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ObjectiveMost studies of rheumatoid arthritis (RA) and sleep have focused on established RA. We here investigate sleep quality and sleep duration in patients with newly diagnosed RA and during 1–12 years after diagnosis.MethodsData were collected on sleep 1–12 years after diagnosis from patients diagnosed 1998–2018 in the Swedish study Epidemiological Investigation of RA. Six sleep domains (sleep problems, non-restorative sleep, insomnia, insufficient sleep, sleep quality perceived as poor and sleep considered a health problem); a global sleep score and time spent in bed were estimated. Using logistic regression, ORs were calculated for each sleep outcome by disease duration. We explored whether pain (low (Visual Analogue Scale=0–20 mm, reference), intermediate=21–70, high=71–100) or functional impairment (Health Assessment Questionnaire>1.0) was associated with problems.ResultsWe had sleep data on 4131 observations (n=3265 individuals). Problems with ≥1 sleep domain (global sleep score) was reported in 1578 observations (38%) and increased with disease duration (OR 1.04, 95% CI 1.02 to 1.07). Median time in bed was 8 hours (Q1-Q3: 7.5–9.0). High-grade pain increased the likelihood of sleep problems ~3–9 fold, and increased functional impairment ~4–8 fold.ConclusionIn this cohort of newly diagnosed patients with RA with access to the current treatment from diagnosis, we did not find any major problems with sleep, and existing sleep problems related mainly to pain and reduced function. Treatment of sleep problems in RA should be guided towards treating the underlying problem causing the sleep disturbance.

Publisher's version (útgefin grein), Objective: To investigate the relationship between anti–citrullinated protein antibodies (ACPAs), specific ACPA subspecificities, rheumatoid factor (RF) isotypes, and incident cardiovascular (CV) events in patients with rheumatoid arthritis (RA). Methods: Serum samples from Swedish patients with new-onset RA (diagnosed within 1 year of symptom onset between 1996 and 2009) were centrally typed for anti–cyclic citrullinated peptide 2 (anti-CCP2) antibodies, 20 ACPA subspecificities, and RF isotypes. Patients were followed up longitudinally in nationwide registers to monitor the occurrence of acute coronary syndrome (ACS), stroke, CV-related death, and major adverse CV events (MACE). The association between each serologic marker and CV outcome, and the impact of adjustment for the Disease Activity Score in 28 joints (DAS28), smoking status, and income at baseline, were assessed using Cox proportional hazards models. In addition, associations of serologic markers with all-cause mortality were explored. Results: In total, 2,814 patients with RA were included in the study. The median follow-up was 13 years, during which the CV end points of ACS, stroke, or CV-related death were reported to occur in 375 patients. Occurrence and/or levels of anti-CCP2 were associated with risk of incident ACS (hazard ratio [HR] 1.46, 95% confidence interval [95% CI] 1.03–2.06), stroke (HR 1.47, 95% CI 1.03–2.10), CV-related death (P = 0.024 for association with anti-CCP2 levels), and MACE (HR 1.34, 95% CI 1.06–1.70). Similarly, an association with the number of ACPA subspecificities was observed; however, this could not be attributed to any individual or group of ACPA subspecificities. Presence of IgM-RF was associated with all CV end points except ACS, and IgA-RF was exclusively associated with CV-related death. Adjustment for smoking status, income, and DAS28 scores decreased most of the HRs, whereas IgA-RF remained associated with CV-related death (HR 1.61, 95% CI 1.05–2.48). All of the assessed serologic makers were associated with all-cause mortality. Conclusion: RF isotypes and ACPAs are associated with future CV events in patients with RA. ACPA levels and number of subspecificities seem more important than the occurrence of particular subspecificities, and these associations were not explained by a history of ever smoking., Karolinska institutet (strategic research area epidemiology), The nordic research council (nordforsk), The rheumatology research foundation (foreum), Stiftelsen för Strategisk Forskning, Vetenskapsrådet, Stockholms Läns Landsting, The swedish heart lung foundation

Rheumatoid arthritis (RA) is a heterogeneous disease, consisting of distinct subsets with partly distinct aetiologies and risk factors. Such risk factors are environmental, including lifestyle mediated and genetic, and these factors must always be considered in the context of stochastic (i.e. chance) factors. As RA is a disease where immune reactions often precede symptoms, and where symptoms that do not involve joint inflammation such as joint pain, bone loss, and fatigue may precede arthritis, and where severe symptoms and comorbidities may follow after the first episode of joint inflammation, we also have to consider risk factors during these different phases of disease development. This chapter focuses on environmental, including lifestyle, factors, and on when and how during disease development such factors are active. The chapter also describes pathogenic mechanisms that may be triggered by such risk factors. Particular emphasis is on recognition of modifiable environmental/lifestyle factors as such knowledge can be used in primary as well as secondary prevention and also to improve effects of current pharmacological treatments.

Patterns of innovation can be sustained (continuous) or rapid, sometimes even ‘disruptive’. A major difference is that in order to support disruptive innovation the support networks and its infrastructure often need to be changed dynamically to accommodate a rapidly evolving landscape to establish the disruptive approach. For example, introducing electric cars disrupts the support network for gasoline cars (network of gas and service stations), and at the same time requires an entirely new system of charging stations. Such disruptions occur in science, and a wonderful example was the creation of monoclonal antibody technologies. The discovery of the principle for production of monoclonal antibodies by Cesar Milstein and Georg Kohler fueled a rapid adoption of new antibody-based technologies in all areas of medicine. This transformation was strongly supported by the open workshops that catalogued antibodies from many laboratories into distinct ‘clusters of differentiation’, thereby providing a new ‘support network’ for the global use of well validated and standardised monoclonal antibodies. This new support network helped the pharmaceutical industry transition from a major focus on small chemical molecules (screened for effects in vitro) to a new targeted approach, first with recombinant proteins, later with monoclonal antibodies with the introduction of anti-tumour necrosis factor (TNF) antibodies as an example. During the last two decades, in both the USA and Europe, the need to develop public–private partnership support networks has been recognised as a means to accelerate innovation and enable translation of the rapidly expanding cellular and molecular understanding of disease pathogenesis into the development of new therapeutic agents. In Europe, the Innovative Medicine Initiative (IMI) was formed to enhance public–private partnerships, and in the USA the Accelerating Medicines Partnership (AMP).1 Identifying, validating and testing new targets based on enhanced understanding are at the core of both AMP and IMI. To facilitate continuous …

Objective The link and interplay between different airway exposures and rheumatoid arthritis (RA) risk are unclear. This study was undertaken to determine whether respiratory disease is associated with development of RA, and specifically to examine this relationship by RA serostatus and smoking exposure. Methods Using data from the Epidemiological Investigation of Rheumatoid Arthritis study, this analysis included 1,631 incident RA cases and 3,283 matched controls recruited from 2006 to 2016. Linking these individuals to the National Patient Register provided information on past acute or chronic, upper or lower respiratory disease diagnoses. For each disease group, we estimated adjusted odds ratios (ORadj ) with 95% confidence intervals (95% CI) for RA, using logistic regression models adjusted for age, sex, residential area, body mass index, and education both overall and stratified by anti-citrullinated protein antibody (ACPA)/rheumatoid factor (RF) status and by smoking status. Results Respiratory disease diagnoses were associated with risk of RA, with an ORadj of 1.2 for acute upper respiratory disease (95% CI 0.8-1.7), 1.4 for chronic upper respiratory disease (95% CI 1.1-1.9), 2.4 for acute lower respiratory disease (95% CI 1.5-3.6), and 1.6 for chronic lower respiratory disease (95% CI 1.5-3.6). These associations were present irrespective of RF or ACPA status, though the association was somewhat stronger for ACPA/RF-positive than ACPA/RF-negative RA. The association between any respiratory disease and RA was stronger for nonsmokers (ORadj 2.1 [95% CI 1.5-2.9]) than for smokers (ORadj 1.2 [95% CI 0.9-1.5]). Conclusion Respiratory diseases increase the risk for both seropositive and seronegative RA, but only among nonsmokers. These findings raise the hypothesis that smoking and airway disease are associated with RA development through partly different mechanisms.

OBJECTIVE To investigate the association between obesity-related traits and risk of rheumatoid arthritis (RA). METHODS We conducted genetic correlation analysis and a 2-sample Mendelian randomization (MR) study, using genome-wide genetic data based on >850,000 individuals of European ancestry. Summary statistics were collected from the largest genome-wide association study conducted to date for body mass index (BMI; n = 806,810), waist-to-hip ratio (WHR; n = 697,734), WHR adjusted for BMI (WHRadjBMI; n = 694,649), and RA (ncase = 14,361, ncontrol = 43,923). We conducted cross-trait linkage disequilibrium score regression and ρ-HESS analyses to quantify genetic correlation between pairs of traits (causal overlap). For each obesity-related exposure, we utilized independent, genome-wide significant single-nucleotide polymorphisms (P < 5 × 10-9 ) as instruments to perform MR analysis (causal relationship). We interrogated the causal relationship both in the general population and in a sex-specific manner and calculated odds ratios (ORs) and 95% confidence intervals (95% CIs). Sensitivity analyses were performed to validate MR model assumptions. RESULTS Despite a negligible overall genetic correlation between the 3 obesity-related traits and RA, we found significant local genetic correlations at several regions on chromosome 6 (positions 28-29M, 30-35M, and 50-52M), highlighting a shared genetic basis. We further observed an increased risk of RA per SD increment (4.8 kg/m2 ) in genetically predicted BMI (OR 1.22 [95% CI 1.09-1.37]). The effect was consistent across sensitivity analyses and comparable between sexes (OR 1.22 [95% CI 1.04-1.44] in male subjects and 1.19 [95% CI 1.04-1.36] in female subjects). However, we did not find evidence supporting a causal role of either WHR (OR 0.98 [95% CI 0.84-1.14]) or WHRadjBMI (OR 0.90 [95% CI 0.79-1.04]) in RA. CONCLUSION Genetically predicted BMI significantly increases RA risk. Future studies are needed to understand the biologic mechanisms underlying this link.

Outcomes of patients with inflammatory rheumatic diseases have significantly improved over the last three decades, mainly due to therapeutic innovations, more timely treatment, and a recognition of the need to monitor response to treatment and to titrate treatments accordingly. Diagnostic delay remains a major challenge for all stakeholders. The combination of electronic health (eHealth) and serologic and genetic markers holds great promise to improve the current management of patients with inflammatory rheumatic diseases by speeding up access to appropriate care. The Joint Pain Assessment Scoring Tool (JPAST) project, funded by the European Union (EU) European Institute of Innovation and Technology (EIT) Health program, is a unique European project aiming to enable and accelerate personalized precision medicine for early treatment in rheumatology, ultimately also enabling prevention. The aim of the project is to facilitate these goals while at the same time, reducing cost for society and patients.

Autoimmune thyroid disease is the most common autoimmune disease and is highly heritable1. Here, by using a genome-wide association study of 30,234 cases and 725,172 controls from Iceland and the UK Biobank, we find 99 sequence variants at 93 loci, of which 84 variants are previously unreported2–7. A low-frequency (1.36%) intronic variant in FLT3 (rs76428106-C) has the largest effect on risk of autoimmune thyroid disease (odds ratio (OR) = 1.46, P = 2.37 × 10−24). rs76428106-C is also associated with systemic lupus erythematosus (OR = 1.90, P = 6.46 × 10−4), rheumatoid factor and/or anti-CCP-positive rheumatoid arthritis (OR = 1.41, P = 4.31 × 10−4) and coeliac disease (OR = 1.62, P = 1.20 × 10−4). FLT3 encodes fms-related tyrosine kinase 3, a receptor that regulates haematopoietic progenitor and dendritic cells. RNA sequencing revealed that rs76428106-C generates a cryptic splice site, which introduces a stop codon in 30% of transcripts that are predicted to encode a truncated protein, which lacks its tyrosine kinase domains. Each copy of rs76428106-C doubles the plasma levels of the FTL3 ligand. Activating somatic mutations in FLT3 are associated with acute myeloid leukaemia8 with a poor prognosis and rs76428106-C also predisposes individuals to acute myeloid leukaemia (OR = 1.90, P = 5.40 × 10−3). Thus, a predicted loss-of-function germline mutation in FLT3 causes a reduction in full-length FLT3, with a compensatory increase in the levels of its ligand and an increased disease risk, similar to that of a gain-of-function mutation. A predicted loss-of-function germline mutation in FLT3 causes a reduction in full-length FLT3, with a compensatory increase in the levels of FLT3 ligand, leading to increased risk of autoimmune thyroid disease.

The current review uses rheumatoid arthritis (RA) as a prominent example for how studies on the interplay between environmental and genetic factors in defined subsets of a disease can be used to formulate aetiological hypotheses that subsequently can be tested for causality using molecular and functional studies. Major discussed findings are that exposures to airways from many different noxious agents including cigarette smoke, silica dust and more interact with major susceptibility genes, mainly HLA-DR genetic variants in triggering antigen-specific immune reactions specific for RA. We also discuss how several other environmental and lifestyle factors, including microbial, neural and metabolic factors, can influence risk for RA in ways that are different in different subsets of RA.The description of these processes in RA provides the best example so far in any immune-mediated disease of how triggering of immunity at one anatomical site in the context of known environmental and genetic factors subsequently can lead to symptoms that precede the classical inflammatory disease symptoms and later contribute also to the classical RA joint inflammation. The findings referred to in the review have led to a change of paradigms for very early therapy and prevention of RA and to efforts towards what we have named 'personalized prevention'. We believe that the progress described here for RA will be of relevance for research and practice also in other immune-mediated diseases.

ObjectiveIn anti-citrullinated protein antibody positive rheumatoid arthritis (ACPA-positive RA), a particular subset of HLA-DRB1 alleles, called shared epitope (SE) alleles, is a highly influential genetic risk factor. Here, we investigated whether non-HLA single nucleotide polymorphisms (SNP), conferring low disease risk on their own, interact with SE alleles more frequently than expected by chance and if such genetic interactions influence the HLA-DRB1 SE effect concerning risk to ACPA-positive RA.MethodsWe computed the attributable proportion (AP) due to additive interaction at genome-wide level for two independent ACPA-positive RA cohorts: the Swedish epidemiological investigation of rheumatoid arthritis (EIRA) and the North American rheumatoid arthritis consortium (NARAC). Then, we tested for differences in the AP p value distributions observed for two groups of SNPs, non-associated and associated with disease. We also evaluated whether the SNPs in interaction with HLA-DRB1 were cis-eQTLs in the SE alleles context in peripheral blood mononuclear cells from patients with ACPA-positive RA (SE-eQTLs).ResultsWe found a strong enrichment of significant interactions (AP pHLA-DRB1 SE alleles and the group of SNPs associated with ACPA-positive RA in both cohorts (Kolmogorov-Smirnov test D=0.35 for EIRA and D=0.25 for NARAC, pHLA-DRB1 SE alleles for disease decreases from 5.2 to 2.5 after removal of the risk alleles of the two top interacting SNPs (rs2476601 and rs10739581).ConclusionOur data demonstrate that there are massive genetic interactions between the HLA-DRB1 SE alleles and non-HLA genetic variants in ACPA-positive RA.

OBJECTIVE Anti-citrullinated protein antibodies (ACPAs) are a hallmark of seropositive rheumatoid arthritis (RA). Yet, the precise disease-relevant autoantigens that are targeted by ACPAs remains a matter of debate. This study utilized patient-derived monoclonal ACPAs, rather than serum autoantibody analysis, to characterize the multireactivity to different protein modifications and to reveal autoantibody subsets in patients with RA. METHODS Twelve human monoclonal ACPAs (positive by the second-generation cyclic citrullinated peptide test) were generated from 6 RA patients, and a head-to-head comparison of their reactivities was performed. For profiling, we used a complementary DNA-based protein array (Engine GmbH) and 3 peptide-screening platforms with RA autoantigens (Thermo Fisher Scientific), citrullinated and carbamylated peptides (NimbleGen/Roche), or histone-derived peptides with different posttranslational modifications (JPT Histone Code), covering >207,000 peptides (>7,800 gene products). RESULTS The fine-specificity profiles of the investigated ACPAs varied, but all of the monoclonal ACPAs displayed multireactivity to a large number of citrullinated peptides/proteins, each characterized by specific binding properties. ACPA subsets could be defined by clone-distinct consensus binding motifs (e.g., Cit-Gly, Gly-Cit, or Arg-Cit-Asp), with the most common ACPA recognition being that of a Gly in the +1 flanking position, but with additional amino acid preferences. For ACPA protein recognition, we observed a preference for citrullinated RNA-binding proteins with high Arg/Gly content. Six of the 12 ACPA clones also bound acetylated lysine (KAc) or homocitrulline peptide motifs, displaying a similar affinity or higher apparent affinity than that for citrullinated peptides. CONCLUSION ACPAs and anti-modified protein autoantibodies represent overlapping facets of RA autoimmunity and bind to a wide variety of modified proteins, extending well beyond the historically recognized set of RA autoantigens. So far, KAc reactivity has been detected only in the context of anti-carbamylated and anti-citrullinated peptide autoantibody responses, postulating the existence of hierarchies of autoreactivity in RA. Future investigations of ACPA fine specificities and functionality should take into consideration the presence of consensus Cit/Carb/KAc motifs and the multireactivity of these autoantibodies in patients with RA.

Objective: Environmental factors are of importance for the etiology of rheumatoid arthritis (RA), but much remains unknown concerning the contributions from distinct occupational hazards. We explored the association between occupation and the risk of anti-citrullinated protein antibody (ACPA) + RA or ACPA- RA. Methods: We analyzed 3,522 cases and 5,580 controls from the Swedish population-based EIRA case-control study. A questionnaire was used to obtain information on work history and lifestyle factors. Blood samples were taken for serologic analyses. Unconditional logistic regression was used to calculate the odds ratio (OR) of RA associated with the last occupation before study inclusion. Analyses were performed with adjustments for known environmental exposures and lifestyle factors, including pack years of cigarette smoking, alcohol use, body mass index (BMI) and education. Results: Among men, bricklayers and concrete workers (OR: 2.9, 95% CI: 1.4-5.7), material handling operators (OR: 2.4, 95% CI: 1.3-4.4) and electrical and electronics workers (OR: 2.1, 95% CI: 1.1-3.8), had an increased risk of ACPA+ RA. For ACPA- RA, bricklayers and concrete workers (OR: 2.4, 95% CI: 1.0-5.7) and electrical and electronics workers (OR: 2.6, 95% CI: 1.3-5.0) had an increased risk. Among women, assistant nurses and attendants had a moderately increased risk of ACPA+ RA (OR: 1.3, 95% CI: 1.1-1.6). No occupations were significantly associated to ACPA- RA among women. Conclusion: Mainly occupations related to potential noxious airborne agents were associated with an increased risk of ACPA+ or ACPA- RA, after adjustments for previously known confounders. This article is protected by copyright. All rights reserved.

Objective To investigate potential associations between dietary intake of polyunsaturated fatty acids (FAs) and pain patterns in early rheumatoid arthritis (RA) patients after 3 months of methotrexate (MTX) treatment. Methods We included 591 early RA patients with MTX monotherapy from a population‐based prospective case–control study, the Epidemiological Investigation of Rheumatoid Arthritis. Dietary data on polyunsaturated FAs (food frequency questionnaires) were linked with data on unacceptable pain (visual analog scale [VAS] >40 mm), noninflammatory/refractory pain (VAS >40 mm and C‐reactive protein [CRP] level 40 mm and CRP level >10 mg/liter) after 3 months. Statistical analysis included logistic regression. Results After 3 months of MTX treatment, 125 patients (21.2%) had unacceptable pain, of which 92 patients had refractory pain, and 33 patients had inflammatory pain. Omega‐3 FA intake was inversely associated with unacceptable pain and refractory pain (odds ratio [OR] 0.57 [95% confidence interval (95% CI) 0.35–0.95] and OR 0.47 [95% CI 0.26–0.84], respectively). The omega‐6:omega‐3 FA ratio, but not omega‐6 FA alone, was directly associated with unacceptable pain and refractory pain (OR 1.70 [95% CI 1.03–2.82] and OR 2.33 [95% CI 1.28–4.24], respectively). Furthermore, polyunsaturated FAs were not associated with either inflammatory pain or CRP level and erythrocyte sedimentation rate at followup. Omega‐3 FA supplementation was not associated with any pain patterns. Conclusion Omega‐3 FA was inversely associated with, and the omega‐6:omega‐3 FA ratio was directly associated with, unacceptable and refractory pain, but not with inflammatory pain or systemic inflammation. The inverse association between omega‐3 FA and refractory pain may have a role in pain suppression in RA.

Editorial summary Genomic medicine has considerable potential to provide novel diagnostic and therapeutic solutions for patients who have molecularly complex diseases and who are not responding to existing therapies. To bridge the gap between genomic medicine and clinical practice, integration of various data types, resources, and joint international initiatives will be required.

Oxidation-associated malondialdehyde (MDA) modification of proteins can generate immunogenic neo-epitopes that are recognized by autoantibodies. In health, IgM antibodies to MDA-adducts are part of the natural antibody pool, while elevated levels of IgG anti-MDA antibodies are associated with inflammatory and autoimmune conditions. Yet, in human autoimmune disease IgG anti-MDA responses have not been well characterized and their potential contribution to disease pathogenesis is not known. Here, we investigate MDA-modifications and anti-MDA-modified protein autoreactivity in rheumatoid arthritis (RA). While RA is primarily associated with autoreactivity to citrullinated antigens, we also observed increases in serum IgG anti-MDA in RA patients compared to controls. IgG anti-MDA levels significantly correlated with disease activity by DAS28-ESR and serum TNF-alpha, IL-6, and CRP. Mass spectrometry analysis of RA synovial tissue identified MDA-modified proteins and revealed shared peptides between MDA-modified and citrullinated actin and vimentin. Furthermore, anti-MDA autoreactivity among synovial B cells was discovered when investigating recombinant monoclonal antibodies (mAbs) cloned from single B cells, and 3.5% of memory B cells and 2.3% of plasma cells were found to be anti-MDA positive. Several clones were highly specific for MDA-modification with no cross-reactivity to other antigen modifications such as citrullination, carbamylation or 4-HNE-carbonylation. The mAbs recognized MDA-adducts in a variety of proteins including albumin, histone 2B, fibrinogen and vimentin. Interestingly, the most reactive clone, originated from an IgG1-bearing memory B cell, was encoded by near germline variable genes, and showed similarity to previously reported natural IgM. Other anti-MDA clones display somatic hypermutations and lower reactivity. Importantly, these anti-MDA antibodies had significant in vitro functional properties and induced enhanced osteoclastogenesis, while the natural antibody related high-reactivity clone did not. We postulate that these may represent distinctly different facets of anti-MDA autoreactive responses.

ObjectivesTo study whether oral contraceptive (OC) use or breastfeeding (BF) influence the risk of rheumatoid arthritis (RA), stratifying the cases by presence/absence of anticitrullinated protein antibodies (ACPA), and whether these factors interact with known risk factors in the development of ACPA-positive RA.MethodsWomen aged ≥18 years, participants in the population-based case–control Swedish Epidemiological Investigation of RA study (2641 cases/4251 controls), completed an extensive questionnaire regarding OC, BF and potential confounders. We calculated ORs, with 95% CIs, adjusted for age, residential area, smoking and alcohol consumption. Attributable proportion due to interaction (AP) was estimated to evaluate presence of interaction.ResultsCompared with never users, ever and past OC users had a decreased risk of ACPA-positive RA (OR=0.84 (95% CI 0.74 to 0.96); OR=0.83 (95% CI 0.73 to 0.95), respectively). No significant associations were found for ACPA-negative RA. Long duration of OC use (>7 years vs never use) decreased the risk of both ACPA-positive (p=0.0037) and ACPA-negative RA (p=0.0356).A history of long BF decreased the risk only of ACPA-positive RA in a dose-dependent manner (p=0.0086), but this trend did not remain after adjustments. A significant interaction was observed between the lack of OC use and smoking (AP=0.28 (95% CI 0.14–0.42)) on the risk of ACPA-positive RA. No interactions were found for BF.ConclusionsOC decreased the risk of RA, especially ACPA-positive RA, where an interaction with smoking was observed. A long duration of OC use decreased the risk of both disease subsets. We could not confirm an association between BF and a decreased risk of either ACPA-positive or ACPA-negative RA.

Background Methotrexate (MTX) is the standard first-line therapy in rheumatoid arthritis (RA) with variable clinical efficacy that is difficult to predict. The glycosylation status of immunoglobulin G (IgG) is altered in RA and influenced by MTX treatment. We aimed to further investigate if IgG glycosylation in untreated early RA can predict therapeutic response to MTX. Methods We used a shotgun proteomic approach to screen for the Fc glycopeptides in the serum of 12 control subjects and 59 untreated patients with early RA prior to and following MTX initiation. MTX treatment response was defined according to the European League Against Rheumatism at a median of 14 weeks (range 13–15) after treatment initiation. Seropositive patients were defined as those testing positive for anticitrullinated protein antibodies and/or rheumatoid factor at baseline (n = 44). Data analysis was performed using uni- and multivariate statistics. Results We could confirm a low abundance of galactosylated glycans in untreated patients with early RA compared with control subjects that was partially restored by MTX treatment. This was more evident among future nonresponders than among responders to MTX treatment. Results were further validated and confirmed by multivariate statistical analysis of the baseline Fc glycan, proteomic, and clinical data. We found that the ratio between the main agalactosylated (FA2) and main mono- and di-galactosylated Fc glycans (FA2G1 and FA2G2) of IgG1 ranked as the most prominent factor distinguishing responders from nonresponders. A low baseline ratio of FA2/[FA2G1 + FA2G2]-IgG1 was associated with nonresponse (OR 5.3 [1.6–17.0]) and was able to discriminate future nonresponders from responders to MTX therapy with a sensitivity of 70% (95% CI 46–88%) and a specificity of 69% (95% CI 52–83%). For seropositive patients (n = 44), this trend was improved with a sensitivity of 73% (95% CI 45–92%) for nonresponse and a specificity of 79% (95% CI 60–92%). Conclusions We show that the FA2/[FA2G1 + FA2G2] of IgG1 is a biomarker candidate that is significantly associated with nonresponding patients and has potential value for prediction of MTX clinical response. Electronic supplementary material The online version of this article (doi:10.1186/s13075-017-1389-7) contains supplementary material, which is available to authorized users.

A key unanswered question in the pathophysiology of rheumatoid arthritis (RA) is how systemic autoimmunity progresses to joint-specific inflammation. In patients with seropositive RA (that is, characterized by the presence of autoantibodies) evidence is accumulating that immunity against post-translationally modified (such as citrullinated) autoantigens might be triggered in mucosal organs, such as the lung, long before the first signs of inflammation are seen in the joints. However, the mechanism by which systemic autoimmunity specifically homes to the joint and bone compartment, thereby triggering inflammation, remains elusive. This Review summarizes potential pathways involved in this joint-homing mechanism, focusing particularly on osteoclasts as the primary targets of anti-citrullinated protein antibodies (ACPAs) in the bone and joint compartment. Osteoclasts are dependent on citrullinating enzymes for their normal differentiation and are unique in displaying citrullinated antigens on their cell surface in a non-inflamed state. The binding of ACPAs to osteoclasts releases the chemokine IL-8, leading to bone erosion and pain. This process initiates a chain of events that could lead to attraction and activation of neutrophils, resulting in a complex series of proinflammatory processes in the synovium, eventually leading to RA.

Patients with rheumatoid arthritis can be divided into two major subsets characterized by the presence versus absence of antibodies to citrullinated protein antigens (ACPAs) and of rheumatoid factor (RF). The antibody-positive subset of disease, also known as seropositive rheumatoid arthritis, constitutes approximately two-thirds of all cases of rheumatoid arthritis and generally has a more severe disease course. ACPAs and RF are often present in the blood long before any signs of joint inflammation, which suggests that the triggering of autoimmunity may occur at sites other than the joints (for example, in the lung). This Review summarizes recent progress in our understanding of this gradual disease development in seropositive patients. We also emphasize the implications of this new understanding for the development of preventive and therapeutic strategies. Similar temporal and spatial separation of immune triggering and clinical manifestations, with novel opportunities for early intervention, may also occur in other immune-mediated diseases.

Objective Antibodies to the citrullinated protein antigens (ACPAs) are important in the diagnosis and pathogenesis of rheumatoid arthritis (RA). However, the prevalence of ACPAs with different fine specificities in different populations is unclear. This study sought to examine the fine specificity of the antibody responses toward citrullinated proteins in RA patients from Malaysia, an area where genetic and environmental determinants of RA are different from those in more frequently studied cohorts of Caucasian subjects. Methods A multiplex analytic microarray system was used to analyze the occurrence of antibodies to 10 different citrullinated peptides (filaggrin [fil307–324], vimentin [Vim2–17, Vim60–75], fibrinogen [Fibα563–583, Fibα580–600, Fibβ36–52, Fibβ62–81a, Fibβ62–81b], enolase [Eno5–21], and type II collagen [CitCII355–378]) in serum samples from 4,089 RA patients (1,231 Malaysian and 2,858 Swedish) and 827 healthy control subjects (249 Malaysian and 578 Swedish). The positive reaction threshold for each peptide was set separately for each population based on a specificity of 98%. Results Distinct differences in the frequencies of 5 ACPA fine specificities (Vim60–75, Vim2–17, Fibβ62–81b, Eno5–21, and CitCII355–378) were found between the Malaysian and Swedish RA populations, despite a nearly identical percentage of patients in each population who were positive for anti–cyclic citrullinated peptide 2 antibodies. In Malaysian RA patients compared with Swedish RA patients, the frequencies of antibodies to Vim60–75 (54% versus 44%, corrected P [P corr] = 1.06 × 10−8) and CitCII355–378 (17% versus 13%, P corr = 0.02) were significantly higher, while the frequencies of antibodies to Vim2–17 (25% versus 32%, P corr = 1.91 × 10−4), Fibβ62–81b (15% versus 30%, P corr = 2.47 × 10−22), and Eno5–21 (23% versus 50%, P corr = 3.64 × 10−57) were significantly lower. Conclusion Serum ACPA fine specificities differ between RA patients in different populations, although the total proportions of individuals positive for ACPAs are similar. Differing patterns of ACPA fine specificity could be attributed to variations in genetic and/or environmental factors.

Background Twin studies are powerful models to elucidate epigenetic modifications resulting from gene–environment interactions. Yet, commonly a limited number of clinical twin samples are available, leading to an underpowered situation afflicted with false positives and hampered by low sensitivity. We investigated genome-wide DNA methylation data from two small sets of monozygotic twins representing different phases during the progression of rheumatoid arthritis (RA) to find novel genes for further research. Methods We implemented a robust statistical methodology aimed at investigating a small number of samples to identify differential methylation utilizing the comprehensive CHARM platform with whole blood cell DNA from two sets of twin pairs discordant either for ACPA (antibodies to citrullinated protein antigens)-positive RA versus ACPA-negative healthy or for ACPA-positive healthy (a pre-RA stage) versus ACPA-negative healthy. To deconvolute cell type-dependent differential methylation, we assayed the methylation patterns of sorted cells and used computational algorithms to resolve the relative contributions of different cell types and used them as covariates. Results To identify methylation biomarkers, five healthy twin pairs discordant for ACPAs were profiled, revealing a single differentially methylated region (DMR). Seven twin pairs discordant for ACPA-positive RA revealed six significant DMRs. After deconvolution of cell type proportions, profiling of the healthy ACPA discordant twin-set revealed 17 genome-wide significant DMRs. When methylation profiles of ACPA-positive RA twin pairs were adjusted for cell type, the analysis disclosed one significant DMR, associated with the EXOSC1 gene. Additionally, the results from our methodology suggest a temporal connection of the protocadherine beta-14 gene to ACPA-positivity with clinical RA. Conclusions Our biostatistical methodology, optimized for a low-sample twin design, revealed non-genetically linked genes associated with two distinct phases of RA. Functional evidence is still lacking but the results reinforce further study of epigenetic modifications influencing the progression of RA. Our study design and methodology may prove generally useful in twin studies. Electronic supplementary material The online version of this article (doi:10.1186/s13073-016-0374-0) contains supplementary material, which is available to authorized users.

IntroductionSmoking has consistently been associated with increased risk of developing rheumatoid arthritis (RA). The aim of this study was to estimate the influence of passive smoking on the risk of developing anti-cyclic citrullinated peptide antibodies (ACPA)-positive and ACPA-negative RA.MethodsA population-based case–control study using incident cases of RA was performed in Sweden, and the study population in this report was restricted to include never-smokers (589 cases, 1764 controls). The incidence of RA among never-smokers who had been exposed to passive smoking was compared with that of never-smokers who had never been exposed, by calculating the OR with a 95% CI employing logistic regression.ResultsNo association was observed between exposure to passive smoking and RA risk (OR 1.0, 95% CI 0.8 to 1.2 for ACPA-positive RA, and OR 0.9, 95% CI 0.7 to 1.2, for ACPA-negative RA). No suggestion of a trend between duration of passive smoking and RA risk was observed.DiscussionsNo association was observed between exposure to passive smoking and RA risk, which may be explained by a threshold below which no association between smoke exposure and RA occurs.

Characterized primarily by a low body-mass index, anorexia nervosa is a complex and serious illness 1, affecting 0.9–4% of women and 0.3% of men 2–4, with twin-based heritability estimates of 50–60% 5. Mortality rates are higher than those in other psychiatric disorders 6, and outcomes are unacceptably poor 7. Here we combine data from the Anorexia Nervosa Genetics Initiative (ANGI) 8,9 and the Eating Disorders Working Group of the Psychiatric Genomics Consortium (PGC-ED) and conduct a genome-wide association study of 16,992 cases of anorexia nervosa and 55,525 controls, identifying eight significant loci. The genetic architecture of anorexia nervosa mirrors its clinical presentation, showing significant genetic correlations with psychiatric disorders, physical activity, and metabolic (including glycemic), lipid and anthropometric traits, independent of the effects of common variants associated with body-mass index. These results further encourage a reconceptualization of anorexia nervosa as a metabo-psychiatric disorder. Elucidating the metabolic component is a critical direction for future research, and paying attention to both psychiatric and metabolic components may be key to improving outcomes.

Background Recent studies have shown divergent associations between rheumatoid arthritis (RA)-associated autoantibodies and RA onset phenotype. Whereas some studies report more inflammation in seronegative patients [1, 2], others report that rheumatoid factor (RF) associates with high baseline disease activity [3]. Objectives To define how individual RA-associated autoantibodies associate with individual disease activity score (DAS28, DAS28CRP) components at the time of RA diagnosis. Methods Sixteen individual ACPA reactivities, anti-CCP2, IgA-, IgG- and IgM-RF were analyzed centrally in baseline sera from 1600 RA patients classified according to the 1987 ACR criteria. All antibody cut-offs were determined as the 98th percentile among controls. The results were related to CRP, ESR, number of swollen and tender joints, DAS28, DAS28CRP, global disease activity (visual analogue scale), and health assessment questionnaire obtained at baseline. Results Individually, anti-CCP2, IgA RF and IgM RF associated with low counts of swollen and tender joints, with strongest association to anti-CCP2, and with high ESR. The association to low joint counts was stronger to number of individual ACPA reactivities than to anti-CCP2 levels (table). In multiple regression adjusted for age, sex and inclusion year, ACPA number associated strictly with low joint counts whereas IgM RF level associated with increased inflammatory markers, especially ESR (table). Also among IgM RF negative patients, occurrence of ACPA associated with low swollen and tender joint counts. Contrary, among ACPA negative patients, IgM showed no association to elevated ESR. The effect of RF on ESR increased with the number of individual ACPA reactivities present, most prominently for IgM RF (figure). Conclusion In early RA, ACPA associate with low counts of affected joints and IgM RF associates with elevated ESR in an ACPA-dependent manner. The latter finding relates to in vitro studies showing enhanced inflammatory effect of ACPA immune complexes with addition of RF[4, 5]. Future RA studies relating autoantibodies to disease activity may benefit from evaluating the impact of individual antibodies as well as distinct DAS components separately. References [1] Barra L, et al. J Rheumatol 2014;41:2361. [2] Nordberg LB, et al. Ann Rheum Dis 2017;76:341. [3] Aletaha D, et al. Arthritis Res Ther 2015;17:229. [4] Laurent L, et al. Ann Rheum Dis 2015;74:1425. [5] Sokolove J, et al. Arthritis Rheumatol 2014;66:813. Disclosure of Interests Eleftheria Pertsinidou: None declared, Vivek Anand Manivel: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Lars Alfredsson: None declared, Linda Mathsson Employee of: employed by Thermo Fisher Scientific, Monika Hansson: None declared, Martin Cornillet: None declared, Guy Serre: None declared, Rikard Holmdahl: None declared, Karl Skriner: None declared, Per-Johan Jakobsson: None declared, Helga Westerlind: None declared, Johan Askling Grant/research support from: Karolinska Institutet (JA) has or has had research agreements with the following pharmaceutical companies, mainly in the context of the ATRIS national safety monitoring programme for rheumatology biologicals: Abbvie, BMS, MSD, Eli Lilly, Pfizer, Roche, Samsung Bioepis, and UCB., Consultant for: Karolinska Institutet has received remuneration for JA participating in ad boards arranged by Lilly, Novartis, and Pfizer., Saedis Saevarsdottir Employee of: Part-time employee at deCODE Genetics/Amgen Inc, working on genetic research unrelated to this project., Johan Ronnelid: None declared

Background The association and role of antibodies to citrullinated proteins (ACPA) on the risk of cardiovascular (CV) co-morbidity in patients with rheumatoid arthritis (RA) is incompletely understood. We have previously reported an association between high levels of CCP2 and risk of acute coronary syndrome (ACS) in RA1. Objectives To further investigate any association between specific ACPA or rheumatoid factor (RF) isotypes, and CV events (ACS, stroke, CV death, and major adverse CV event (MACE)). Methods 2533 patients with RA from the Swedish EIRA study were tested for ACPA specificities on a custom-made microarray chip. All antibodies (Ab) detected with a prevalence >= 10% were included in the analysis. “Ab load” was defined as the number of specificities expressed in an individual, and categorized into four groups. ACPA was also measured by a commercial anti-CCP2 assay and anti-CCP2 levels divided into 1500 arbitrary units/mL, where The data was linked to the National Patient Register and the Cause of Death register, and events of ACS (ICD10=I20.0, I21, or cause of death listed as “I21”), stroke (ICD10=I60-I64), CV death (cause of death listed as “I”), or MACE (any of the above) identified. We used Cox proportional hazard model, adjusted for sex, age and calendar period of RA diagnosis, to assess associations between ACPA/RF status and each CV outcome. Results Median age at diagnosis was 52 years, and median follow-up was 12 years. The incidences per 1000 person-years were 4.3 for ACS, 4.0 for stroke, 2.4 for CV deaths, and 9.4 for MACE. 66% were anti-CCP2 positive. This was associated with ACS, stroke and MACE. There was a trend with increasing CV risk with increasing anti-CCP2 levels (Table). For RF, the pattern was markedly different across isotypes; IgM RF associated with ACS, stroke and MACE whereas IgA RF associated to CV death (Table). 18 different ACPA specificities (Fil 307-324 (CPP-1), Vim 60-75, Vim 2-17, Fib β36-52, Fib alpha 580-600, Eno 5-21 (CEP-1), Fib α621-635, Fib α36-50, Fib β60-74, Ptm13, Ptm36, Pept Z1, Pept Z2, Pept 1, Pept 5, Bla26) had a frequency >10% and included in the analyses. Median Ab load was 6 (IQR:2). There was a significant p-value for trend between Ab load and CV risk for stroke and MACE. Fib β36-52 was the only Ab associated with all 4 outcomes, and, together with CPP3 and ptm13, the only ACPAs associated to ACS. No association to ACS remained when all Abs were jointly included in the model. For stroke, 13 of the 18 Abs associated with risk, but only Fib β60-74 remained (HR 1.91 (95% CI 1.07-3.42)) in the full model. For CV death and MACE, 14 Abs were associated, but no associations remained in the full model. Conclusion In patients with RA, RF and ACPA are linked to CV risk. For RF, CV risks differ with isotype. For ACPAs, very high levels, and the number of individual ACPAs, are linked to CV risk, suggesting that Ab load may be more important than individual ACPAs. Reference [1] Mantel A, et al, 2015. PMID 26138387 Disclosure of Interests Helga Westerlind: None declared, Johan Ronnelid: None declared, Monika Hansson: None declared, Lars Alfredsson: None declared, Linda Mathsson Employee of: employed by Thermo Fisher Scientific, Guy Serre: None declared, Martin Cornillet: None declared, Rikard Holmdahl: None declared, Per-Johan Jakobsson: None declared, Karl Skriner: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Saedis Saevarsdottir Employee of: Part-time employee at deCODE Genetics/Amgen Inc, working on genetic research unrelated to this project., Johan Askling Grant/research support from: Karolinska Institutet (JA) has or has had research agreements with the following pharmaceutical companies, mainly in the context of the ATRIS national safety monitoring programme for rheumatology biologicals: Abbvie, BMS, MSD, Eli Lilly, Pfizer, Roche, Samsung Bioepis, and UCB., Consultant for: Karolinska Institutet has received remuneration for JA participating in ad boards arranged by Lilly, Novartis, and Pfizer.

Background: Retrospective studies have shown that anti-citrullinated protein antibodies (ACPA) are a risk factor for the development of clinical arthritis. Objectives: We aimed to investigate in a prospective setting if ACPA and other biomarkers could predict development of ultrasound detected arthritis. Methods: Subjects with positive ACPA-test referred from primary care to the Rheumatology clinic that lacked arthritis in hands, feet and any other symptomatic joints by clinical and ultrasound examination (according to EULAR-OMERACT definition), were recruited into the Risk-RA research program during 2015-2016 and were followed up to the end of 2017. At inclusion a detailed clinical examination was performed and blood samples were analyzed for 13 specific ACPA reactivities (using a custom made peptide microarray) as well as 92 inflammation-associated protein biomarkers (using a multiplex immunoassay with Olink proximity extension technology). Presence of HLA-SE was analyzed using DR low-resolution kit. Univariate and multivariate analysis were used to investigate the association between clinical and laboratory parameters and development of ultrasound detected arthritis adjusting for the follow-up time. Results: 42% (27 out of 65) of the Risk RA subjects developed ultrasound detectable arthritis during a median follow up of 8 months. The remaining 58% (38 out of 65) were followed for a median of 25 months (range 12-44) without any signs of ultrasound detectable arthritis. Subjects developing arthritis had higher prevalence of HLA-SE (89% vs 56%) and increased occurrence of ultrasound detected tenosynovitis (44% vs 5%), as compared to those not developing arthritis. ACPA reactivities to citrullinated vimentin peptides (cit vim 2-17: 22% vs 6%; and cit vim 60-75: 70% vs 43%) and citrullinated histone peptides (cit H4 31-50: 89% vs 49%; and cit H3 21-44: 48% vs 23%) were a more common occurrence in subjects developing ultrasound detectable arthritis. Backward selection in a Cox regression model showed that ultrasound detectable arthritis could be predicted in a model including HLA-SE, tenosynovitis and ACPA reactivity to cit H4 31-50. Hazard ratio (HR) for arthritis development were 3.4 (95% CI 1.0-12, p 0.06) for HLA-SE carriers, 2.9 (95% CI 1.3-6.7, p 0.01) for tenosynovitis and 4.1 (95% CI 1.2-14, p 0.02) for Anti-citrullinated H4 31-50 positivity. Only modest differences were observed for few of the tested inflammatory markers in those developing as compared to those not developing ultrasound detectable arthritis: Interleukin- 6 (3.9 vs 3.3 AU/ML), Programmed death-ligand 1 (4.9 vs 5.2 AU/ML) and Chemokine (C-X-C motif) ligand 6 (9.2 vs 9.5 AU/ML). Conclusion: Certain ACPA fine specificities, HLA-SE and tenosynovitis predict the development of ultrasound detectable arthritis in seropositive individuals with musculoskeletal symptom who are at risk for RA. Disclosure of Interests: Aase Hensvold: None declared, Yogan Kisten: None declared, Alexandra Circiumaru: None declared, Monika Hansson: None declared, Meng Sun Grant/research support from: Yes, but not for presented project., Guozhong Fei: None declared, Nancy Vivar: None declared, Erik Af Klint: None declared, Hamed Rezaei: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Aleksandra Antovic: None declared, Anca Catrina Grant/research support from: Yes, but not for the presented study.

Background: Seropositive rheumatoid arthritis (RA) is associated with autoreactivity to citrullinated proteins and rheumatoid factor activity. The adaptive immune system and B cells are postulated to be central in RA pathogenesis, yet possible B-cell dysregulations have not been extensively studied. Here, we use exploratory mass cytometry and next generation sequencing to study overall B cell repertoire shifts in RA patients compared to healthy individuals. Objectives: We hypothesized that there are an underlying B cells repertoire distortion in RA that may be an important key to understanding the autoimmune pathogenesis. Methods: B cells enriched from PBMCs from nine ACPA pos., seven ACPA neg. RA patients, and six matched heathy controls were phenotyped with mass cytometry (CyTOF) using a 35-marker panel. Single cell data from all samples were pooled clustered via flowSOM in R to identify distinct cell populations, and visualized with tSNE. Cell numbers in each cluster/population were calculated to identify over-representation in patient groups or controls. ANOVA was performed to account for confounding factors such as age, sex and cell preparation date and differential expression of markers between groups was calculated via t-test. In parallel, PBMC B cell receptor (BCR) repertoires were investigated in 13 ACPA pos. RA patients and six age-matched healthy donors using the Illumina MiSeq platform and PCR multiplex amplicon libraries with a molecular barcode strategy to generate full variable region coverage. Sequences were filtered using pRESTO, annotated by IMGT and Change-O, finally generating 587 000 unique V-regions. Total serum IgM levels were screened by sandwich ELISA in 157 population controls, 193 ACPA pos., and 50 ACPA neg. RA patients. Variable gene frequency was analyzed by Chi-square with Yates correction and serum IgM levels with Kruskal-Wallis test. Results: Several B-cell phenotypes were found to be significantly different in ACPA pos. RA compared to controls including an increase in HLA-DR across subsets, CD11c in IgA memory and CD22 expression in clusters of mature naive IgM positive B cells. Moreover, we could see lower circulating cell counts in ACPA pos. RA in IgG memory (p=0.01) and trends for elevation in an CXCR5/CCR6 high transitional B cell cluster (p=0.06), with parallel lower number of transitional B cells with lower CCR6 expression (p=0.06). Notably, ACPA neg. RA generally had an intermediate phenotype between healthy controls and ACPA pos. RA. Several significant shifts in the RA BCR repertoire could be observed, including an expected higher frequency of VH N-linked glycosylation in highly mutated BCR (p Conclusion: Previous studies have shown that anti-citrulline autoreactivity in RA is primarily originates from memory B cells and characterized by high somatic mutations and N-glycosylation sites. However, here the largest B cell distortions in ACPA positive RA are observed in the naive B cell population that have not undergone germinal center responses. These differences could reflect baseline shifts and elevated natural autoreactivity as an underlying mechanism in RA pathogenesis. Disclosure of Interests: Yan Wang: None declared, Katy A. Lloyd: None declared, Ioannis Melas Employee of: Employed by UCB Pharma, Daniel Ramskold: None declared, Diana Zhou: None declared, Radha Thyagarajan: None declared, Karin Lundberg: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Anca Catrina Grant/research support from: Yes, but not for the presented study., Stephen Rapecki Employee of: Employed by UCB Pharma, Vivianne Malmstrom: None declared, Caroline Gronwall: None declared

Background: The role of psycho-social factors in the development of rheumatoid arthritis (RA) is debated. Objectives: We investigated whether psychosocial stress measured as low sense of social support, and low decision latitude at work, were linked to risk of RA, and whether they related to known lifestyle risk factors for RA. Methods: The Swedish population-based EIRA study included incident RA cases (N=3724) and controls (N=5937), matched for age, sex and residential area. Responders filled in questionnaires regarding self-reported social support, decision latitude at work and life-style-factors. The distribution of answers among controls were used to define exposure, thus for social support, those in the lowest quartile of social support were considered exposed to low social support and similarly for decision latitude, those in the lowest quartile were considered exposed to low decision latitude at work. Using logistic regression, we first evaluated whether exposures associated with RA risk, considering potential confounding of established risk factors. Then, we investigated whether the frequency of those factors differed between individuals reporting low social support or low decision latitude at work or not, among cases and controls. Results: There were 898 cases with low social support and 285 cases with low decision latitude at work (latter only available in first part of EIRA). Low social support was not associated with RA risk in unadjusted analyses (OR= 1.05, 95%CI=0.95-1.15). Low decision latitude at work did associate with a higher RA risk in the unadjusted analyses (OR=1.52, 95% CI=1.20-1.94), but this association was no longer significant after further adjustment for smoking, obesity and university degree (adjusted OR=1.24, 95% CI=0.93-1.63). Associations between those life-style risk factors and RA were confirmed (no university degree, OR=1.50; smoking OR=1.71; obesity OR=1.15). Next, we evaluated whether low social support or low decision latitude at work differed by previously established risk factors. Cases with RA reporting low sense of social support were more often men (OR=1.60, 95%CI=1.40-1.83), current smokers (OR=1.46, 95%CI=1.26-1.70), obese (OR=1.29, 95%CI=1.09-1.54), physically inactive (OR=2.78, 95%CI=1.98-3.90) and without a university-degree (OR=2.04, 95%CI=1.77-2.36); with similar pattern among the controls. For working-conditions, cases reporting low decision latitude at work were also more often current smokers (OR=2.05, 95%CI=1.33-3.16) and with no university degree (OR=8.23, 95%CI=5.13-13.22), but less often male (OR = 0.40, 95%CI=0.26-0.60). Again, the pattern was similar among controls. RF/ACPA-positivity did not associate with low social support or low decision latitude. Conclusion: Neither low social support nor low decision latitude at work were associated with an increased risk of RA after adjustment for other known lifestyle risk factors for RA. An initial crude association between low decision latitude at work and risk for RA was explained by differences in smoking and educational level. However, both low social support and low decision latitude at work associate strongly with known, and here validated, risk factors for RA (smoking, obesity, no university degree) with similar pattern among both cases and controls. Acknowledgement: The EIRA study group Disclosure of Interests: Louise Hedenstierna: None declared, Christina H. Opava: None declared, Sofia Ernestam: None declared, Johan Askling Grant/research support from: Karolinska Institutet (JA) has or has had research agreements with the following pharmaceutical companies, mainly in the context of the ATRIS national safety monitoring programme for rheumatology biologicals: Abbvie, BMS, MSD, Eli Lilly, Pfizer, Roche, Samsung Bioepis, and UCB., Consultant for: Karolinska Institutet has received remuneration for JA participating in ad boards arranged by Lilly, Novartis, and Pfizer., Lars Klareskog Grant/research support from: Yes, but not for the presented study., Lars Alfredsson: None declared, Saedis Saevarsdottir Employee of: Part-time employee at deCODE Genetics/Amgen Inc, working on genetic research unrelated to this project.

Background: The presence of comorbidities in patients with rheumatoid arthritis (RA) contributes to increased morbidity and mortality(1). Patients with RA have an increased risk of comorbidities e.g. interstitial lung (IL) disease (7.7% incidence(2); up to 60% IL abnormalities in early RA(3)), depression (up to 200%(4); 16.8%(5)), cardiovascular disease (40-70%(6); 5-12.9%(7)) and diabetes (IR of 8.6 per 1000 person-years(8); 20%(9)). Yet, there are few comprehensive recommendations on the management of RA-related comorbidities. Objectives: This study aimed to identify models of good quality care for patients with RA and their associated comorbidities in Europe and understand how these practices can be widely implemented. Methods: Existing published recommendations across Europe on good practice in RA care including screening/managing selected comorbidities were reviewed. Team members of 12 specialist centres across Europe were interviewed. The interventions identified were reviewed and prioritised to form a selection of considerations by a consensus process involving 18 experts including rheumatologists, a patient rep., a nurse and also RA comorbidity specialists: cardiologist, psychologist, pulmonologist and diabetologist. Results: The interventions were prioritised for each patient profile: suspected RA: rapid access to care (online referral, triage, ultrasound–guided diagnosis) enhanced communication with primary care (hotline, education sessions) early arthritis clinic (timely clinical assessment and diagnosis) recently diagnosed: enabling self–management (self–monitoring and disease activity management support) early arthritis clinic comprehensive comorbidity assessment (standalone or in conjunction with RA appointment) established disease: dedicated comorbidity specialist integrating patient registries into daily clinical practice enabling self–management Eleven other interventions were identified including task-shifting to non-physician healthcare professionals, tailored education to patients and family members, and developing care networks. Conclusion: Despite limited European recommendations on management of RA comorbidities, a range of good practice care model interventions across Europe were identified which are non-complex, high-impact and meaningful. Next step will be to assess how these care models can be implemented in different healthcare systems for the benefit of patients with RA. References: [1] Dougados, et al. Ann Rheum Dis2014; 73:62 [2] Bongartz, et al. Arthritis Rheum2010; 62(6):1583 [3] Reynisdottir, et al. Arthritis Rheum2014; 66:31 [4] Sheehy, et al. Rheum2006; 45(11):1325-1327 [5] Matcham, et al. Rheumatology2013; 52:2136 [6] Holmquist, et al. Ann Rheum Dis2017; 76:1642 [7] Van Halm, et al. Ann Rheum Dis2009; 68(9):1395 [8] Solomon D, et al. Ann Rheum Dis2010; 69(12):2114 [9] Albrecht K, et al. Rheum2018; 57(2):329-336 Disclosures: Most authors have received funding from the industry including Sanofi Genzyme who solely funded this study Disclosure of Interests: Tore K. Kvien Grant/research support from: AbbVie, BMS, MSD, Pfizer, Roche and UCB., Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi, Mylan and UCB, Speakers bureau: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi and UCB, Karel Pavelka: None declared, Joaquim Polido-Pereira: None declared, Anne Grete Semb: None declared, Magnus Skold: None declared, Alejandro Balsa Grant/research support from: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Consultant for: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Sandoz, Lilly, Paid instructor for: Pfizer, Speakers bureau: Pfizer, Novartis, UCB, Nordic, Sanofi, Sandoz, Lilly, Neil Betteridge Consultant for: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Speakers bureau: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Maya Buch Grant/research support from: Pfizer LTD, UCB, Consultant for: AbbVie, Eli Lilly, EMD Serono, Pfizer Ltd., Sanofi, Patrick Durez Speakers bureau: Bristol-Myers Squibb, Eli Lilly, Sanofi, Celltrion, Ennio Favalli: None declared, Guillaume Favier: None declared, Cem Gabay Grant/research support from: Roche, Pfizer, AB2 Bio Ltd, Consultant for: Roche, Pfizer, Lilly, AbbVie, Sanofi, Regeneron, Bristol-Myers Squibb, Novartis, UCB, AB2 Bio Ltd, Debiopharm, Rinie Geenen: None declared, Ioanna Gouni-Berthold: None declared, Frank van den Hoogen: None declared, Alison Kent: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, maxime dougados Grant/research support from: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma, Consultant for: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma

Background: Patients with rheumatoid arthritis (RA) have an increased risk of comorbidities such as diabetes (IR of 8.6 per 1000 person-years(1); 20% prevalence(2)), interstitial lung disease (7.7% incidence(3); up to 60% (interstitial lung abnormalities in early RA)(4)), depression (up to 200%(5); 16.8%(6)), and cardiovascular disease (40-70%(7); 5-12.9%(8)) which contributes to increased long-term morbidity and mortality(9). However, despite advances in treatment there are few established recommendations on the management of RA-related comorbidities. Objectives: This study aimed to identify examples of good practice in the care of RA and associated comorbidities meeting standards of patient-centred care, and consider how these could be implemented in other European centres. Methods: Following a literature review, multidisciplinary teams including specialists in rheumatology, cardiology and internal medicine, nurses, physiotherapists, psychologists, patient liaisons and care coordinators at 12 selected specialist centres across Europe (1 centre per country) were interviewed (approx. 180 interviews). The models identified were critically reviewed by a group of experts including a patient representative, and the degree to which the interventions impacted patient care and could be implemented in other centres was evaluated. Results: Several care model interventions were identified which may improve quality and the patient’s experience of care, e.g. fully integrated screening and diagnosis of comorbidities; coordination and sharing of care across different disciplines of comorbidity management; tailored individual education of patients and family members on lifestyle; enabling virtual engagement between patients on lifestyle management; and optimised convenience for patients having to attend multiple specialty appointments. Conclusion: This study identified and evaluated interventions that may improve patient outcomes and quality of care in RA and associated comorbidities. The next steps will be to disseminate and implement these examples of good practices in a variety of European healthcare systems and settings. References [1] Solomon D, et al. Ann Rheum Dis2010; 69(12):2114-7 [2] Albrecht K, et al. Rheum2018; 57(2):329-336 [3] Bongartz, et al. Arthritis Rheum2010; 62(6):1583-1591 [4] Reynisdottir, et al. Arthritis Rheum2014; 66(1):31-39 [5] Sheehy, et al. Rheum2006; 45(11):1325-1327 [6] Matcham, et al. Rheumatology2013; 52:2136-2148 [7] Holmquist M, et al. Ann Rheum Dis2017;76:1642-47 [8] Van Halm, et al. Ann Rheum Dis2009; 68(9):1395-1400 [9] Dougados, et al. Ann Rheum Dis2014; 73(1):62-68 Disclosures: Most authors have received funding from the industry including Sanofi Genzyme who solely funded this study Disclosure of Interests: Neil Betteridge Consultant for: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Speakers bureau: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Alejandro Balsa Grant/research support from: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Consultant for: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Sandoz, Lilly, Paid instructor for: Pfizer, Speakers bureau: Pfizer, Novartis, UCB, Nordic, Sanofi, Sandoz, Lilly, Maya Buch Grant/research support from: Pfizer LTD, UCB, Consultant for: AbbVie, Eli Lilly, EMD Serono, Pfizer Ltd., Sanofi, maxime dougados Grant/research support from: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma, Consultant for: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma, Patrick Durez Speakers bureau: Bristol-Myers Squibb, Eli Lilly, Sanofi, Celltrion, Ennio Favalli: None declared, Guillaume Favier: None declared, Cem Gabay Grant/research support from: Roche, Pfizer, AB2 Bio Ltd, Consultant for: Roche, Pfizer, Lilly, AbbVie, Sanofi, Regeneron, Bristol-Myers Squibb, Novartis, UCB, AB2 Bio Ltd, Debiopharm, Rinie Geenen: None declared, Ioanna Gouni-Berthold: None declared, Frank van den Hoogen: None declared, Alison Kent: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Mikkel Ostergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Karel Pavelka: None declared, Joaquim Polido-Pereira: None declared, Anne Grete Semb: None declared, Magnus Skold: None declared, Tore K. Kvien Grant/research support from: AbbVie, BMS, MSD, Pfizer, Roche and UCB., Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi, Mylan and UCB, Speakers bureau: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi and UCB

Background IgM RF and anti-CCP2 have been shown to associate with young age at RA diagnosis [1, 2]. By contrast, little is known about the association between other RF isotypes and age at onset, or sex. Objectives To examine the association between individual RA autoantibodies, sex and age at RA onset. Methods Anti-CCP2, IgA-, IgG- and IgM-RF were analysed centrally in baseline sera from 1600 Epidemiological Investigations in RA (EIRA) patients aged 18-70 years and classified according to the 1987 ACR criteria within one year of first symptoms. Cut-offs for RF isotypes were determined at the 98th percentile based on the EIRA RA-free controls, close to the 98.4% anti-CCP2 specificity. Results Anti-CCP2, IgA-, IgG- and IgM RF were found in 1020 (64%), 692 (43%), 529 (33%), and 916 (57%), of the patients, respectively. Mean (median) age at diagnosis among men was 54 (57) year, higher than 51 (54) years among women (p Conclusion On average, IgA RF positive (vs. negative) RA patients are almost four years older at the time of diagnosis; the opposite was found for anti-CCP2 and IgM RF. Whereas sex-differences explain the age-association for IgM RF, this is not the case for anti-CCP2 and for IgA RF. References [1] Diaz FJ, et al. Joint Bone Spine 2011;78:175. [2] Jacobsen S. Clin Rheumatol 2004;23:121. Disclosure of Interests Eleftheria Pertsinidou: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Lars Alfredsson: None declared, Linda Mathsson Employee of: employed by Thermo Fisher Scientific, Monika Hansson: None declared, Helga Westerlind: None declared, Johan Askling Grant/research support from: Karolinska Institutet (JA) has or has had research agreements with the following pharmaceutical companies, mainly in the context of the ATRIS national safety monitoring programme for rheumatology biologicals: Abbvie, BMS, MSD, Eli Lilly, Pfizer, Roche, Samsung Bioepis, and UCB., Consultant for: Karolinska Institutet has received remuneration for JA participating in ad boards arranged by Lilly, Novartis, and Pfizer., Saedis Saevarsdottir Employee of: Part-time employee at deCODE Genetics/Amgen Inc, working on genetic research unrelated to this project., Johan Ronnelid: none declared

Background Autoantibodies against citrullinated proteins (ACPAs) have been suggested to play important roles in RA pathogenesis (1-3). Objectives In order to further dissect how ACPAs influence bone homeostasis and inflammation in the joints we analyzed the binding of different ACPA clones to target antigens produced by synovial fibroblasts, osteoclasts (OCs) or neutrophil granulocytes. Methods Fibroblasts were isolated from synovial tissue of RA patients by enzymatic digestion. Monocytes and neutrophil granulocytes were isolated from the peripheral blood of healthy individuals. Osteoclasts were generated from monocyte-derived dendritic cells in the presence of M-CSF and RANK-L. Polyclonal ACPAs were purified from pooled serum samples of RA patients using protein G and Cyclic Citrullinated Peptide-based affinity chromatography. Monoclonal ACPAs were isolated from synovial plasma cells of RA patients, as described (4). Protein citrullination was analyzed with mass spectrometry. ACPA binding was analyzed using confocal microscopy and flow cytometry. Neutrophil extracellular trap (NET) formation was monitored using IncuCyte and confocal microscopy. Results Synovial fibroblasts expressed surface antigens to the ACPA clone 1325:01B09 following exposure to cellular stress (serum withdrawal) or IL-8 stimulation. Osteoclasts and their precursors were characterized by steady state protein citrullination and these cells were recognized by another distinct ACPA clone 1325:04C03. Using mass spectrometry, we detected citrullinated actin and vimentin in developing OCs. Interestingly, both proteins were present on the cell surface, showing a partial colocalization with the cell-bound 1325:04C03 antibodies. Neutrophil granulocytes exposed a large amount of citrullinated targets for both 1325:04C03 and 1325:01B09 as well as for polyclonal ACPAs in neutrophil extracellular traps (NETs), irrespectively of the stimulus that triggered NETosis. Activation of the cells by Ca2+ ionophores triggered a rapid NETosis and cellular disintegration, in parallel with a profound reactivity of all tested ACPAs with both intracellular or surface antigens. Other activation signals, e.g. PMA, nigericin, zymosan or IL-8 did not induce protein citrullination in the cells, even in conditions where citrullinated proteins were detected in NETs. Conclusion Distinct monoclonal ACPAs target different cell types, suggesting unique pathological roles for individual ACPA clones. OCs might be among the earliest ACPA targets due to their physiological protein citrullination. Fibroblasts, on the contrary, acquired ACPA sensitivity only following cellular stress signals. Intact neutrophils were not targeted by ACPAs, whereas damaged cells and the extruded NET products might be important sources of citrullinated antigens that form immune complexes with ACPAs. References [1] Harre, U. et al. J Clin Invest (2012) [2] Krishnamurthy, A. et al. Ann Rheum Dis (2016) [3] Wigerblad, G. et al. Ann Rheum Dis (2016) [4] Steen, J. et al. Arthritis Rheumatol (2018) Disclosure of Interests Bence Rethi: None declared, Meng Sun Grant/research support from: Yes, but not for presented project., Alexandra Circiumaru: None declared, Akilan Krishnamurthy: None declared, Heidi Wahamaa: None declared, Jimmy Ytterberg Employee of: Currently employed by Sobi, Stockholm, Sweden. Earlier, during his contribution in the presented study he was 100% employed by the Karolinska Institutet., Vivianne Malmstrom Grant/research support from: Yes, but not for the presented study., Lars Klareskog Grant/research support from: Yes, but not for the presented study., Anca Catrina Grant/research support from: Yes, but not for the presented study.

Background Anti-citrullinated protein antibodies (ACPA) play an important role in rheumatoid arthritis (RA) pathogenesis. They recognize a wide number of citrullinated targets and show limited cross-reactivity to acetylated ones(1). Objectives We aimed to investigate the effect of monoclonal ACPAs with different binding patterns on RA synovial tissue derived fibroblasts (SF). Methods Synovial fibroblasts were isolated from synovial tissue of RA patients by enzymatic digestion. ACPA and control monoclonal antibodies (mAbs) were derived from single B cells isolated from RA patients. Two monoclonal ACPA (1325:01B09 and 1325:05C06) showed cross-reactivity to acetylated-targets while four of them (1325:04C03, 1325:07E07, 14CFCT2D09, 14CFCT2H12) did not(1). mAbs were tested in synovial fibroblast migration (Incucyte live time image analysis) and osteoclast formation (TRAP) assays. The role of mAbs cross-reactivity was tested in fibroblast migration assays using inhibitors of peptidylarginine deiminases (Cl-amidine), histone acetyltransferase (anacardic acid) and histone deacetylase (trichostatin A). Binding patterns of monoclonal ACPAs were tested in synovial biopsies obtained from both healthy donors and RA patients. Results One acetylation cross-reactive ACPA (1325:01B09) and two with no cross reactivity (14CFCT2D09 14CFCT2H12) significantly enhanced fibroblast migration (mean±SD fold increase of 1.9±0.5, 1.7±0.4 and 1.8±0.6, respectively) compared to control mAb 1362:01E02 (p Conclusion Monoclonal ACPAs have distinct cellular effects on synovial fibroblasts and osteoclasts that are not related to cross reactivity towards acetylated targets References [1] K. A. Lloyd, G. Wigerblad, P. Sahlstrom, M. G. Garimella, K. Chemin, J. Steen, P. J. Titcombe, B. Marklein, D. Zhou, R. Stalesen, E. Ossipova, C. Lundqvist, O. Ekwall, J. Ronnelid, D. L. Mueller, M. C. I. Karlsson, M. J. Kaplan, K. Skriner, L. Klareskog, F. Wermeling, V. Malmstrom, C. Gronwall, Differential ACPA Binding to Nuclear Antigens Reveals a PAD-Independent Pathway and a Distinct Subset of Acetylation Cross-Reactive Autoantibodies in Rheumatoid Arthritis. Front Immunol9, 3033 (2018). Disclosure of Interests Meng Sun Grant/research support from: Yes, but not for presented project., Akilan Krishnamurthy: None declared, Alexandra Circiumaru: None declared, Marianne Engstrom: None declared, Johanna Steen: None declared, Philip Titcombe: None declared, Vivianne Malmstrom: None declared, Heidi Wahamaa: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Bence Rethi: None declared, Anca Catrina Grant/research support from: Yes, but not for the presented study.

Background: In rheumatoid arthritis (RA), autoantibodies against citrullinated proteins (ACPAs) have been reported to be associated with bone loss, pain and tenosynovitis prior to disease onset. Objectives: We aimed to investigate if transfer of human ACPAs into mice could reproduce these clinical observations. Methods: Monoclonal ACPA (1325:04C03 and 1325:01B09) and control (1362:01E02) antibodies (mAbs) were generated from synovial plasma or memory B cells of RA patients. 2mg of combination of monoclonal ACPAs or control antibody were injected in BALB/c female mice (12-16 Weeks) with or without a consecutive intra-articular injection of LPS after 8 days. Pain-like behavior was monitored by measuring mechanical hypersensitivity using von Frey filaments every 3 days and estimation by up-down Dixon method. Bone mineral density was measured by micro-CT. Using specially designed mobilization casts, dedicated mouse MRI coils, and gadolinium enhanced contrast medium, the hind limbs of these mice were scanned and evaluated for any signs of soft tissue joint inflammation. Blinded to ACPA and controls, the MRI images were scored for the presence of synovial thickening, effusion and tendon inflammatory changes by 3 readers in consensus. Results: ACPAs (1325:04C03 and 1325:01B09) induced significantly more pronounced pain-like behavior (lasting for at least 4 weeks) and reduction of the trabecular bone thickness in the hind limbs, whereas no such effect was seen with the control mabs generated in the same way as the monoclonal ACPAs. While no macroscopic sign of joint inflammation could be detected, preliminary MRI data shows that sub-clinical joint inflammation (such as tenosynovitis) in mice injected with ACPAs but not those injected with control mAb. Intra-articular LPS injection resulted in significantly increased prolonged mechanical hypersensitivity in mice initially receiving sub-optimal doses of monoclonal ACPA as compared to those receiving control mAb. This was associated with higher levels of sub-clinical inflammation (as shown by MRI scans) in ACPA injected mice. Conclusion: We show that ACPA induces pain-like behavior, bone loss and sub-clinical inflammation in mice, a model that mimics the pre-clinical state of ACPA positive RA. References [1] Harre, U. et al. J Clin Invest (2012) [2] Krishnamurthy, A. et al. Ann Rheum Dis (2016) [3] Wigerblad, G. et al. Ann Rheum Dis (2016) [4] KleyerA, Seminars in Arthritis and Rheumatism (2016) Disclosure of Interests: Akilan Krishnamurthy: None declared, Yogan Kisten: None declared, Katalin Sandor: None declared, Alexandra Circiumaru: None declared, Gustaf Wigerblad: None declared, Peter Damberg: None declared, Koji Sakurabas: None declared, Heidi Wahamaa: None declared, Patrik Jarvolli: None declared, Juan Jimenez Jimenez Andrade: None declared, Vivianne Malmstrom: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Camilla Svensson: None declared, Bence Rethi: None declared, Anca Catrina Grant/research support from: Yes, but not for the presented study.

Background Long-term morbidity and mortality in patients with rheumatoid arthritis (RA) are increased(1) due to the increased risk of comorbidities including cardiovascular disease (40-70% incidence(2); 5-12.9% prevalence(3)), diabetes (IR of 8.6 per 1000 person-years(4); 20%(5)), interstitial lung disease (7.7%(6); up to 60% (interstitial lung abnormalities in early RA)(7)) and depression (up to 200%(8); 16.8%(9)). In addition to differing health care delivery systems throughout Europe, there is also variability in the roles and responsibilities of healthcare professionals (HCPs) across and within countries(10). Objectives This study aimed to identify good practices within the roles of HCPs in the care of RA and associated comorbidities and to understand how these practices may be implemented in other centres. Methods This study interviewed multidisciplinary teams at 12 selected specialist centres across Europe (1 centre per country) and examples of HCPs who had expanded roles and responsibilities were identified. Further, the questions whether these practices improved quality of care and could be implemented in other centres were addressed. Results This Europe-wide study identified good practice examples of enhanced roles and responsibilities for HCPs such as nurses, physiotherapists, occupational therapists and podiatrists that varied with different categories of patients and their corresponding needs. The scope and depth of extended roles also varied between different countries and health systems. Examples included: Conclusion Expanding the roles of HCP team members can help broaden perspectives on healthcare delivery, relieve the burden put on specialists and enable the provision of well-rounded, patient-centred holistic care that may improve quality of life for patients with RA, especially related to their associated comorbidities. References [1] Dougados, et al. Ann Rheum Dis 2014;73:62-68 [2] Holmquist M, et al. Ann Rheum Dis 2017;76:1642-47 [3] Van Halm, et al. Ann Rheum Dis 2009; 68(9) :1395-1400 [4] Solomon D, et al. Ann Rheum Dis 2010; 69(12): 2114-7 [5] Albrecht K, et al. Rheum 2018; 57(2):329-336 [6] Bongartz, et al. Arthritis Rheum 2010; 62(6):1583-1591 [7] Reynisdottir, et al. Arthritis Rheum 2014; 66, 31-39 [8] Sheehy, et al. Rheum 2006; 45(11):1325-1327 [9] Matcham, et al. Rheumatology 2013; 52:2136-21481; 53(8):1491-1496 Disclosures Most authors have received funding from the industry including Sanofi Genzyme who solely funded this study Disclosure of Interests Alison Kent: None declared, Cem Gabay Grant/research support from: Roche, Pfizer, AB2 Bio Ltd, Consultant for: Roche, Pfizer, Lilly, AbbVie, Sanofi, Regeneron, Bristol-Myers Squibb, Novartis, UCB, AB2 Bio Ltd, Debiopharm, Rinie Geenen: None declared, Ioanna Gouni-Berthold: None declared, Frank van den Hoogen: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Karel Pavelka: None declared, Joaquim Polido-Pereira: None declared, Anne Grete Semb: None declared, Magnus Skld: None declared, Alejandro Balsa Grant/research support from: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Consultant for: Abbvie, Pfizer, Novartis, BMS, Nordic, Sanofi, Sandoz, Lilly, Paid instructor for: Pfizer, Speakers bureau: Pfizer, Novartis, UCB, Nordic, Sanofi, Sandoz, Lilly, Neil Betteridge Consultant for: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Speakers bureau: Amgen, Eli Lilly, Grunenthal, GSK, Heart Valve Voice, Janssen, Roche, Sanofi Genzyme and Sanofi Regeneron, Maya Buch Grant/research support from: Pfizer LTD, UCB, Consultant for: AbbVie, Eli Lilly, EMD Serono, Pfizer Ltd., Sanofi, maxime dougados Grant/research support from: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma, Consultant for: Eli Lilly and Company, Pfizer, AbbVie, and UCB Pharma, Patrick Durez Speakers bureau: Bristol-Myers Squibb, Eli Lilly, Sanofi, Celltrion, Ennio Favalli: None declared, Guillaume Favier: None declared, Tore K. Kvien Grant/research support from: AbbVie, BMS, MSD, Pfizer, Roche and UCB., Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi, Mylan and UCB, Speakers bureau: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi and UCB

Background We have previously shown that structural changes, increased tissue citrullination, signs of local inflammation and ACPA are present in the pulmonary compartment of early seropositive RA. These findings suggest a potential role for the lungs in generation of RA-associated autoimmunity. Objectives To identify citrulline reactive B cells in the lung compartment of early untreated RA patients and to generate and characterize the corresponding monoclonal antibodies. Methods Bronchoalveolar lavage (BAL) fluid cells (13 and 22.5 million respectively) were obtained from two early untreated non-smoking ACPA positive RA patients and single CD19+ B cells were sorted by flow cytometry. Immunoglobulin variable region genes were sequenced and expressed to generate recombinant monoclonal antibodies (mAbs). The citrulline reactivity was determined by in-house ELISA against different citrullinated peptides and controls. Results Single sorted CD19+ B cells (n=768) from each patient (RA.1 and RA.2) were processed and the variable region amplification and sequencing yielded 192 (RA.1) and 213 (RA.2) paired heavy and light chain sequences. Based on previously published data showing SHM-introduced N-linked glycosylation in the Fab regions of ACPA [1], 22 sequences from each patient were pre-selected with such features, and monoclonal antibodies were expressed. Two antibodies from each patient were ACPAs as determined by their reactivity against CCP2. The 4 ACPAs have varying ACPA fine specificity against citrullinated enolase, filaggrin, vimentin and fibrinogen peptides (figure 1). Sequence analysis of the heavy chain variable region revealed unique V gene usage of the ACPAs arising from different patients, V4-39 for the 2 mAbs from RA.1 and V3-49 for RA.2. Conclusion We demonstrate for the first time that citrulline-reactive B cells are present in the lung compartment of early untreated RA. Further analysis and functional characterization are needed and ongoing to understand their role in RA. Reference [1] Lloyd, K.A., et al., Variable domain N-linked glycosylation and negative surface charge are key features of monoclonal ACPA: Implications for B-cell selection. Eur J Immunol, 2018. 48(6): p.1030-1045. Disclosure of Interests Vijay Joshua: None declared, Malena Loberg-Haarhaus: None declared, Heidi Wahamaa: None declared, Aase Hensvold: None declared, Magnus Skold: None declared, Johan Grunewald: None declared, Lars Klareskog Grant/research support from: Yes, but not for the presented study., Vivianne Malmstrom: None declared, Anca Catrina Grant/research support from: Yes, but not for the presented study.

ANTI-MODIFIED PROTEIN AUTOANTIBODIES IN RA DISPLAY IMPORTANT PEPTIDE CROSS-REACTIVITY BUT YET PROTEIN RECOGNITION SELECTIVITY

This study aimed to investigate the periodontal health of patients with established rheumatoid arthritis (RA) in relation to oral microbiota, systemic and oral inflammatory mediators, and RA disease activity. Forty patients underwent full-mouth dental/periodontal and rheumatological examination, including collection of blood, saliva, gingival crevicular fluid (GCF) and subgingival plaque. Composition of plaque and saliva microbiota were analysed using 16S rRNA sequencing and levels of inflammatory mediators by multiplex-immunoassay. The majority of the patients (75%) had moderate or severe periodontitis and the rest had no/mild periodontitis. Anti-citrullinated protein antibody (ACPA) positivity was significantly more frequent in the moderate/severe periodontitis (86%) compared to the no/mild group (50%). No significance between groups was observed for RA disease duration or activity, or type of medication. Levels of sCD30/TNFRSF8, IFN-&alpha, 2, IL-19, IL-26, MMP-1, gp130/sIL-6R&szlig, and sTNF-R1 were significantly higher in serum or GCF, and April/TNFSF13 was significantly higher in serum and saliva samples in moderate/severe periodontitis. The microbial composition in plaque also differed significantly between the two groups. In conclusion, the majority of RA patients had moderate/severe periodontitis and that this severe form of the disease was significantly associated with ACPA positivity, an altered subgingival microbial profile, and increased levels of systemic and oral inflammatory mediators.

Synovial IgG-expressing B cells from patients with rheumatoid arthritis show specificity for citrullinated autoantigens., Antibodies targeting citrullinated proteins (ACPAs [anticitrullinated protein antibodies]) are commonly found in patients with rheumatoid arthritis (RA), strongly associate with distinct HLA-DR alleles, and predict a more aggressive disease course as compared with seronegative patients. Still, many features of these antibodies, including their site of production and the extent of MHC class II–driven T cell help, remain unclarified. To address these questions, we have used a single B cell–based cloning technology to isolate and express immunoglobulin (Ig) genes from joint-derived B cells of active RA patients. We found ∼25% of synovial IgG-expressing B cells to be specific for citrullinated autoantigens in the investigated ACPA+ RA patients, whereas such antibodies were not found in ACPA− patients. The citrulline-reactive monoclonal antibodies did not react with the unmodified arginine peptides, yet several reacted with more than one citrullinated antigen. A role for active antigen selection of the citrulline-reactive synovial B cells was supported by the strong bias toward amino acid replacement mutations in ACPA+ antibodies and by their loss of reactivity to citrullinated autoantigens when somatic mutations were reverted to the corresponding germline sequences.

Objective: Anti-citrullinated protein antibodies (ACPAs) develop many years before the clinical onset of rheumatoid arthritis (RA). This study was undertaken to address the molecular basis of the specificity and cross-reactivity of ACPAs from patients with RA. Methods: Antibodies isolated from RA patients were expressed as monoclonal chimeric antibodies with mouse Fc. These antibodies were characterized for glycosylation using mass spectrometry, and their cross-reactivity was assessed using Biacore and Luminex immunoassays. The crystal structures of the antigen-binding fragment (Fab) of the monoclonal ACPA E4 in complex with 3 different citrullinated peptides were determined using x-ray crystallography. The prevalence of autoantibodies reactive against 3 of the citrullinated peptides that also interacted with E4 was investigated by Luminex immunoassay in 2 Swedish cohorts of RA patients. Results: Analysis of the crystal structures of a monoclonal ACPA from human RA serum in complex with citrullinated peptides revealed key residues of several complementarity-determining regions that recognized the citrulline as well as the neighboring peptide backbone, but with limited contact with the side chains of the peptides. The same citrullinated peptides were recognized by high titers of serum autoantibodies in 2 large cohorts of RA patients. Conclusion: These data show, for the first time, how ACPAs derived from human RA serum recognize citrulline. The specific citrulline recognition and backbone-mediated interactions provide a structural explanation for the promiscuous recognition of citrullinated peptides by RA-specific ACPAs.

B cells are postulated to be central in seropositive rheumatoid arthritis (RA). Here, we use exploratory mass cytometry (n = 23) and next-generation sequencing (n = 19) to study B-cell repertoire shifts in RA patients. Expression of several B-cell markers were significantly different in ACPA(+) RA compared to healthy controls, including an increase in HLA-DR across subsets, CD22 in clusters of IgM(+) B cells and CD11c in IgA(+) memory. Moreover, both IgA(+) and IgG(+) double negative (IgD(-) CD27(-)) CD11c(+) B cells were increased in ACPA+ RA, and there was a trend for elevation in a CXCR5/CCR6(high) transitional B-cell cluster. In the RA BCR repertoire, there were significant differences in subclass distribution and, notably, the frequency of VH with low somatic hypermutation (SHM) was strikingly higher, especially in IgG1 (p amp;lt; 0.0001). Furthermore, both ACPA(+) and ACPA(-) RA patients had significantly higher total serum IgA and IgM compared to controls, based on serology of larger cohorts (n = 3494 IgA; n = 397 IgM). The observed elevated Ig-levels, distortion in IgM(+) B cells, increase in double negative B cells, change in B-cell markers, and elevation of unmutated IgG(+) B cells suggests defects in B-cell tolerance in RA. This may represent an underlying cause of increased polyreactivity and autoimmunity in RA. Funding Agencies|UCB PharmaUCB Pharma SA; Swedish Research CouncilSwedish Research Council; Swedish Rheumatism Association, King Gustaf Vs 80-year Foundation; Ake Wibergs stiftelse; FOREUM, Foundation for Research in Rheumatology; European Research Council (ERC) under the European UnionEuropean Research Council (ERC); EU/EFPIA Innovative Medicines Initiative (IMI) [BTCure 115142, RTCure 777357]; Karolinska InstituteKarolinska Institutet

IntroductionAnticitrullinated peptide antibody (ACPA) responses for 22 citrullinated peptides in patients with early rheumatoid arthritis (RA) were analysed and related to radiological and clinical outcome during the first 2 years in a prospective inception cohort.MethodsThe ACPA reactivities were assessed in 1022 patients with early RA (symptoms ResultsFrequency of ACPA reactivities varied between 13.3% and 63.1%. Of the anticyclic citrullinated peptide-2 (anti-CCP2) antibody-negative patients, ACPA reactivities were positive in 32.6%. Smoking, human leucocyte antigen-shared epitope (HLA-SE), anti-CCP2/rheumatoid factor, protein tyrosine phosphatase non-receptor type 22 (1858C/T) and DAS28 were significantly associated with number of ACPA reactivities. The ACPA reactivities modified differently the development of DAS28 over 24 months (identified using trajectories). Anti-Filaggrin307-324, anti-hnRNP (Peptide)-Z1 and anti-F4-CIT-R antibodies anticipated lower DAS28 values (pConclusionsSeveral ACPA reactivities modified significantly the DAS28 development during the first 24 months and were significantly associated with Larsen score at baseline, 24 months and radiological progression.

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.

ObjectivesRheumatoid arthritis (RA)-specific anti-citrullinated protein/peptide antibodies (ACPAs) might contribute to bone loss and arthralgia before the onset of joint inflammation. We aimed to dissect additional mechanisms by which ACPAs might contribute to development of joint pathology.MethodsFibroblast-like synoviocytes (FLS) were isolated from the synovial membrane of patients with RA. The FLS cultures were stimulated with polyclonal ACPAs (anti-CCP-2 antibodies) purified from the peripheral blood of patients with RA or with monoclonal ACPAs derived from single synovial fluid B cells. We analysed how ACPAs modulate FLS by measuring cell adhesion and mobility as well as cytokine production. Expression of protein arginine deiminase (PAD) enzymes and protein citrullination were analysed by immunofluorescence, and signal transduction was studied using immunoblotting.ResultsChallenge of FLS by starvation-induced stress or by exposure to the chemokine interleukin-8 was essential to sensitise the cells to ACPAs. These challenges led to an increased PAD expression and protein citrullination and an ACPA-mediated induction of FLS migration through a mechanism involving phosphoinositide 3-kinase activation. Inhibition of the PAD enzymes or competition with soluble citrullinated proteins or peptides completely abolished the ACPA-induced FLS migration. Different monoclonal ACPAs triggered distinct cellular effects in either fibroblasts or osteoclasts, suggesting unique roles for individual ACPA clones in disease pathogenesis.ConclusionWe propose that transient synovial insults in the presence of a certain pre-existing ACPA repertoire might result in an ACPA-mediated increase of FLS migration.

Recent advances in single-cell sequencing technologies enable the generation of large-scale data sets of paired TCR sequences from patients with autoimmune disease. Methods to validate and characterize patient-derived TCR data are needed, as well as relevant model systems that can support the development of antigen-specific tolerance inducing drugs. We have generated a pipeline to allow streamlined generation of ‘artificial’ T cells in a robust and reasonably high throughput manner for in vitro and in vivo studies of antigen-specific and patient-derived immune responses. Hereby chimeric (mouse-human) TCR alpha and beta constructs are re-expressed in three different formats for further studies: (i) transiently in HEK cells for peptide-HLA tetramer validation experiments, (ii) stably in the TCR-negative 58 ​T cell line for functional readouts such as IL-2 production and NFAT-signaling, and lastly (iii) in human HLA-transgenic mice for studies of autoimmune disease and therapeutic interventions. As a proof of concept, we have used human HLA-DRB1∗04:01 restricted TCR sequences specific for a type I diabetes-associated GAD peptide, and an influenza-derived HA peptide. We show that the same chimeric TCR constructs can be used in each of the described assays facilitating sequential validation and prioritization steps leading to humanized animal models., Highlights • Peptide-HLA-TCR interactions are central to autoimmune disease and can be targeted. • Experimental model systems are needed to study patient peptide-HLA-TCR interactions. • Large scale TCR sequencing efforts need assays to validate and prioritize patient TCRs. • Chimeric TCR expression constructs can be used as a versatile discovery platform.

Objective To investigate the frequency of remaining pain in early rheumatoid arthritis (RA) after 3 months of treatment with methotrexate as the only disease modifying antirheumatic drug, with a special focus on patients with a good clinical response. Methods The study base was cases reported to a population-based early RA cohort who had followup data from the Swedish Rheumatology Quality Register (n = 1,241). The Disease Activity Score in 28 joints European League Against Rheumatism (EULAR) response criteria were used to evaluate clinical response to treatment as good, moderate, and no response. The primary end point was remaining pain at the 3-months followup visit, defined as pain >20 mm on a 100-mm visual analog scale (VAS). Results Remaining pain in spite of a EULAR good response at followup was associated with higher baseline disability, using the Health Assessment Questionnaire (adjusted odds ratio [OR] 2.2 [95% confidence interval (95% CI) 1.4–3.4] per unit increase), and less baseline inflammation, using the erythrocyte sedimentation rate (adjusted OR 0.81 [95% CI 0.70–0.93] per 10-mm increase). Similar associations were detected for remaining pain at followup in spite of low inflammatory activity, defined as a C-reactive protein level

Purpose of review Rheumatoid arthritis (RA) is not a homogenous disease entity but a syndrome with different causes and abnormalities with shared clinical manifestations. One major subset is anticitrullinated protein antibody (ACPA)-positive RA, which represents the larger fraction of RA patients and where autoantibodies and HLA class II association implicate an autoimmune condition. In the past few years, the specificity of the ACPA response and the possibility to subdivide patients based on ACPA subgroups have received much attention whereas the effector functions of the autoantibodies and underlying lymphocytes have not. Recent findings The review, based on HLA, will discuss the generation of the autoreactive citrulline-specific T-cell repertoire, highlight our current understanding of T-cell specificities and effector functions of both the T cells and ACPAs. Summary Dividing RA into subsets has only influenced clinical practice to a limited degree, that is, by indicating a better response to therapies modulating adaptive immunity, such as rituximab, in the ACPA+ disease subset. A more detailed understanding of the immune reactions underlying various subsets of RA may, however, change our view on RA therapeutics and prevention with the assumption that autoimmune variants of RA should be both curable and preventable.