Background Since individuals with inflammatory rheumatic diseases (IRDs) were excluded from the SARS-CoV-2 vaccination trials (1), uncertainty on the tolerability of the vaccines in this population was high. This caused a lower willingness to be vaccinated compared to the general population. Gaining more information on vaccine reaction in this population is critical. Objectives The aim of the study was to improve knowledge of the tolerability of SARS-CoV-2 vaccination in patients with IRD and to identify potential specific risks of this population by comparison with a healthy cohort. Methods IRD patients were recruited from the outpatient clinic of the Division of Rheumatology and Clinical Immunology at the hospital of the LMU Munich. Health care workers served as healthy controls. Questionnaires were used to identify adverse effects in all study participants after each SARS-CoV-2 vaccination and to obtain information about patients’ disease and therapy. Descriptive statistics and non-parametric tests were used to discern differences between IRD patients and controls. Results 235 IRD patients (60% female), mean (±SD) age 54 (±15) years, and 102 healthy individuals (67% female), mean age 48 (±16) years, were recruited between Jan 2021 and Sep 2022. Pain at the injection site and fatigue were the most common adverse events in both groups. (Table 1) Patients presented adverse events significantly less often after the first vaccination (59.6%) compared to healthy individuals (84.3%) (OR=0.274 [95% CI: 0.151-0.497]; P<0.0001). With 58.7% of patients and 78.4% of controls experiencing adverse events after the second vaccination the difference stayed significant (OR=0.391 [0.228-0.670]; P<0.001). Same goes for the third vaccination with 56.4% of patients and 69.3% of controls presenting adverse events (OR=0.573 [0.348-0.946]; P=0.029). No difference was seen when the occurrence of local effects were compared. However, systemic effects were experienced significantly less by patients compared to controls after the first (41.3% vs 59.8%) (P=0.002), second (38.7% vs 58.8%) (P<0.001) and third vaccination (39.0% vs 51.5%) (P=0.036). Younger age and female sex showed higher frequencies of adverse events in both groups. 2% of patients experienced an activation of their IRD. Serious adverse events did not occur. Conclusion IRD patients are at no higher risk of experiencing adverse events than controls after SARS-CoV-2 vaccination. In fact, systemic effects seem to occur less frequently in patients compared to healthy individuals, which potentially shows an influence of IRDs or their therapies on vaccination reactions. Reference [1]Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med. 2020;383(27):2603-15. Acknowledgements This work was supported by the Verbundanträge ‘GAIN’ (project 8, 01GM1910C) and ‘COVIM’ (project AP8, 01KX2021), both by the Federal Ministry of Education and Research of Germany; and by the FöFoLe program of the medical faculty of the LMU Munich. We thank all physicians that helped in patient-recruitment and all participants, because without them this work would not have been possible. Disclosure of Interests None Declared.

Background In SLE, new-onset proteinuria and albuminuria raise concern for renal involvement, even when isolated and subnephrotic. In women of childbearing age, pregnancy-related complications are other causes of renal protein loss. Distinguishing renal disease from pregnancy-related complications of SLE is difficult because SLE is associated with adverse maternal and fetal events, while pregnancy is also a cause of disease relapses. Common to all causes of pathologic proteinuria in SLE is that they are related to disease activity and/or the need for intervention, as proteinuria does not normalize on its own. Objectives We report a case of a patient with inactive SLE who intermittently developed significant isolated proteinuria and albuminuria of glomerular origin that was directly related to spontaneous abortion in early (possibly twin-)pregnancy. Methods A 39-year-old female with SLE on hydroxychloroquine presented at our clinic for a routine check-up. Physical examination and laboratory tests were performed. To that date, SLEDAI-2K during most visits had a score of 0, indicating inactive disease. Results The patient reported feeling well, and the physical examination was unremarkable. Stable low-grade thrombocytopenia was the only relevant abnormality in recent years. On the current examination, the urine showed significant proteinuria and A3 albuminuria in the protein/albumin to creatinine ratio (uPCR 724 mg/g, uACR 488 mg/g). IgG/creatinine was markedly elevated (74.4 mg/g), and α1-microglobulin was normal, indicating nonselective glomerular proteinuria without tubular impairment. There were no other abnormalities suggestive of SLE activity. After she recalled having vaginal spotting a week earlier, a pregnancy test was performed and was positive. Subsequently, the βHCG level increased insufficiently, and ultrasound detection of a live embryo was not successful, but the presence of two amniotic cavities was suspected. An early incomplete miscarriage was diagnosed, and the gestational age was calculated to be 6 + 5 weeks. Shortly thereafter, a planned suckling curettage was performed. One week later, she had a final vaginal bleed. At this time, the urine showed a decrease in proteinuria of over 50% (uPCR 317 mg/g, uACR 210 mg/g, IgG 26.9 mg/g). Three weeks later, urine protein was completely normalized, which proved stable 12 weeks after initial diagnosis. Throughout the follow-up period, she did not show any SLE relapse. Conclusion After exclusion of differential diagnoses (chart), causality of the miscarriage with the urinary findings seems evident. To date, there have been no reports of the concomitant occurrence of early pregnancy miscarriage, possibly LN-indicative glomerular proteinuria, and its spontaneous regression in a clinically and serologically inactive SLE patient. Recently, observations were confirmed that a large proportion of patients with a uPCR <1g/g had LN histology, whereas a relevant proportion had inactive sediment or normal serology like our patient. As the kidney is the organ most affected in SLE pregnancy, it is important to be aware of intermittent proteinuria, as the consequences may be very different from persistent proteinuria as would be expected in nephritis. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared.

OBJECTIVES:Biologics, including tumour necrosis factor inhibitors such as adalimumab (ADA), have significantly improved outcomes in rheumatoid arthritis (RA). Because the clinical course of RA and response to therapy may be influenced by the genetic background of the patient, the objective of this retrospective parallel-assigned case-control analysis was to evaluate the associations between candidate genetic markers for RA with clinical and radiographic responses to ADA + methotrexate (MTX) or MTX monotherapy in the Optimal Protocol for Treatment Initiation with MTX and ADA (OPTIMA) study. METHODS:Three candidate genetic markers were tested: HLA-DRB1 shared epitope (SE), interleukin 4 receptor (IL4R) single nucleotide polymorphism (SNP) rs1805010, and Fc gamma receptor IIb (FcgRIIb) SNP rs1050501. Genetic associations with week 26 clinical and radiographic responses during treatment with ADA + MTX or MTX monotherapy were assessed using summary statistics, chi-square or Fisher's exact test, correlation, regression models, and corrected for multiple-comparisons. RESULTS:Low disease activity (p=0.008) and improvement in American College of Rheumatology 20%, 50% and 70% response criteria (p=0.02, 0.01, and 0.02, respectively) were associated with HLA-DRB1 SE copy numbers in the ADA + MTX treatment arm, and the FcgRIIb SNP was a predictor of remission. The IL4R SNP correlated with radiographic progression in patients receiving MTX monotherapy, supporting previous findings. CONCLUSIONS:This pharmacogenetic analysis identified genetic components that contribute to clinical responses to anti-rheumatic therapy.

Introduction Regulatory T cells (Tregs) play a critical role in maintaining homeostasis and limiting autoimmunity. The transcription factor Forkhead box P3 (Foxp3) has been identified as the key regulator of Treg function and development. Its activity and stability are tightly regulated by acetylation dependent on the interplay between histone deacetylases (HDAC) and histone acetyltransferases (HAT). Tregs express distinctively on their cell surface glycoprotein A repetitions predominant (GARP). GARP binds latent TGFb and provides to Tregs an available pool of TGFb. The function of this TGFb source for Tregs has not been investigated yet. Treg-derived TGFb might on the one hand be involved in mediating suppressive functions of Tregs and on the other hand be important for maintaining Treg homeostasis. Objectives To analyse the function of surface TGFb bound to GARP utilising GARP-deficient Tregs from conditional CD4 specific GARP knockout mice. Methods CD4 positive CD25 +or CD25- T cell from GARP-deficient or wild type mice were purified using MACS separation and stimulated with anti-CD3 and anti-CD28 in the presence or absence of TGFb for different times. mRNA expression profile was evaluated in non-stimulated and stimulated cells by Affymetrix gene array analysis and confirmed by real-time PCR. Acetylation, Foxp3 protein expression and Smad2/3 phosphorylation were assessed by intracellular flow cytometry. Half-life of Foxp3 was evaluated in cell cultures using cycloheximid. Acetylation of Foxp3 was determined by fluorescence resonance energy transfer (FRET) utilising a FRET antibody pair for Foxp3 and acetylated lysine. The regulatory capacity of Treg was assessed in vivo in reconstitution experiments of Rag-deficient mice with CD25- CD4 T cells or bone marrow cells. Results GARP-deficient Tregs exhibited a markedly diminished intracellular protein acetylation. Acetylation of Foxp3 was also significantly lower. Consistently, expression of a Treg specific HDAC, HDAC9, was up regulated in Tregs lacking GARP. Both acetylation and HDAC9 expression levels could be restored by addition of exogenous TGFb. In this regard basal phosphorylation of TGFb-dependent transcription factors Smad2/3 was diminished in Tregs lacking GARP. Further analysis revealed an unstable phenotype of GARP-deficient Tregs characterised by a shorter half-life of Foxp3, a faster loss of Foxp3 in response to anti-CD3/28 stimulation and restricted regulatory capacity. Conclusions Lack of GARP on the cell surface results in a reduced TGFb availability and in a decreased TGFb signalling in CD4 Tregs. Diminished TGFb signalling leads in turn to an elevated HDAC9 expression and to a decreased Foxp3 acetylation. Lower acetylated Foxp3 determines an instable phenotype of GARP-deficient Tregs and their failure to proper regulate an immune reaction. Acknowledgements This work supported by DFG grants SK59/09–1 and Schu1683/10–1, and by BMBF Projekt Arthromark 01Ec1401B. Disclosure of interest None declared

Background: In Germany, the number of clinical fellows, who decide for a scientific career in basic research, is decreasing, leading to a growing lack of junior physician scientists (PS) highly needed to advance basic research.1 Structured mentoring and funding programs as well as other incentives might be necessary to attract young physicians and support starting a scientific career in basic science. Objectives: To identify expectations, motivating factors and barriers of final year medical students interested in rheumatology, of fellows and of physicians in rheumatology to start a scientific career in basic research. Methods: An online survey was distributed by email and via facebook and twitter to members of the German Network of Young Rheumatologists (rheumadocs), medical students in their final year participating in a student program of the German Society for Rheumatology (DGRh), and by direct contact to PS. The questions focused on demographics, scientific background (including experience in basic research), expectations such as scientific self-realization, acquirement of a postdoctoral degree, enhanced career options, as well as motivating factors (e.g. “fun”, financial benefits, travel bursaries, mentoring programs and others) and barriers (e.g. positions in basic science, exemption from clinical duties, lack of experience and/or assistance in fund-raising and scientific methods) with regard to a career in basic research. Results: Of the 91 responders, 75% was aged below 35 years (11% <25 yrs, 32% 25–29 yrs, 57% >29 yrs) and 58% were female. 19% were currently working in basic research. 23% were students. 35% were fellows currently in the clinic. 23% were primary attendants. Basic research experience was reported by 49% of all clinicians. Only 10% indicated not to be interested in performing basic research. Among the students, 48% were currently performing a laboratory-based medical thesis. Of interest, no substantial differences in expectations or barriers were found between students, PS and clinicians. As to motivational factors, PS named time spent in research accounted for rheumatology training (74%), support by excellence programs (71%) and enhanced career options with a postdoctoral degree (65%) more often than clinicians and students (57%, 50% and 42% respectively). Other common motivational factors were “fun” (76%) and travel bursaries for international meetings (62%). Financial benefits in terms of standard or even senior physician salaries were no major motivators (41% and 24%, respectively). Regarding expectations, 71% indicated scientific self-realization, 58% named enhanced career options. 78% indicated lacking exemption from clinical duties and lack of experience in fund-raising and scientific methods (58% and 48%) as a barrier for basic research. Conclusions: This study shows a high interest among young rheumatologists and students to work in basic research, and indicates a need for programs, which facilitate the start of a career as physician scientist by providing a general framework with no drawbacks regarding rheumatology specialty training, (at least partial) exemption from clinical duties and support in development of research projects. Reference 1. Schölmerich J. Where Have All the Physician Scientists Gone. German Research2010;32(2–3). Disclosure of Interest: None declared

Rheumatic diseases are among the most common chronic inflammatory disorders. Besides severe pain and progressive destruction of the joints, rheumatoid arthritis (RA), spondyloarthritides (SpA) and psoriatic arthritis (PsA) impair working ability, reduce quality of life and if treated insufficiently may enhance mortality. With the introduction of biologics to treat these diseases, the demand for biomarkers of early diagnosis and therapeutic stratification has been growing continuously. The main goal of the consortium ArthroMark is to identify new biomarkers and to apply modern imaging technologies for diagnosis, follow-up assessment and stratification of patients with RA, SpA and PsA. With the development of new biomarkers for these diseases, the ArthroMark project contributes to research in chronic diseases of the musculoskeletal system. The cooperation between different national centers will utilize site-specific resources, such as biobanks and clinical studies for sharing and gainful networking of individual core areas in biomarker analysis. Joint data management and harmonization of data assessment as well as best practice characterization of patients with new imaging technologies will optimize quality of marker validation.

Introduction Anti-tumour therapy with immune checkpoint inhibitors for programmed-death 1 receptor (PD1), such as nivolumab is often accompanied by immune-related adverse events (irAE). The cellular and molecular mechanisms underlying this phenomenon are not defined yet. Interaction of PD-1 with its ligand (PD-L1) mediates potent inhibitory signals to hinder proliferation and effector function of T cells. Interruption of PD1:PD-L1 interaction by nivolumab during anti-tumour therapy might therefore amplify T cell receptor (TCR) signalling and facilitate the development of a pro-inflammatory autoimmune response. Objectives To investigate the impact of PD1 inhibition on intracellular signalling mechanisms down-stream of the TCR such as calcium (Ca2+) influx and activation of mitogen-activated protein kinases (MAPK) pathway and to assess the effect of PD1 inhibition on T cell effector function by evaluating the cytokine profile of the nivolumab-treated T cells. Methods CD4 memory T cells were stimulated with anti-CD3 and anti-CD28 in the presence of nivolumab for 24 hour. Afterwards intracellular Ca2+ influx in response to ionomycin was assessed by flow cytometry following loading the cells with Fluo-8. Expression of proteins involved in store-operated Ca2+ entry (SOCE), stromal activation molecule (STIM) 1, an activator of Ca2+ release-activated Ca2+ (CRAC) channels, and Orai1, a component of CRAC channels was determined by TaqMan real-time PCR. Phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2) in response to anti-CD3/28 was determined by intracellular flow cytometry. The cytokine profile of nivolumab-treated cells was assessed after four-day culture by intracellular flow cytometry. Results Treatment of CD4 T cells with nivolumab led to a pronounced increase of the ionomycin-mediated Ca2+ influx. At the same time expression of SOCE proteins, STIM1 and Orai1, was significantly up regulated in the nivolumab-treated cells. Phosphorylation of Erk1/2 in response to short anti-CD3/CD28 restimulation was almost twice as high in CD4 T cells cultured with as without nivolumab. Finally nivolumab-treated cells contained higher frequencies of IL-17-producing T cells (Th17 cells). Conclusions Interruption of PD1:PD-L1 interaction by nivolumab activate SOCE and promotes Erk1/2 activation. Both T cell signalling pathways are essential for a proper mounting an immune response. Their deregulation might therefore precede an abnormal T cell response as shown for example by increased Th17 cell frequency and facilitate the onset of autoimmune phenomena such as irAE. Acknowledgements This work was supported by DFG grants SK59/09–1 and Schu1683/10–1, and by BMBF Project Arthromark 01EC1401B. Disclosure of interest None declared

Abstract Determining biosimilarity involves a comprehensive exercise with a focus on determining the comparability of the molecular characteristics and preclinical profile of the biosimilar and reference product, such that there is less need for extensive clinical testing to assure comparability of clinical outcomes. Three anti-TNF biosimilar agents are approved for patients with rheumatic diseases in the European Union. The infliximab (Remicade®) biosimilars CT-P13 (Remsima® and Inflectra®) and SB2 (Flixabi®) and the etanercept (Enbrel®) biosimilar SB4 (Benepali®) have shown close comparability to their reference medicinal products, having undergone extensive evaluations. Guidelines on the treatment of rheumatic diseases have acknowledged that biosimilars and biologic DMARDs (bDMARDs) are interchangeable in clinical practice, except when patients experience lack of efficacy or tolerability with the reference agent. Given that cost is a barrier to effective bDMARD use, the introduction of less costly biosimilars is likely to widen access and dissipate treatment inequalities. Physicians faced with prescribing decisions should be reassured by the robust and exhaustive process that is involved in assuring comparability of biosimilars with their reference agents. De novo usage of a biosimilar and switching to a biosimilar following lack of efficacy or tolerability with a different reference biologic agent are likely to be strategies most easily adopted, although switching during successful treatment should also be considered given the potential cost implications. The introduction of biosimilar bDMARDs has the potential to improve patient access to effective biologic therapy, to better accommodate restraints within healthcare budgets and to improve overall patient outcomes.

Background Consistent with models of experimental arthritis implicating IL-22 in the development of joint destruction we could previously demonstrate that elevated IL-22 serum levels were associated with the development of erosive disease in patients with early RA. Objectives To study value of IL-22 as a marker for erosive disease in established RA, to assess whether IL-22 is increased in other joint destructive rheumatic diseases, and to evaluate the influence of comorbidities on IL-22 serum levels. Methods We measured serum IL-22 levels by Enzyme-Linked Immunosorbant Assay (ELISA) and analyzed their correlation to erosive disease (assessed by radiographs of hand and feet) and clinical parameters in patients with established RA (n=142), psoriatic arthritis (n=15), gout (n=15), age-matched patients with hypertension (n=10), diabetes (n=10), coronary heart disease (n=10), and healthy individuals as controls. Results 81 of 142 patients with established RA demonstrated elevated IL-22 levels compared with the range of healthy controls. A significant greater percentage of these “IL-22 high” patients (59%) demonstrated erosive disease compared the “IL-22 normal” patients (37%, p<0.05). In the “IL-22 high” compared to “IL-22 normal” group the fractions of patients positive for RF (70% vs 83%) and ACPA (74% vs 64%) were slightly higher, however not statistically significant different. Similar, measures of disease activity including DAS28 (2.3 vs 2.8) and CRP (0.5 vs 0.3 mg/dl) only tended to be higher in the “IL-22 high” than the “IL-22 low” group. Irrespective of erosive joint disease, patients with psoriatic arthritis and gout demonstrated lower IL-22 levels compared to established RA and only slightly higher than healthy individuals. Patients with hypertension, diabetes and coronary heart disease had IL-22 serum levels comparable to healthy controls. Conclusions High IL-22 levels are associated with erosive disease also in established RA, potentially in parts independent of serology, and might serve as a marker for joint destruction also in this cohort. Disclosure of Interest None declared

Background Previously, T helper (Th) cell subsets have been regarded as irreversibly differentiated endpoints. However, evidence suggests that Th cell differentiation is a plastic process in response to certain (e.g. inflammatory) conditions. Mechanisms leading to the pathogenetic important predominance of Th17 cells in rheumatoid arthritis (RA) are not yet understood. Objectives Therefore, we investigated plasticity and underlying molecular mechanisms to address the question if an altered T cell plasticity contributes to the shift towards the Th17 phenotype in RA. Methods A unique cohort of 40 patients with early, active and untreated RA (to exclude effects of immunosuppressive drugs on T cells) and 41 age- and sex- matched healthy controls (HC) were studied. Viable in vivo-originated Th1, Th2 and Th17 cells were FACS-sorted and trans-differentiated under Th1-, Th2- or Th17-inducing conditions. The cytokine Th profile of the trans-differentiated cells was assessed by flow cytometry. Epigenetic modifications including histone modifications and DNA methylation of Th cell-associated cytokine and transcription factor gene loci were analyzed by ChiP assay and bisulfite sequencing. Relative expression of cytokine and transcription factors was measured by ELISA and qRT-PCR. Results Th17 cells from RA patients cultured under Th1 and Th2 conditions showed a strikingly diminished trans-differentiation capacity into both Th1 and Th2 phenotypes and retained their IL-17 expression to a significantly higher degree compared to Th17 cells from HC. Vice versa, RA Th1 and Th2 cells demonstrated an enhanced capacity to re-differentiate into Th17 cells. We found higher RORC expression in RA Th1 cells that were trans-differentiated under Th17 conditions as a basis for increased re-differentiation of Th1 to Th17 cells in RA. With regard to epigenetic regulation, an overrepresentation of the permissive histone modification H3 actetylation over the repressive H3K27 methylation was found in the IL17 and RORC loci of T cells from RA patients. Moreover, DNA methylation was decreased in RA Th17 cells compared to HC enabling higher IL-17 expression. Conclusions Our data indicate that in vivo-originated Th17 cells in RA are resistant to changes in their phenotype, whereas other Th subsets are prone to Th17 cell trans-differentiation. Increased RORC expression, permissive histone modifications and a less DNA methylation at Th17 genes facilitating IL-17 expression might contribute to the altered Th plasticity in RA, thereby contributing to the pathogenic Th17 shift. Disclosure of Interest None declared

Background Genetic factors related to treatment response in rheumatoid arthritis (RA) have been described. International recommendations for the management of RA suggest initial therapy with synthetic DMARDs, with methotrexate (MTX) typically administered as first-line therapy. However, responses to MTX are variable, and more than 30%1 of patients fail to respond. Despite many studies, few genetic factors specifically associated with MTX response have been identified. Objectives To identify genetic variants associated with response to MTX in patients with early RA. Methods OPTIMA was a 78-week, multicenter, randomized, double-period, double-blind study in which patients were randomized 1:1 to combination therapy with adalimumab plus MTX or MTX alone during the initial study period (26 weeks). Enrolled patients were invited to participate in a genetic sub-study and asked to provide written, informed consent. 384 variants in genes previously shown to be associated with RA or treatment response were assayed using the Illumina BeadXpress GoldenGate Assay. Changes in the 28-joint disease activity score (DAS28) and the total Sharp score (TSS) following 26 weeks of treatment were assessed for association with allele status using genotypic tests. Results A total of 448 patients randomized to MTX were included in the genetic sub-study. Two SNPs in MTHFR (rs1801133 and rs1801131) and one SNP in ATIC (rs2372536)1, previously shown to be associated with MTX response, were not associated with a change in DAS28 or TSS following MTX treatment. However, other SNPs within genes that have been associated with RA or treatment response, such as ABCB1, TNF-alpha, PTPRC, STAT4 and HLA-DRB1, did show association with MTX treatment (Table). For some genes, such as ABCB1, multiple SNPs were identified, suggesting that haplotype analysis could identify stronger associations. SNPs within ABCB1 and PTPRC were also associated with a change in TSS. In addition, a SNP within ADORA2a associated with a change in TSS. SNPs within this gene have previously been associated with MTX toxicity, however, analysis of the impact of this gene on efficacy have been more limited. Conclusions Genetic polymorphisms in genes such as ABCB1, TNF-alpha, PTPRC, STAT4 and HLA-DRB1 were shown to associate with MTX treatment in the OPTIMA study. These results may prove useful for the development of future diagnostic tests or personalized therapeutics for MTX treatment. References Malik et al. Pharmacogenomics (2013). 14(3), 305-314. Acknowledgements AbbVie sponsored the study (NCT00420927), contributed to its design, and participated in the collection, analysis, and interpretation of the data, and in the writing, reviewing, and approval of the final version. Medical writing support was provided by Laurel M. Farmer, PhD, of AbbVie Inc. Disclosure of Interest A. Skapenko: None declared, H. Schulze-Koops Consultant for: AbbVie Inc., V. Devanarayan Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., K. Idler Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., F. Hong Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., J. Smolen Grant/research support: AbbVie Inc., Amgen, AstraZeneca, BMS, Celgene, Janssen, Glaxo, Lilly, Pfizer, MSD, Novo-Nordisk, Roche, Sandoz, and UCB, Consultant for: AbbVie Inc., Amgen, AstraZeneca, BMS, Celgene, Janssen, Glaxo, Lilly, Pfizer, MSD, Novo-Nordisk, Roche, Sandoz, and UCB, A. Kavanaugh Grant/research support: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Consultant for: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, H. Kupper Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., J. Waring Shareholder of: AbbVie Inc., Employee of: AbbVie Inc. DOI 10.1136/annrheumdis-2014-eular.1318

Background Factors related to increased susceptibility to rheumatoid arthritis (RA) have been described, with numerous genes and alleles having been identified that may be associated with the onset of the disease or disease progression. In-depth knowledge about RA susceptibility genes may thus prove useful for the development of future diagnostic tests or personalized therapeutics. Objectives Previously reported RA susceptibility gene frequencies from patients enrolled in the OPTIMA trial were compared to a control database to identify genetic risk factors for RA. Methods OPTIMA was a 78-week, multicenter, randomized, double-period, double-blind study designed to assess adalimumab plus methotrexate therapy. The study enrolled 1,032 early RA patients, of which 921 signed informed consents for genetic analysis. Frequency rates for 168 identified RA susceptibility alleles from 53 genes were compared to the European cohort of the 1000 Genomes Project as a reference control.1 Genotypic variants were assayed using the Illumina BeadXpress GoldenGate Assay. Deviations in the OPTIMA minor allele frequencies (MAFs) >0.05 were further investigated. Results The majority of MAFs from the OPTIMA study did not deviate >0.05 from MAFs reported in the European cohort from the 1000 Genomes Project. Five gene SNPs demonstrated a MAF deviation >0.05 compared to reference controls (Table). The BTLA gene G allele (MAF 0.15 compared to 0.04 control) displayed the highest odds ratio (OR) for RA risk (3.60 OR, 95% CI 2.49 – 5.20); the minor allele was weakly associated with DAS28 baseline score, but significantly more associated with reduced age of study participants suggesting susceptibility to early onset of disease. The PTPN22 gene minor allele was associated with increased RA risk when homozygous, supporting previous findings.2 STAT4 minor allele homozygosity was associated with higher baseline DAS28 scores; however, HLA-DRB1 and NOS3 were not associated with elevated DAS28 scores in this study. Conclusions Genes identified with increased RA risk have known roles in autoimmunity including mediation of lymphocyte signaling, proliferation, and differentiation. For five gene SNPs, MAFs in the OPTIMA study differed from a healthy control population, strengthening their potential role in RA susceptibility. References Clarke et al; Nat Methods. 2012 Apr 27;9(5):459-62. Begovich et al; Am J Hum Genet. 2004 Aug;75(2):330-7. Acknowledgements AbbVie was responsible for the study design, research, analysis, data collection, interpretation of data, and writing, reviewing, and approving of the publication. Medical writing support was provided by Douglas E. Dylla, PhD, of AbbVie Inc. Disclosure of Interest J. Waring Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., V. Devanarayan Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., K. Idler Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., F. Hong Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., J. Smolen Grant/research support from: AbbVie Inc., Amgen, AstraZeneca, BMS, Celgene, Centocor-Janssen, Glaxo, Lilly, Pfizer (Wyeth), MSD (Schering-Plough), Novo-Nordisk, Roche, Sandoz, and UCB, Consultant for: AbbVie Inc., Amgen, AstraZeneca, BMS, Celgene, Centocor-Janssen, Glaxo, Lilly, Pfizer (Wyeth), MSD (Schering-Plough), Novo-Nordisk, Roche, Sandoz, and UCB, A. Kavanaugh Grant/research support from: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Consultant for: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, H. Kupper Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., H. Schulze-Koops Consultant for: AbbVie Inc., A. Skapenko: None Declared

Background Previous analyses suggested that the HLA-DRB1 shared epitope (SE), and the IL4R V50I and the FcγRIIb I232T single nucleotide polymorphisms (SNPs) affected response to adalimumab (ADA) plus methotrexate (MTX)1. Their effect on long-term responses is unclear. Objectives To examine 78-wk clinical responses according to 3 candidate loci: HLA-DRB1 SE, and IL4R I50V and FcγRIIb I232T SNPs. Methods MTX-naïve patients (pts) ≥18 yr with RA <1 yr, active disease [DAS28 (CRP)>3.2, ESR≥28 mm/hr or CRP≥1.5 mg/dL], and >1 erosion, RF+, or anti-CCP+ were randomized to ADA+MTX or placebo (PBO)+MTX for 26 wks (Period 1, P1). Pts who achieved a stable LDA target (DAS28<3.2 at wks 22 & 26) with ADA+MTX were re-randomized to continue ADA+MTX or have ADA blindly withdrawn for 52 wks (P2). Pts who achieved the target with PBO+MTX continued blinded therapy. Pts who did not achieve the target were offered open-label (OL) ADA+MTX. Results Baseline demographics were similar across alleles. The table shows the percentage of pts achieving DAS28<3.2 at wk 78. There were no consistent patterns for the IL4R alleles in any group. While limited by small sample sizes, pts with FcγRIIb-CC appeared to have higher responses at wk 78 among groups initially exposed to ADA+MTX during P1. The positive influence of SE was apparent at wk 78 in groups originally exposed to ADA+MTX, particularly in pts who did not achieve the stable LDA target at wks 22 & 26 but continued ADA+MTX. However, this pattern was not observed in pts who failed to achieve the target with MTX and were subsequently treated with ADA+MTX. The interaction between SE and IL4R observed during P1 was not apparent in long-term responses to ADA+MTX. Conclusions Regardless of genetic background, wk 78 responses were generally higher for pts who achieved the stable LDA target at wks 22 & 26. The positive effects of HLA-DRB1 SE and FcγRIIb-CC in response to ADA+MTX previously noted at wk 26 were less apparent at wk 78, but noticeable in pts who failed to achieve the target. Further, while SE predicted clinical response to ADA+MTX, particularly when combined with IL4R alleles, it had no influence on the ability to withdraw ADA in pts who achieved LDA. These findings may indicate that genetic factors have a stronger influence on initial treatment response than on sustained disease control. References Skapenko et al. EULAR 2011 #THU0309. Disclosure of Interest A. Skapenko: None Declared, J. Smolen Grant/Research support from: Abbott, Amgen, Astra-Zeneca, BMS, Celgene Centocor-Janssen, Glaxo, Lilly, Pfizer (Wyeth), MSD (Schering-Plough), Novo-Nordisk, Roche, Sandoz, UCB, Consultant for: Abbott, Amgen, Astra-Zeneca, BMS, Celgene Centocor-Janssen, Glaxo, Lilly, Pfizer (Wyeth), MSD (Schering-Plough), Novo-Nordisk, Roche, Sandoz, UCB, A. Kavanaugh Grant/Research support from: Abbott, Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Consultant for: Abbott, Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, S. Santra Shareholder of: Abbott, Employee of: Abbott, H. Kupper Shareholder of: Abbott, Employee of: Abbott, H. Schulze-Koops Consultant for: Abbott

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

Background RhuDex, under development as an orally available immunomodulating agent, inhibits the CD80-CD28 costimulatory pathway, thus preventing the interaction between T lymphocyte and APC receptors necessary for T cell activation and proliferation. Objectives We have investigated the effect of RhuDex in vitro on the activation, proliferation and T helper subclass differentiation of naïve, memory and activated T cells. Methods Monocyte-derived dendritic cells, maturated in vitro and expressing CD80, were co-cultured with allogeneic naïve and memory T cells in the presence of a monoclonal antibody to CD3. Preactivated T cells, additionally stimulated by an anti-CD28 antibody and thus independent of further co-stimulatory signals, were used as control. RhuDex and the comparator drug abatacept, also interfering with costimulation, were added at the start of the culture. T cell proliferation was measured using a CFSE assay, while T cell activation was assessed by CD25 surface expression using flow cytometry, and release of cytokines IFNγ, IL-4, IL-17A and TNFα was measured by ELISA. Results RhuDex blocked the activation of naïve T cells with a half-maximal inhibitory concentration (IC50) of 8-10μg/mL, while higher concentrations (up to 30μg/ml) were needed to inhibit memory T cell activation. Similarly high concentrations of RhuDex did not show any reversive effect on the activation status of preactivated T cells. Proliferation of naïve and memory T cells was inhibited by RhuDex with an IC50 of ∼3μg/ml, while the effect on activated T cells was much less pronounced, with concentrations as high as 30μg/ml resulting in only a weak (35%) reduction of proliferation. IFNγ-release, a Th1 response indicator, from naïve and memory T cells was inhibited in the presence of RhuDex with an IC50 of 2-4μg/ml, but this was not observed for activated T cells. A similar pattern of effect was also observed for IL-17A release from these types of T cells. In contrast, RhuDex exposure increased IL-4 release, an indicator for Th2-activation, in naïve T cells up to 4-fold. Importantly, this latter effect was not observed with the comparator drug abatacept. However, RhuDex also showed no or only weak effects on IL-4 secretion from memory- and activated T cells. Finally, RhuDex was also found to inhibit TNFα release from naïve, memory and activated T cells, with an IC50 of ∼2μg/ml, and >10μg/ml, respectively. Conclusions These results support blockade of T cell activation resulting in reduced proliferation and cytokine secretion as the primary mode of action of RhuDex. In line with current knowledge, this blockade appears to be more effective in resting T cell populations that are, in contrast to already activated T cells, more dependent on co-stimulatory signals for activation and proliferation. Furthermore, RhuDex inhibited cytokine release from naïve and memory T cells, with a pronounced inhibitory effect on Th1- and Th17 cytokines. Taken together, the observed inhibitory effect on T cell activation, proliferation and cytokine-release suggests RhuDex as a promising candidate for the treatment of rheumatoid arthritis. Disclosure of Interest F. Wartha Employee of: MediGene AG, P. Hofmann-Goebel Employee of: MediGene AG, A. Skapenko: None Declared, H. Schulze-Koops Consultant for: MediGene AG