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ID PMID Title PublicationDate abstract
27149996 Reduced glutathione as a physiological co-activator in the activation of peptidylarginine 2016 May 5 BACKGROUND: Citrullination catalysed by peptidylarginine deiminases (PADs) plays an important pathogenic role in anti-citrullinated protein antibody (ACPA)-positive rheumatoid arthritis (RA) and, possibly, several other inflammatory diseases. Non-physiological reducing agents such as dithiothreitol (DTT) are normally added to the reaction buffer when determining PAD activity in vitro. We investigated the ability of reduced glutathione (GSH), the most abundant intracellular small-molecule thiol in vivo, to activate PADs. METHODS: Activity of recombinant human (rh) PAD2 and PAD4, PADs contained in synovial fluid (SF) samples from RA patients and PADs released from phorbol 12-myristate 13-acetate (PMA)-stimulated cells was measured using an in-house PAD activity assay detecting citrullination of fibrinogen. RESULTS: No activity of rhPAD2, rhPAD4 or PADs within SF was observed without addition of an exogenous reducing agent. Activity of both recombinant and SF PAD was observed in the presence of 1 mM DTT or 10-15 mM GSH. Following stimulation with PMA, human isolated leucocytes, but not mononuclear cells, released enzymatically active PAD, the activity of which was abolished upon pre-incubation of the cells with the glutathione reductase inhibitor 2-AAPA. No PAD activity was observed in the corresponding supernatants, but addition of exogenous GSH restored activity. CONCLUSIONS: Catalytic activity of PAD requires reducing conditions. GSH meets this requirement at concentrations comparable with those found within cells. Active PAD, reduced by GSH, is released from PMA-stimulated granulocytes, but becomes inactivated in the extracellular space.
26123215 Enhanced neutrophil phagocytic capacity in rheumatoid arthritis related to the autoantibod 2015 Jun 30 BACKGROUND: There is no consensus on the mechanisms by which anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) influence the pathogenesis of rheumatoid arthritis (RA). The current study verified if the presence of RF or anti-CCP is associated with phagocytic capacity and reactive oxygen species (ROS) production by phagocytes in RA patients to better clarify the role played by these antibodies in pathogenesis of the disease. METHODS: A cohort of 30 RA patients followed from early stages of the disease were characterized by positivity for RF or anti-CCP, disease activity score (DAS-28), health assessment questionnaire (HAQ), use of synthetic or biologic therapy, lifestyle, comorbidities and radiographic erosions. Phagocytic capacity against Saccharomyces cerevisiae and superoxide anion production were assessed in RA patients and compared with 20 healthy controls. Phagocytic capacity and superoxide anion production were also compared between RF- and anti-CCP-positive and -negative RA patients. RESULTS: Anti-CCP- and RF-positive RA patients had higher neutrophil phagocytic capacity than anti-CCP- (p = 0.005) and RF (p = 0.005)-negative individuals through pattern-recognition receptors. As assessed via pattern recognition or opsonin receptors, neutrophils and monocytes from RA patients presented overall higher phagocytic capacity than neutrophils and monocytes from healthy controls (p < 0.05). Furthermore, RA patients also showed a higher capacity for producing cytotoxic oxygen radicals (p = 0.0026). Phagocytosis and superoxide anion production did not correlate with any of the clinical variables analyzed in this study. CONCLUSIONS: This study showed increased phagocytosis by neutrophils in RA patients who were positive for anti-CCP and RF autoantibodies. Furthermore, there was an overall hyperactivation of the phagocytes in RA patients. Our data suggest that anti-CCP and RF may indirectly enhance the inflammation cascade involving neutrophils and may indirectly sustain tissue damage in RA. Targeting the production of these autoantibodies may be a promising strategy in the management of RA.
27550190 Subsidence of total ankle component associated with deterioration of an ankle scale in non 2017 May OBJECTIVES: Modern three-component total ankle arthroplasty (TAA) has favorable clinical results and survival rates. However, radiographic deterioration and worsening of clinical symptoms may occur in patients with rheumatoid arthritis (RA) or non-inflammatory arthritis (NA). The associations between outcomes and clinical and radiological factors are not clear. We compared midterm clinical and radiographic outcomes after TAA between patients with RA and those with NA. METHODS: Twenty-six TAAs were performed using a three-component prosthesis, the FINE Total Ankle System during the study period. Fourteen TAAs with 11 RA patients undergoing primary TAA were compared with twelve TAAs with 12 NA patients. Clinical and radiographic outcomes were evaluated before and after operation, and at the final follow-up. RESULTS: The Japanese Society for Surgery of the Foot (JSSF) scale improved significantly following TAA in both groups (p = 0.0039 and 0.0156, respectively). Tibial subsidence, talar subsidence and age were significantly associated with postoperative JSSF score only in the NA group (p = 0.0027, 0.0017 and p < 0.0001, respectively). Stepwise regression analysis showed that talar subsidence was an independent predictor of a worse JSSF score in the NA group (F = 10.3). CONCLUSIONS: The final clinical outcome was negatively influenced by talar subsidence in patients with NA, but not in those with RA.
24716596 TNFα, PDGF, and TGFβ synergistically induce synovial lining hyperplasia via inducible PI 2015 Jan OBJECTIVES: To determine the mechanism underlying hypertrophic synovium in rheumatoid arthritis (RA). METHODS: We examined micromass cultures of fibroblast-like synoviocytes (FLSs) stimulated with tumor necrosis factor α (TNFα), platelet-derived growth factor (PDGF), and/or transforming growth factor β (TGFβ). The hypertrophic architecture of the micromasses, expression of phosphoinositide 3 kinase (PI3K) isoforms, and persistent activation of PI3K-Akt pathways were investigated. FLSs transfected with siRNA were also examined in the micromass cultures. RESULTS: The combination of TNFα, PDGF, and TGFβ (TPT condition) induced obvious hypertrophic architecture of the intimal lining layer in FLSs in micromass cultures, and was accompanied by upregulated expression of matrix metalloproteinase-3 (MMP3), Cadherin-11, and PI3Kδ. In monolayer FLSs, the TPT condition enhanced the expression of PI3Kδ and persistent activation of the PI3K-Akt pathway. Knockdown of PI3Kδ significantly inhibited the formation of the hypertrophic synovial lining in the TPT condition. CONCLUSIONS: These results collectively indicate that inducible PI3Kδ plays a crucial role in persistent activation of PI3K-Akt in FLSs, and in the formation of a hypertrophic synovial lining. PI3Kδ may be an alternative treatment target for the regulation of proliferative synovium in RA.
25470338 Potential mechanisms leading to the abnormal lipid profile in patients with rheumatoid art 2015 Mar OBJECTIVE: Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). Systemic inflammation is proposed to play a fundamental role in the altered lipid metabolism associated with RA; however, the underlying mechanisms are unknown. We undertook this study to compare cholesterol and lipoprotein kinetics in patients with active RA with those in matched healthy volunteers. METHODS: This was a phase I open-label mechanism-of-action study. Cholesterol and lipoprotein kinetics were assessed with (13) C-cholesterol and (13) C-leucine infusions. RA patients were reevaluated after receiving oral tofacitinib 10 mg twice daily for 6 weeks. RESULTS: Levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, total cholesterol, and apolipoprotein A-I (Apo A-I) as well as HDL cholesterol particle number were lower in RA patients (n = 36) than in healthy volunteers (n = 33). In contrast, the cholesterol ester fractional catabolic rate was higher in RA patients, but no differences were observed in cholesterol ester transfer protein, cholesterol ester production rate, HDL-associated Apo A-I fractional catabolic rate, or LDL-associated Apo B fractional catabolic rate. Following tofacitinib treatment in RA patients, the cholesterol ester fractional catabolic rate decreased and cholesterol levels increased. The decrease in cholesterol ester fractional catabolic rate correlated significantly with the increase in HDL cholesterol. Additionally, HDL cholesterol particle number increased and markers of HDL cholesterol function improved. CONCLUSION: This is the first study to assess cholesterol and lipoprotein kinetics in patients with active RA and matched healthy volunteers. The data suggest that low cholesterol levels in patients with active RA may be driven by increases in cholesterol ester catabolism. Tofacitinib treatment reduced cholesterol ester catabolism, thereby increasing cholesterol levels toward those in healthy volunteers, and markers of antiatherogenic HDL function improved.
26681695 Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results 2016 Jun OBJECTIVES: Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke. METHODS: Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case-control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI. RESULTS: Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2). CONCLUSIONS: This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene-environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.
26809797 Predictive factors of abatacept therapy discontinuation in patients with rheumatoid arthri 2016 Apr The aim of this paper was to look for predictors of abatacept (ABA) therapy discontinuation in patients with rheumatoid arthritis (RA). Seventy-one RA patients treated with ABA were followed up. Demographical, clinical, and laboratory parameters of the patients, including peripheral blood T and B cell populations, different rheumatoid factor and anti-cyclic citrullinated peptide autoantibodies isotypes, and serum free light chains were evaluated. Comparing patients who discontinued ABA with those still in therapy we observed: a higher proportion of smokers (51.9 vs 25.6 %; p = 0.03); a non significant lower proportion of anti-cyclic citrullinated peptide positivity (76 vs 89.5 %; p = 0.13); a lower proportion of terminally differentiated effector memory cells (TDEM) among total CD8+ T lymphocytes at baseline (22.0 % (7.8-39.2) vs 38.7 % (20.7-55.9); p = 0.002). Logistic multivariate analysis showed that only the proportion of CD8+TDEM T cells was an independent predictive factor of therapy discontinuation (OR (95 % IC) = 6.2 (1.2 to 30.8); p = 0.026). Receiver-operating characteristic analysis showed a significant performance of this biomarker for prediction of therapy discontinuation (using a cut-off of 30.6 %: AUC: 0.760 ± 0.07; p = 0.002). Patients with a low proportion of CD8+TDEM at baseline had a higher probability of discontinuing the treatment during time (log-rank test: p < 0.01). T cell characterization for identification of TDEM CD8+ T cells might be a useful test to predict discontinuation of ABA therapy.
27112532 Safety, Tolerability, Pharmacokinetic and Pharmacodynamic Properties of SBI-087, a CD20-Di 2016 Jun PURPOSE: SBI-087 is a Small Modular Immunopharmaceutical Protein™(SMIP™) drug that binds to CD20 and has been reported to deplete B cells in murine/primate studies. The safety, tolerability and pharmacokinetic/pharmacodynamic properties of SBI-087 were evaluated in patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE). METHODS: Single-dose SBI-087 was evaluated in 2 Phase I, open-label, escalating-dose studies in patients with RA or SLE. The studies included 6 IV/4 SC escalating doses (RA) and 1 IV/4 SC escalating doses (SLE). Escalation was determined by tolerability/rate of B-cell depletion. Serum was collected for analyses of pharmacokinetic and pharmacodynamic (CD19(+) B cells) properties and immunogenicity. Patients were followed until B-cell counts were normalized or stabilized. Safety, tolerability was evaluated from adverse events, physical examinations, vital sign measurements, ECG, and clinical laboratory results. FINDINGS: Sixty patients with RA (IV, 28; SC, 32) and 30 patients with SLE (6 per cohort) were enrolled. Mild to moderate infusion reactions occurred in several patients at the top doses in the RA study despite a pretreatment regimen of IV doses. Unanticipated reactions after SC administration of SBI-087 included fever, chills, and malaise, seen on the day of dosing in the lowest-dose cohorts in both studies. These events were abrogated in subsequent cohorts by a pre/postdose treatment regimen consisting of oral corticosteroids, acetaminophen, and an antihistamine. SBI-087 clearance (IV) ranged from 22 to 229 mL/h; volume of distribution at steady state ranged from 5 to 12 L. Apparent clearance (SC) ranged from 44.7 to 105 mL/h; volume of distribution ranged from 14.3 to 32.1 L. Overall, PK properties were similar at equivalent doses between IV/SC administrations in patients with RA/SLE. Mean t½ (IV) ranged from 2.1 to 10.7 days (less at lower doses). SBI-087 concentration and B-cell depletion were generally dose proportional across IV and SC cohorts. However, the extent of B-cell depletion was less, and rate of repletion was faster, in patients with SLE versus RA. In both studies, B-cell repletion to baseline did not occur in the majority of patients by the end of the observation period. Overall, the prevalence and type of adverse events were similar to those seen with other anti-CD20-depleting agents. IMPLICATIONS: In patients with mild RA/SLE, SBI-087 was well tolerated when administered intravenously or subcutaneously with pre- and posttreatment regimens. B-cell depletion is long lasting, and the duration and extent of depletion may be greater in RA compared with SLE. SBI-087 exhibited slow elimination and low distribution in both populations. Clinicaltrials.gov identifiers: NCT00641225 (RA) and NCT00714116 (SLE).
27307211 Reduction of GPSM3 expression akin to the arthritis-protective SNP rs204989 differentially 2016 Sep G Protein Signaling Modulator-3 (GPSM3) is a leukocyte-specific regulator of G protein-coupled receptors (GPCRs), which binds inactivated Gαi·GDP subunits and precludes their reassociation with Gβγ subunits. GPSM3 deficiency protects mice from inflammatory arthritis and, in humans, GPSM3 single-nucleotide polymorphisms (SNPs) are inversely associated with the risk of rheumatoid arthritis development; recently, these polymorphisms were linked to one particular SNP (rs204989) that decreases GPSM3 transcript abundance. However, the precise role of GPSM3 in leukocyte biology is unknown. Here, we show that GPSM3 is induced in the human promyelocytic leukemia NB4 cell line following retinoic acid treatment, which differentiates this cell line into a model of neutrophil physiology (NB4*). Reducing GPSM3 expression in NB4* cells, akin to the effect ascribed to the rs204989 C>T transition, disrupts cellular migration toward leukotriene B4 (LTB4) and (to a lesser extent) interleukin-8 (a.k.a. IL-8 or CXCL8), but not migration toward formylated peptides (fMLP). As the chemoattractants LTB4 and CXCL8 are involved in recruitment of neutrophils to the arthritic joint, our results suggest that the arthritis-protective GPSM3 SNP rs204989 may act to decrease neutrophil chemoattractant responsiveness.
25577534 Leflunomide-induced acute interstitial pneumonia in a patient treated for rheumatoid arthr 2015 Leflunomide is a disease-modifying anti-rheumatic drug that is used in patients with rheumatoid arthritis (RA), who do not respond well to standard RA treatment. Leflunomide therapy may, however, be related with significant pulmonary complications in predisposed individuals. We present a patient with RA treated with leflunomide, in whom leflunomide lung injury had a fatal outcome. Potential risk factors for pulmonary complications of leflunomide treatment and the management of patients with leflunomide lung injury are discussed.
27411480 MicroRNA-155 regulates monocyte chemokine and chemokine receptor expression in Rheumatoid 2016 Nov OBJECTIVE: To test the hypothesis that miR-155 regulates monocyte migratory potential via modulation of chemokine and chemokine receptor expression in RA, and thereby is associated with disease activity. METHODS: The miR-155 copy-numbers in monocytes from peripheral blood (PB) of healthy (n = 22), RA (n = 24) and RA SF (n = 11) were assessed by real time-PCR using synthetic miR-155 as a quantitative standard. To evaluate the functional impact of miR-155, human monocytes were transfected with control or miR-155 mimic, and the effect on transcript levels, and production of chemokines was evaluated by Taqman low-density arrays and multiplex assays. A comparative study evaluated constitutive chemokine receptor expression in miR-155(-/-) and wild-type murine (CD115 (+) Ly6C (+) Ly6G(-)) monocytes. RESULTS: Compared with healthy monocytes, the miR-155 copy-number was higher in RA, peripheral blood (PB) and SF monocytes (PB P < 0.01, and SF P < 0.0001). The miR-155 copy-number in RA PB monocytes was higher in ACPA-positive compared with ACPA-negative patients (P = 0.033) and correlated (95% CI) with DAS28 (ESR), R = 0.728 (0.460, 0.874), and with tender, R = 0.631 (0.306, 0.824) and swollen, R = 0.503 (0.125, 0.753) joint counts. Enforced-expression of miR-155 in RA monocytes stimulated the production of CCL3, CCL4, CCL5 and CCL8; upregulated CCR7 expression; and downregulated CCR2. Conversely, miR155(-/-) monocytes showed downregulated CCR7 and upregulated CCR2 expression. CONCLUSION: Given the observed correlations with disease activity, these data provide strong evidence that miR-155 can contribute to RA pathogenesis by regulating chemokine production and pro-inflammatory chemokine receptor expression, thereby promoting inflammatory cell recruitment and retention in the RA synovium.
27029564 Inhibition of GSK-3β Alleviates Collagen II-Induced Rheumatoid Arthritis in Rats. 2016 Mar 31 BACKGROUND: Glycogen synthase kinase-3β (GSK-3β) inhibitor is a serine/threonine kinase with an inhibitory role in glycogen synthesis, which is essential in inflammatory and immunological diseases. The purpose of our study was to determine if TDZD-8 can alleviate collagen II-induced rheumatoid arthritis in rats. MATERIAL/METHODS: Twenty collagen II-induced rheumatoid arthritis rats were treated with selective GSK-3β inhibitor. The effects of GSK-3β inhibition on collagen II-induced rheumatoid arthritis in the rats were evaluated by paw edema, histological examination of arthritic synovium, radiographic examination of knee joint, and the level of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine. The level of cytokines such as IL-6, IL-12, IL-10, and TNF-α, was examined by Elisa. RESULTS: GSK-3β inhibitor significantly reduced the development of rheumatoid arthritis in rats. The levels of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine were decreased in the TDZD-8 group. Serum levels of IL-6, IL-12, and TNF-α were significantly reduced in the TDZD-8 group compared with the RA group. CONCLUSIONS: Treatment with GSK-3β inhibitor suppressed inflammatory response in RA rats. These findings suggest that the inhibition of GSK-3β can be an effective treatment for RA.
24845391 Systemic inflammation and cardiovascular risk factors predict rapid progression of atheros 2015 Jun OBJECTIVE: To estimate atherosclerosis progression and identify influencing factors in rheumatoid arthritis (RA). METHODS: We used carotid ultrasound to measure intima-media thickness (IMT) in RA patients, and ascertained cardiovascular (CV) risk factors, inflammation markers and medications. A second ultrasound was performed approximately 3 years later. We calculated the progression rate by subtracting the baseline from the follow-up IMT, divided by the time between the two scans. We used logistic regression to identify baseline factors predictive of rapid progression. We tested for interactions of erythrocyte sedimentation rate (ESR) with CV risk factors and medication use. RESULTS: Results were available for 487 RA patients. The mean (SD) common carotid IMT at baseline was 0.571 mm (0.151). After a mean of 2.8 years, the IMT increased by 0.050 mm (0.055), p≤0.001, a progression rate of 0.018 mm/year (95% CI 0.016 to 0.020). Baseline factors associated with rapid progression included the number of CV risk factors (OR 1.27 per risk factor, 95% CI 1.01 to 1.61), and the ESR (OR 1.12 per 10 mm/h, 95% CI 1.02 to 1.23). The ESR×CV risk factor and ESR×medication product terms were significant, suggesting these variables modify the association between the ESR and IMT progression. CONCLUSIONS: Systemic inflammation and CV risk factors were associated with rapid IMT progression. CV risk factors may modify the role of systemic inflammation in determining IMT progression over time. Methotrexate and antitumour necrosis factor agents may influence IMT progression by reducing the effect of the systemic inflammation on the IMT.
27393451 Polymorphisms in DNA repair genes XRCC1 and OGG1 lead to the progression of rheumatoid art 2016 Jul This study points at the elucidation of a possible association of Rheumatoid arthritis (RA) with Ser326Cys in OGG1 Arg194Trp and Arg399Gln polymorphisms of XRCC1 using a sample size of 100 patients and 100 controls from a Pakistani population. This association was determined using Random Fragment Length Polymorphism Analysis as well as the DAS scoring system. In RA, oxidative damage due to free radical production leads to destructive proliferative synovitis showing cellular transformations of synoviocytes into a tumorigenic state. XRCC1 and OGG1 genes, which are part of the DNA Break Excision Repair pathway, manifest various polymorphisms which may cause a variation in the response to inflammation by changing DNA repair potential. Our results showed a significant association between the DAS28 score values as well as the genotypic state of the RA patients. It was seen that the score was significantly higher in GG genotypes thereby corroborating the role of the polymorphism XRCC1 Arg399Gln. Using a Pearson's correlation test it was found to be <0.000003. It has been shown by the results in this research that an increased risk of DNA damage exists when the polymorphic genotypes studied, exist in a RA patient.
27426444 NETosis: At the crossroads of rheumatoid arthritis, lupus, and vasculitis. 2017 May Suicidal NETosis differs from other mechanisms of cell death by the release of a lattice, composed of DNA associated with proteins citrullinated by protein-arginine deiminase 4, from neutrophils. These 'NETs' are composed of granule-derived proteins with microbicidal activity. A similar type of release occurs during vital NETosis, in which anuclear neutrophils maintain their chemotactic ability and imprison live bacteria, even after NET extrusion. Mitochondrial NETosis is limited to the expulsion of oxidised mitochondrial DNA and cytoplasmic enzymes. NETs include the targets of most autoantibodies found in rheumatoid arthritis, lupus, and vasculitis. The clinical and biological overlaps sometimes observed between bronchectiasis and RA, RA and SLE, or SLE and vasculitis, implicate NETosis as a major triggering event common to these disorders. NETosis increases the possibility of association between autoantigens and infectious antigens in mucosal biofilms, impairing the clearance of pathogens and possibly triggering autoimmune reactions. NETosis aggravates these three conditions and increases endothelial damage and the risk of thrombosis. However, the pathogenesis of RA, SLE, and vasculitis is not confined to autoantibodies against NET components, and other mechanisms have been suggested to explain the breakdown of tolerance to NET autoantigens, such as hypercitrullination. The question of whether continuous presentation of autoantigens mixed with antigens from dormant intracellular pathogens (released following suicidal, vital, or mitochondrial NETosis) is required to induce and sustain autoimmunity must be addressed. Inhibiting NETois may not be sufficient to improve autoimmune disorders whereas such latent infections remain uncontrolled.
27143337 Arthritogenic peptide binding to DRB1*01 alleles correlates with susceptibility to rheumat 2016 Aug Genetic susceptibility to rheumatoid arthritis (RA) is often defined by the presence of a shared epitope (QKRAA, QRRAA, or RRRAA) at positions 70-74 in HLA-DRβ1. However, DRβ1*01:01 and 01:02 contain the same QRRAA epitope, but differ considerably in their susceptibility to RA. The purpose of this study was to determine if this difference could be explained by their ability to bind three arthritogenic peptides that we have previously shown to bind to the archetypal RA-susceptible allele, DRβ1*04:01, but not to the resistant DRβ1*08:01 allele. Binding of type II collagen(258-272), citrullinated and native vimentin(66-78), and citrullinated and native α-enolase(11-25) were measured on cell lines expressing either DRβ1*01:01, *01:02 or *01:03 in association with DRα1*01:01. DRβ1*01:01 and *01:02 both exhibited a 6.5-fold preference for citrullinated vimentin(66-78) compared to native vimentin. However, DRβ1*01:01 also exhibited a 1.7-fold preference for citrullinated α-enolase(11-25) and bound collagen(258-272), while DRβ1*01:02 bound neither of these peptides. Consistent with its known resistance to RA, DRβ1*01:03 preferentially bound native vimentin(66-78) and α-enolase(11-25) over the citrullinated forms of these peptides, and also failed to bind collagen(258-272). Site-directed mutagenesis was performed to determine which amino acid residues were responsible for the differences between these alleles. Mutating position 86 in DRβ1*01:01 from glycine to the valine residue found in DRβ1*01:02 eliminated binding of both citrullinated α-enolase(11-25) and collagen(258-272), thereby recapitulating the peptide-binding profile of DRβ1*01:02. The difference in susceptibility to rheumatoid arthritis between DRβ1*01:01 and *01:02 thus correlates with the effect of position 86 on the binding of these arthritogenic peptides. Consistent with their association with RA resistance, positions I67, D70 and E71 all contributed to the inability of DRβ1*01:03 to bind these arthritogenic peptides.
24608401 Are patients with rheumatoid arthritis still at an increased risk of tuberculosis and what 2015 Jun OBJECTIVE: To estimate the risk of tuberculosis (TB) in patients with rheumatoid arthritis (RA) both with and without exposure to biological therapy and to directly compare the risks between therapies. METHODS: Data from the Swedish National Population Registers, Tuberculosis Register and the Swedish Biologics Register were used to conduct a prospective population-based national cohort study (2002-2011). We estimated the rate of incident TB in the general population and in a cohort of biological-naïve and biological-exposed patients diagnosed with RA. Cox models were used to estimate HRs with particular attention to risks by calendar and follow-up time and individual biologics. RESULTS: Compared to the general population, RA patients not exposed to biologicals had a fourfold increased risk of TB (HR 4.2; 95% CI 2.7 to 6.7), which did not decline over calendar time. In contrast, the risk of TB in the biological-exposed RA population decreased since 2002 compared with biological-naïve; from HR=7.9 (95% CI 3.3 to 18.9) in 2002-2006 to HR=2.4 (95% CI 0.9 to 6.1) in 2007-2011. The HRs for most recent exposure to adalimumab and infliximab compared with etanercept were 3.1 (95% CI 0.8 to 12.5) and 2.7 (95% CI 0.7 to 10.9), respectively, and the HR for etanercept compared with biological-naïve RA was 1.7 (95% CI 0.6 to 4.6). CONCLUSIONS: In the past decade, the risk of TB has decreased among biological-exposed RA patients but remains higher than in biological-naïve RA patients. Most cases of TB in RA occur in biological-naïve RA patients, underscoring the elevated risk also in these patients.
26808309 Agreements and Discrepancies between FDA Reports and Journal Papers on Biologic Agents App 2016 BACKGROUND: Sponsors that seek to commercialize new drugs apply to the Food and Drug Administration (FDA) which independently analyzes the raw data and reports the results on its website. OBJECTIVES: This study sought to determine if there are differences between the FDA assessments and journal reports on biologic agents developed for the treatment of rheumatoid arthritis. METHODS: Available data on FDA-approved drugs were extracted from the website, and a systematic literature search was conducted to identify matching studies in peer-reviewed medical journals. Outcome measures were the American College of Rheumatology response criteria ACR20 (efficacy) and withdrawal due to adverse events (safety). As effect size odds ratios were estimated for each active trial arm vs. control arm (i.e. for both sources: FDA and journal report), followed by calculation of the ratios of the FDA and journal report odds ratios. A ratio of odds ratios not equal to 1 was categorized as a discrepancy. RESULTS: FDA reports were available for 8 of 9 FDA-approved biologic agents for rheumatoid arthritis; all identified trials (34) except one were published in peer-reviewed journals. Overall, discrepancies were noted for 20 of the 33 evaluated trials. Differences in the apparent benefit reporting were found in 39% (24/61) pairwise comparisons and in 11 cases these were statistically significant; the FDA report showed greater benefit than the journal publication in 15 comparisons and lesser benefit in 9. Differences in the reported harms were found in 51% (28/55) pairwise comparisons and were statistically significant in 5. The "signal" in FDA reports showed a less harmful effect than the journal publication in 17 comparisons whereas a more harmful effect in 11. The differences were attributed to differences in analytic approach, patient inclusion, rounding effect, and counting discrepancies. However, no differences were categorized as critical. CONCLUSION: There was no empirical evidence to suggest biased estimates between the two sources. Increased and detailed transparency in publications would improve the understanding and credibility of published results. Further, the FDA report was found to be a useful source when data are missing in the published report (i.e. reporting bias).
26750762 The clinical relevance of early anti-adalimumab antibodies detection in rheumatoid arthrit 2016 Mar OBJECTIVES: To evaluate the relevance of anti-adalimumab (anti-ADA) antibodies (Abs) and their relationship with clinical/laboratory features in rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA). METHODS: Fifty-eight patients affected with RA, AS and PsA were prospectively enrolled. Clinical/laboratory characteristics, disease activity, anti-ADA, anti-nuclear (ANA), anti-double strand (ds)DNA, anti-extractable nuclear antigens (anti-ENA) and anti-phospholipid Abs (aPL) were evaluated at baseline, 4, 12 and 24 weeks of adalimumab treatment. RESULTS: Anti-ADA Abs were observed in 11/58 (19%) patients; they were detected within the 4th week of therapy in 90.9% of the positive subjects. Anti-ADA positivity was associated with significantly lower mean adalimumab serum levels (P<0.05). Treatment failure was observed in 20/58 (34.5%) patients and was significantly associated with anti-ADA Abs (P<0.05). Mean adalimumab serum levels were significantly lower in patients with treatment failure than in the responders one, both in the whole cohort (P<0.01) and in the group of anti-ADA positive patients (P<0.01). Adverse events happened more often in anti-ADA positive then in anti-ADA negative patients (27.3% vs 14.9%). CONCLUSIONS: Anti-ADA abs could be considered an early marker associated to a poor clinical response to adalimumab treatment. Routine ANA/anti-ENA/aPL monitoring did not reveal as useful tools to predict the development of anti-ADA abs.
25319955 Macrophages from the synovium of active rheumatoid arthritis exhibit an activin A-dependen 2015 Feb Rheumatoid arthritis (RA) is a chronic inflammatory disease whose pathogenesis and severity correlates with the presence of macrophage-derived pro-inflammatory cytokines within the inflamed synovium. Macrophage-derived cytokines fuel the pathological processes in RA and are targets of clinically successful therapies. However, although macrophage polarization determines cytokine production, the polarization state of macrophages in RA joints remains poorly defined. To dissect the molecular basis for the tissue-damaging effects of macrophages in RA joints, we undertook the phenotypic and transcriptomic characterization of ex vivo isolated CD14(+) RA synovial fluid (RA-SF) macrophages. Flow cytometry and gene profiling indicated that RA-SF macrophages express pro-inflammatory polarization markers (MMP12, EGLN3, CCR2), lack expression of markers associated with homeostatic and anti-inflammatory polarization (IGF1, HTR2B) and exhibit a transcriptomic profile that resembles the activin A-dependent gene signature of pro-inflammatory in vitro-generated macrophages. In fact, high levels of Smad-activating activin A were found in RA-SF and, accordingly, the Smad signalling pathway was activated in ex vivo-isolated RA-SF macrophages. In vitro experiments on monocytes and macrophages indicated that RA-SF promoted the acquisition of pro-inflammatory markers (INHBA, MMP12, EGLN3, CCR2) but led to a significant reduction in the expression of genes associated with homeostasis and inflammation resolution (FOLR2, SERPINB2, IGF1, CD36), thus confirming the pro-inflammatory polarization ability of RA-SF. Importantly, the macrophage-polarizing ability of RA-SF was inhibited by an anti-activin A-neutralizing antibody, thus demonstrating that activin A mediates the pro-inflammatory macrophage-polarizing ability of RA-SF. Moreover, and in line with these findings, multicolour immunofluorescence evidenced that macrophages within RA synovial membranes (RA-SM) also express pro-inflammatory polarization markers whose expression is activin A-dependent. Altogether, our results demonstrate that macrophages from RA synovial fluids and membranes exhibit an MMP12(+) EGLN3(+) CCR2(+) pro-inflammatory polarization state whose acquisition is partly dependent on activin A from the synovial fluid.