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Search for: rheumatoid arthritis    methotrexate    autoimmune disease    biomarker    gene expression    GWAS    HLA genes    non-HLA genes   

ID PMID Title PublicationDate abstract
22586159 Parental history of lupus and rheumatoid arthritis and risk in offspring in a nationwide c 2013 Apr OBJECTIVES: To examine the familial risk of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), including juvenile rheumatoid/idiopathic arthritis (JRA), in a population-based setting; and to determine whether patterns of transmission differ according to the sex of the parent or offspring, in order to provide insight into the potential impact of X-chromosomal factors on sex disparities in these autoimmune diseases. METHODS: A population-based cohort of parent-offspring triads from Denmark (1977-2010) was established. SLE and RA incidence rates among offspring were calculated, and Cox regression was performed to assess the sex-specific risk of disease in offspring according to maternal or paternal disease history. RESULTS: Among 3 513 817 parent-offspring triads, there were 1258 SLE cases among offspring (1095 female, 163 male) and 9118 cases of RA/JRA (6086 female, 3032 male). Among female offspring, SLE risk was nearly the same according to maternal (HR 14.1) or paternal (HR 14.5) history (p=NS); likewise among male offspring, risk according to maternal (HR 5.5) and paternal (no cases) history were similar (p=NS). For RA, all risk estimates were similar, regardless of the sex of the offspring or parent (HR 2.6-2.9; p=NS). CONCLUSIONS: The authors quantified the familial risk of SLE and RA in a nationwide cohort study. For both diseases, transmission was comparable among both female and male offspring of maternal and paternal cases. These data provide evidence at the population level that X-chromosomal factors do not play a major role in sex disparities associated with the risk of SLE and RA.
23777782 Orally available and efficacious α4β1/α4β7 integrin inhibitors. 2013 Aug 1 A series of potent α4β1/α4β7 integrin inhibitors is reported, including an inhibitor 12d with remarkable oral exposure and efficacy in rat models of rheumatoid arthritis and Crohn's disease.
24331074 A systematic review of validated methods for identifying patients with rheumatoid arthriti 2013 Dec 30 PURPOSE: To review the evidence supporting the validity of billing, procedural, or diagnosis code, or pharmacy claim-based algorithms used to identify patients with rheumatoid arthritis (RA) in administrative and claim databases. METHODS: We searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to RA and reference lists of included studies were searched. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria and extracted the data. Data collected included participant and algorithm characteristics. RESULTS: Nine studies reported validation of computer algorithms based on International Classification of Diseases (ICD) codes with or without free-text, medication use, laboratory data and the need for a diagnosis by a rheumatologist. These studies yielded positive predictive values (PPV) ranging from 34 to 97% to identify patients with RA. Higher PPVs were obtained with the use of at least two ICD and/or procedure codes (ICD-9 code 714 and others), the requirement of a prescription of a medication used to treat RA, or requirement of participation of a rheumatologist in patient care. For example, the PPV increased from 66 to 97% when the use of disease-modifying antirheumatic drugs and the presence of a positive rheumatoid factor were required. CONCLUSIONS: There have been substantial efforts to propose and validate algorithms to identify patients with RA in automated databases. Algorithms that include more than one code and incorporate medications or laboratory data and/or required a diagnosis by a rheumatologist may increase the PPV.
24438724 Use of Bayesian multivariate meta-analysis to estimate the HAQ for mapping onto the EQ-5D 2014 Jan BACKGROUND: In health technology assessment, decisions about reimbursement for new health technologies are largely based on effectiveness estimates. Sometimes, however, the target effectiveness estimates are not readily available. This may be because many alternative instruments measuring these outcomes are being used (and not all always reported) or an extended follow-up time of clinical trials is needed to evaluate long-term end points, leading to the limited data on the target clinical outcome. In the areas of highest priority in health care, decisions are required to be made on a short time scale. Therefore, alternative clinical outcomes, including surrogate end points, are increasingly being considered for use in evidence synthesis as part of economic evaluation. OBJECTIVE: To illustrate the potential effect of reduced uncertainty around the clinical outcome on the utility when estimating it from a multivariate meta-analysis. METHODS: Bayesian multivariate meta-analysis has been used to synthesize data on correlated outcomes in rheumatoid arthritis and to incorporate external data in the model in the form of informative prior distributions. Estimates of Health Assessment Questionnaire were then mapped onto the health-related quality-of-life measure EuroQol five-dimensional questionnaire, and the effect was compared with mapping the Health Assessment Questionnaire obtained from the univariate approach. RESULTS: The use of multivariate meta-analysis can lead to reduced uncertainty around the effectiveness parameter and ultimately uncertainty around the utility. CONCLUSIONS: By allowing all the relevant data to be incorporated in estimating clinical effectiveness outcomes, multivariate meta-analysis can improve the estimation of health utilities estimated through mapping methods. While reduced uncertainty may have an effect on decisions based on economic evaluation of new health technologies, the use of short-term surrogate end points can allow for early decisions. More research is needed to determine the circumstances under which uncertainty is reduced.
23253928 Bone remodelling in inflammatory arthritis. 2013 Apr The inflammatory arthropathies that include rheumatoid arthritis, the seronegative spondyloarthropathies and systemic lupus erythematosus are characterised by marked alterations in the architecture and structural integrity of peri-articular bone; however, the pattern and natural history of the skeletal changes differs in these conditions. In part, this can be attributed to differences in the primary anatomical site of the inflammation, but also there is evidence that there are differences in the biological properties and products produced by inflammatory tissues. This review will focus on recent advances in the understanding of the cellular and molecular mechanisms that contribute to the differential pattern of articular bone remodelling in these prototypical inflammatory forms of arthritis.
24223605 Research of the methylation status of miR-124a gene promoter among rheumatoid arthritis pa 2013 OBJECTIVE: To analyze the methylation status of miR-124a loci in synovial tissues of rheumatoid arthritis (RA) patients using methylation-specific polymerase chain reaction (MSP). MATERIALS AND METHODS: DNA obtained from the frozen tissue of 7 RA samples, 6 osteoarthritis (OA) samples, and 3 healthy controls were undergoing bisulfite conversion and then analyzed for miR-124a promoter methylation using MSP assay. RESULTS: miR-124-a1 and miR-124-a2 promoter methylation were both seen in 71.4% of RA samples compared to 16.7% of OA samples. miR-124-a3 promoter methylation was seen in 57.1% of RA samples and 0% of OA samples. All the three loci were unmethylated in 3 healthy controls. CONCLUSION: The methylation status of miR-124a seen in this study concurs with that reported in tumor cells, indicating epigenetic dysregulation constituents, a mechanism in the development of rheumatoid arthritis.
24477729 A systematic review of the influence of anti-TNF on infection rates in patients with rheum 2013 Nov OBJECTIVE: The present article aims to provide a systematic review of the influence of antitumor necrosis factor (TNF) on infection rates in patients with rheumatoid arthritis (RA). METHOD: Medline was searched to obtain quality control information on infection rates in RA patients treated with anti-TNF. RESULTS: A high proportion of RA patients are now established users of anti-TNF agents. Data from national registries in European countries of patients with RA treated with anti-TNF suggest that biological therapies are closely linked to sepsis. Although previous studies reported a higher risk of infections, there are now emerging data with longer duration of follow-up that suggested an adjusted hazard risk of 1.2. Elderly patients and those with longstanding disease may have a higher rate of serious infections compared to their counterparts who were younger with early disease. There are now emerging data to suggest that anti-TNF therapy is associated with the development of neutropenia shortly after the commencement of treatment. The biologic registries found that RA patients treated with monoclonal antibodies are at increased risk of tuberculosis (TB) compared to those on TNF receptor blockers. This risk of infection needs to be weighed against the established benefits of TNF blockers. CONCLUSION: Current evidence suggests that anti-TNF treatment in RA is closely linked to infection. Patients need to be aware of the risk of infection together with the established benefits of TNF blockers in order to give informed consent for treatment.
25115097 Ascidian tunicate extracts attenuate rheumatoid arthritis in a collagen-induced murine mod 2014 Jun Murine rheumatoid arthritis models are often used to investigate the potential therapeutic effects of candidate drugs. The present study has been conducted in order to investigate the therapeutic efficacy of ascidian tunicate extracts in a collagen-induced arthritis DBA1/J mice model. Four types of formulas, ascidian tunicate extracts (ATE), crude ascidian tunicate glycans (ATEC), ascidian tunicate extracts with licorice extracts (ATEL), and crude ascidian tunicate glycans with licorice extracts (ATECL) were orally administered into DBA/1J mice for 3 weeks and paw edema and thickness were evaluated. Changes in inflammatory proteins and cytokines levels were monitored in hind leg tissues by Western blot and quantitative PCR analysis. The oral administration of ascidian tunicate extracts alleviated paw edema and improved the histological hind leg cartilage status. The extracts also reduced the matrix metalloproteinase-9 (MMP-9) protein and prostaglandin E synthase (PGES) levels. In addition, the extracts-treated groups showed increased interleukin-10 (IL-10) levels compared with the non-treated group. These findings suggest that orally administered ascidian tunicate extracts might have potential therapeutic effects for the treatment of rheumatoid arthritis.
25292482 IgA rheumatoid factor as a serological predictor of poor response to tumour necrosis facto 2014 Nov AIM: The main objective of this study is to elucidate the role of immunoglobulin A (IgA) rheumatoid factor (RF) in predicting the clinical response to tumour necrosis factor α inhibitors (TNFi) among patients with rheumatoid arthritis (RA). METHOD: We recruited all patients with RA who were ever on TNFi for a minimum duration of 3 months at our centre. Based on the European League Against Rheumatism response criteria, subjects were further divided into responders and non-responders. Age-matched RA patients who were on conventional disease-modifying anti-rheumatic drugs and in remission were enrolled as controls. Subjects were tested for quantitative values of IgA, IgM, IgG RF and anti-citrulinated cyclic peptides (CCP). Further, all subjects were assessed for the disease activity score that includes 28 joints (DAS28) and Stanford Health Assessment Questionnaire (HAQ) 8-item Disability Index (HAQ-DI). RESULTS: A total of 31 subjects with RA who had received TNFi and 15 controls were enrolled in this study. There was a trend for the non-responders (n = 10) to have higher levels of all isotypes of RF and anti-CCP. However, only the IgA RF and anti-CCP levels were significantly higher in the non-responder group compared to the responders and controls (P = 0.001, P = 0.034, respectively). On multivariate analysis, only the IgA RF remained significant (OR 0.989; 95% CI 0.980-0.999; P = 0.026). CONCLUSION: IgA RF is potentially a novel predictor of response to TNFi in RA patients. Testing for pretreatment IgA RF levels could be a reasonable consideration before commencement of TNFi.
25435301 Piperlongumine attenuates collagen-induced arthritis via expansion of myeloid-derived supp 2015 Apr Piperlonguminine (PL), a key compound from the Piper longum fruit, is known to exhibit anti‑tumor and anti‑inflammatory activities. However, little is known about its effects on collagen‑induced arthritis (CIA). Fibroblast‑like synoviocytes (FLS) have a pivotal role in the development of rheumatoid arthritis (RA). Myeloid‑derived suppressor cells (MDSCs) are able to suppress T cell responses and have important roles in the regulation of autoimmune arthritis. The current study investigated whether PL alters the progression of RA. It was determined that PL reduces the arthritis score and histopathologic lesions in a mouse model of CIA. PL also reduces the expression levels of serum anti‑collagen II antibodies (anti‑CⅡ), tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑1β, IL‑23 and IL‑17 in CIA mice. In draining lymph nodes (DLNs), MDSCs were significantly expanded, however, the number of Th17 cells was markedly decreased by PL treatment. Additionally, PL reduced secretion of IL‑1β, IL‑23 and IL‑17 by TNF‑α‑stimulated human RA FLS. PL significantly inhibited the migration and invasion of TNF‑α‑stimulated human RA FLS. These results indicate that PL may be a candidate therapeutic agent for the treatment of RA, via the expansion of MDSCs and the inhibition of the Th17 response and activation of FLS.
25274894 Which factors influence radiographic progression during treatment with tumor necrosis fact 2014 Dec OBJECTIVE: To investigate baseline characteristics associated with radiographic progression and the effect of disease activity, drug, switching, and withdrawal on radiographic progression in tumor necrosis factor (TNF) inhibitor-naive patients with rheumatoid arthritis (RA) followed for about 2 years after anti-TNF initiation in clinical practice. METHODS: DANBIO-registered patients with RA who had available radiographs (anti-TNF initiation and ∼2 yrs followup) were included. Radiographs were scored, blinded to chronology with the Sharp/van der Heijde method and linked with DANBIO data. Baseline characteristics were investigated with univariate regression and significant variables included in a multivariable logistic regression analysis with ± radiographic progression [Δ total Sharp score (TSS) > 0] as dependent variable. Effect of time-averaged C-reactive protein (CRP), 28-joint Disease Activity Score with CRP (DAS28-CRP), and treatment status at followup were investigated with univariate regression analysis. RESULTS: The study included 930 patients. They were 75% women, 79% positive for IgM-rheumatoid factor (IgM-RF), median age was 57 yrs (range 19-88), disease duration 9 yrs (1-59), DAS28-CRP 5.0 (1.4-7.8), TSS median 15 [3-45 interquartile range (IQR)] and mean 31 (SD 40). Patients started treatment with infliximab (59%), etanercept (18%), or adalimumab (23%). At followup (median 526 days, IQR 392-735), 61% were treated with the initial anti-TNF, 29% had switched TNF inhibitor, and 10% had withdrawn. Twenty-seven percent of patients had progressed radiographically. ΔTSS was median 0.0 [0.0-0.5 IQR/mean 0.6 (SD 2.4)] units/year. Higher TSS, older age, positive IgM-RF, and concomitant prednisolone at baseline were associated with radiographic progression. Time-averaged DAS28-CRP and time-averaged CRP, but not type of TNF inhibitor, were associated with radiographic progression. Patients who stopped/switched during followup progressed more than patients who continued treatment. CONCLUSION: High TSS, older age, IgM-RF positivity, and concomitant prednisolone were associated with radiographic progression during 2 years of followup of 930 anti-TNF-treated patients with RA in clinical practice. High disease activity and switching/stopping anti-TNF treatment were associated with radiographic progression.
24336335 Genetic risk scores and number of autoantibodies in patients with rheumatoid arthritis. 2015 Apr OBJECTIVE: Certain HLA-DRB1 alleles and single-nucleotide polymorphisms (SNPs) are associated with rheumatoid arthritis (RA). Our objective was to examine the combined effect of these associated variants, calculated as a cumulative genetic risk score (GRS) on RA predisposition, as well as the number of autoantibodies (none, one or two present). METHOD: We calculated four GRSs in 4956 patients and 4983 controls from four European countries. All four scores contained data on 22 non-HLA-risk SNPs, and three scores also contained HLA-DRB1 genotypes but had different HLA typing resolution. Most patients had data on both rheumatoid factor (RF) and anti-citrullinated proteins antibodies (ACPA). The GRSs were standardised (std.GRS) to account for population heterogeneity. Discrimination between patients and controls was examined by receiveroperating characteristics curves, and the four std.GRSs were compared across subgroups according to autoantibody status. RESULTS: The std.GRS improved its discriminatory ability between patients and controls when HLA-DRB1 data of higher resolution were added to the combined score. Patients had higher mean std.GRS than controls (p=7.9×10(-156)), and this score was significantly higher in patients with autoantibodies (shown for both RF and ACPA). Mean std.GRS was also higher in those with two versus one autoantibody (p=3.7×10(-23)) but was similar in patients without autoantibodies and controls (p=0.12). CONCLUSIONS: The GRS was associated with the number of autoantibodies and to both RF and ACPA positivity. ACPA play a more important role than RF with regards to the genetic risk profile, but stratification of patients according to both RF and ACPA may optimise future genetic studies.
23754804 Trends in the use of biologic agents among rheumatoid arthritis patients enrolled in the U 2013 Nov OBJECTIVE: Self-injectable biologic agents have been covered by Medicare Part D since 2006. We hypothesized that this coverage benefit and related financial considerations would lead to increased use of self-injectable biologic agents overtime and would be influential in determining which rheumatoid arthritis (RA) patients received infusion versus self injected biologic agents. METHODS: We used 100% of US Medicare data (2006–2009) to calculate the prevalence of use of different RA biologic agents and evaluated factors associated with receipt of infliximab versus etanercept or adalimumab among patients starting their first anti–tumor necrosis factor (anti-TNF) agent. RESULTS: Through 2009, the prevalence of biologic agent use overall (~ 27%) and via infusion (16–17%) or self-injection(10–11%) remained unchanged among Medicare beneficiaries with RA. After adjusting for patient characteristics,stronger physician preference for infused biologic agents was related to physician reimbursement and associated with an increased likelihood of using infliximab as the first anti-TNF agent (odds ratio [OR] comparing the highest to lowest quartile of physician preference 7.3, 95% confidence interval [95% CI] 6.4–8.3). Lower-income patients who received state assistance for Medicare coverage had lower out-of-pocket payments for injectable biologic agents ($4.10/prescription) and were less likely to use infliximab (OR 0.41, 95% CI 0.37–0.45) compared with etanercept or adalimumab. CONCLUSION: The prevalence of injection and infusion biologic agents in RA remained stable in the Medicare program through 2009. The choice between an intravenous infusion versus an injectable anti-TNF agent as first-line treatment appeared to be strongly influenced by financial considerations affecting both patients and physicians.
25227461 Analysis of autoantibody profiles in osteoarthritis using comprehensive protein array conc 2014 Nov 7 Osteoarthritis (OA) is the most common rheumatic disease and one of the most disabling pathologies worldwide. To date, the diagnostic methods of OA are very limited, and there are no available medications capable of halting its characteristic cartilage degeneration. Therefore, there is a significant interest in new biomarkers useful for the early diagnosis, prognosis, and therapeutic monitoring. In the recent years, protein microarrays have emerged as a powerful proteomic tool to search for new biomarkers. In this study, we have used two concepts for generating protein arrays, antigen microarrays, and NAPPA (nucleic acid programmable protein arrays), to characterize differential autoantibody profiles in a set of 62 samples from OA, rheumatoid arthritis (RA), and healthy controls. An untargeted screen was performed on 3840 protein fragments spotted on planar antigen arrays, and 373 antigens were selected for validation on bead-based arrays. In the NAPPA approach, a targeted screening was performed on 80 preselected proteins. The autoantibody targeting CHST14 was validated by ELISA in the same set of patients. Altogether, nine and seven disease related autoantibody target candidates were identified, and this work demonstrates a combination of these two array concepts for biomarker discovery and their usefulness for characterizing disease-specific autoantibody profiles.
24914212 An interactive network of elastase, secretases, and PAR-2 protein regulates CXCR1 receptor 2014 Jul 25 CXCL8 (IL-8) recruits and activates neutrophils through the G protein-coupled chemokine receptor CXCR1. We showed previously that elastase cleaves CXCR1 and thereby impairs antibacterial host defense. However, the molecular intracellular machinery involved in this process remained undefined. Here we demonstrate by using flow cytometry, confocal microscopy, subcellular fractionation, co-immunoprecipitation, and bioluminescence resonance energy transfer that combined α- and γ-secretase activities are functionally involved in elastase-mediated regulation of CXCR1 surface expression on human neutrophils, whereas matrix metalloproteases are dispensable. We further demonstrate that PAR-2 is stored in mobilizable compartments in neutrophils. Bioluminescence resonance energy transfer and co-immunoprecipitation studies showed that secretases, PAR-2, and CXCR1 colocalize and physically interact in a novel protease/secretase-chemokine receptor network. PAR-2 blocking experiments provided evidence that elastase increased intracellular presenilin-1 expression through PAR-2 signaling. When viewed in combination, these studies establish a novel functional network of elastase, secretases, and PAR-2 that regulate CXCR1 expression on neutrophils. Interfering with this network could lead to novel therapeutic approaches in neutrophilic diseases, such as cystic fibrosis or rheumatoid arthritis.
23377397 New-onset vitiligo during long-term, stable infliximab treatment of pityriasis rubra pilar 2013 Feb Incidents of new-onset vitiligo attributed to infliximab therapy for rheumatoid arthritis and ulcerative colitis have been reported. Reported cases share a common theme in that symptoms manifested in close proximity to the initiation or significant dose increase of the medication. This case describes the presentation of infliximab-induced vitiligo in a patient using it for long-term treatment of stable pityriasis rubra pilaris. The patient was initiated and titrated to a stable dose of infliximab totaling 27 months' duration. He was able to achieve near-complete resolution of symptoms before developing depigmented patches consistent with vitiligo. Infliximab was discontinued. Tacrolimus 0.1% ointment and narrow-band ultraviolet B light successfully repigmented the patches. The association of discontinuing infliximab and resolution of vitiligo suggests infliximab had a role in this case. Though the mechanism of involvement is undetermined, infliximab may have induced an autoimmune process by paradoxically activating lymphocytes. Alternatively, infliximab antibodies may have led to the process by disrupting the normal balance of cytokines.
25378980 Early effects of tumor necrosis factor inhibition on bone homeostasis after soluble tumor 2014 Nov BACKGROUND/AIMS: Our aim was to assess whether short-term treatment with soluble tumor necrosis factor (TNF) receptor affects circulating markers of bone metabolism in rheumatoid arthritis (RA) patients. METHODS: Thirty-three active RA patients, treated with oral disease-modifying antirheumatic drugs (DMARDs) and glucocorticoids for > 6 months, were administered etanercept for 12 weeks. Serum levels of bone metabolism markers were compared among patients treated with DMARDs at baseline and after etanercept treatment, normal controls and naive RA patients not previously treated with DMARDs (both age- and gender-matched). RESULTS: Bone-specific alkaline phosphatase (BSALP) and serum c-telopeptide (CTX)-1 levels were lower in RA patients treated with DMARDs than in DMARD-naive RA patients. After 12 weeks of etanercept treatment, serum CTX-1 and sclerostin levels increased. In patients whose DAS28 improved, the sclerostin level increased from 1.67 ± 2.12 pg/mL at baseline to 2.51 ± 3.03 pg/mL, which was statistically significant (p = 0.021). Increases in sclerostin levels after etanercept treatment were positively correlated with those of serum CTX-1 (r = 0.775), as were those of BSALP (r = 0.755). CONCLUSIONS: RA patients treated with DMARDs showed depressed bone metabolism compared to naive RA patients. Increases in serum CTX-1 and sclerostin levels after short-term etanercept treatment suggest reconstitution of bone metabolism homeostasis.
23849770 [Interleukin-1 and the interleukin-1 receptor antagonist gene polymorphisms study in patie 2013 Dec OBJECTIVES: One of the most important pro-inflammatory cytokines in the pathophysiology of rheumatoid arthritis (RA) is interleukin 1 (IL-1). The purpose of this study is to evaluate the association between IL-1B (-511), IL-1 (+3953), IL-1 RN variable number of tandem repeat (VNTR) polymorphisms and the occurrence in Algerian patients with rheumatoid arthritis. We also analyze their correlations with clinical and biological phenotypes. PATIENTS AND METHODS: One hundred and forty-seven patients with RA (119 women, 28 men) and 127 controls (70 women, 57 men) were included in the study. The analysis of two polymorphisms of IL-1B-511 and IL-1B+3953 was done by PCR-RFLP. Analysis of IL1-RN VNTR polymorphism was performed by PCR. RESULTS: No significant difference in genotype, allelic and haplotype distribution at the three polymorphisms was observed between RA patients and controls. However, the genotype (T/T) polymorphism of IL-1B-511 is more frequent in the group of patients with positive ACPA compared with negative ACPA group (Pc=0.01, OR=4.65). Moreover, we noted that the haplotype (IL-1RN* 1/IL-1B-511T/IL-1B+3953C) was more frequent (Pc=0.03, OR=2.05) in the positive ACPA group. CONCLUSION: The association between the allele 1 of IL-1 RN VNTR, T allele of IL1B-511 and C allele of IL1-B +3953 polymorphisms seems to predispose to the synthesis of ACPA and therefore to the occurrence of ACPA positive RA. Further studies with a larger number of patients are needed to define the real role of IL-1 in the susceptibility to or severity of RA.
23574520 Antigen presentation by dendritic cells in rheumatoid arthritis. 2013 Rheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disease that affects largely synovial joints. It has been postulated that activated autoreactive CD4 T cells play a key role in triggering and/or maintaining the chronic inflammatory process in RA. Dendritic cells (DCs) are antigen-presenting cells that activate cognate clonal CD4 T cells in the lymph nodes. The activation process involves the formation of a molecular structure at the DC-CD4 T cell contact zone called immunological synapse (IS). In RA, the synovium, a thin layer of tissue below the capsule in the joints, shows a massive infiltration of DCs and CD4 T cells. Subjects bearing HLA-DRB1 alleles of the Major Histocompatibility Complex II gene displaying a motif called RA "shared epitope (SE)", have an enhanced susceptibility to suffer RA. Interestingly, the SE-containing HLA-DRB1 molecules display a pocket with a high affinity for citrullinated antigens, which are found at higher levels in subjects prone to develop RA. Thus, it is possible that the DCs of susceptible individuals may form IS with particular features that may present citrullinated peptides to autorreactive naïve CD4 T clones that, after being activated, contribute to the initiation or development of the disease. Herein I put forward a model of RA initiation based on current information on the immune response and RA.
24574216 Gene associated with retinoid-interferon-induced mortality 19 attenuates murine autoimmune 2014 Mar OBJECTIVE: STAT-3 is a key transcriptional factor in the interleukin-6 (IL-6)-mediated differentiation of Th17 cells. Because Th17 is believed to be a central player in rheumatoid arthritis (RA), we sought to evaluate whether an endogenous inhibitor of the STAT3 gene, GRIM-19 (gene associated with retinoid-interferon-induced mortality 19), could attenuate the progression and severity of murine collagen-induced arthritis (CIA) through suppression of Th17 cells and, reciprocally, could increase expression of Treg cells. METHODS: Overexpression of GRIM-19 was produced either by intravenous/intramuscular administration of a GRIM-19 overexpression vector in DBA1/J mice or by development of GRIM-19-transgenic (Tg) mice on a C57BL/6 background. Clinical signs were scored for arthritis severity, and mouse splenocytes, serum, and joint tissue were obtained for immunostaining and histologic analyses. RESULTS: The numbers of CD4+IL-17+ cells and CD4+pSTAT3+ cells were decreased, while the numbers of CD4+CD25+Foxp3+ cells and CD4+pSTAT5+ cells were increased, in both GRIM-19 vector-transfected and GRIM-19-Tg mice. Administration of the GRIM-19 overexpression vector into mice with CIA markedly suppressed the clinical and histologic signs of arthritis in the affected joints. Similarly, when CIA was induced in GRIM-19-Tg mice, the arthritis phenotype was markedly attenuated and the expression of inflammatory cytokines (IL-1β, IL-6, tumor necrosis factor α, and IL-17) in the arthritic joints was also significantly reduced. Moreover, bone marrow-derived monocyte/macrophages obtained from GRIM-19-Tg mice showed attenuated RANKL-induced osteoclastogenesis in vitro. CONCLUSION: GRIM-19 improved the clinical and histologic features of CIA and also inhibited osteoclast formation. These findings suggest that GRIM-19 may be a novel treatment agent for RA.