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ID PMID Title PublicationDate abstract
12218116 Major differences in antigen-processing correlate with a single Arg71<-->Lys substitution 2002 Sep 15 Several HLA-DR alleles are genetically associated with rheumatoid arthritis. DRB1*0401 predominates in Northern Europe and has a characteristic (70)QKRAA motif. This sequence contacts bound peptides and the TCR. Further interactions have been suggested with additional proteins during Ag loading. We explored the much stronger processing/presentation of full-length recombinant human acetylcholine receptor alpha subunit to a specific T cell clone by APC from DRB1*0401+ than *0408+ donors. Using DR*04 transfectants, we show that this difference results largely from the single Lys71<-->Arg interchange (0401<-->0408), which scarcely affects epitope binding, rather than from any other associated polymorphism. Furthermore, we proved our recombinant polypeptides to contain the Escherichia coli 70-kDa heat shock protein molecule DnaK and its requirement for efficient processing and presentation of the epitope by DRB1*0401+ cells. According to a recent report, 70-kDa heat shock protein chaperones preferentially bind to the QKRAA, rather than the QRRAA, motif. Variations between the shared epitope motifs QKRAA and QRRAA are emphasized by underlining. We propose that such interactions enhance the intracellular epitope loading of *0401 molecules. They may thus broaden immune responses to pathogens and at least partially explain the distinct contributions of DRB1*0401 and other alleles to disease predisposition.
15540281 Apolipoprotein A-I infiltration in rheumatoid arthritis synovial tissue: a control mechani 2004 The production of tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) by monocytes is strongly induced by direct contact with stimulated T lymphocytes, and this mechanism may be critical in the pathogenesis of rheumatoid arthritis (RA). Apolipoprotein A-I (apoA-I) blocks contact-mediated activation of monocytes, causing inhibition of TNF-alpha and IL-1beta production. This study examined the hypothesis that apoA-I may have a regulatory role at sites of macrophage activation by T lymphocytes in inflamed RA synovial tissue. Synovial tissue samples were obtained after arthroscopy from patients with early untreated RA or treated RA and from normal subjects. As determined by immunohistochemistry, apoA-I was consistently present in inflamed synovial tissue that contained infiltrating T cells and macrophages, but it was absent from noninflamed tissue samples obtained from treated patients and from normal subjects. ApoA-I staining was abundant in the perivascular areas and extended in a halo-like pattern to the surrounding cellular infiltrate. C-reactive protein and serum amyloid A were not detected in the same perivascular areas of inflamed tissues. The abundant presence of apoA-I in the perivascular cellular infiltrates of inflamed RA synovial tissue extends the observations in vitro that showed that apoA-I can modify contact-mediated macrophage production of TNF-alpha and IL-1beta. ApoA-I was not present in synovium from patients in apparent remission, suggesting that it has a specific role during phases of disease activity. These findings support the suggestion that the biologic properties of apoA-I, about which knowledge is newly emerging, include anti-inflammatory activities and therefore have important implications for the treatment of chronic inflammatory diseases.
15516150 Durability and rapidity of response to anakinra in patients with rheumatoid arthritis. 2004 Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disease that ultimately leads to disability and functional decline. Because patients usually develop RA in mid-life, they may experience its consequences for 20-30 years or longer. Proinflammatory cytokines, notably interleukin (IL)-1 and tumour necrosis factor-alpha, are believed to play significant pathophysiological roles. Clinical trials of biologicals that block these cytokines confirm their importance.Anakinra, a recombinant human IL-1 receptor antagonist, improves clinical signs and symptoms, and slows radiographic progression in patients with active RA. In clinical trials, patients receiving anakinra doses >1 mg/kg, whether administered alone or in combination with methotrexate, were two to three times more likely than patients receiving placebo to achieve a sustained ACR20 (American College of Rheumatology criteria) response. Notably, bone erosion slows to a greater extent and shows accelerated benefit when anakinra treatment is continued for periods beyond 24 weeks. Anakinra has a rapid onset of action, with substantial improvements in biochemical indices (C-reactive protein) seen within 1 week and clinical responses (ACR20 or joint counts) seen within 4 weeks of starting treatment. Anakinra is generally well tolerated, with injection site reactions being the most common adverse event. These reactions are generally mild and typically resolve within 2-3 weeks of treatment. The anakinra product labelling does include a warning regarding an increased risk of infections of 2% in anakinra-treated patients versus <1% in patients receiving placebo.
12161987 (Hydroxy)-chloroquine retinal toxicity: two case reports and safety guidelines. 2002 Retinal toxicity as a result of antimalarial therapy has been reported for many years. Retinopathy may be divided into reversible premaculopathy and irreversible true retinopathy. Risk factors for the development of toxicity are daily dosage related to body weight, total drug dosage and the specific drug used. The daily dosage of chloroquine should not exceed 4 mg/kg lean body weight a day. Exceeding the total dosage of 300 g increases the risk. The daily dosage of hydroxychloroquine should not exceed 6.5 mg/kg lean body weight a day with increased risk when the duration of treatment exceeds 8 years (1330 g for a patient of 70 kg). Regular dilated fundus examination, visual field testing using Amsler grid test and automated central 10-2 perimetry (to a red test object) is advised to detect reversible premaculopathy. Hydroxychloroquine toxicity due to excessive cumulative dosage is discussed in case 1. Chloroquine toxicity due to excessive daily dosage is discussed in case 2.
15570632 A distinct multicytokine profile is associated with anti-cyclical citrullinated peptide an 2004 Dec OBJECTIVE: Early inflammatory arthritis is clinically heterogenous and biologically-based indicators are needed to distinguish severe from self-limited disease. Anti-cyclical citrullinated peptides (CCP) have been identified as potential prognostic markers in early arthritis cohorts. Since cytokine networks are known to play a critical role in the pathogenesis of rheumatoid arthritis (RA) and other forms of inflammatory arthritis, a panel of pro- and antiinflammatory cytokines was measured to identify biologically-based subsets of early arthritis, relating cytokine profiles to clinical measures and to the presence of RA-associated autoantibodies. METHODS: Plasma concentrations of cytokines [interleukin 1beta (IL-1beta), IL-2, IL-4, IL-5, IL-6, IL-7, CXCL8 (IL-8), IL-10, IL-12p70, IL-13, IL-17, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon-g (IFN-g), CCL2 (monocyte chemoattractant protein-1, MCP-1), CCL4 (MIP-1beta), and tumor necrosis factor-a (TNF-a)] were measured in patients with early, untreated inflammatory arthritis [symptom duration < or = 12 months; > or = 1 swollen joint; RA, n = 41; undifferentiated arthritis (UA), n = 23]. Cytokine expression patterns were determined using cluster analysis. RESULTS: Both pro- and antiinflammatory cytokines were elevated in patients over controls (n = 21). RA clustered into subgroups based solely on cytokine profiles. The "mild" RA subgroup (n = 23) had higher CCL4 (MIP-1beta), CXCL8 (IL-8), IL-2, IL-12, IL-17, IL-5, and IL-10 levels, lower IL-6, IFN-g, GM-CSF, and IL-4 levels, less CCP positivity (52% vs 82%; p < 0.05), and lower CCP titers [71 (78) vs 153 (94); p < 0.01], but similar erythrocyte sedimentation rate, C-reactive protein, and joint counts compared to the "severe" RA groups. CCL4 (MIP-1beta), IL-13, IL-12, TNF-a, and IL-4 best distinguished the groups. Combining UA with RA samples preserved cytokine subgroups and strengthened the autoantibody associations. Fewer UA patients in the "mild" cluster (n = 16) were RF-positive (24% vs 100%; p < 0.002) or CCP-positive (24% vs 66%; p < 0.08) compared to the "severe" group. CONCLUSION: Early untreated inflammatory arthritis can be categorized into distinct subgroups based on cytokine profiles. These subgroups are associated with CCP and RF autoantibodies. Integration of cytokine profiles with autoantibody status may assist prognostication and treatment decisions in these patients.
12115243 Differential role of neutrophil Fcgamma receptor IIIB (CD16) in phagocytosis, bacterial ki 2002 May OBJECTIVE: To determine the roles played by the neutrophil Fcgamma receptor type II (FcgammaRII) (CD32) and FcgammaRIIIb (CD16) in phagocytosis, bacterial killing, and activation by immune complexes (ICs) and to test the hypothesis that inhibition of pathologic effector neutrophil function is possible without compromising host defense. METHODS: Receptor function was probed by enzymic removal of FcgammaRIIIb from the cell surface and by use of Fab/F(ab')(2) fragments of monoclonal antibodies to block receptor-ligand binding. Cells were challenged with (a) serum-opsonized Staphylococcus aureus, (b) serum- and IgG-opsonized latex particles, and (c) synthetic soluble and insoluble ICs to mimic bacterial and inflammatory stimuli. RESULTS: Phosphatidylinositol-phospholipase C treatment removed >97% of surface FcgammaRIIIb from neutrophils previously treated with tumor necrosis factor alpha to mobilize intracellular stores of receptor. This treatment profoundly inhibited activation of primed neutrophils by soluble ICs of the type found in diseased rheumatoid joints, but had no effect on phagocytosis and killing of serum-opsonized S aureus. CONCLUSION: FcgammaRIIIb plays a major role in the secretion of toxic products in response to ICs, but little or no role in the phagocytosis and killing of serum-opsonized bacteria. The selective suppression of effector neutrophil function is therefore possible. FcgammaRIIIb, or its intracellular signaling pathway, is a potential therapeutic target in inflammatory diseases such as rheumatoid arthritis, because disruption of its function should decrease inflammatory tissue damage, but not jeopardize host protection against infection.
12030277 Vitamin B12 deficiency, tumor necrosis factor-alpha, and epidermal growth factor: a novel 2002 May Vitamin B12 deficiency was recently shown to be associated with elevated levels of tumor necrosis factor-alpha and decreased levels of epidermal growth factor in both rats and humans. These findings suggest a novel pathogenetic mechanism underlying the neuropathology of vitamin B12 deficiency. They may also explain putative relationships between vitamin B12 deficiency and certain disorders, including Alzheimer's disease, rheumatoid arthritis, and AIDS.
12154206 Analysis of improvements, full responses, remission and toxicity in rheumatoid patients tr 2002 Aug OBJECTIVE: To evaluate two monotherapies followed by step-up combination therapy with two or three complementary drugs in active rheumatoid arthritis (RA) in comparison with sulphasalazine (SSZ) alone. METHODS: One hundred and twenty-six consecutive patients with early active RA were enrolled in this open controlled clinical trial. The primary end-point was 50% improvement according to the ACR criteria (ACR50) at 6, 12 or 18 months. The secondary end-points were a full response (Magnusson criteria) and/or remission (ACR criteria) at 3 yr. Methotrexate (MTX) (group 1), cyclosporin A (CsA) (group 2) or SSZ (group 3) was used first. After 6 months, a combination of two drugs (CsA and MTX) was employed in groups 1 and 2. SSZ was added after 12 months if improvement was less than ACR50 with the combination. Group 3 continued with SSZ alone. RESULTS: After 6 months, 57% of patients in group 1, 31% of group 2 (MTX vs CsA, P=0.002) and 33% of group 3 (MTX vs SSZ, P=0.01) had reached ACR50 improvement according to intention-to-treat analysis. At month 12 after starting a drug combination, 67% of group 1 and 76% of group 2 had reached ACR50 compared with 24% of group 3. At the 18-month follow-up, 90% of group 1 and 88% of group 2 but only 24% of group 3 had reached ACR50. After 18 months, 62% of group 1, 60% of group 2 and 48% of group 3 showed side-effects and three, five and eight patients in the three groups respectively had dropped out of the study. At the 3-yr follow-up, 9% of the patients in groups 1 and 2 and 7% of group 3 were in remission according to the ACR criteria; according to the Magnusson criteria, 40% showed a full response in groups 1 and 2 but only 21% did so in group 3. CONCLUSION: MTX appears to be the fastest-acting agent. A step-up approach with MTX plus CsA plus SSZ led to a 50% improvement according to the ACR criteria in most patients. After 3 yr, 40% of patients receiving combination therapy and 21% of patients receiving monotherapy showed a full response, while 9 and 7% respectively attained remission.
12848288 A biomarker of n-3 compliance in patients taking fish oil for rheumatoid arthritis. 2003 Apr Dietary fish oil supplements have been shown to have benefits in rheumatoid arthritis (RA), other inflammatory diseases, and in cardiovascular disease. As with any medical advice, variability will exist with regard to adherence and consequent biochemical or pharmacophysiologic effects. The aim was to explore the utility of plasma phospholipid EPA as a measure of n-3 PUFA intake and response to standardized therapeutic advice given in an outpatient or office practice setting, to increase dietary n-3 PUFA, including a fish oil supplement. Patients with early RA were given verbal and written advice to alter their dietary n-3 PUFA intake, including ingestion of 20 mL of bottled fish oil on juice daily. The advice included instructions to increase n-3 PUFA and to avoid foods rich in n-6 PUFA. Every 3 mon, blood samples were obtained for analysis of plasma phospholipid FA. Plasma phospholipid EPA was used as the primary index of n-3 PUFA intake. A diverse response was seen, with about one-third of patients achieving a substantial elevation of plasma phospholipid EPA over the 12-mon study period. A third had little change, with the remainder achieving intermediate levels. Data obtained longitudinally from individual patients indicated that substantial elevations of EPA (> 5% total plasma phospholipid FA) could be maintained for more than 3 yr. Plasma phospholipid EPA is a convenient measure of adherence to advice to take a dietary n-3 PUFA-rich fish oil supplement This measure may prove a useful adjunct to intention to treat analyses in determining the effect of dietary fish oil supplements on long-term outcomes in arthritis and other chronic inflammatory diseases. It may also provide a guide to the effectiveness of therapeutic and preventive messages designed to increase n-3 PUFA intake.
12516200 Liver abnormalities in rheumatic diseases. 2002 Nov Abnormalities of LFTs and liver function occur not infrequently in patients with rheumatic conditions, and many diagnostic possibilities exist. Systemic inflammation that is related to uncontrolled rheumatic disease and periods of disease remission have been described as a cause for fluctuations in levels of serum aminotransferases. Although these benign extra-articular manifestations of rheumatic disease are the most common manifestations, more serious hepatic involvement, including vasculitis, nodular regenerative hyperplasia, and primary biliary cirrhosis, have been observed in specific rheumatic diseases. The cause of rheumatic disease is unclear. Occult HCV infection and associated cryoglobulinemia can mimic rheumatic disease. HCV infection should be suspected routinely in patients with mixed cryoglobulinemia, especially because antiviral therapy may be beneficial. The medical management of rheumatic disease involves medications that are often hepatotoxic. Routine laboratory monitoring, imaging studies, and, if necessary, biopsy examination in situations in which serum aminotransferases remain abnormal, are recommended.
15170913 Activation of synovial cell p38 MAP kinase by macrophage migration inhibitory factor. 2004 Jun OBJECTIVE: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine important in animal models of rheumatoid arthritis (RA). We investigated the utilization by MIF of mitogen activated protein (MAP) kinase signalling pathways in the stimulation of fibroblast-like synoviocytes (FLS), cyclooxygenase-2 (COX-2), prostaglandin E(2) (PGE(2)), and interleukin 6 (IL-6) and IL-8 expression. METHODS: Cultured human RA FLS were treated with recombinant MIF. Activation of MAPK was measured by Western blotting and blocked using specific inhibitors. The expression of COX-2, PGE(2), IL-6, and IL-8 were measured using flow cytometry, ELISA, and real-time polymerase chain reaction. RESULTS: MIF induced the phosphorylation of FLS p38 and extracellular-signal regulated kinase (ERK) MAP kinase. MIF significantly induced COX-2 and IL-6 protein and mRNA expression as well as PGE(2) and IL-8 production. Antagonism of p38 MAP kinase inhibited MIF induction of COX-2, PGE(2), and IL-6. In contrast, antagonism of ERK had no effect on COX-2, PGE(2), or IL-6. Neither antagonist inhibited MIF-induced IL-8. CONCLUSION: MIF activates RA FLS COX-2 and IL-6 expression via p38 MAP kinase activation and induces IL-8 via p38 and ERK MAP kinase-independent pathways.
12705064 Selective COX-2 inhibitors: a health economic perspective. 2003 The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is common in patients with osteoarthritis and rheumatoid arthritis. However, due to gastrointestinal side effects, the health-related and economic burden related to these drugs is considerable. Therefore, substituting or supplementing conventional NSAIDs with safer drugs that have a better risk profile not only may avoid serious complications but may also be an efficient allocation of scarce resources. Because of their better gastrointestinal risk profile, the newly developed selective COX-2 inhibitors celecoxib and rofecoxib are discussed as cost-effective alternatives to common NSAIDs. This paper provides an overview of health economic evaluations, conducted during the last few years, that investigate the economic consequences of switching patients from traditional NSAIDs to selective COX-2 inhibitors. This review of the health economic literature shows that results of the health economic assessments of COX-2 inhibitors are highly contradictory. The main divergence between studies occurs in estimated economic consequences of adopting COX-2 inhibitors in patients at low or average risk for developing gastrointestinal side effects. The economic consequences of the introduction of COX-2 inhibitors as well as the asynchronous development of scientific acceptance of the benefit of the new drugs and their actual diffusion and spread are discussed taking a broader, healthcare-system perspective.
15182626 [Analysis of the change in clonotypes of T cells accumulated in 4 feet joints of SKG mice] 2004 Jan AIM: To understand the relationship between T cell clonotypes and RA invasion through clonotypes of analysis of T cells accumulated in 4 feet joints of SKG mice. METHODS: Comparative analysis of T cells clonotypes of accumulated in the joints of SKG mice, a spontaneous RA mouse model, was carried out by RT-PCR/SSCP at the initial and late-stages of RA. RESULTS: The identical rate of Vbeta2 and Vbeta8.2 T cell clonotypes in 4 feet joints increased significantly at the late stage of RA (72.3% and 60.2%, respectively). CONCLUSION: The T cells with Vbeta2 or Vbeta8.2 TCR may play an important role in the RA development of SKG mice.
12905467 Serologic changes following B lymphocyte depletion therapy for rheumatoid arthritis. 2003 Aug OBJECTIVE: To explore the changes in serologic variables and clinical disease activity following B lymphocyte depletion in 22 patients with rheumatoid arthritis (RA). METHODS: B lymphocyte depletion was attained using combination therapy based on the monoclonal anti-CD20 antibody rituximab. Levels of a serologic indicator of inflammation, C-reactive protein (CRP), of antimicrobial antibodies, of autoantibodies including IgA-, IgM-, and IgG-class rheumatoid factors (RF), and of antibodies to cyclic citrullinated peptide (anti-CCP) were assayed. RESULTS: The majority of patients showed a marked clinical improvement after treatment with rituximab, with benefit lasting up to 33 months. Levels of total serum immunoglobulins fell, although the mean values each remained within the normal range. Whereas the IgM-RF response paralleled the changes in total serum IgM levels, the levels of IgA-RF, IgG-RF, and IgG and anti-CCP antibodies decreased significantly more than did those of their corresponding total serum immunoglobulin classes. The kinetics for the reduction in CRP levels also paralleled the decreases in autoantibody levels. In contrast, levels of antimicrobial antibodies did not change significantly. B lymphocyte return occurred up to 21 months posttreatment. The time to relapse after B lymphocyte return was often long and unpredictable (range 0-17 months). Relapse was, however, closely correlated with rises in the level of at least one autoantibody. Increased autoantibody levels were rarely observed in the absence of clinical change. CONCLUSION: Following B lymphocyte depletion in patients with RA, a positive clinical response occurred in correlation with a significant drop in the levels of CRP and autoantibodies. Antibacterial antibody levels were relatively well maintained. B lymphocyte return preceded relapse in all patients. There was also a temporal relationship between clinical relapse and rises in autoantibody levels. Although these observations are consistent with a role for B lymphocytes in the pathogenesis of RA, the precise mechanisms involved remain unclear.
15180893 B cell depletion in autoimmune disease. 2003 The CD20 cell marker appears early in the process of B cell development. In this review we focus on the results of attempts to utilize B cell depletion based on the use of a chimeric monoclonal antibody (MAb) specific for human CD20, rituximab, for the treatment of patients with autoimmune diseases. In 1997, rituximab was approved for the treatment of low-grade B cell non-Hodgkin's lymphoma. Following these encouraging results, rituximab started to be used experimentally in other diseases presumed to be due to B cell pathology. The first autoimmune disease to be treated effectively was chronic idiopathic thrombocytopaenia. More recent success has been demonstrated in patients with rheumatoid arthritis and systemic lupus erythematosus.
11867114 Drug-induced systemic lupus erythematosus associated with etanercept therapy. 2002 Feb 16 Specific antagonists of tumour necrosis factor (TNF)-alpha have rapidly gained popularity for the treatment of rheumatoid arthritis. The monoclonal antibody against TNF-alpha, infliximab, has been associated with induction of systemic lupus erythematosus (SLE); however, there have been no published reports of drug-induced SLE associated with the soluble TNF-alpha receptor etanercept. We describe four female patients who developed signs and symptoms of SLE during treatment with etanercept; in two SLE was unambiguous. On diagnosis of SLE, etanercept was discontinued and the SLE-related symptoms promptly resolved. Etanercept should be considered in the list of agents associated with drug-induced SLE.
15022309 Autoantibodies to cyclic citrullinated peptides predict progression to rheumatoid arthriti 2004 Mar OBJECTIVE: Rheumatoid arthritis (RA) is a common, severe, chronic inflammatory joint disease. Since the disease may initially be indistinguishable from other forms of arthritis, early diagnosis can be difficult. Autoantibodies seen in RA can be detected years before clinical symptoms develop. In an inception cohort of patients with recent-onset arthritis, we undertook this study to assess the predictive value of RA-specific autoantibodies to cyclic citrullinated peptides (CCPs) in patients with undifferentiated arthritis (UA). METHODS: Anti-CCP2 antibody tests were performed at baseline in 936 consecutive, newly referred patients with recent-onset arthritis. Patients who could not be properly classified 2 weeks after inclusion were categorized as having UA. Patients with UA were followed up for 3 years and evaluated for progression of their disease to RA as defined by the American College of Rheumatology (ACR) 1987 revised criteria. RESULTS: Three hundred eighteen of 936 patients with recent-onset arthritis were classified as having UA and were available for analysis. After 3 years of followup, 127 of 318 UA patients (40%) had been classified as having RA. RA had developed in 63 of 249 patients (25%) with a negative anti-CCP test and in 64 of 69 patients (93%) with a positive anti-CCP test (odds ratio 37.8 [95% confidence interval 13.8-111.9]). Multivariate analysis of the presence of anti-CCP antibodies and parameters from the ACR criteria identified polyarthritis, symmetric arthritis, erosions on radiographs, and anti-CCP antibodies as significant predictors of RA. CONCLUSION: Testing for anti-CCP antibodies in UA allows accurate prediction of a substantial number of patients who will fulfill the ACR criteria for RA.
14611115 Increased serum levels of interleukin-15 in rheumatoid arthritis with long- term disease. 2003 Sep OBJECTIVE: To study the serum levels of IL-15 in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), seronegative spondyloarthropathies (SSd) and healthy donors. METHODS: The IL-15 serum levels were measured by ELISA in sera from 50 RA patients, 30 patients with SLE, 30 patients with SSd and 30 healthy donors. In RA patients, several clinical and demographic parameters were also obtained at the time of sample collection. IL-15 levels were compared in different RA subpopulations (positive or negative rheumatoid factor [RF], long term or recent onset disease, high or low disease activity). In addition, the possible association with other demographic and clinical parameters (gender, age, disease duration, etc) was also analysed. RESULTS: RA patients had significantly higher serum levels of IL-15 (102.4 +/- 150 pg/ml; p = 0.0001) than SLE patients (9.8 +/- 15.3 pg/ml), SSd patients (7.9 +/- 14.6 pg/ml) and healthy donors' (5.2 +/- 11.6 pg/ml). RA patients with a disease evolution less than 2 years showed lower IL-15 levels (33.7 +/- 62.2 pg/ml) than those with long-term disease (152.4 +/- 64.6 pg/ml; p = 0.004). In addition, a significant correlation between IL15 in serum and the number of disease-modifying antirheumatic drugs (DMARDs) prescribed was detected in RA patients (r = 0.42; p = 0.002). No association between IL-15 levels and age, gender, RF or disease activity was observed in this group. CONCLUSION: IL-15 is elevated in RA patients, specially in those with long term disease, compared to other rheumatic disorders. This finding supports that IL-15 is involved in the perpetuation of RA synovitis.
12105681 [Role of cell migration in the pathogenesis of rheumatoid arthritis: in vivo studies in SC 2002 Apr OBJECTIVE: Adhesion mechanisms play a central role in the recruitment of leukocytes which characteristically infiltrate rheumatoid synovium. Therefore, we adapted an animal model, in which human rheumatoid synovium was transplanted into severe combined immunodeficient (SCID) mice, to study the effects of Tumor Necrosis Factor-alpha (TNF-alpha) in modulatine leukocyte migration and to investigate the chemotactic potential of Stromal Derived Factor-1 alpha (SDF-1 alpha). MATERIALS AND METHODS: Human synovium samples, obtained from patients undergoing joint replacement, were divided into two parts. One was analysed by immunohistology and the other was implanted subcutaneously into SCID mice under general anaesthesia. Four weeks post-transplantation, grafts were injected with optimal dose of SDF-1, TNF-alpha or saline (negative control). At the same time, animals were injected iv with fluorescently labelled cells. 48 hours later mice were sacrificed and grafts removed for cryo-hystology. The number of cells migrating to the grafts was determined by UV-microscopy and the results expressed as cells per high power field. RESULTS AND CONCLUSIONS: In these studies we provide the evidence that: 1) the animal model, in which human tissues are grafted into SCID mice, can be used to study cell migration under controlled experimental conditions; 2) direct intragraft injection of TNF-alpha increases lymphocytes migration and up-regulates the expression of human adhesion molecules (CAMs) and 3) SDF-1 alphainjected intragraft increases the migration of the pro-myelo-monocytic U937 cells to synovial transplants, even more efficiently than TNF-alpha, but without modifications of CAMs' expression.
12428225 Cell-derived microparticles in synovial fluid from inflamed arthritic joints support coagu 2002 Nov OBJECTIVE: To determine the cellular origin of synovial microparticles, their procoagulant properties, and their relationship to local hypercoagulation. METHODS: Microparticles in synovial fluid and plasma from patients with rheumatoid arthritis (RA; n = 10) and patients with other forms of arthritis (non-RA; n = 10) and in plasma from healthy subjects (n = 20) were isolated by centrifugation. Microparticles were identified by flow cytometry. The ability of microparticles to support coagulation was determined in normal plasma. Concentrations of prothrombin fragment F(1+2) (by enzyme-linked immunosorbent assay [ELISA]) and thrombin-antithrombin (TAT) complexes (by ELISA) were determined as estimates of the coagulation activation status in vivo. RESULTS: Plasma from patients and healthy controls contained comparable numbers of microparticles, which originated from platelets and erythrocytes. Synovial microparticles from RA patients and non-RA patients originated mainly from monocytes and granulocytes; few originated from platelets and erythrocytes. Synovial microparticles bound less annexin V (which binds to negatively charged phospholipids) than did plasma microparticles, exposed tissue factor, and supported thrombin generation via factor VII. F(1+2) (median 66 nM) and TAT complex (median 710 microg/liter) concentrations were elevated in synovial fluid compared with plasma from the patients (1.6 nM and 7.0 microg/liter, respectively) as well as the controls (1.0 nM and 2.9 microg/liter, respectively). CONCLUSION: Synovial fluid contains high numbers of microparticles derived from leukocytes that are strongly coagulant via the factor VII-dependent pathway. We propose that these microparticles contribute to the local hypercoagulation and fibrin deposition in inflamed joints of patients with RA and other arthritic disorders.