-tendonitis and is present in anti-CCP +at risk individuals and RA patients where it is associated with MCPJ swelling and tenderness. IT inflammation can occur as the lone MRI abnormality in CCP +at risk individuals suggesting the interossei may be an early extra-capsular target in the development of RA. References [1] Rowbotham, et al. Eur Radiol2015. [2] Mangnus, et al. Arthritis Rheum2016. Acknowledgements D Glinatsi, M Ostergaard, P Bird Disclosure of Interest None declared