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ID PMID Title PublicationDate abstract
10335743 The SF-36 Arthritis-Specific Health Index (ASHI): II. Tests of validity in four clinical t 1999 May OBJECTIVE: The SF-36 Arthritis-Specific Health Index (ASHI) was constructed to improve the responsiveness of the SF-36 Health Survey to changes in the severity of arthritis through the use of arthritis-specific scoring algorithms. This study compared the responsiveness of the ASHI and other generic scales and summary measures scored from the SF-36 in clinical trials of health outcomes for patients with arthritis. METHODS: Longitudinal data for patients (n = 835) participating in four placebo-controlled trials were analyzed. Study participants had at least a 6-month history of moderate to severe osteoarthritis or rheumatoid arthritis of the knee or hip. All had undergone a washout period of 3 to 14 days before baseline assessment to bring about a flare state in osteoarthritis or rheumatoid arthritis symptoms. Their average age was 60 years, and 72% were female. Responders and nonresponders were classified on the basis of physician assessments of changes in arthritis severity, with blinding as to treatment group; treated and untreated (placebo) groups were also compared. For the SF-36 ASHI, generic physical (PCS) and mental (MCS) component summary measures and each of eight subscales scored from the SF-36 (acute version) change scores were computed by subtracting scores before treatment from scores at 2-week follow-up. To evaluate empirical validity, analyses of variance were performed. For each measure, an F-ratio was computed for the comparison between clinically defined groups of responders and nonresponders and between groups of patients assigned to placebo versus drug therapy. Relative validity (RV) coefficients were computed for the ASHI in comparison with PCS, MCS, and the best SF-36 scale to determine which was more responsive. RESULTS: In analyses of each of the four trials and all trials combined, RV coefficients for the ASHI were higher than those for both of the generic SF-36 summary measures and for the most valid SF-36 scale (Bodily Pain), with only one exception. Across 40 tests of validity in distinguishing treated from untreated patients, the ASHI was 5% to 19% more valid than the best SF-36 scale (RV = 1.05-1.19; RV = 1.10 in all trials combined). The generic summary measures (PCS and MCS) were much less valid in these tests (RV = 0.67 and 0.27, respectively). In analyses of responders and nonresponders, RV coefficients for the ASHI ranged from 0.70 to 1.22 (RV = 1.04 in all trials combined), in comparison with the best SF-36 subscale, which was always Bodily Pain. RV coefficients were lower for PCS (RV = 0.75) and much lower than the MCS (RV = 0.18) in comparisons of treatment outcomes based on all trials combined. CONCLUSION: The ASHI appears to be more valid than the eight SF-36 scales and PCS and MCS summary measures for purposes of distinguishing between treated and untreated patients and between clinical responders and nonresponders. This study demonstrates the feasibility of improving the validity of the SF-36 through the use of arthritis-specific scoring while retaining the option of generic scoring, which makes it possible to also compare results across diseases and treatments.
9431590 Inadequate calcium, folic acid, vitamin E, zinc, and selenium intake in rheumatoid arthrit 1997 Dec OBJECTIVES: To determine the adequacy of calcium, folic acid, vitamin E, zinc, and selenium intake in patients with rheumatoid arthritis (RA). METHODS: We conducted an observational study on 48 patients (13 men, 35 women; mean age, 64.5 years) with RA attending a specialty clinic in New Zealand comparing their dietary intake as measured by a 5-day dietary survey with recommended dietary intake (RDI) guidelines. Information on disease activity, functional ability, and drug therapy also was obtained. RESULTS: The percentage of patients who achieved the RDI was 23% for calcium, 46% for folic acid, 29% for vitamin E, 10% for zinc, and only 6% for selenium. Patients on methotrexate had a significantly reduced intake of folic acid as a percentage of RDI (P < .05) compared with those on other therapies. In contrast, dietary intake of iron and protein was largely adequate and unrelated to anemia. CONCLUSIONS: Patients with RA should receive dietary education or supplementation to bring their intake of calcium, folic acid, vitamin E, zinc, and selenium up to the RDI.
11083277 Modulation of fibroblast-mediated cartilage degradation by articular chondrocytes in rheum 2000 Nov OBJECTIVE: To determine the role of chondrocytes and factors released from chondrocytes in cartilage destruction by fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA). METHODS: RA FLS from 2 patients were implanted into SCID mice, together with fresh articular cartilage or with cartilage that had been stored for 24 hours at 4 degrees C or at 37 degrees C. The invasion of the same RA FLS into the fresh and stored cartilage was compared histologically using a semiquantitative scoring system. In addition, we investigated whether protein synthesis in chondrocytes affects the invasion of RA FLS in vitro. A 3-dimensional cartilage-like matrix formed by cultured chondrocytes was labeled with 35S. After formation of the cartilage-like matrix, protein synthesis was blocked with cycloheximide. The invasion of RA FLS from 6 patients into cycloheximide-treated and untreated matrix was assessed by measuring the released radioactivity in coculture with and without interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha). RESULTS: The SCID mouse experiments showed a significant invasion of RA FLS into the cartilage (overall mean score 3.2) but revealed significant differences when the invasion of the same RA FLS into fresh and stored cartilage was compared. RA FLS that were implanted with fresh articular cartilage showed a significantly higher invasiveness than those implanted with pieces of cartilage that had been stored for 24 hours (overall mean score 2.3). Storage at 37 degrees C and 4 degrees C resulted in the same reduction of invasion (35% and 37%, respectively). In the in vitro experiments, RA FLS rapidly destroyed the cartilage-like matrix. Blocking of chondrocyte protein biosynthesis significantly decreased the invasion of RA FLS, as shown by a decreased release of radioactivity. Addition of IL-1beta, but not TNFalpha, to the cocultures partially restored the invasiveness of RA FLS. CONCLUSION: These data underline the value of the SCID mouse in vivo model of rheumatoid cartilage destruction and demonstrate that chondrocytes contribute significantly to the degradation of cartilage by releasing factors that stimulate RA FLS. Among those, IL-1beta-mediated mechanisms might be of particular importance.
11083276 Expression of osteoclast differentiation factor in rheumatoid arthritis. 2000 Nov OBJECTIVE: To analyze the expression pattern of osteoclast differentiation factor (ODF) and its contribution to osteoclastogenesis in rheumatoid arthritis (RA). METHODS: The expression of ODF was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) in RA synovial fibroblasts (RASF) isolated from 7 RA patients and in normal skin fibroblasts. Using RNA probes specific for ODF, in situ hybridization was performed. Immunohistochemical double labeling for CD68 was applied to characterize the ODF-expressing cells. ODF protein and messenger RNA (mRNA) expression by RASF with or without 1,25(OH)2D3 was studied by Western blot analysis and quantitative real-time PCR. In addition, we performed coculture experiments with RASF and normal peripheral blood mononuclear cells with or without 1,25(OH)2D3. RESULTS: By RT-PCR, ODF mRNA expression was found in all RASF investigated, but not in normal skin fibroblasts. In situ hybridization revealed that in RA synovial tissues, ODF mRNA was expressed mainly in the lining layer and at sites where synovium was attached to bone. Immunohistochemical double labeling demonstrated ODF mRNA expression mainly in CD68-fibroblast-like synoviocytes and CD68+ multinucleated osteoclast-like cells. By Western blotting, all RASF expressed ODF protein. However, different levels of ODF expression were found in the RASF from different patients. Interestingly, RASF expressing higher levels of ODF induced a larger number of osteoclast-like cells than did RASF expressing only low levels of ODF. Although 1,25(OH)2D3 did not alter the levels of ODF expression in RASF on either Western blot or quantitative real-time PCR, osteoclastogenesis required the presence of 1,25(OH)2D3. CONCLUSION: The present results suggest that activated RASF, by expressing ODF, play an important role in rheumatoid bone destruction. Moreover, the data provide evidence that RASF not only activate osteoclasts, but also contribute directly to osteoclastogenesis.
11291608 [Five year clinical evaluation of treatment efficacy with methotrexate in patients with rh 2000 May The objective of this study was to determine long term efficacy and safety of low dose methotrexate (MTX) in treatment of rheumatoid arthritis (RA). Thirty patients receiving MTX for RA were prospectively studied over a mean treatment period of 60 months. Standard clinical and laboratory measures of disease activity were assessed by the same investigator at baseline, and at 3, 6, 24, and 60 months. The occurrence of adverse reactions was noted. Initially MTX was given orally 7.5 mg once a week. In the course of the observation the dose ranged between 5 and 15 mg/week. 13 patients (43%) completed 5-years study. Treatment with MTX was stopped due to adverse events in 4 cases, inefficacy in 7 patients, poor compliance and fear of toxicity in 3 patients and death in 3 patients. The factors related to their death were unrelated in all 3 cases to study MTX therapy. In 13 patients who completed 60 months of therapy, a significant improvement was noted comparing to baseline in 9 out of 12 clinical disease variables and acute phase reactants. There was also a significant decrease in the mean daily dosage of NSAIDs. Adverse events occurred in 64% of the patients, but only 13% of the patients discontinued MTX permanently. The side effects occurred more often in older patients. RA patients treated for five years with MTX showed statistically significant clinical improvement and decrease of inflammation parameters. MTX treatment may be helpful also in patients with advanced forms of RA.
9417865 Induction and expression of human cartilage glycoprotein 39 in rheumatoid inflammatory and 1997 Nov 25 Human cartilage glycoprotein 39 (HC gp-39) has been described as a major secreted product of cultured articular chondrocytes, synovial fibroblasts, and the osteosarcoma line MG63. However, its expression in these cells types has not been directly linked to corresponding cell types in vivo. In this report, expression of HC gp-39 is demonstrated from peripheral blood-derived macrophages in association with their differentiation from monocytes to macrophages. Consistent with macrophage specificity, HC gp-39 expression is also induced upon selective stimulation of the pluripotent promyelocytic leukemia cell line HL-60 toward the monocyte/macrophage lineage with vitamin D3 or phorbol 12-myristate 13-acetate (PMA), while treatments stimulating granulocyte and eosinophilic pathways do not induce expression. Furthermore, HC gp-39 expression levels correlate with the degree of morphological differentiation induced by PMA and vitamin D3 treatments. PMA-induced mRNA expression occurs by 36 h and is a secondary transcriptional response since its synthesis is inhibited by cycloheximide. Apparently, HC gp-39 expression is tied to later events in the differentiation of monocytes into macrophages. The in vivo significance of these results is validated by the in situ detection of HC gp-39 mRNA in inflammatory macrophages associated with rheumatoid synovium. Thus, macrophages appear to be an important source of HC gp-39, which has been shown to be present at elevated levels in the blood and synovium of rheumatoid arthritis patients. The implications of this extend well beyond the previously restricted observations in cell types associated with the joint and suggest a potential involvement of macrophage-derived HC gp-39 in other aspects of inflammation, tissue remodeling, and host defense.
10337031 Inhibitory effects of anti-rheumatic drugs on vascular endothelial growth factor in cultur 1999 May Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis and is constitutively expressed in the synovium of rheumatoid arthritis (RA). Over-expression of VEGF may play an important role in pathogenic vascularization and synovial hyperplasia of RA. In the present study, we examined whether disease-modifying anti-rheumatic drugs (DMARDs), including bucillamine (BUC), gold sodium thiomalate (GST), methotrexate (MTX) and salazosulfapiridine (SASP), act by inhibiting the production of VEGF by cultured synovial cells of patients with RA. Treatment of cultured synoviocytes with lipopolysaccharide (LPS) significantly increased VEGF production by cultured synovial cells. BUC significantly inhibited LPS-induced VEGF production, while GST tended to inhibit the production of VEGF. The inhibitory effects on VEGF production were dose-dependent. In contrast, MTX and SASP did not affect VEGF production. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that BUC also inhibited LPS-induced VEGF mRNA expression in RA synovial cells. The present study provides the first evidence that BUC inhibits VEGF production and the expression of its mRNA in synovial cells of RA patients. Our results indicate that the anti-rheumatic effects of BUC are mediated by suppression of angiogenesis and synovial proliferation in the RA synovium through the inhibition of VEGF production by synovial cells.
9308520 Use of grommets for flexible implant resection arthroplasty of the metacarpophalangeal joi 1997 Sep In 1987, after 11 years of research, press fit titanium circumferential grommets were introduced for arthroplasty of the metacarpophalangeal joint to protect the flexible hinge implant midsection from sharp bony edges and shearing forces that can initiate implant abrasions and tears leading to implant fracture and formation of silicone wear particles. The effectiveness of the titanium circumferential grommets was assessed by comparing the results of 170 metacarpophalangeal joint implant (high performance) arthroplasties performed with (139 joints) and without (31 joints) grommets in 38 patients presenting an average 5.8 years followup. Both groups obtained pain relief, functional motion, stability, and correction of deformity. There was no evidence of particulate synovitis or infection. There were four implant fractures (12.9%) in the nongrommet group, and one (0.7%), because of implant rotation, in the grommet group. Although favorable bone remodeling was observed in both groups, the grommet group showed greater bone preservation at the metaphyseal and midshaft levels and increased intramedullary bone production around the implant stems. The results depend on appropriate surgical staging, meticulous operative and postoperative techniques, severity and progression of disease, and implant durability. The circumferential grommets safely and effectively protect the implant to bone interface to further the durability of implant arthroplasty of the metacarpophalangeal joint.
11213361 Effects of nitric oxide on matrix metalloproteinase-2 production by rheumatoid synovial ce 2001 Jan 12 Nitric oxide (NO) is a multifunctional messenger molecule generated from L-arginine by a family of enzymes, including nitric oxide synthase (NOS). This study was performed to examine whether NO modulates the production of matrix metalloproteinases (MMPs), which degrade all components of extracellular matrix (ECM), in rheumatoid synovial cells. We investigated the effects of exogenously generated NO by a NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), on the MMPs production by rheumatoid synovial cells. Culture media conditioned by SNAP-treated synovial cells were examined by gelatin zymography and immunoblot analysis. Incubation of synovial cells with SNAP resulted in gelatinase A production in a dose-dependent fashion. Furthermore, RT-PCR analysis demonstrated that MMP-2 mRNA expression was induced in SNAP-treated synovial cells. In contrast, SNAP did not influence the production of TIMP-1 and TIMP-2, which preferentially inhibit MMP-2, by rheumatoid synovial cells. Our data indicate that NO could modulate MMP production by rheumatoid synovial cells and therefore contribute to ECM degradation of articular components in RA.
11084949 Sex hormone adjuvant therapy in rheumatoid arthritis. 2000 Nov RA is an autoimmune rheumatic disorder resulting from the combination of several predisposing factors, including the relation between epitopes of possible triggering agents and histocompatibility epitopes, the status of the stress response system, and the sex hormone status. Estrogens are implicated as enhancers of humoral immunity, and androgens and progesterone are natural immune suppressors. Sex hormone concentrations have been evaluated in RA patients before glucocorticoid therapy and have frequently been found to be altered, especially in premenopausal women and male patients. In particular, low levels of gonadal and adrenal androgens (testosterone and DHT, DHEA and DHEAS) and a reduced androgen:estrogen ratio have been detected in body fluids (i.e., blood, synovial fluid, smears, saliva) of male and female RA patients. These observations support a possible pathogenic role for the decreased levels of the immune-suppressive androgens. Exposure to environmental estrogens (estrogenic xenobiotics), genetic polymorphisms of genes coding for hormone metabolic enzymes or receptors, and gonadal disturbances related to stress system activation (hypothalamic-pituitary-adrenocortical axis) and physiologic hormonal perturbations such as during aging, the menstrual cycle, pregnancy, the postpartum period, and menopause may interfere with the androgen:estrogen ratio. Sex hormones might exert their immune-modulating effects, at least in RA synovitis, because synovial macrophages, monocytes, and lymphocytes possess functional androgen and estrogen receptors and may metabolize gonadal hormones. The molecular basis for sex hormone adjuvant therapy in RA is thus experimentally substantiated. By considering the well-demonstrated immune-suppressive activities exerted by androgens, male hormones and their derivatives seem to be the most promising therapeutic approach. Recent studies have shown positive effects of androgen replacement therapy at least in male RA patients, particularly as adjuvant treatment. Interestingly, the increase in serum androgen metabolism induced by RA treatment with CSA should be regarded as a possible marker of androgen-mediated immune-suppressive activities exerted by CSA, at least in RA and at the level of sensitive target cells and tissues (i.e., synovial macrophages). The absence of altered serum levels of estrogens in RA patients and the reported immune-enhancing properties exerted by female hormones have represented a poor stimulus to test estrogen replacement therapy in RA. The different results obtained with OC use seem to depend on dose-related effects and the different type of response to estrogens in relation to the cytokine balance between Th1 cells (cellular immunity, i.e., RA) and Th2 cells (humoral immunity, i.e., SLE). The androgen replacement obtained directly (i.e., testosterone, DHT, DHEAS) or indirectly (i.e., antiestrogens) may represent a valuable concomitant or adjuvant treatment to be associated with other disease-modifying antirheumatic drugs (i.e., MTX, CSA) in the management of RA.
11122506 Diagnostic strategies for the histological examination of muscle biopsy specimens for the 2000 Dec 30 For the diagnosis of rheumatoid vasculitis (RV), histological examination of a blindly-taken muscle biopsy is advocated. If fibrinoid necrosis (FN) is observed in one or more tissue sections of the biopsy the diagnosis of RV is confirmed. The diagnostic value of such histological investigation depends on the prevalence of FN in biopsies of RV patients, the number of tissue sections that are investigated, and the sampling design with which the tissue sections are obtained from the biopsy. In this paper we determine the mathematical relation between the sensitivity of the RV diagnosis and these three factors for four different models for the FN distribution in RV biopsies. The goodness-of-fit of these models was assessed by analysing 18 829 tissue sections of the biopsies of 56 patients, among which were 24 (otherwise histologically proven) RV patients. It appeared that the sensitivity was moderate: FN was observed in only 14 out of 24 (58 per cent) muscle biopsies of the RV patients. The prevalence of FN in the tissue sections of those 14 biopsies was low, about 17 per cent according to the best fitting model. We proved that the sampling design, maximizing the minimum distance between tissue sections (equidistant sampling) was optimal, and that with such optimal sampling, examination of about 20 tissue sections was sufficient. With practical sampling designs, however, considerably more tissue sections had to be inspected. FN appeared to cluster in the RV biopsies, and a first-order Markov model satisfactorily described the (auto)correlation between adjacent tissue sections in RV biopsies.
10460194 Old drug, new tricks: haloperidol inhibits secretion of proinflammatory cytokines. 1999 Sep OBJECTIVES: It was noted that treatment of a patient with acute mania by haloperidol was associated with marked improvement in activity of rheumatoid arthritis. The objective of this study was to examine the effects of haloperidol on inflammatory cytokine release in vitro, as a potential mechanism to explain the in vivo anti-inflammatory effects of haloperidol. METHODS: The effect of haloperidol on the production of inflammatory cytokines interleukin 1beta (IL1beta) and tumour necrosis factor alpha (TNFalpha) was measured in bacterial lipopolysaccharide stimulated whole blood cultures and on the promonocyte cell line THP-1, using commercial and in house enzyme linked immunosorbent assays to measure cytokine concentrations. RESULTS: Haloperidol inhibited lipopolysaccharide stimulated production of both IL1beta and TNFalpha in vitro in a dose dependent manner and over a prolonged time period. Marked inhibition was seen over a range of concentrations of haloperidol from 0.5 microgram/ml to 50 microgram/ml, including those predicted to occur in the patient's blood. CONCLUSIONS: Haloperidol treatment seemed to alleviate inflammation in rheumatoid arthritis. In vitro experiments would suggest that the mechanism is by direct inhibition of proinflammatory cytokine release. This phenomenon requires further investigation and may potentially lead to the development of novel treatment.
9195519 Synoviocyte proliferation in joints of SCID mice induced by toxic shock syndrome toxin-1 s 1997 Jun OBJECTIVE: To investigate the histopathological arthropathy in severe combined immunodeficient (SCID) mice given intraarticular injection of toxic shock syndrome toxin-1 (TSST-1) stimulated T cells from patients with rheumatoid arthritis (RA). METHODS: Unstimulated or TSST-1 stimulated T cell blasts (TB-TSST) of synovial fluid mononuclear cells from patients with RA (RASFMC) were intraarticularly injected into the knee joint of SCID mice. Four weeks later, the knee joints were histopathologically examined and the numbers of fibroblasts in the synovial tissues were compared with those of controls. Total RNA of the SCID mouse knee joints was isolated and Southern analysis for human T cell receptor (TCR) V beta 2 and human tumor necrosis factor-alpha (TNF-alpha) was carried out. RESULTS: Hyperplasia and increased numbers of the fibroblasts as well as neovascularization of the synovial tissues were observed in the SCID mouse knee joint tissues injected with TB-TSST of RASFMC compared with those injected with unstimulated T cells from RASFMC or with TB-TSST from peripheral blood of healthy controls. Messenger RNA for human TCR V beta 2 and TNF-alpha were detected in the SCID mouse knee joint tissues injected with TB-TSST from RASFMC. CONCLUSION: Superantigen TSST-1 stimulated T cells from RASFMC have the ability to induce chronic arthropathy with fibroblast proliferation and neovascularization in the SCID mouse.
9120404 Presence of cyclophilin A in synovial fluids of patients with rheumatoid arthritis. 1997 Mar 3 Cyclophilins have been suggested to act as leukocyte chemotactic factors produced in the course of inflammation. Therefore we looked for the presence of cyclophilins in the synovial fluids (SF) from patients with rheumatoid arthritis (RA). Peptidyl prolyl cis-trans isomerase activity (PPIase) was measured in SF from knee punctures of 26 patients with RA and five patients with knee osteoarthritis (OA). PPIase was detected in SF from RA patients, but not in samples from OA patients. Enzyme activity was sensitive to inhibition by cyclosporin A (IC50 = 28-50 nM). Estimated concentrations of the SF-derived cyclophilin based on the enzyme activity were in the range of 11 to 705 nM. The presence of cyclophilin in the SF showed disease correlation; its concentration correlated with the number of cells in the SF (r = 0.91, P < 0.0001) and with the percentage of neutrophils in the cellular infiltrate and was higher in more acute cases of joint swelling. In immunoblots of partially purified preparations of SF from RA patients, an approximately 18-kD protein band reacted with polyclonal antibodies that recognize cyclophilin A and B, but not with antibodies specific for cyclophilin B. Sequencing of this protein revealed identity of the NH2-terminal amino acids with those of human cyclophilin A. The finding is unexpected since cyclophilin B rather than A is generally regarded as the secreted isoform, the presence of cyclophilin A being confined to the cytoplasm. Our data support the hypothesis that cyclophilins may contribute to the pathogenesis of inflammatory diseases, possibly by acting as cytokines. This may offer a possible explanation of the effectiveness of cyclosporin A in RA, in addition to the known immunosuppressive effects of the drug.
10912314 DMARDs in the treatment of rheumatoid arthritis: current agents and future developments. 2000 May The purpose of this paper is to review the benefits and limitations of current disease-modifying antirheumatic drugs (DMARDs) used for the treatment of rheumatoid arthritis (RA). Literature about DMARD use in RA, both as monotherapy and in combination therapy, is reviewed. The efficacy and safety of methotrexate, antimalarials, gold-containing compounds, sulphasalazine, D-penicillamine, azathioprine and cyclosporin, as well as several new antirheumatic agents are considered. Controlled short-term clinical studies demonstrate that DMARDs are superior to placebo. Early and continuous use of DMARDs is necessary to slow joint damage and improve long-term outcomes. Unfortunately, long-term treatment with these drugs is frequently limited by loss of response and/or onset of serious adverse events. The efficacy of combination DMARD therapy has also been tested, but with mixed success, and the goals of combination DMARD therapy have yet to be fully realised. New DMARDs that have recently been introduced offer promise for future RA management.
10777254 Interference of rheumatoid factor activity by aspartame, a dipeptide methyl ester. 1999 Sep Circulating autoimmune complexes of IgM rheumatoid factors (RF) bound to the Fc portions of normal, polyclonal IgG antibodies are frequently present in humans with rheumatoid arthritis (RA). The sweet tasting methyl ester of L-Asp-L-Phe (aspartame or APM) was found to relieve pain and improve joint mobility in subjects with osteo- and mixed osteo/rheumatoid arthritis [Edmundson, A. B. and Manion, C. V. (1998). Clin. Pharmac. Ther. 63, 580-593]. These clinical observations prompted the testing of the inhibition by APM of the binding interactions of human IgM RFs with IgG Fc regions. The propensity of APM to inhibit IgM RF binding was assessed by competitive enzyme immunoassays with solid-phase human IgG. Ten RA serum samples and three purified monoclonal cryoglobulins, all of which had RF activity, were tested in this system. We found that the presence of APM significantly reduced the binding of IgM RFs. The inhibitory propensity of APM with monoclonal RF cryoglobulins was increased by the addition of CaCl(2) to the binding buffer. Similar inhibition of the binding of RA derived RFs to IgG was observed for Asp-Phe and its amidated derivative, indicating that the methyl ester is not required for APM's interaction with IgM antibodies. A human (Mez) IgM known to bind octameric peptides derived from the Fc portion of a human IgG(1) antibody was tested for binding of dipeptides by the Pepscan method of combinatorial chemistry. The relative binding constants of Asp-Phe and Phe-Asp were ranked among the highest values for 400 possible combinations of the 20 most common amino acids. Possible blocking interactions of APM were explored by computer-assisted docking studies with the model of a complex of an RF Fab with the Fc of a human IgG(4) antibody. Modeling of ternary immune complexes revealed a few key residues, which could act as molecular recognition sites for APM. A structural hypothesis is presented to explain the observed interference with RF reactivity by APM. Extrapolations of the current results suggest that APM may inhibit the binding of IgG in a substantial proportion of IgM RFs. Interference of RF reactivity, especially in RA patients, may alleviate the pain and immobility resulting from chronic inflammation of the joints.
10643713 Tumor necrosis factor alpha promotes the expression of stem cell factor in synovial fibrob 2000 Jan OBJECTIVE: To investigate the expression of the stroma cell product stem cell factor (SCF) in synovial fibroblasts (SFB) in patients with rheumatoid arthritis (RA) and osteoarthritis (OA), and to analyze the capacity of SFB to induce mast cell (MC) chemotaxis. METHODS: Synovial tissue was obtained from 29 patients with RA and 25 patients with OA. Tissue was dispersed by enzymatic digestion using collagenase. SFB were grown in serial passage and exposed to tumor necrosis factor alpha (TNFalpha) or control medium. Expression of SCF in cultured SFB was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and immunostaining. The ability of SFB (supernatants) to induce MC migration was analyzed using a double-chamber chemotaxis assay and the human mast cell line HMC-1. In situ expression of SCF in synovial tissue from patients with RA (n = 6) and OA (n = 6) was examined by double immunohistochemistry using antibodies against SCF and the fibroblast-specific antibody AS02. RESULTS: In both RA and OA, cultured SFB were found to express SCF messenger RNA, as assessed by RT-PCR. In addition, the SCF protein was detectable in cell lysates and supernatants of SFB by ELISA. Incubation of SFB with TNFalpha resulted in an increased expression and release of SCF. Recombinant human SCF (rHuSCF) and SFB supernatants induced significant migration of HMC-1 cells above control levels. In addition, exposure of SFB to TNFalpha led to an increased migration of HMC-1, and a blocking anti-SCF antibody inhibited the rHuSCF- and SFB-induced migration of HMC-1. In situ double immunostaining revealed expression of SCF in AS02-positive SFB in the synovium of patients with RA. CONCLUSION: Our results show that SFB (in RA and OA) express SCF and induce MC chemotaxis. Furthermore, TNFalpha was found to augment SCF expression in SFB. It is hypothesized that these cellular interactions play an important role in MC accumulation and related events in RA.
9059141 Increased expression of integrins on fibroblast-like synoviocytes from rheumatoid arthriti 1997 Jan OBJECTIVE: To compare in vitro expression of beta 1, beta 3, and beta 4 integrins in normal fibroblast-like synoviocytes (FBS) and in FBS from rheumatoid arthritis (RA) synovium and to investigate the adhesion of normal FBS and RA-FBS to the integrin binding extracellular matrix (ECM) proteins: collagen type IV, fibronectin, laminin, and tenascin. METHODS: Expression of integrin receptors of cultured FBS was detected by flow cytometry. Attachment of FBS to ECM proteins was quantified by adhesion assays. Inhibition studies were performed using monoclonal antibodies to the integrin subunits. RESULTS: Compared with normal FBS, RA-FBS showed increased expression of alpha 1 to alpha 6, beta 1, and beta 4 integrin subunits and enhanced binding of ECM proteins. Binding to ECM proteins was partly or completely blocked by an anti-beta 1 integrin antibody and antibodies to alpha 3, alpha 5, and alpha 6 integrin subunits. The blocking efficiency was significantly (P < 0.05) higher in RA-FBS than in normal FBS. CONCLUSIONS: The enhanced expression of the beta 1 integrin receptors on cultured RA-FBS correlated with increased attachment to ECM proteins. Adhesion of normal and RA-FBS to ECM proteins is mediated through beta 1 integrin receptors. Therefore, the tight binding of rheumatoid FBS to the matrix via beta 1 integrins might play a role in ECM remodelling in the rheumatoid process in vivo.
10827366 [Treatment of rheumatoid polyarthritis with methotrexate in Dakar: efficacy, tolerance and 2000 Jan Methotrexate (MTX), which has been used for years in cancer treatment, is now being proposed as a first-line treatment for rheumatoid arthritis (RA), despite its potential side effects. The aim of this study was to investigate the short-term efficacy, safety and relative cost of low-dose MTX for the treatment of RA. We carried out an open, nonrandomized trial in which patients received a 7 mg injection of MTX once per week, with clinical and biological follow up. A single physician performed the weekly assessments, which involved evaluation of the duration of morning stiffness, the number of night awakenings, the number of painful and swollen joints and Ritchie's index. Blood cell count and erythrocyte sedimentation rate were determined monthly. Twelve RA patients were enrolled in the trial, over a mean treatment period of 356 +/- 175 days. A significant improvement was observed in all variables except the number of swollen joints. Ritchie's index decreased from a mean of 31.8 +/- 11.85 to 6.5 +/- 8.98 (p<1.6 x 10- 4). Minor adverse reactions were observed but none indicated treatment withdrawal: 6 cases of nausea, 2 of a moderate increase in transaminase activity, 1 of bronchitis, in which the responsibility of MTX was not definitely established and 3 cases in which hemoglobin levels decreased. The monthly cost of the treatment, including the drug itself and laboratory tests, is lower than that of gold salt injection. Three issues of key importance in our region were investigated in this study: 1) the possible desire to become pregnant of female patients undergoing MTX treatment. In addition, some of the young and unmarried patients did not understand or appreciate the contraceptive effects of the treatment; 2) poor compliance with the treatment due to limited financial resources. Many patients did not regularly attend for their follow-up appointments and many stopped taking the medication. One third of the patients were lost to follow-up during this study; 3) the prevalence of chronic hepatitis, which may limit the use of MTX in our region. Serological tests should be performed before the treatment is started and a liver biopsy is recommended for patients with chronic hepatitis B or C.
9506880 Detection of cytokine mRNA in human, articular cartilage from patients with rheumatoid art 1998 Cytokines are signalling glycoproteins mediating acute inflammation, chronic inflammation, and connective tissue destruction. The present study was designed to characterize the profile of cytokine message in normal human articular cartilage and from patients with rheumatoid arthritis (RA) and osteoarthritis (OA), by means of the reverse transcriptase-polymerase chain reaction (RT-PCR). Message RNA (mRNA) was extracted from fresh or frozen cartilage. The results showed expression of mRNA for IL-6, IL-6R, IL-7, IL-8, IL-10, and IL-12 (p35 and p40) exclusively in the RA cartilage. Except for mRNA for IL-8 and IL-10, no other cytokine or cytokine receptor was expressed in OA and control cartilage. mRNA for IL-1beta, IL-4, TNF-alpha, and TNFR-p75, was not detected in any cartilage sample except for one RA specimen expressing IL-1beta mRNA. However, the expression of message for pro-inflammatory cytokines was far more prominent than anti-inflammatory cytokines. This may suggest a disturbed balance of pro- and anti-inflammatory activity in RA cartilage.