Search

Background and objectivesVascular disease is common in systemic lupus erythematosus (SLE) and patients with antiphospholipid antibodies (aPL) are at high risk to develop arterial and venous thrombosis. Since HLA class II genotypes have been linked to the presence of pro-thrombotic aPL, we investigated the relationship between HLA-DRB1 alleles, aPL and vascular events in SLE patients.Methods665 SLE patients of Caucasian origin and 1403 controls were included. Previous manifestations of ischaemic heart disease, ischaemic cerebrovascular disease (ICVD) and venous thromboembolism (together referred to as any vascular events (AVE)) were tabulated. aPL were measured with ELISA. Two-digit HLA-DRB1 typing was performed by sequence-specific primer-PCR.ResultsHLA-DRB1*04 was more frequent among SLE patients with ICVD compared to unaffected patients. This association remained after adjustment for known traditional cardiovascular risk factors. HLA-DRB1*13 was associated with AVE. All measured specificities of aPL—cardiolipin IgG and IgM, β2-glycoprotein-1 IgG, prothrombin (PT) IgG and a positive lupus anticoagulant test were associated with HLA-DRB1*04—while HLA-DRB1*13 was associated with IgG antibodies (β2-glycoprotein-1, cardiolipin and PT). In patients with the combined risk alleles, HLA-DRB1*04/*13, there was a significant additive interaction for the outcomes AVE and ICVD.ConclusionsThe HLA-DRB1*04 and HLA-DRB1*13 alleles are associated with vascular events and an aPL positive immune-phenotype in SLE. Results demonstrate that a subset of SLE patients is genetically disposed to vascular vulnerability.

Type II collagen (CII) posttranslationally modified by reactive oxygen species (ROS-CII) that are present in the inflamed joint is an autoantigen in rheumatoid arthritis (RA). The aim of this study was to investigate the potential use of anti-ROS-CII autoantibodies as a biomarker of RA.CII was exposed to oxidants that are present in the rheumatoid joint. Autoreactivity to ROS-CII was assessed by enzyme-linked immunosorbent assays in synovial fluid (SF) and serum samples obtained from patients during various phases of RA. This group included disease-modifying antirheumatic drug (DMARD)-naive patients with early RA (n = 85 serum samples) and patients with established RA (n = 80 serum and 50 SF samples), who were categorized as either DMARD responders or DMARD nonresponders. Control subjects included anti-citrullinated protein antibody (ACPA)-positive patients with arthralgia (n = 58 serum samples), patients with osteoarthritis (OA; n = 49 serum and 52 SF samples), and healthy individuals (n = 51 serum samples).Reactivity to ROS-CII among DMARD-naive patients with early RA was significantly higher than that among patients with ACPA-positive arthralgia, patients with OA, and healthy control subjects (P0.0001), with 92.9% of serum samples from the patients with early RA binding to anti-ROS-II. There was no significant difference in anti-ROS-CII reactivity between ACPA-positive and ACPA-negative patients with RA, with 93.8% and 91.6% of serum samples, respectively, binding to ROS-CII. The sensitivity and specificity of binding to ROS-CII in patients with early RA were 92% and 98%, respectively. Among patients with established RA, serum reactivity in DMARD nonresponders was significantly higher than that in DMARD responders (P0.01); 58.3% of serum samples from nonresponders and 7.6% of serum samples from responders bound to HOCl-ROS, while the respective values for SF were 70% and 60%. In patients with longstanding RA, autoreactivity to ROS-CII changed longitudinally.Autoantibodies to ROS-CII have the potential to become diagnostic biomarkers of RA.

ObjectiveEnvironmental factors may play a role in the development of rheumatoid arthritis (RA). We examined whether long-term exposures to air pollution were associated with the risk of RA in the Swedish Epidemiological Investigation of Rheumatoid Arthritis Study.MethodsWe studied 1497 incident RA cases and 2536 controls. Local levels of particulate matter (PM10) and gaseous pollutants (sulphur dioxide (SO2) and nitrogen dioxide (NO2)) from traffic and home heating were predicted for all residential addresses. We examined the association of an IQR increase (2 µg/m3for PM10, 8 µg/m3for SO2and 9 µg/m3for NO2) in each pollutant at different time points before symptom onset and average exposure with the risk of all RA and the risk of the rheumatoid factor and anti-citrullinated protein antibody (ACPA) RA phenotypes.ResultsThere was no evidence of an increased risk of RA with PM10. Total RA risks were modestly elevated for the gaseous pollutants, but were not statistically significant after adjustment for smoking and education (OR 1.18, 95% CI 0.97 to 1.43 and OR 1.09, 95% CI 0.99 to 1.19 for SO2and NO2in the 10th year before onset). Stronger elevated risks were observed for individuals with less than a university education and with the ACPA-negative RA phenotype.ConclusionsNo consistent overall associations between air pollution in the Stockholm area and the risk of RA were observed. However, there was a suggestion of increased risks of RA incidence with increases in NO2from local traffic and SO2from home heating sources with stronger associations for the ACPA-negative phenotype.

The Study Group for Risk Factors for Rheumatoid Arthritis was established by the EULAR Standing Committee on Investigative Rheumatology to facilitate research into the preclinical and earliest clinically apparent phases of rheumatoid arthritis (RA). This report describes the recommendation for terminology to be used to define specific subgroups during different phases of disease, and defines the priorities for research in this area. Terminology was discussed by way of a three-stage structured process: A provisional list of descriptors for each of the possible phases preceding the diagnosis of RA were circulated to members of the study group for review and feedback. Anonymised comments from the members on this list were fed back to participants before a 2-day meeting. 18 participants met to discuss these data, agree terminologies and prioritise important research questions. The study group recommended that, in prospective studies, individuals without RA are described as having: genetic risk factors for RA; environmental risk factors for RA; systemic autoimmunity associated with RA; symptoms without clinical arthritis; unclassified arthritis; which may be used in a combinatorial manner. It was recommended that the prefix ‘pre-RA with:’ could be used before any/any combination of the five points above but only to describe retrospectively a phase that an individual had progressed through once it was known that they have developed RA. An approach to dating disease onset was recommended. In addition, important areas for research were proposed, including research of other tissues in which an adaptive immune response may be initiated, and the identification of additional risk factors and biomarkers for the development of RA, its progression and the development of extra-articular features. These recommendations provide guidance on approaches to describe phases before the development of RA that will facilitate communication between researchers and comparisons between studies. A number of research questions have been defined, requiring new cohorts to be established and new techniques to be developed to image and collect material from different sites.

Autoimmunity is complicated by bone loss. In human rheumatoid arthritis (RA), the most severe inflammatory joint disease, autoantibodies against citrullinated proteins are among the strongest risk factors for bone destruction. We therefore hypothesized that these autoantibodies directly influence bone metabolism. Here, we found a strong and specific association between autoantibodies against citrullinated proteins and serum markers for osteoclast-mediated bone resorption in RA patients. Moreover, human osteoclasts expressed enzymes eliciting protein citrullination, and specific N-terminal citrullination of vimentin was induced during osteoclast differentiation. Affinity-purified human autoantibodies against mutated citrullinated vimentin (MCV) not only bound to osteoclast surfaces, but also led to robust induction of osteoclastogenesis and bone-resorptive activity. Adoptive transfer of purified human MCV autoantibodies into mice induced osteopenia and increased osteoclastogenesis. This effect was based on the inducible release of TNF-α from osteoclast precursors and the subsequent increase of osteoclast precursor cell numbers with enhanced expression of activation and growth factor receptors. Our data thus suggest that autoantibody formation in response to citrullinated vimentin directly induces bone loss, providing a link between the adaptive immune system and bone.

The presence of antibodies against cyclic citrullinated peptides has been demonstrated to precede the onset of symptoms of rheumatoid arthritis (RA) by several years. The aim of this study was to analyze antibodies against 10 citrullinated autoantigen-derived peptides for reactivity before the onset of RA symptoms.A case-control study was conducted within the Medical Biobank of Northern Sweden. The study was performed in 409 individuals, 386 of whom donated 717 blood samples before the onset of symptoms of RA (pre-patients). The median period of time predating the onset of RA was 7.4 years. A total of 1,305 population-based control subjects were also studied. Antibodies to 10 citrullinated peptides, fibrinogen α573 (Fibα573), Fibα591, Fibβ36-52, Fibβ72, Fibβ74, α-enolase (citrullinated α-enolase peptide 1 [CEP-1]), triple-helical type II collagen peptide C1 (citC1III), filaggrin, vimentin 2-17 (Vim2-17), and Vim60-75, were analyzed using a microarray system.The fluorescence intensity of antibodies against Fibβ36-52, Fibβ74, CEP-1, citC1III, and filaggrin was significantly increased in pre-patients compared with controls (P0.001). The levels of the earliest-detectable antibodies (Fibα591 and Vim60-75) fluctuated over time, with only a slight increase after the onset of disease. The frequency of antibodies against Fibβ36-52, CEP-1, and filaggrin increased gradually, reaching the highest levels before symptom onset. The frequency of a cluster of antibodies, citC1III, Fibα573, and Fibβ74, increased only slightly before the onset of symptoms but increased prominently after disease onset. The odds ratio for the development of RA in individuals expressing both CEP-1 and Fibβ36-52 antibodies (using data from samples obtained3.35 years predating symptom onset) was 40.4 (95% confidence interval 19.8-82.3) compared with having either antibody alone.Development of an immune response toward citrullinated peptides is initially restricted but expands with time to induce a more specific response, with levels, particularly those of antibodies against CEP-1, Fibβ36-52, and filaggrin, increasing during the predating time period closer to the onset of symptoms.

Type II collagen (CII) is a cartilage-specific protein to which a loss of immune tolerance may trigger autoimmune reactions and cause arthritis. The major T cell epitope on CII, amino acids 259-273, can be presented by several HLA-DRB1 04 alleles in its native or posttranslational glycosylated form. The present study was undertaken to functionally explore and compare CII-autoreactive T cells from blood and synovial fluid of patients with rheumatoid arthritis (RA).Peripheral blood was obtained from HLA-DRB1 04-positive RA patients (n = 10) and control subjects (n = 10) and stimulated in vitro with several variants of the CII(259-273) epitope, i.e., unmodified, glycosylated on Lys-264, glycosylated on Lys-270, or glycosylated on both Lys-264 and Lys-270. Up-regulation of CD154 was used to identify responding T cells. These cells were further characterized by intracellular staining for interleukin-17 (IL-17), interferon-γ (IFNγ), and IL-2 by flow cytometry. Synovial T cells from RA patients were investigated in parallel.Multifunctional T cell responses toward all examined variants of the CII(259-273) peptide could be detected in RA patients and, to a lesser extent, also in healthy HLA-matched controls (P0.001). In RA patients, a comparison between blood- and joint-derived T cell function revealed a significant increase in levels of the proinflammatory cytokine IFNγ in synovial T cells (P = 0.027). Studies of longitudinally obtained samples showed that T cell responses were sustained over the course of disease, and even included epitope spreading.The identification of inflammatory T cell responses to both glycosylated and nonglycosylated variants of the major CII epitope in RA patients suggests that CII autoreactivity in RA may be more common than previously recognized.

Understanding etiology and molecular pathogenesis of rheumatoid arthritis is key to the development of precise prevention and curative therapy for this disease. Recent progress on how genes and environment interact in causing immune reactions that may induce arthritis in humans as well as in mice, have provided a conceptual basis for the development of new prevention and treatment strategies which need to be different for different subsets of RA. In order to bring this emerging knowledge to the level where basic and clinical academic science can collaborate with industry for rapid development of the potential new therapies, there is a need for closer collaboration between basic and clinical scientists from many centers, and for increased collaboration between industry and academia in translational medicine. In Europe, both the EU-funded framework programs and the EU and industry funded Innovative Medicine Initiative (IMI) funder programs in rheumatology are geared to accomplishing these goals. This presentation will be concerned both with the scientific basis of these programs and with a descriptions of the challenges and potential promises that these new collaborative programs offer to rheumatology.

INTRODUCTION: The aim of this study was to investigate the association between exposure to cosmetics, often containing mineral oil, and the risk of developing rheumatoid arthritis (RA). The study was performed against the background that occupational exposure to mineral oil has recently been shown to be associated with an increased risk for RA in man, and that injection of or percutaneous exposure to mineral-oil-containing cosmetics can induce arthritis in certain rat strains. METHODS: A population-based case-control study of incident cases of RA was performed among the population aged 18 to 70 years in a defined area of Sweden during May 1996 to December 2003. A case was defined as an individual from the study base, who received for the first time a diagnosis of RA according to the 1987 American College of Rheumatology criteria. Controls were randomly selected from the study base with consideration taken for age, gender and residential area. Cases (n = 1,419) and controls (n = 1,674) answered an extensive questionnaire regarding environmental and lifestyle factors including habits of cosmetic usage. The relative risk of developing RA was calculated for subjects with different cosmetic usage compared with subjects with low or no usage. Analysis was also performed stratifying the cases for presence/absence of rheumatoid factor and antibodies to citrulline-containing peptides. RESULTS: The relative risks of developing RA associated with use of cosmetics were all close to one, both for women and men, for different exposure categories, and in relation to different subgroups of RA. CONCLUSION: This study does not support the hypothesis that ordinary usage of common cosmetics as body lotions, skin creams, and ointments, often containing mineral oil, increase the risk for RA in the population in general. We cannot exclude, however, that these cosmetics can contribute to arthritis in individuals carrying certain genotypes or simultaneously being exposed to other arthritis-inducing environmental agents. En artikel av författargruppen Epidemiological Investigation of Rheumatoid Arthritis Study Group

An infectious aetiology in rheumatoid arthritis (RA) has for long been suggested, although no conclusive evidence for this is at present available. Lately a large interest has been devoted to the involvement of heat shock proteins (hsps) in autoimmune disorders due to their conserved structure and immunogenic properties. Immunity to hsps has been observed both in human autoimmune conditions and in experimental models of autoimmune disease. We have studied the role of the bacterial flora and hsp immunity in the arthritic response in three experimental models of arthritis; type II collagen arthritis (CIA), adjuvant arthritis (AA) and oil induced arthritis (OIA); by using germ free and conventional DA rats. A high incidence of severe arthritis developed in all the models evaluated irrespectively of whether the animals were in the conventional or germ free state. This confirms earlier results which show a minor effect of the bacterial flora in CIA and AA in high responder strains. These results also show that a severe OIA can develop in germ free animals. Despite the severe arthritic response induced, no serum antibody levels to hsp 65 could be detected in the germ free animals, which was in contrast to the conventional animals where a positive anti-hsp 65 serum response was seen in 35–80% of the animals with CIA, AA or OIA. These results show that development of a humoral response to hsp 65 in these models of arthritis is dependent on the presence of a bacterial flora. Further, the lack of humoral immunity in germ free animals despite a severe arthritic response indicates that humoral immunity to hsp 65 is not involved in development of disease in these three models of experimental arthritis.

Twenty four systemic lupus erythaematosus patients and 17 patients with other diagnoses were investigated regarding the presence of cells producing C1q reactive antibodies in peripheral blood mononuclear cells using the ELISPOT technique. These results were then compared with parallel serum levels of C1q reactive antibodies. Current production of anti-C1q was almost entirely confined to the systemic lupus erythaematosus group. Longitudinal analysis of anti-C1q ELISPOT positive patients showed rapid changes in the number of anti-C1q producing cells, but only slowly changing serum levels of the corresponding antibodies in response to glucocorticoids. In one systemic lupus erythaematosus patient prednisolone treatment had a selective effect on this autoantibody production, as the production of anti-C1q spot forming cells rapidly dropped to zero, at the same time as the number of total spot-forming cells showed only less change. In another patient, self-limiting connective tissue disease was associated with temporal occurrence of IgM anti-C1q. We believe, from these data, that the ELISPOT method for determination of current antibody production may be of particular value in longitudinal evaluation of disease course and therapeutic effects in systemic lupus erythaematosus and other rheumatic diseases.

Objective. To investigate the production of type II collagen (CII) antibodies in the synovial fluid (SF) of rheumatoid arthritis (RA) patients, and to examine the HLA dependence of this local production. Methods. The ELISPOT method was used for enumerating anti-CII—reactive cells. Serologic tissue typing was performed. Results. Anti-CII—reactive cells were found in the SF of 16 of 31 patients, but not in any of the peripheral blood samples obtained in parallel. SF anti-CII antibody production showed no correlation with clinical parameters, but its frequency increased significantly with age. The IgG anti-CII response occurred exclusively in patients who were positive for HLA—DR4 and was significantly associated with DR4. Conclusion. Anti-CII production may be important in local immune complex formation. The indirect demonstration of a DR4-restricted T cell response to CII is an indication of a pathogenetic role of collagen autoimmunity in RA.

Monoclonal anti-parathyroid antibodies have been utilized to isolate a single-chain glycoprotein of 500 kDa, which apparently acts as a sensor of the extracellular calcium concentration and is expressed on the surface of human parathyroid, placental, and kidney tubule cells. The present contribution reports the isolation of a cDNA clone encoding this protein in human placenta and subsequent Northern blots confirming the mRNA expression also in human parathyroid and kidney cells. Close similarity in sequence as well as in tissue distribution is demonstrated with the rat Heymann nephritis antigen, a kidney tubule glycoprotein with calcium-binding ability. The 500-kDa protein belongs to the LDL-receptor superfamily of glycoproteins, claimed to function primarily as protein receptors and characterized by functionally important calcium-binding capacity. It is proposed that the currently identified protein constitutes part of a common structure for the sensing of extracellular calcium concentrations and influences calcium homeostasis in different organs.

To define synovial apoptosis with respect to disease duration, inflammatory cell type, FLIP (FLICE-like inhibitory protein), and cytokines expression in patients with rheumatoid arthritis (RA).Synovial biopsy specimens from 11 patients with longstanding RA (median disease duration 21 years) and eight with early RA (median disease duration five months) were investigated. Apoptosis (TUNEL method combined with morphological analysis), cell surface markers (CD3, CD68), cytokines (interleukin (IL) 1alpha, IL1beta, tumour necrosis factor alpha, and IL6), and FLIP expression were evaluated. Computer assisted image analysis was used for quantification.The apoptosis level in RA synovium was significantly higher in the group of patients with longstanding RA than in the patients with early RA (8.8% v 0.6%, p=0.001), while the number of macrophages and FLIP expression were higher in the group with early disease than in the group with longstanding RA (16.2% v 8.3%, p=0.02 and 31.1% v 0.2%, p=0.001 respectively). All three markers correlated significantly with disease duration (R=-0.7, p0.001 for FLIP, R=0.6, p=0.001 for apoptosis, and R=-0.5, p0.05 for CD68). Cytokine expression and T cell score were not significantly different in early RA from longstanding RA. No differences were seen between patients treated or not treated with corticosteroids or between patients treated or not treated with disease modifying antirheumatic drugs.The findings suggest that RA synovial macrophages are resistant to apoptosis in early RA and express high levels of FLIP. During natural or drug modified disease progression the apoptotic mechanism may be restored with a specific increase of synovial apoptosis in patients with longstanding arthritis.

Autoimmune rheumatic diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS) and systemic sclerosis (SSc) constitute a majority of the inflammatory immune-mediated disorders. This group of diseases is characterized by systemic inflammation sustained by cellular activation and production of inflammatory mediators. The diseases lead a relapsing and remitting course with increasing disability and destruction of joints and vital organs as a result. RA, being the largest disease entity within this group, has become a prototype disease for defining the molecular and pathological basis of chronic inflammatory syndromes in general and autoimmune rheumatic disease in particular [1, 2].

OBJECTIVE: The contribution of low-penetrance single nucleotide polymorphisms to methotrexate efficacy in rheumatoid arthritis (RA) is inconsistent between studies. We sought to elucidate architecture of methotrexate response in three cohorts of patients with RA treated with methotrexate. METHODS: Single nucleotide polymorphism frequencies in genes from folate, purine, and pyrimidine pathways were measured to develop a model of gene-gene interactions using multifactor dimensionality reduction in 439 patients who received methotrexate in the USA and The Netherlands. A third cohort of 530 patients with RA from Sweden was used to replicate the findings. Methotrexate efficacy was assessed using the European League Against Rheumatism criteria in the majority of patients. RESULTS: Nonlinear patterns of gene-gene interactions between variants in aminoimidazole carboxamide ribonucleotide transformylase (C347G), reduced-folate carrier (G80A) and inosine-triphosphate pyrophosphatase (C94A) revealed a predisposing genetic attribute significantly associated with methotrexate response in the USA and Dutch cohorts [odds ratio (OR)=2.9, 95% confidence interval (CI): 1.9-4.2; P

The genetic association of the major histocompatibility complex (MHC) to rheumatoid arthritis risk has commonly been attributed to alleles in HLA-DRB1. However, debate persists about the identity of the causal variants in HLA-DRB1 and the presence of independent effects elsewhere in the MHC. Using existing genome-wide SNP data in 5,018 individuals with seropositive rheumatoid arthritis (cases) and 14,974 unaffected controls, we imputed and tested classical alleles and amino acid polymorphisms in HLA-A, HLA-B, HLA-C, HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1 and HLA-DRB1, as well as 3,117 SNPs across the MHC. Conditional and haplotype analyses identified that three amino acid positions (11, 71 and 74) in HLA-DRβ1 and single-amino-acid polymorphisms in HLA-B (at position 9) and HLA-DPβ1 (at position 9), which are all located in peptide-binding grooves, almost completely explain the MHC association to rheumatoid arthritis risk. This study shows how imputation of functional variation from large reference panels can help fine map association signals in the MHC.

Microsomal PGE synthase 1 (mPGES-1) is the terminal enzyme in the induced state of prostaglandin E-2 (PGE(2)) synthesis and constitutes a therapeutic target for rheumatoid arthritis (RA) treatment. We examined the role of the prostaglandin E synthase (PTGES) gene polymorphism in susceptibility to and severity of RA and related variations in the gene to its function. The PTGES gene polymorphism was analyzed in 3081 RA patients and 1900 controls from two study populations: Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) and the Leiden Early Arthritis Clinic (Leiden EAC). Baseline disease activity score (DAS28) was employed as a disease severity measure. mPGES-1 expression was analyzed in synovial tissue from RA patients with known genotypes using immunohistochemistry. In the Swedish study population, among women a significant association with risk for RA was observed for PTGES single-nucleotide polymorphisms (SNPs) in univariate analysis and for the distinct haplotype. These results were substantiated by meta-analysis of data from EIRA and Leiden EAC studies with overall OR 1.31 (95% confidence interval 1.11-1.56). Several PTGES SNPs were associated with earlier onset of disease or with higher DAS28 in women with RA. Patients with the genotype associated with higher DAS28 exhibited significantly higher mPGES-1 expression in synovial tissue. Our data reveal a possible influence of PTGES polymorphism on the pathogenesis of RA and on disease severity through upregulation of mPGES-1 at the sites of inflammation. Genetically predisposed individuals may develop earlier and more active disease owing to this mechanism. European Journal of Human Genetics (2011) 19, 908-914; doi:10.1038/ejhg.2011.50; published online 30 March 2011

Atherosclerotic lesions can result in fatal cardiovascular disease, but what triggers the formation of the atheroma plaques and their progression still begs further investigation. In 'Bench to Bedside', Goran K Hansson and Lars Klareskog peruse how the NLRP3 inflammasome can be activated by cholesterol crystals and worsen atherosclerosis by triggering inflammation through the release of IL-1β from macrophages. But these cells can also die at the lesion site, forming a necrotic core in the atheroma by building up apoptotic cells and debris. In 'Bedside to Bench', Ira Tabas discusses a human study showing that lesional necrosis along with thinning of the fibrotic cap are predictive of culprit lesions involved in fatal disease. Understanding the molecular underpinnings of these two morphological features may lead to new therapies to prevent or decrease the risk for major cardiovascular disease.

Non-Hodgkin lymphoma (NHL) represents a diverse group of hematological malignancies, of which follicular lymphoma (FL) is a prevalent subtype. A previous genome-wide association study has established a marker, rs10484561 in the human leukocyte antigen (HLA) class II region on 6p21.32 associated with increased FL risk. Here, in a three-stage genome-wide association study, starting with a genome-wide scan of 379 FL cases and 791 controls followed by validation in 1,049 cases and 5,790 controls, we identified a second independent FL–associated locus on 6p21.32, rs2647012 (ORcombined = 0.64, Pcombined = 2×10−21) located 962 bp away from rs10484561 (r2, Author Summary Earlier studies have established a marker rs10484561, in the HLA class II region on 6p21.32, associated with increased follicular lymphoma (FL) risk. Here, in a three-stage genome-wide association study of 1,428 FL cases and 6,581 controls, we identified a second independent FL–associated marker on 6p21.32, rs2647012, located 962 bp away from rs10484561. The associations at two SNPs remained genome-wide significant after mutual adjustment. Haplotype and coalescence analyses indicated that rs2647012 arose on an evolutionarily distinct lineage from that of rs10484561 and tags a novel allele with an opposite, protective effect on FL risk. Moreover, in an analysis of the top 6 FL–associated SNPs in 4,449 cases of other NHL subtypes, rs10484561 was associated with risk of diffuse large B-cell lymphoma. Our results reveal the presence of allelic heterogeneity at 6p21.32 in FL risk and suggest a shared genetic etiology with the common diffuse large B-cell lymphoma subtype.

OBJECTIVE: Glutathione-S-transferases (GSTs) play an important role in tobacco smoke detoxification, interestingly approximately 50% of individuals in most human populations lack the gene GSTM1 due to copy number variation (CNV). We aimed to investigate GSTM1 CNV in Rheumatoid Arthritis (RA) in relation to smoking and HLA-DRB1 shared epitope; the two best known risk factors for RA and in addition, to perform subanalyses in patients where relations between variations in GSTM1 and RA have previously been described. METHODS: qPCR was performed using TaqMan Copy Number assays (Applied Biosystems) for 2426 incident RA cases and 1257 controls from the Swedish EIRA. Odds ratio (OR) together with 95% confidence intervals (CI) was calculated and used as a measure of the relative risk of developing RA. RESULTS: No association between RA and GSTM1 CNV was observed when analyzing whole EIRA. However, ≥1 copy of GSTM1 appears to be a significant risk factor for autoantibody positive RA in non-smoking females ≥60 years (OR: 2.00 95% CI: 1.07-3.74), a population where such relationships have previously been described. Our data further suggest a protective effect of GSTM1 in ACPA-negative smoking men (OR: 0.56 95% CI: 0.35-0.90). CONCLUSION: We assessed the exact number of GSTM1 gene copies in relation to development and severity of RA. Our data provide support for the notion that variations in copy numbers of GSTM1 may influence risk in certain subsets of RA, but do not support a role for GSTM1 CNV as a factor that more generally modifies the influence of smoking on RA.

Epidemiology and candidate gene studies indicate a shared genetic basis for celiac disease (CD) and rheumatoid arthritis (RA), but the extent of this sharing has not been systematically explored. Previous studies demonstrate that 6 of the established non-HLA CD and RA risk loci (out of 26 loci for each disease) are shared between both diseases. We hypothesized that there are additional shared risk alleles and that combining genome-wide association study (GWAS) data from each disease would increase power to identify these shared risk alleles. We performed a meta-analysis of two published GWAS on CD (4,533 cases and 10,750 controls) and RA (5,539 cases and 17,231 controls). After genotyping the top associated SNPs in 2,169 CD cases and 2,255 controls, and 2,845 RA cases and 4,944 controls, 8 additional SNPs demonstrated P, Author Summary Celiac disease (CD) and rheumatoid arthritis (RA) are two autoimmune diseases characterized by distinct clinical features but increased co-occurrence in families and individuals. Genome-wide association studies (GWAS) performed in CD and RA have identified the HLA region and 26 non-HLA genetic risk loci in each disease. Of the 26 CD and 26 RA risk loci, previous studies have shown that six are shared between the two diseases. In this study we aimed to identify additional shared risk alleles and, in doing so, gain more insight into shared disease pathogenesis. We first empirically investigated the distribution of putative risk alleles from GWAS across both diseases (after removing known risk loci for both diseases). We found that CD risk alleles are non-randomly distributed in the RA GWAS (and vice versa), indicating that CD risk alleles have an increased prior probability of being associated with RA (and vice versa). Next, we performed a GWAS meta-analysis to search for shared risk alleles by combing the RA and CD GWAS, performing both directional and opposite allelic effect analyses, followed by replication testing in independent case-control datasets in both diseases. In addition to the already established six non-HLA shared risk loci, we observed statistically robust associations at eight SNPs, thereby increasing the number of shared non-HLA risk loci to fourteen. Finally, we used gene expression studies and pathway analysis tools to identify the plausible candidate genes in the fourteen associated loci. We observed remarkable overrepresentation of T-cell signaling molecules among the shared genes.

Background To investigate the associations between HLA-DRB1 shared epitope (SE) alleles and rheumatoid arthritis in subsets of rheumatoid arthritis defined by autoantibodies in three Asian populations from Malaysia. Methods 1,079 rheumatoid arthritis patients and 1,470 healthy controls were included in the study. Levels of antibodies to citrullinated proteins (ACPA) and rheumatoid factors were assessed and the PCR-SSO method was used for HLA-DRB1 genotyping. Results The proportion of ACPA positivity among Malay, Chinese and Indian rheumatoid arthritis patients were 62.9%, 65.2% and 68.6%, respectively. An increased frequency of SE alleles was observed in ACPA-positive rheumatoid arthritis among the three Asian ethnic groups. HLA-DRB1*10 was highly associated with rheumatoid arthritis susceptibility in these Asian populations. HLA-DRB1*0405 was significantly associated with susceptibility to rheumatoid arthritis in Malays and Chinese, but not in Indians. HLA-DRB1*01 did not show any independent effect as a risk factor for rheumatoid arthritis in this study and HLA-DRB1*1202 was protective in Malays and Chinese. There was no association between SE alleles and ACPA- negative rheumatoid arthritis in any of the three Asian ethnic groups. Conclusion The HLA-DRB1 SE alleles increase the risk of ACPA-positive rheumatoid arthritis in all three Asian populations from Malaysia.

Inflammation of synovium is one of the hallmarks of rheumatoid arthritis (RA). Analysis of synovial tissue has increased our understanding of RA pathogenesis, aided in identifying potential therapeutic targets and has been used in the response and mechanistic evaluation of antirheumatic treatments. In addition, studies are ongoing, aimed at the identification of diagnostic and prognostic biomarkers in the synovium. This paper outlines the currently used procedures for sampling and processing of synovial tissue, and presents a standardised recommendation to support multicentre translational research.

Patterns of genetic diversity have previously been shown to mirror geography on a global scale and within continents and individual countries. Using genome-wide SNP data on 5174 Swedes with extensive geographical coverage, we analyzed the genetic structure of the Swedish population. We observed strong differences between the far northern counties and the remaining counties. The population of Dalarna county, in north middle Sweden, which borders southern Norway, also appears to differ markedly from other counties, possibly due to this county having more individuals with remote Finnish or Norwegian ancestry than other counties. An analysis of genetic differentiation (based on pairwise F-st) indicated that the population of Sweden's southernmost counties are genetically closer to the HapMap CEU samples of Northern European ancestry than to the populations of Sweden's northernmost counties. In a comparison of extended homozygous segments, we detected a clear divide between southern and northern Sweden with small differences between the southern counties and considerably more segments in northern Sweden. Both the increased degree of homozygosity in the north and the large genetic differences between the south and the north may have arisen due to a small population in the north and the vast geographical distances between towns and villages in the north, in contrast to the more densely settled southern parts of Sweden. Our findings have implications for future genome-wide association studies (GWAS) with respect to the matching of cases and controls and the need for within-county matching. We have shown that genetic differences within a single country may be substantial, even when viewed on a European scale. Thus, population stratification needs to be accounted for, even within a country like Sweden, which is often perceived to be relatively homogenous and a favourable resource for genetic mapping, otherwise inferences based on genetic data may lead to false conclusions.

Objective.To investigate the role of the FcαRI 844 A>G functional polymorphism in the genetic predisposition to rheumatoid arthritis (RA) and systemic sclerosis (SSc) susceptibility.Methods.The study population was composed of 1401 patients with SSc, 642 patients with RA, and 1317 healthy controls. The FcαRI (CD89) single-nucleotide polymorphism rs16986050 was genotyped by pyrosequencing.Results.We observed no significant deviation of the genotype and allele frequencies in RA and SSc compared to controls. A metaanalysis and a recessive and dominant model yielded similar negative results.Conclusion.Our data show that the FcαRI 844 A>G polymorphism is not associated with SSc or RA susceptibility.

Genome-wide association (GWA) studies have identified numerous, replicable, genetic associations between common single nucleotide polymorphisms (SNPs) and risk of common autoimmune and inflammatory (immune-mediated) diseases, some of which are shared between two diseases. Along with epidemiological and clinical evidence, this suggests that some genetic risk factors may be shared across diseases—as is the case with alleles in the Major Histocompatibility Locus. In this work we evaluate the extent of this sharing for 107 immune disease-risk SNPs in seven diseases: celiac disease, Crohn's disease, multiple sclerosis, psoriasis, rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes. We have developed a novel statistic for Cross Phenotype Meta-Analysis (CPMA) which detects association of a SNP to multiple, but not necessarily all, phenotypes. With it, we find evidence that 47/107 (44%) immune-mediated disease risk SNPs are associated to multiple—but not all—immune-mediated diseases (SNP-wise P CPMA, Author Summary Over the last five years we have found over 100 genetic variants predisposing to common diseases affecting the immune system. In this study we analyze 107 such variants across seven diseases and find that almost half are shared across diseases. We also find that the patterns of sharing across diseases cluster these variants into groups; proteins encoded near variants in the same group tend to interact. This suggests that genetic variation may influence entire pathways to create risk to multiple diseases.

MRL/Mp-lpr/lpr (MRL/l) mice spontaneously develop autoimmune disease, characterized by glomerulonephritis, polyarteritis and polyarthritis. The lpr mice have defects in the Fas antigen, which plays a role in apoptosis, and it has been suggested that lack of negative selection of autoreactive T cells explains the initiation of the disease. The extremely high amount of autoantibodies may reflect additional immunoregulatory abnormalities. Antibody feedback regulation is an efficient way of up- or downregulating antibody responses. We have for the first time determined whether IgG-mediated suppression as well as IgM-mediated enhancement operates normally in these mice. MRL/l and MRL/Mp(-)+/+ (MRL/n) mice of different ages were therefore immunized with sheep erythrocyte (SRBC)-specific IgG or IgM antibodies followed by SRBC. Control groups received antigen alone. Five days later, the antigen-specific plaque-forming cell response was measured. IgG induced more than 90% suppression in both MRL/l and MRL/n in mice of all ages tested. This degree of suppression is in the same range as for other, normal mouse strains. In contrast, IgM-mediated enhancement was completely absent in 12-week-old MRL/l mice but normal in 8-week-old MRL/l as well as in MRL/n mice of all ages tested. When spleens and lymph nodes were immunohistochemically studied using a mAb specific for complement receptors 1 and 2 (CR1/CR2), an abnormal follicular structure was demonstrated in 12-week-old MRL/l mice. The antibody response of both 8- and 13-week-old MRL/l mice in vivo, after downregulation of these receptors, was inhibited by 85-96%. Thus, the presented data demonstrate that MRL/l mice with overt autoimmune disease are refractory to IgM-mediated enhancement of antigen-specific antibody production. We believe that this abnormal antibody feedback regulation is due to abnormal follicular structure in lymphoid organs of old MRL/l mice, hence the inability to localize and present antigen in a normal way.

Background Rheumatoid arthritis (RA) can be divided into two major subsets based on the presence or absence of antibodies to citrullinated peptide antigens (ACPA). Until now, data from genome-wide association studies (GWAS) have only been published from ACPA-positive subsets of RA or from studies that have not separated the two subsets. The aim of the current study is to provide and compare GWAS data for both subsets. Methods and results GWAS using the Illumina 300K chip was performed for 774 ACPA-negative patients with RA, 1147 ACPA-positive patients with RA and 1079 controls from the Swedish population-based case–control study EIRA. Imputation was performed which allowed comparisons using 1 723 056 single nucleotide polymorphisms (SNPs). No SNP achieved genome-wide significance (2.9 × 10–8) in the comparison between ACPA-negative RA and controls. A case–case association study was then performed between ACPA-negative and ACPA-positive RA groups. The major difference in this analysis was in the HLA region where 768 HLA SNPs passed the threshold for genome-wide significance whereas additional contrasting SNPs did not reach genome-wide significance. However, one SNP close to the RPS12P4 locus in chromosome 2 reached a p value of 2 × 106 and this locus can thus be considered as a tentative candidate locus for ACPA-negative RA. Conclusions ACPA-positive and ACPA-negative RA display significant risk allele frequency differences which are mainly confined to the HLA region. The data provide further support for distinct genetic aetiologies of RA subsets and emphasise the need to consider them separately in genetic as well as functional studies of this disease.

Prevention of disease can in principle be accomplished by identification of environmental and/or lifestyle risk and protective factors followed by public health measures (such as for smoking and lung cancer), or by modification of the individual's reactions to disease-inducing factors (such as in vaccinations against microbes). This review discusses both options based on emerging understanding of aetiologies in inflammatory rheumatic diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The major current opportunity for public health-based prevention lies in avoiding smoking. In RA, recent studies have calculated that, in Sweden (a country characterised by a low frequency of smoking), 20% of all RA cases and 33% of all cases of ACPA-positive RA would not have occurred in a smoke-free society. Smoking is also a major risk factor for SLE but no population attribution is yet available. New avenues for individualised and biology-based prevention are provided by the demonstration that several autoimmune rheumatic diseases are preceded by emergence of subclinical autoimmunity followed by laboratory-based signs of inflammation and finally overt disease. Examples of this process are provided from studies of autoimmunity to citrullinated proteins (in RA), to dsDNA (in SLE in general) and to Ro52 epitopes (in the case of neonatal heart block). The recognition of this sequence of events provides opportunities to intervene specifically and potentially curatively before onset of full-blown disease. Such prevention can be accomplished by modification of inciting antigens (environment), by modification of immunity (more or less specific immunomodulation) or by modification of specific gene functions. In all cases, prevention will be different in different subsets of disease and differ at different time points of disease development. Thus, the road map towards prevention of autoimmune rheumatic diseases includes increased understanding of how genes, environment and immunity interact.

This review describes how studies on interactions between genetic variants, and environmental factors, mainly smoking, contribute to the understanding of how autoimmunity to post-translationally (citrullinated) proteins/peptides may occur and potentially contribute to certain subsets of rheumatoid arthritis. A main message is that studies on specific immune mechanisms in a complex and heterogeneous disease like RA should be undertaken with the help of results from genetic epidemiology. By those means, it may be possible to identify subsets of RA in a way that in the end allows development and testing of precise and subset-specific interventions against environment as well as genetically defined molecular pathways, in particular those that regulate specific immune responses.

Introduction The goal of this study was to identify serum markers that are modulated by treatment with golimumab with or without methotrexate (MTX) and are associated with clinical response. Methods Sera were collected at weeks 0 and 4 from a total of 336 patients (training dataset, n = 100; test dataset, n = 236) from the GO-FORWARD study of patients with active rheumatoid arthritis despite MTX. Patients were randomly assigned to receive placebo plus MTX; golimumab, 100 mg plus placebo; golimumab, 50 mg plus MTX; or golimumab, 100 mg plus MTX. Subcutaneous injections were administered every 4 weeks. Samples were tested for select inflammatory, bone, and cartilage markers and for protein profiling using multianalyte profiles. Results Treatment with golimumab with or without MTX resulted in significant decreases in a variety of serum proteins at week 4 as compared with placebo plus MTX. The American College of Rheumatology (ACR) 20, ACR 50, and Disease Activity Score (DAS) 28 responders showed a distinct biomarker profile compared with nonresponding patients. Conclusions ACR 20 and ACR 50 responders among the golimumab/golimumab + MTX-treated patients had a distinct change from baseline to week 4 in serum protein profile as compared with nonresponders. Some of these changed markers were also associated with multiple clinical response measures and improvement in outcome measures in golimumab/golimumab + MTX-treated patients. Although the positive and negative predictive values of the panel of markers were modest, they were stronger than C-reactive protein alone in predicting clinical response to golimumab. Trial registration http://ClinicalTrials.gov identification number: NCT00264550.

Objective To determine whether cigarette smoking influences the response to treatment in patients with early rheumatoid arthritis (RA). Methods We retrieved clinical information about patients entering the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) early RA cohort from 1996 to 2006 (n = 1,998) who were also in the Swedish Rheumatology Register (until 2007). Overall, 1,430 of the 1,621 registered patients were followed up from the time of inclusion in the EIRA cohort. Of these, 873 started methotrexate (MTX) monotherapy at inclusion, and 535 later started treatment with a tumor necrosis factor (TNF) inhibitor as the first biologic agent. The primary outcome was a good response according to the European League Against Rheumatism criteria at the 3-month visit. The influence of cigarette smoking (current or past) on the response to therapy was evaluated by logistic regression, with never smokers as the referent group. Results Compared with never smokers, current smokers were less likely to achieve a good response at 3 months following the start of MTX (27% versus 36%; P = 0.05) and at 3 months following the start of TNF inhibitors (29% versus 43%; P = 0.03). In multivariate analyses in which clinical, serologic, and genetic factors were considered, the inverse associations between current smoking and good response remained (adjusted odds ratio [OR] for MTX response 0.60 [95% CI 0.39–0.94]; adjusted OR for TNF inhibitor response 0.52 [95% CI 0.29–0.96]). The lower likelihood of a good response remained at later followup visits. Evaluating remission or joint counts yielded similar findings. Past smoking did not affect the chance of response to MTX or TNF inhibitors. Evaluating the overall cohort, which reflects all treatments used, current smoking was similarly associated with a lower chance of a good response (adjusted ORs for the 3-month, 6-month, 1-year, and 5-year visits 0.61, 0.65, 0.78, 0.66, and 0.61, respectively). Conclusion Among patients with early RA, current cigarette smokers are less likely to respond to MTX and TNF inhibitors.

It has repeatedly been suggested that the development of complex diseases can be elucidated by gene-gene interactions. Recently, we found that HTR2A, a member of the serotonin receptor family, is associated with rheumatoid arthritis (RA). This study was aimed to investigate the possibility of a gene-gene interaction between HTR2A and the major genetic risk factor for RA, HLA-DRB1 shared epitope (SE) alleles. We studied 4095 RA cases and 3223 controls from three different populations from Sweden, the United States and the Netherlands - to test for interaction between the protective HTR2A haplotype and HLA-DRB1 SE alleles. Further, we analyzed mRNA and/or protein expression of HTR2A and HLA-DR in biopsy samples and in synovial fibroblasts from RA patients. The interaction was defined as departure from additivity of effects using attributable proportion due to interaction. First, we could demonstrate and further replicate an interaction between a protective haplotype in HTR2A and HLA-DRB1 SE alleles regarding risk of developing autoantibody-positive RA. Second, we could show that both genes are constitutively expressed in fibroblasts from synovial tissue of RA patients, and, by double immunofluorescence staining, we demonstrated that these two proteins are colocalized in these cells. In conclusion, our data demonstrate a statistical interaction between HTR2A and HLA-DRB1 SE alleles and colocalization of the product of these two genes in inflamed synovial tissue, which suggest a possible biological relationship between these two proteins. This finding may lead to the development of treatment based on enhancing the protective features of 5-HT2A in individuals with a certain HLA genotype. European Journal of Human Genetics (2010) 18, 821-826; doi: 10.1038/ejhg.2010.12; published online 24 February 2010

Contains fulltext : 88498.pdf (Publisher’s version ) (Closed access) To identify new genetic risk factors for rheumatoid arthritis, we conducted a genome-wide association study meta-analysis of 5,539 autoantibody-positive individuals with rheumatoid arthritis (cases) and 20,169 controls of European descent, followed by replication in an independent set of 6,768 rheumatoid arthritis cases and 8,806 controls. Of 34 SNPs selected for replication, 7 new rheumatoid arthritis risk alleles were identified at genome-wide significance (P < 5 x 10(-8)) in an analysis of all 41,282 samples. The associated SNPs are near genes of known immune function, including IL6ST, SPRED2, RBPJ, CCR6, IRF5 and PXK. We also refined associations at two established rheumatoid arthritis risk loci (IL2RA and CCL21) and confirmed the association at AFF3. These new associations bring the total number of confirmed rheumatoid arthritis risk loci to 31 among individuals of European ancestry. An additional 11 SNPs replicated at P < 0.05, many of which are validated autoimmune risk alleles, suggesting that most represent genuine rheumatoid arthritis risk alleles. 01 juni 2010

Objective The protective effect of HLA–DRB1 alleles on the development of rheumatoid arthritis (RA) is poorly understood. The aim of this study was to perform a meta-analysis of 4 European populations to investigate which HLA–DRB1 alleles are associated with protection in anti–citrullinated protein antibody (ACPA)–positive RA and ACPA-negative RA. Methods Data for >2,800 patients and >3,000 control subjects for whom information on HLA–DRB1 typing and ACPA status was available were collected from 4 European countries: Norway, Sweden, The Netherlands, and Spain. The odds ratios (ORs) and 95% confidence intervals (95% CIs) associated with the different HLA–DRB1 alleles were analyzed in a combined meta-analysis focused on protective alleles and classifications. The analysis of ACPA-positive RA was stratified for the shared epitope (SE) alleles, to correct for skewing due to this association. Results In ACPA-positive RA, the only alleles that conveyed protection after stratification for SE were HLA–DRB1*13 alleles (OR 0.54 [95% CI 0.38–0.77]). The protective effect of the allele classifications based on the DERAA and D70 sequences was no longer present after exclusion of DRB1*13 (for D70, OR 0.97 [95% CI 0.75–1.25]), indicating that DRB1*13, rather than the DERAA or D70 sequence as such, is associated with protection. Among the DRB1*13 alleles, only DRB1*1301 was associated with protection (OR 0.24 [95% CI 0.09–0.59]). Protection appeared to follow a north-to-south gradient, with the strongest association in northern European countries. In ACPA-negative RA, there were no robust associations with HLA–DRB1 alleles. Conclusion Our data do not support any of the classifications of protective alleles and indicate that protection against ACPA-positive RA is predominantly associated with HLA–DRB1*1301.

T cells play a major role in the pathogenesis of rheumatoid arthritis (RA). The programmed death 1 (PD-1)/programmed death ligand 1 (PDL-1) pathway is involved in peripheral tolerance through inhibition of T cells at the level of synovial tissue. The aim of this study was to examine the role of PD-1/PDL-1 in the regulation of human and murine RA.In synovial tissue and synovial fluid (SF) mononuclear cells from patients with RA, expression of PD-1/PDL-1 was examined by immunohistochemistry and flow cytometry, while PD-1 function was assessed in RA peripheral blood (PB) T cells after stimulation of the cells with anti-CD3 and PDL-1.Fc to crosslink PD-1. Collagen-induced arthritis (CIA) was induced in PD-1(-/-) C57BL/6 mice, and recombinant PDL-1.Fc was injected intraperitoneally to activate PD-1 in vivo.RA synovium and RA SF were enriched with PD-1+ T cells (mean +/- SEM 24 +/- 5% versus 4 +/- 1% in osteoarthritis samples; P = 0.003) and enriched with PDL-1+ monocyte/macrophages. PD-1 crosslinking inhibited both T cell proliferation and production of interferon-gamma (IFNgamma) in RA patients; PB T cells incubated with RA SF, as well as SF T cells from patients with active RA, exhibited reduced PD-1-mediated inhibition of T cell proliferation at suboptimal, but not optimal, concentrations of PDL-1.Fc. PD-1(-/-) mice demonstrated increased incidence of CIA (73% versus 36% in wild-type mice; P0.05) and greater severity of CIA (mean maximum arthritis score 5.0 versus 2.3 in wild-type mice; P = 0.040), and this was associated with enhanced T cell proliferation and increased production of cytokines (IFNgamma and interleukin-17) in response to type II collagen. PDL-1.Fc treatment ameliorated the severity of CIA and reduced T cell responses.The negative costimulatory PD-1/PDL-1 pathway regulates peripheral T cell responses in both human and murine RA. PD-1/PDL-1 in rheumatoid synovium may represent an additional target for immunomodulatory therapy in RA.

Objective T cells play a major role in the pathogenesis of rheumatoid arthritis (RA). The programmed death 1 (PD-1)/programmed death ligand 1 (PDL-1) pathway is involved in peripheral tolerance through inhibition of T cells at the level of synovial tissue. The aim of this study was to examine the role of PD-1/PDL-1 in the regulation of human and murine RA. Methods In synovial tissue and synovial fluid (SF) mononuclear cells from patients with RA, expression of PD-1/PDL-1 was examined by immunohistochemistry and flow cytometry, while PD-1 function was assessed in RA peripheral blood (PB) T cells after stimulation of the cells with anti-CD3 and PDL-1.Fc to crosslink PD-1. Collagen-induced arthritis (CIA) was induced in PD-1−/− C57BL/6 mice, and recombinant PDL-1.Fc was injected intraperitoneally to activate PD-1 in vivo. Results RA synovium and RA SF were enriched with PD-1+ T cells (mean ± SEM 24 ± 5% versus 4 ± 1% in osteoarthritis samples; P = 0.003) and enriched with PDL-1+ monocyte/macrophages. PD-1 crosslinking inhibited both T cell proliferation and production of interferon-γ (IFNγ) in RA patients; PB T cells incubated with RA SF, as well as SF T cells from patients with active RA, exhibited reduced PD-1–mediated inhibition of T cell proliferation at suboptimal, but not optimal, concentrations of PDL-1.Fc. PD-1−/− mice demonstrated increased incidence of CIA (73% versus 36% in wild-type mice; P < 0.05) and greater severity of CIA (mean maximum arthritis score 5.0 versus 2.3 in wild-type mice; P = 0.040), and this was associated with enhanced T cell proliferation and increased production of cytokines (IFNγ and interleukin-17) in response to type II collagen. PDL-1.Fc treatment ameliorated the severity of CIA and reduced T cell responses. Conclusion The negative costimulatory PD-1/PDL-1 pathway regulates peripheral T cell responses in both human and murine RA. PD-1/PDL-1 in rheumatoid synovium may represent an additional target for immunomodulatory therapy in RA.

Background Polymorphism in the neuropeptide S receptor gene NPSR1 is associated with asthma and inflammatory bowel disease. NPSR1 is expressed in the brain, where it modulates anxiety and responses to stress, but also in other tissues and cell types including lymphocytes, the lungs, and the intestine, where it appears to be up-regulated in inflammation. We sought to determine whether genetic variability at the NPSR1 locus influences the susceptibility and clinical manifestation of rheumatoid arthritis (RA). Methodology/Principal Findings From the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) case-control study, 1,888 rheumatoid arthritis patients and 888 controls were genotyped for 19 single-nucleotide polymorphisms (SNPs) spanning the entire NPSR1 gene and 220 KB of DNA on chromosome 7p14. The association between individual genetic markers and their haplotypic combinations, respectively, and diagnosis of RA, presence of autoantibodies to citrullinated proteins (ACPA), and disease activity score based on 28 joints (DAS28) was tested. There was no association between diagnosis of RA and NPSR1 variants. However, several associations of nominal significance were detected concerning susceptibility to ACPA-negative RA and disease activity measures (DAS28). Among these, the association of SNP rs324987 with ACPA-negative RA [(p = 0.004, OR = 0.674 (95% CI 0.512–0.888)] and that of SNP rs10263447 with DAS28 [p = 0.0002, OR = 0.380 (95% CI 0.227–0.635)] remained significant after correction for multiple comparisons. Conclusions/Significance NPSR1 polymorphism may be relevant to RA susceptibility and its clinical manifestation. Specific alleles at the NPSR1 locus may represent common risk factors for chronic inflammatory diseases, including RA.

BACKGROUND: Although the use of TNF inhibitors has fundamentally changed the way rheumatoid arthritis (RA) is treated, not all patients respond well. It is desirable to facilitate the identification of responding and non-responding patients prior to treatment, not only to avoid unnecessary treatment but also for financial reasons. In this work we have investigated the transcriptional profile of synovial tissue sampled from RA patients before anti-TNF treatment with the aim to identify biomarkers predictive of response. METHODOLOGY/PRINCIPAL FINDINGS: Synovial tissue samples were obtained by arthroscopy from 62 RA patients before the initiation of infliximab treatment. RNA was extracted and gene expression profiling was performed using an in-house spotted long oligonucleotide array covering 17972 unique genes. Tissue sections were also analyzed by immunohistochemistry to evaluate cell infiltrates. Response to infliximab treatment was assessed according to the EULAR response criteria. The presence of lymphocyte aggregates dominated the expression profiles and a significant overrepresentation of lymphocyte aggregates in good responding patients confounded the analyses. A statistical model was set up to control for the effect of aggregates, but no differences could be identified between responders and non-responders. Subsequently, the patients were split into lymphocyte aggregate positive- and negative patients. No statistically significant differences could be identified except for 38 transcripts associated with differences between good- and non-responders in aggregate positive patients. A profile was identified in these genes that indicated a higher level of metabolism in good responding patients, which indirectly can be connected to increased inflammation. CONCLUSIONS/SIGNIFICANCE: It is pivotal to account for the presence of lymphoid aggregates when studying gene expression patterns in rheumatoid synovial tissue. In spite of our original hypothesis, the data do not support the notion that microarray analysis of whole synovial biopsy specimens can be used in the context of personalized medicine to identify non-responders to anti-TNF therapy before the initiation of treatment.

Objective Anti–tumor necrosis factor α (anti-TNF) therapy is a mainstay of treatment in rheumatoid arthritis (RA). The aim of the present study was to test established RA genetic risk factors to determine whether the same alleles also influence the response to anti-TNF therapy. Methods A total of 1,283 RA patients receiving etanercept, infliximab, or adalimumab therapy were studied from among an international collaborative consortium of 9 different RA cohorts. The primary end point compared RA patients with a good treatment response according to the European League Against Rheumatism (EULAR) response criteria (n = 505) with RA patients considered to be nonresponders (n = 316). The secondary end point was the change from baseline in the level of disease activity according to the Disease Activity Score in 28 joints (▵DAS28). Clinical factors such as age, sex, and concomitant medications were tested as possible correlates of treatment response. Thirty-one single-nucleotide polymorphisms (SNPs) associated with the risk of RA were genotyped and tested for any association with treatment response, using univariate and multivariate logistic regression models. Results Of the 31 RA-associated risk alleles, a SNP at the PTPRC (also known as CD45) gene locus (rs10919563) was associated with the primary end point, a EULAR good response versus no response (odds ratio [OR] 0.55, P = 0.0001 in the multivariate model). Similar results were obtained using the secondary end point, the ▵DAS28 (P = 0.0002). There was suggestive evidence of a stronger association in autoantibody-positive patients with RA (OR 0.55, 95% confidence interval [95% CI] 0.39–0.76) as compared with autoantibody-negative patients (OR 0.90, 95% CI 0.41–1.99). Conclusion Statistically significant associations were observed between the response to anti-TNF therapy and an RA risk allele at the PTPRC gene locus. Additional studies will be required to replicate this finding in additional patient collections.

OBJECTIVE: Anti-tumor necrosis factor alpha (anti-TNF) therapy is a mainstay of treatment in rheumatoid arthritis (RA). The aim of the present study was to test established RA genetic risk factors to determine whether the same alleles also influence the response to anti-TNF therapy. METHODS: A total of 1,283 RA patients receiving etanercept, infliximab, or adalimumab therapy were studied from among an international collaborative consortium of 9 different RA cohorts. The primary end point compared RA patients with a good treatment response according to the European League Against Rheumatism (EULAR) response criteria (n = 505) with RA patients considered to be nonresponders (n = 316). The secondary end point was the change from baseline in the level of disease activity according to the Disease Activity Score in 28 joints (triangle upDAS28). Clinical factors such as age, sex, and concomitant medications were tested as possible correlates of treatment response. Thirty-one single-nucleotide polymorphisms (SNPs) associated with the risk of RA were genotyped and tested for any association with treatment response, using univariate and multivariate logistic regression models. RESULTS: Of the 31 RA-associated risk alleles, a SNP at the PTPRC (also known as CD45) gene locus (rs10919563) was associated with the primary end point, a EULAR good response versus no response (odds ratio [OR] 0.55, P = 0.0001 in the multivariate model). Similar results were obtained using the secondary end point, the triangle upDAS28 (P = 0.0002). There was suggestive evidence of a stronger association in autoantibody-positive patients with RA (OR 0.55, 95% confidence interval [95% CI] 0.39-0.76) as compared with autoantibody-negative patients (OR 0.90, 95% CI 0.41-1.99). CONCLUSION: Statistically significant associations were observed between the response to anti-TNF therapy and an RA risk allele at the PTPRC gene locus. Additional studies will be required to replicate this finding in additional patient collections

Background: Several studies point to a role of Toll-like receptors (TLRs) in the development of rheumatoid arthritis (RA). We investigated if genetic variants in TLR genes are associated with RA and response to tumour necrosis factor blocking (anti-TNF) medication. Methodology and Principal Findings: 22 single nucleotide polymorphisms (SNPs) in seven TLR genes were genotyped in a Dutch cohort consisting of 378 RA patients and 294 controls. Significantly associated variants were investigated in replication cohorts from The Netherlands, United Kingdom and Sweden (2877 RA patients and 2025 controls). 182 of the Dutch patients were treated with anti-TNF medication. Using these patients and a replication cohort (269 Swedish patients) we analysed if genetic variants in TLR genes were associated with anti-TNF outcome. In the discovery phase of the study we found a significant association of SNPs rs2072493 in TLR5 and rs3853839 in TLR7 with RA disease susceptibility. Meta-analysis of discovery and replication cohorts did not confirm these findings. SNP rs2072493 in TLR5 was associated with anti-TNF outcome in the Dutch but not in the Swedish population. Conclusion: We conclude that genetic variants in TLRs do not play a major role in susceptibility for developing RA nor in anti-TNF treatment outcome in a Caucasian population. Original Publication:Marieke J H Coenen, Christian Enevold, Pilar Barrera, Mascha M V A P Schijvenaars, Erik J M Toonen, Hans Scheffer, Leonid Padyukov, Alf Kastbom, Lars Klareskog, Anne Barton, Wietske Kievit, Tim L Jansen, Dorine Swinkels, Piet L C M van Riel, Barbara Franke, Klaus Bendtzen and Timothy R D J Radstake, Genetic Variants in Toll-Like Receptors Are Not Associated with Rheumatoid Arthritis Susceptibility or Anti-Tumour Necrosis Factor Treatment Outcome, 2010, PLOS ONE, (5), 12.http://dx.doi.org/10.1371/journal.pone.0014326Licensee: Public Library of Science (PLoS)http://www.plos.org/

4 páginas, 2 figuras, 2 tablas.-- Spanish Scleroderma Group., Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and internal organs that leads to profound disability and premature death. To identify new SSc susceptibility loci, we conducted the first genome-wide association study in a population of European ancestry including a total of 2,296 individuals with SSc and 5,171 controls. Analysis of 279,621 autosomal SNPs followed by replication testing in an independent case-control set of European ancestry (2,753 individuals with SSc (cases) and 4,569 controls) identified a new susceptibility locus for systemic sclerosis at CD247 (1q22–23, rs2056626, P = 2.09 × 10−7 in the discovery samples, P = 3.39 × 10−9 in the combined analysis). Additionally, we confirm and firmly establish the role of the MHC (P = 2.31 × 10−18), IRF5 (P = 1.86 × 10−13) and STAT4 (P = 3.37 × 10−9) gene regions as SSc genetic risk factors., This work was supported by the following grants: T.R.D.J.R. was funded by the VIDI laureate from the Dutch Association of Research (NWO) and Dutch Arthritis Foundation (National Reumafonds). J.M. was funded by GEN-FER from the Spanish Society of Rheumatology, SAF2009-11110 from the Spanish Ministry of Science, CTS-4977 from Junta de Andalucía, Spain and in part by Redes Temáticas de Investigación Cooperativa Sanitaria Program, RD08/0075 (RIER) from Instituto de Salud Carlos III (ISCIII), Spain (J.M.). R.B. is supported by the I3P Consejo Superior de Investigaciones Científicas program funded by the 'Fondo Social Europeo'. B.Z.A. is supported by the Netherlands Organization for Health Research and Development (ZonMW grant 016.096.121). B.K. is supported by the Dutch Diabetes Research Foundation (grant 2008.40.001) and the Dutch Arthritis Foundation (Reumafonds, grant NR 09-1-408). Genotyping of the Dutch control samples was sponsored by US National Insitutes of Mental Health funding, R01 MH078075 (R.O.A.). The German controls were from the PopGen biobank (to B.K.).

The question of whether there is a preferential use of certain V genes in T cells entering an inflamed joint has hitherto been studied mainly using unfractionated cells from synovial fluid and tissue respectively, and no clear answer to the question has yet been provided. Concomitantly. evidence has been provided that the use of V genes may differ considerably between CD4+ and CD8+ T cells, and consequently that detection of biased V-gene expression within an inflammatory lesion may require separate analysis of the two T-cell subsets. In this paper we have therefore studied T-cell receptor V-gene expression in rheumatoid arthritis by means of double stainings of synovial fluid and blood for available anti-TCR monoclonal antibodies and antibodies to CD4 and CD8. respectively. Double stainings were also performed with anti-TCR antibodies and antibodies to activation markers HLA-DR and 1L-2R. A certain bias towards the preferential use of certain V genes was seen particularly in the synovial fluid samples within both the CD4+ and CD8+ T-cell populations, but no uniform pattern was evident among the 35 patients investigated.

Objective To systematically investigate the expression of major histocompatibility complex (MHC) class II antigens (human leukocyte antigens, HLA-DR, -DP, and -DQ) on columnar epithelium in the fallopian tube during the menstrual cycle. Study Design Biopsies were collected from the fallopian tube during laparotomy sterilization and immunoperoxidase staining was performed. Settings Departments of Gynecology and Obstetrics and Clinical Immunology and Transfusion Medicine, Uppsala University, Uppsala, Sweden. Patients Twenty healthy fertile women undergoing sterilization at different times of the menstrual cycle. Interventions None. Main Outcome Measures The staining of the columnar epithelium was judged on a 4-graded scale according to the distribution of class II antigens. Results A widespread preovulatory HLA-DR expression was observed almost completely lining the columnar epithelial cells including the luminal surface, whereas postovulatory the HLA-DR expression was withdrawn from the surface. The HLA-DP and -DQ antigens varied in a similar way, although not as pronounced. Conclusions The MHC class II antigen variation in the fallopian tube epithelium seen in this study may indicate a hormonal regulation that could reflect variable need for local immunocompetence during the menstrual cycle: a preovulatory need for immunoreactivity against invading microbes and postovulatory an optimal survival of the foreign preimplantation embryo.

Objective. We studied the incidence, severity, histopathologic features, and status of infection in a spontaneous polyarthritis which occurs in male DBA/1 mice. Methods. Over a 25-week period, the arthritis was evaluated macroscopically in naive mice of different strains. The histopathology was evaluated at different phases of the disease. Virologic and bacteriologic investigations were performed. Results. The arthritis occurs in ∼80% of aging male DBA/1 mice. The disease is chronic and destructive, and the affected joints are characterized by synovial lining proliferation and infiltration of inflammatory cells, mainly mononuclear. The susceptibility appears to be dependent on both sex-linked and non-sex-linked genes, since female DBA/1 mice are not affected and since male BALB/c housed in the same colony are only marginally affected. Conclusion. This first description of a spontaneous arthritis in aging male DBA/1 mice should provide new opportunities to study general features of a chronic and intermittent arthritis in a well-characterized strain, in which no generalized aberrations of the immune system have been described.

ObjectiveTo study the association between silica exposure, separately as well as combined with smoking, and the risk of developing rheumatoid arthritis (RA) with or without the presence of antibodies against citrullinated peptide antigens (ACPA).MethodsThis Swedish population based case–control study analysed 577 incident RA cases and 659 randomly selected controls, all men aged 18–70 years, included during May 1996 to May 2006. Self-reported silica exposure, defined as exposure to stone dust, rock drilling or stone crushing and cigarette smoking was registered. ACPA status among cases was analysed.ResultsSilica-exposed subjects were found to have a moderately increased risk of ACPA-positive RA (odds ratio (OR) adjusted for age and residency=1.67 (95% CI 1.13 to 2.48), but not of ACPA-negative RA (OR=0.98 (95% CI 0.57 to 1.66)), compared with subjects unexposed to silica. Subjects exposed to rock drilling were found to have a somewhat more markedly increased risk of ACPA-positive RA (OR=2.34 (95% CI 1.17 to 4.68)). A high risk of developing ACPA-positive RA was observed among silica-exposed current smokers (OR=7.36 (95% CI 3.31 to 16.38)), exceeding the risk expected from the separate effects of silica exposure and current smoking, indicating an interaction between these exposures (attributable proportion due to interaction=0.60 (95% CI 0.26 to 0.95)).ConclusionSilica exposure combined with smoking among men is associated with an increased risk of developing ACPA-positive RA. These results suggest that different inhalation exposures may interact in the aetiology of ACPA-positive RA.