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ID PMID Title PublicationDate abstract
21720763 Infliximab therapy efficacy and persistence at a Canadian academic centre despite a change 2012 Feb Patients treated with infliximab at our centre through a special access programme (initiation group) had long-standing, treatment-resistant rheumatoid arthritis. The clinical experience for these patients may be different than that of patients initiating treatment after provincial government approval and cost coverage for all anti-tumour necrosis factor (anti-TNF) therapies became effective (contemporary group). We compared adverse events, drug survival and reasons for discontinuation in these two groups. A prospective cohort of patients treated with an anti-TNF therapy was assembled following the availability of infliximab in 2000. By protocol, patients are assessed for treatment response, discontinuation or switching of biologic agents and occurrence of adverse events. We report on 231 patients treated with infliximab therapy (680 patient-years). Both groups had similar drug survival (median 2.2 years) and rates of serious adverse events including infusion reactions (6.8 per 100 patient-years) and serious infections (3.4 per 100 patient-years). More patients in the initiation group discontinued infliximab for adverse events [39/139 (28%) vs. 15/92 (16%), p = 0.04] and developed drug-induced lupus [8/139 (6%) vs. 0%, p = 0.02]. Subsequent biologics were discontinued for the same reason as infliximab in only 12% (15/123) of cases. Patients treated with infliximab through a special access programme have comparable drug survival compared to a contemporary group, despite experiencing more adverse events. Only a minority of patients discontinuing infliximab due to the lack of effect or adverse events experience the same fate with subsequent anti-TNF agents.
21221690 Damage accrual, cumulative glucocorticoid dose and depression predict anxiety in patients 2011 Jun The burden of anxiety in patients with systemic lupus erythematosus (SLE) compared to those with other inflammatory rheumatological conditions is unclear. We aimed to compare the frequency and level of anxiety between patients with SLE, rheumatoid arthritis (RA), and gout and healthy individuals and explore independent predictors for anxiety in SLE patients. Consecutive patients with SLE, RA and gout and healthy individuals who were age and sex matched with the SLE group were evaluated for anxiety using the Hospital Anxiety and Depression Scale (HADS). Sociodemographic and disease-related variables were compared between all groups. Predictors for anxiety were studied by regression models, with construction of a prediction model for the presence of anxiety in SLE patients by the receiver operating characteristic (ROC) analysis. Amongst 271 subjects studied, 60 had lupus, 50 had gout, 100 had RA and 61 were healthy controls. The frequency and level of anxiety were significantly higher in SLE patients than patients with gout, RA and healthy controls. SLE per se was independently associated with higher HADS-anxiety score after controlling for potential confounders. Logistic regression model showed that higher damage accrual, higher cumulative glucocorticoid dose, depression and fewer regular medications predicted anxiety in SLE patients, with an accuracy of 90% by the ROC analysis.
21813064 Anti-IL-6 receptor antibody (tocilizumab): a B cell targeting therapy. 2011 Jul BACKGROUND: IL-6 mediated inflammation is induced by binding to IL-6 receptor (IL-6R) or IL-6/IL-6R complex binding gp130. Tocilizumab, a recombinant humanised monoclonal antibody that acts as IL-6R antagonist has been recently introduced for the treatment of rheumatoid arthritis (RA). OBJECTIVES: To evaluate whether tocilizumab therapy may induce B cells to undergo phenotypic changes compatible with regulatory function. METHODS: B cells from treated RA patients were isolated before and after 3 months of treatment with tocilizumab and were stained for the expression of intracellular TGF-β, IL-10, membrane CD69, and MHCII. These markers were assessed in CD25(high) B cells considered to belong to a regulatory/suppressive subset of B cells. All markers were expressed in mean flow cytometry intensity (MFI), with results given in mean ± SEM. Data was compared before and after tocilizumab treatment. RESULTS: Clinical improvement was noted three months following the initiation of tocilizumab, namely: DAS improvement from 6.8 ± 0.3 at baseline to 3.1 ± 0.4, p<0.002, and ESR decrease from 44.4 ± 8.6 at baseline to 7.4 ± 2.3, p<0.006. This clinical benefit was found to occur in association with the expansion of a B cell subset with regulatory properties namely: the expression of intracellular TGF-β in CD25-high B cells was significantly increased (from 5.2 ± 2.3 at baseline to 8.1 ± 2.8; p<0.02); In addition, the expression of MHC-II and of CD69 on B cells were significantly reduced (from 9.1 ± 2.2 at baseline to 4.2 ± 0.4; p<0.04), and (from 7.6 ± 2.4 at baseline to 2.7 ± 0.7; p<0.03) respectively. CONCLUSIONS: The present finding of a shift in B cell properties following tocilizumab treatment, namely the increase in TGF-β expression and the alteration in the activation status (CD69 expression) and APC properties (MHC-II expression) in CD25(high) B cells, suggests that the induction/expansion of B regulatory cells may be one of the mechanisms by which tocilizumab may possibly produce its beneficial clinical effects.
22258992 Neuromodulators for pain management in rheumatoid arthritis. 2012 Jan 18 BACKGROUND: Pain management is a high priority for patients with rheumatoid arthritis (RA). Despite deficiencies in research data, neuromodulators have gained widespread clinical acceptance as adjuvants in the management of patients with chronic musculoskeletal pain. OBJECTIVES: The aim of this review was to determine the efficacy and safety of neuromodulators in pain management in patients with RA. Neuromodulators included in this review were anticonvulsants (gabapentin, pregabalin, phenytoin, sodium valproate, lamotrigine, carbamazepine, levetiracetam, oxcarbazepine, tiagabine and topiramate), ketamine, bupropion, methylphenidate, nefopam, capsaicin and the cannabinoids. SEARCH METHODS: We performed a computer-assisted search of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, 4th quarter), MEDLINE (1950 to week 1 November 2010), EMBASE (Week 44, 2010) and PsycINFO (1806 to week 2 November 2010). We also searched the 2008 and 2009 American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) conference abstracts and performed a handsearch of reference lists of articles. SELECTION CRITERIA: We included randomised controlled trials which compared any neuromodulator to another therapy (active or placebo, including non-pharmacological therapies) in adult patients with RA that had at least one clinically relevant outcome measure. DATA COLLECTION AND ANALYSIS: Two blinded review authors independently extracted data and assessed the risk of bias in the trials. Meta-analyses were used to examine the efficacy of a neuromodulator on pain, depression and function as well as their safety. MAIN RESULTS: Four trials with high risk of bias were included in this review. Two trials evaluated oral nefopam (52 participants) and one trial each evaluated topical capsaicin (31 participants) and oromucosal cannabis (58 participants).The pooled analyses identified a significant reduction in pain levels favouring nefopam over placebo (weighted mean difference (WMD) -21.16, 95% CI -35.61 to -6.71; number needed to treat (NNT) 2, 95% CI 1.4 to 9.5) after two weeks. There were insufficient data to assess withdrawals due to adverse events. Nefopam was associated with significantly more adverse events (RR 4.11, 95% CI 1.58 to 10.69; NNTH 9, 95% CI 2 to 367), which were predominantly nausea and sweating.In a mixed population trial, qualitative analysis of patients with RA showed a significantly greater reduction in pain favouring topical capsaicin over placebo at one and two weeks (MD -23.80, 95% CI -44.81 to -2.79; NNT 3, 95% CI 2 to 47; MD -34.40, 95% CI -54.66 to -14.14; NNT 2, 95% CI 1.4 to 6 respectively). No separate safety data were available for patients with RA, however 44% of patients developed burning at the site of application and 2% withdrew because of this.One small, low quality trial assessed oromucosal cannabis against placebo and found a small, significant difference favouring cannabis in the verbal rating score 'pain at present' (MD -0.72, 95% CI -1.31 to -0.13) after five weeks. Patients receiving cannabis were significantly more likely to suffer an adverse event (risk ratio (RR) 1.82, 95% CI 1.10 to 3.00; NNTH 3, 95% CI 3 to 13). These were most commonly dizziness (26%), dry mouth (13%) and light headedness (10%). AUTHORS' CONCLUSIONS: There is currently weak evidence that oral nefopam, topical capsaicin and oromucosal cannabis are all superior to placebo in reducing pain in patients with RA. However, each agent is associated with a significant side effect profile. The confidence in our estimates is not strong given the difficulties with blinding, the small numbers of participants evaluated and the lack of adverse event data. In some patients, however, even a small degree of pain relief may be considered worthwhile. Until further research is available, given the relatively mild nature of the adverse events, capsaicin could be considered as an add-on therapy for patients with persistent local pain and inadequate response or intolerance to other treatments. Oral nefopam and oromucosal cannabis have more significant side effect profiles however and the potential harms seem to outweigh any modest benefit achieved.
21693023 The association between microvascular and macrovascular endothelial function in patients w 2011 Jun 21 INTRODUCTION: Patients with rheumatoid arthritis (RA) are at an increased risk for cardiovascular disease (CVD). One of the earliest manifestations of CVD is endothelial dysfunction (ED). ED can occur in both the microcirculation and the macrocirculation, and these manifestations might be relatively independent of each other. Little is known about the association between endothelial function in the microcirculation and the macrocirculation in RA. The objectives of the present study were to examine the relationship between microvascular and macrovascular endothelial function in patients with RA. METHODS: Ninety-nine RA patients (72 females, mean age (± SD) 56 ± 12 years), underwent assessments of endothelial-dependent (acetylcholine) and endothelial-independent (sodium nitroprusside) microvascular vasodilatory function (laser Doppler imaging with iontophoresis), as well as endothelial-dependent (flow-mediated dilation) and endothelial-independent (glyceryl trinitrate-mediated dilation) macrovascular vasodilatory function. Vasodilatory function was calculated as the percentage increase after each stimulus was applied relative to baseline values. RESULTS: Pearson correlations showed that microvascular endothelial-dependent function was not associated with macrovascular endothelial-dependent function (r (90 patients) = 0.10, P = 0.34). Similarly, microvascular endothelial-independent function was not related to macrovascular endothelial-independent function (r (89 patients) = 0.00, P = 0.99). CONCLUSIONS: Microvascular and macrovascular endothelial function were independent of each other in patients with RA, suggesting differential regulation of endothelial function in these two vascular beds. Assessments of both vascular beds may provide more meaningful clinical information on vascular risk in RA, but this hypothesis needs to be confirmed in long-term prospective studies.
22219138 TNF blockade requires 1,25(OH)2D3 to control human Th17-mediated synovial inflammation. 2012 Apr OBJECTIVES: T helper 17 (Th17) cells from patients with early rheumatoid arthritis (RA) induce a proinflammatory feedback loop upon RA synovial fibroblast (RASF) interaction, including autocrine interleukin (IL)-17A production. A major challenge in medicine is how to control the pathogenic Th17 cell activity in human inflammatory autoimmune diseases. The objective of this study was to examine whether tumour necrosis factor (TNF) blockade and/or 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) controls Th17-mediated synovial inflammation. METHODS: Peripheral CD4+CD45RO+CCR6+ Th17 cells of patients with early RA, Th17-RASF cocultures and synovial biopsy specimens were cultured with or without 1,25(OH)(2)D(3) and/or TNFα blockade. Intracellular cytokine expression was detected by flow cytometry. Cytokine and matrix metalloprotease (MMP) production was determined by ELISA. RESULTS: The authors show that the 1,25(OH)(2)D(3), but not TNFα blockade, significantly suppressed autocrine IL-17A production in Th17-RASF and synovial biopsy cultures. Combining 1,25(OH)(2)D(3) and TNFα blockade had a significant additive effect compared with single treatment in controlling synovial inflammation, indicated by a further reduction in IL-6, IL-8, MMP-1 and MMP-3 in Th17-RASF cocultures and IL-6 and IL-8 expression in cultures of RA synovial tissue. CONCLUSIONS: These data show that TNF blockade does not suppress IL-17A and IL-22, which can be overcome by 1,25(OH)(2)D(3). The combination of neutralising TNF activity and 1,25(OH)(2)D(3) controls human Th17 activity and additively inhibits synovial inflammation. This indicates more valuable therapeutic potential of activation of Vitamin D receptor signalling over current TNF neutralisation strategies in patients with RA and potentially other Th17-mediated inflammatory diseases.
21720103 [Efficacy and safety of combination therapy with mizoribine and methotrexate for rheumatoi 2011 Background. MZB is a purine analog, and is used as a disease modifying anti-rheumatic drug (DMARD). We conducted an open label uncontrolled clinical trial to evaluate the efficacy and safety of combination therapy with methotrexate (MTX) and mizoribine (MZB). Methods. Thirty one RA patients (9 males, 22 females, 68±12 year-old) who fulfilled ACR criteria of RA and did not show sufficient clinical response to MTX were included. MZB (150 mg/day, once a day) were added to MTX. DAS28-CRP was measured at day 0 and 1, 3, 6, and 12 months after the treatment. Adverse events were recorded. Results. Overall DAS28-CRP was significantly decreased from 4.4±1.0 to 3.1±1.3 at 3 months (p<0.01), 2.7±0.68 at 6 months (p<0.01), 2.4±1.4 at 12 months (p<0.01). Seventeen patients (55%) achieved significant improvement of DAS28-CRP. Number of swollen joints of responders before the treatment was significantly fewer than that of non-responders. Improvement of DAS28-CRP was significantly different between the responders (0.91±0.74) and non-responders (0.18±0.66) at 1 month (p<0.01). Nine patients (29%) could achieve remission Four patients experienced adverse events. Conclusions. MTX and MZB combination therapy was effective and relatively safety.
22802649 Structural basis for receptor sharing and activation by interleukin-20 receptor-2 (IL-20R2 2012 Jul 31 Interleukin 20 (IL-20) is a pleotropic IL-10 family cytokine that protects epithelial surfaces from pathogens. However, dysregulated IL-20 signaling is implicated in several human pathologies including psoriasis, rheumatoid arthritis, atherosclerosis, and osteoporosis. IL-20, and related cytokines IL-19 and IL-24, designated IL-20 subfamily cytokines (IL-20SFCs), induce cellular responses through an IL-20R1/IL-20R2 (type I) receptor heterodimer, whereas IL-20 and IL-24 also signal through the IL-22R1/IL-20R2 (type II) receptor complex. The crystal structure of the IL-20/IL-20R1/IL-20R2 complex reveals how type I and II complexes discriminate cognate from noncognate ligands. The structure also defines how the receptor-cytokine interfaces are affinity tuned to allow distinct signaling through a receptor complex shared by three different ligands. Our results provide unique insights into the complexity of IL-20SFC signaling that may be critical in the design of mechanistic-based inhibitors of IL-20SFC-mediated inflammatory disease.
22843486 Targeted delivery of cytokine therapy to rheumatoid tissue by a synovial targeting peptide 2013 Jan OBJECTIVES: The synovial endothelium targeting peptide (SyETP) CKSTHDRLC has been identified previously and was shown to preferentially localise to synovial xenografts in the human/severe combined immunodeficient (SCID) mouse chimera model of rheumatoid arthritis (RA). The objective of the current work was to generate SyETP-anti-inflammatory-cytokine fusion proteins that would deliver bioactive cytokines specifically to human synovial tissue. METHODS: Fusion proteins consisting of human interleukin (IL)-4 linked via a matrix metalloproteinase (MMP)-cleavable sequence to multiple copies of either SyETP or scrambled control peptide were expressed in insect cells, purified by Ni-chelate chromatography and bioactivity tested in vitro. The ability of SyETP to retain bioactive cytokine in synovial but not control skin xenografts in SCID mice was determined by in vivo imaging using nano-single-photon emission computed tomography-computed tomography (nano-SPECT-CT) and measuring signal transducer and activator of transcription 6 (STAT6) phosphorylation in synovial grafts following intravenous administration of the fusion protein. RESULTS: In vitro assays confirmed that IL-4 and the MMP-cleavable sequence were functional. IL-4-SyETP augmented production of IL-1 receptor antagonist (IL-1ra) by fibroblast-like synoviocytes (FLS) stimulated with IL-1β  in a dose-dependent manner. In vivo imaging showed that IL-4-SyETP was retained in synovial but not in skin tissue grafts and the period of retention was significantly enhanced through increasing the number of SyETP copies from one to three. Finally, retention correlated with increased bioactivity of the cytokine as quantified by STAT6 phosphorylation in synovial grafts. CONCLUSIONS: The present work demonstrates that SyETP specifically delivers fused IL-4 to human rheumatoid synovium transplanted into SCID mice, thus providing a proof of concept for peptide-targeted tissue-specific immunotherapy in RA. This technology is potentially applicable to other biological treatments providing enhanced potency to inflammatory sites and reducing systemic toxicity.
22225630 Plasma proteins present in osteoarthritic synovial fluid can stimulate cytokine production 2012 Jan 8 INTRODUCTION: Osteoarthritis (OA) is a degenerative disease characterized by cartilage breakdown in the synovial joints. The presence of low-grade inflammation in OA joints is receiving increasing attention, with synovitis shown to be present even in the early stages of the disease. How the synovial inflammation arises is unclear, but proteins in the synovial fluid of affected joints could conceivably contribute. We therefore surveyed the proteins present in OA synovial fluid and assessed their immunostimulatory properties. METHODS: We used mass spectrometry to survey the proteins present in the synovial fluid of patients with knee OA. We used a multiplex bead-based immunoassay to measure levels of inflammatory cytokines in serum and synovial fluid from patients with knee OA and from patients with rheumatoid arthritis (RA), as well as in sera from healthy individuals. Significant differences in cytokine levels between groups were determined by significance analysis of microarrays, and relations were determined by unsupervised hierarchic clustering. To assess the immunostimulatory properties of a subset of the identified proteins, we tested the proteins' ability to induce the production of inflammatory cytokines by macrophages. For proteins found to be stimulatory, the macrophage stimulation assays were repeated by using Toll-like receptor 4 (TLR4)-deficient macrophages. RESULTS: We identified 108 proteins in OA synovial fluid, including plasma proteins, serine protease inhibitors, proteins indicative of cartilage turnover, and proteins involved in inflammation and immunity. Multiplex cytokine analysis revealed that levels of several inflammatory cytokines were significantly higher in OA sera than in normal sera, and levels of inflammatory cytokines in synovial fluid and serum were, as expected, higher in RA samples than in OA samples. As much as 36% of the proteins identified in OA synovial fluid were plasma proteins. Testing a subset of these plasma proteins in macrophage stimulation assays, we found that Gc-globulin, α1-microglobulin, and α2-macroglobulin can signal via TLR4 to induce macrophage production of inflammatory cytokines implicated in OA. CONCLUSIONS: Our findings suggest that plasma proteins present in OA synovial fluid, whether through exudation from plasma or production by synovial tissues, could contribute to low-grade inflammation in OA by functioning as so-called damage-associated molecular patterns in the synovial joint.
21585303 New approaches in the detection of calcium-containing microcrystals in synovial fluid. 2011 May BACKGROUND: The presence of calcium phosphate crystals such as basic calcium phosphate and calcium pyrophosphate dihydrate in intra-articular fluid is linked to a number of destructive arthropathies and detection of these deposits is often pivotal for early diagnosis and appropriate management of such disease. RESULTS: We describe the use of a calcium-sensitive dye, Fluo-4, to selectively label calcium-containing mineral deposits in synovial fluid, which can then be easily visualized using a standard fluorescence microscope. Furthermore, we have combined the fluorescent properties of the tagged crystals with flow cytometry as a fast and semi-quantitative method of detection. CONCLUSION: Dot-plots were used to quantify differences between various types of arthropathies and confirmed by visual observation of the crystals under a fluorescence microscope.
21739426 Resistin and insulin/insulin-like growth factor signaling in rheumatoid arthritis. 2011 Oct OBJECTIVE: Human resistin has proinflammatory properties that activate NF-κB-dependent pathways, whereas its murine counterpart is associated with insulin resistance. The aim of this study was to examine potential cross-talk between resistin and insulin/insulin-like growth factor (IGF) signaling in rheumatoid arthritis (RA). METHODS: Levels of IGF-1, IGF binding protein 3, and resistin were measured in the blood and synovial fluid of 60 patients with RA and 39 healthy control subjects. Human RA synovium was implanted subcutaneously into SCID mice, and the mice were treated with resistin-targeting small interfering RNA. Primary synovial fibroblasts from patients with RA, as well as those from patients with osteoarthritis, and the human fibroblast cell line MRC-5 were stimulated with resistin. Changes in the IGF-1 receptor (IGF-1R) signaling pathway were evaluated using histologic analysis, immunohistochemistry, and reverse transcription-polymerase chain reaction. RESULTS: Resistin and IGF-1R showed different expression profiles in RA synovia. Low levels of IGF-1 in RA synovial fluid were associated with systemic inflammation and inversely related to the levels of resistin. Stimulation of synovial fibroblasts with resistin induced phosphorylation of IGF-1R to a degree similar to that with insulin, and also induced phosphorylation of transcription factor Akt. This was followed by gene expression of GLUT1, IRS1, GSK3B, and the Akt inhibitors PTPN and PTEN. Abrogation of resistin expression in vivo reduced the expression of IGF-1R, the phosphorylation of Akt, and the expression of PTPN and PTEN messenger RNA in RA synovium implanted into SCID mice. CONCLUSION: Resistin utilizes the IGF-1R pathway in RA synovia. Abrogation of resistin synthesis in the RA synovium in vivo leads to reductions in the expression of IGF-1R and level of phosphorylation of Akt.
21557526 Patterns of medication use during pregnancy in rheumatoid arthritis. 2011 May OBJECTIVE: To characterize therapies prescribed during pregnancy to women with rheumatoid arthritis (RA). METHODS: We conducted a cohort study of women with RA with pregnancies using health care utilization data from 2002-2008. We examined the distribution of RA drugs by therapeutic classes, including nonsteroidal antiinflammatory drugs (NSAIDs)/coxibs, glucocorticoids, nonbiologic disease-modifying antirheumatic drugs (DMARDs), and biologic DMARDs, during 90-day pregnancy trimesters and the 180 days prior to pregnancy. Drugs were characterized according to the Food and Drug Administration risk classification system. Differences in exposure by period were determined by chi-square tests. RESULTS: A total of 393 pregnancies were identified among 34,169 women with RA. Seventy-two percent of pregnancies ended in a delivery. Approximately 24% of women with RA received a DMARD during preconception. At any point during pregnancy, 23% of women with deliveries were dispensed ≥1 DMARD and the proportion of use declined from the first to the third trimester (P = 0.03). Similar to DMARD therapy, use of NSAIDs/coxibs and exposure to category D/X medications were significantly lower compared to prepregnancy use (P < 0.05). In contrast, more women were prescribed glucocorticoids during pregnancy than before pregnancy. Use of biologics occurred in 12.5% of pregnancies. Compared to women with deliveries, women who experienced abortions were more frequently exposed to NSAIDs/coxibs (P < 0.05). Dispensing of category D/X medications was also higher in women with spontaneous abortions and primarily involved methotrexate (P < 0.05). CONCLUSION: Approximately 24% of women with RA received a DMARD in the 180 days before conception, and the proportion dropped during pregnancy. Glucocorticoid use remained high throughout pregnancy. Our results suggest that continued efforts directed at counseling women and their physicians about the potential risks/benefits of RA therapies during pregnancy are warranted.
21166654 Interleukin-1β-induced interleukin-6 production in A549 cells is mediated by both phospha 2011 Apr The aim of this study is to investigate whether PI3K (phosphatidylinositol-3-kinase) is involved in IL-1β (interleukin-1β)-induced IL-6 production in A549 (human lung adenocarcinoma epithelial cell) and human RASF (rheumatoid arthritis synovial fibroblast). PI3K inhibitor, LY294002 significantly reduced IL-1β-induced IL-6 production in A549 cells but not in RASF, indicating that IL-1β-induced IL-6 production was partially mediated by PI3Kin A549 cells but not in RASF. siRNA (small interfering RNA) of IRAK4 (IL-1 receptor-associated kinase 4) treatment decreased IRAK4 mRNA level by up to 90% in A549 cells. In this condition, IL-1β-induced increase of IL-6 mRNA and protein level was decreased by up to 93% and 70%, respectively. Furthermore, the combination of IRAK4 siRNA and LY294002 treatment decreased protein induction level of IL-6 in A549 cells compared with that of IRAK4 siRNA or LY294002 alone. These results indicate that IL-1β-induced IL-6 production in A549 cells is mediated by both PI3K and IRAK4 and suggest that involvement of PI3K in the IL-1-induced IL-6 production is cell type specific.
21568621 Quantifying changes in fibrin fiber network morphology. 2011 Aug During blood clotting, thrombin and fibrinogen interact, whereby thrombin cleaves the fibrinogen molecule into two peptides, the fibrinopeptides, ultimately forming fibrin monomers. These fibrinogen monomers assemble to form a fibrin network that may be studied using ultrastructural techniques. This study investigates the use of a grid, placed onto a micrograph, to quantify changes in morphology. The fibrin fiber micrographs of a healthy donor were compared to a database of donors and were shown to be a true representative of a typical healthy individual. Eighteen micrographs of this single donor were taken at 40,000× machine magnification, and a grid was placed over the micrographs. The grid dimensions were calculated by using the scale bar inserted onto the micrograph. Each grid block was equal to 0.5 by 0.5 µm for a total grid area of 28 µm(2). A percentage changed fibrin fiber morphology was then calculated for each 28 µm(2) of fibrin clot produced in the laboratory. It is concluded that this effortless and simple grid technique to quantify changes in ultrastructure of fibrin clot morphology may provide a method to statistically quantify changes in fibrin fiber ultrastructure when studying conditions affecting hemostasis.
22257038 Joint tenderness and swelling in biologic-treated inflammatory arthritis patients - a tric 2012 Feb OBJECTIVE: To compare the pattern of joint responses in patients with rheumatoid arthritis and psoriatic arthritis treated with TNF inhibitor (TNFi) therapy. METHODS: A total of 182 PsA/Rheumatoid arthritis (RA) patients attending the rheumatology unit of a tertiary referral centre in Ireland were recruited and prospectively followed up by the attendant rheumatologists. Clinical progress of the patients was noted at baseline and 6 months after starting TNFi therapy. RESULTS: A total of 114 RA and 68 PsA patients were assessed; 20% of the patients had one of either tender joints or swollen joints after 6 months of therapy. Rheumatoid arthritis patients had a significantly higher proportion of non-tender swollen joints compared with PsA patients, whereas PsA patients had a higher proportion of tender non-swollen joints (p < 0.05). CONCLUSION: Residual joint swelling was found more commonly in RA patients than in PsA patients following TNFi therapy, whereas residual tender joints occurred more frequently in PsA; this may reflect enthesiopathy or periostitis.
22239037 Peptidyl-arginine deiminase: an additional marker of rheumatoid arthritis. 2011 BACKGROUND: Antibodies against cyclic citrullinated peptide (anti-CCP) were thought to be more specific than rheumatoid factor (RF) for the diagnosis of rheumatoid arthritis (RA). The determination of anti-CCP in addition to RF could be helpful in the serological diagnosis and monitoring of patients with RA. Citrullination of proteins involves the enzymatic conversion of protein containing arginine residues to citrulline residues by the enzyme peptidylarginine deiminase (PAD). The present investigation was undertaken to estimate serum PAD enzyme activity in RA patients with a view to find its importance as a new diagnosis marker in a rheumatology clinic. METHODS: The activity of the PAD enzyme was measured by spectrophotometric method at 530 nm in sera of control subjects and in patients of RA (Group I: RF negative and CCP positive: Group II: both RF and CCP positive) in terms of citrulline formation using benzoyl-arginine ethyl ester (BAEE) as substrate. Anti-CCP and RF were also estimated in two groups by enzyme immunoassay and immunoturbidimetry for comparison. Clinical variables (duration of morning stiffness, swollen and tender joint counts, patient's assessment of pain) and C-reactive protein were also evaluated. RESULTS: A marked increase in PAD enzyme activity (p < 0.001) was noted in RA patients in comparison to controls and the level diminished appreciably along with two known serological markers (anti-CCP and RF) after six months of disease modifying antirheumatic drug (DMARD) treatment. The Group II RA patients showed much higher enzyme activity than Group I RA patients. However, clinical variables did not differ significantly between the two Groups of RA patients. CONCLUSIONS: We conclude that determination of PAD enzyme activity may be used as an additional marker for monitoring disease progression and regression along with anti-CCP and RF in patients with RA. Moreover, this method is rapid, sensitive, and inexpensive and can be adopted in a laboratory having modest facilities.
20890981 Prevalence of atherosclerotic risk factors and the metabolic syndrome in patients with chr 2011 Feb OBJECTIVE: To evaluate the prevalence of the metabolic syndrome in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA). METHODS: Consecutive patients with RA, AS, or PsA who attended our outpatient arthritis clinics between July and November 2009 were recruited for a study of atherosclerotic risk factors and the metabolic syndrome, defined according to the 2009 joint statements using the Asian criteria for central obesity. RESULTS: Nine hundred thirty patients were studied (699 with RA, 122 with AS, and 109 with PsA; 70% women, mean±SD age 51.1±12.7 years). The mean±SD disease duration for patients with RA, AS, and PsA was 5.3±5.4, 6.0±5.6, and 3.6±3.1 years, respectively. The prevalence of metabolic syndrome was significantly higher in PsA (38%) than RA (20%) or AS (11%; P<0.001). The odds ratios (ORs) for the metabolic syndrome compared to age- and sex-matched controls were 0.98 (95% confidence interval [95% CI] 0.78-1.23, P=0.88), 0.59 (95% CI 0.30-1.15, P=0.12), and 2.68 (95% CI 1.60-4.50, P<0.001), respectively, for RA, AS, and PsA. Patients with PsA had a significantly higher prevalence of impaired fasting glucose (30%; P<0.001), low high-density lipoprotein (HDL) cholesterol (33%; P<0.001), high triglycerides level (21%; P=0.008), central obesity (65%; P<0.001), and high blood pressure (56%; P=0.045). In a logistic regression model, the adjusted OR for the metabolic syndrome in PsA was 2.44 (95% CI 1.48-4.01, P<0.001) relative to RA or AS. The adjusted ORs for central obesity, impaired fasting glucose, hypertriglyceridemia, and low HDL cholesterol were also significantly higher in PsA patients. CONCLUSION: Patients with PsA, but not RA or AS, have a significantly higher prevalence of the metabolic syndrome compared to the general population. Among the 3 diseases studied, PsA has the highest prevalence of the metabolic syndrome and is associated with the highest cardiovascular risk.
21466939 Increased rheumatoid factor interference observed during immunogenicity assessment of an F 2011 Jul 15 Protein therapeutics may elicit an anti-therapeutic antibody (ATA) response in patients. This response depends on a number of factors including patient population, disease state, route of delivery or characteristics specific to the product. Therapeutics for immunological indications often target relatively young and healthy patients with hyperactive immune systems who have periodic flares and remissions. The hyperactive immune system of these patients can add several levels of bioanalytical complexity due to the presence of cross reactive molecules such as autoantibodies. In addition, the long-term chronic dosing regimen often necessary in this patient population can increase their risks of immunogenicity against the therapeutic and lead to safety concerns. Therefore, development of a sensitive and drug-tolerant ATA method is important. Bridging ATA assays are usually very sensitive and drug-tolerant methods for immunogenicity assessment; however these methods are particularly vulnerable to any factor that is able to bridge the conjugated therapeutics used as reagents and can generate false positive signal. Although there are many potential interfering factors in serum, rheumatoid factors (RFs), autoantibodies associated with rheumatoid arthritis (RA), are of particular concern in this type of assay. MTRX1011A is a non-depleting anti-CD4 monoclonal antibody therapeutic that was clinically tested in RA patients. This paper will discuss the bioanalytical challenges encountered during development of a clinical ATA assay for MTRX1011A. These challenges highlight interference due to patient disease state, in this case presence of RF in RA patients, as well as specific molecule-related interference caused by an engineered mutation in the Fc region of MTRX1011A designed to enhance its binding to the neonatal Fc receptor (FcRn). We will discuss the characterization work used to identify the cross-reactive epitope and our strategy to overcome this interference during development of an effective ATA assay to support clinical evaluation of MTRX1011A.
23165896 The exposure of autoantigens by microparticles underlies the formation of potent inflammat 2013 Feb Immunoglobulins, antigens and complement can assemble to form immune complexes (IC). ICs can be detrimental as they propagate inflammation in autoimmune diseases. Like ICs, submicron extracellular vesicles termed microparticles (MP) are present in the synovial fluid from patients affected with autoimmune arthritis. We examined MPs in rheumatoid arthritis (RA) using high sensitivity flow cytometry and electron microscopy. We find that the MPs in RA synovial fluid are highly heterogeneous in size. The observed larger MPs were in fact MP-containing ICs (mpICs) and account for the majority of the detectable ICs. These mpICs frequently express the integrin CD41, consistent with platelet origin. Despite expression of the Fc receptor FcγRIIa by platelet-derived MPs, we find that the mpICs form independently of this receptor. Rather, mpICs display autoantigens vimentin and fibrinogen, and recognition of these targets by anti-citrullinated peptide antibodies contributes to the production of mpICs. Functionally, platelet mpICs are highly pro-inflammatory, eliciting leukotriene production by neutrophils. Taken together, our data suggest a unique role for platelet MPs as autoantigen-expressing elements capable of perpetuating formation of inflammatory ICs.