Patterns of expression of tumor necrosis factor alpha, tumor necrosis factor beta, and their receptors in synovia of patients with juvenile rheumatoid arthritis and juvenile spondylarthropathy

Treatment of ankylosing spondylitis by inhibition of tumor necrosis factor alpha

BACKGROUND

There are few effective treatments for ankylosing spondylitis, which causes substantial morbidity. Because of the central role of tumor necrosis factor alpha in the spondyloarthritides, we performed a randomized, double-blind, placebo-controlled trial of etanercept, a recombinant human tumor necrosis factor receptor (p75):Fc fusion protein, in patients with ankylosing spondylitis.

METHODS

Forty patients with active, inflammatory ankylosing spondylitis were randomly assigned to receive twice-weekly subcutaneous injections of etanercept (25 mg) or placebo for four months. The primary end point was a composite of improvements in measures of morning stiffness, spinal pain, functioning, the patient's global assessment of disease activity, and joint swelling. Patients were allowed to continue taking nonsteroidal antiinflammatory drugs, oral corticosteriods (< or =10 mg per day), and disease-modifying antirheumatic drugs at stable doses during the trial.

RESULTS

Treatment with etanercept resulted in significant and sustained improvement. At four months, 80 percent of the patients in the etanercept group had a treatment response, as compared with 30 percent of those in the placebo group (P=0.004). Improvements over base-line values for various measures of disease activity, including morning stiffness, spinal pain, functioning, quality of life, enthesitis, chest expansion, erythrocyte sedimentation rate, and C-reactive protein, were significantly greater in the etanercept group. Longitudinal analysis showed that the treatment response was rapid and did not diminish over time. Etanercept was well tolerated, with no significant differences in rates of adverse events between the two groups.

CONCLUSIONS

Treatment with etanercept for four months resulted in rapid, significant, and sustained improvement in patients with ankylosing spondylitis.

Etanercept in the treatment of adult patients with Still's disease

OBJECTIVE

To evaluate the safety and efficacy of etanercept in the treatment of adult patients with Still's disease.

METHODS

Twelve adult patients who met criteria for Still's disease and had active arthritis were enrolled in a 6-month open-label trial of etanercept given in biweekly doses of 25 mg. The mean disease duration at study entry was 10.7 years. All patients had been treated unsuccessfully with other disease-modifying antirheumatic drugs. Efficacy was evaluated according to American College of Rheumatology (ACR) improvement criteria, and adverse events were recorded.

RESULTS

Ten patients successfully completed the study; 2 withdrew due to disease flare. In 4 patients, the dosage of etanercept was increased from 25 mg biweekly to 25 mg 3 times per week. Seven patients met ACR 20% response criteria. Of these 7 responders, 4 met ACR 50% response criteria and 2 met ACR 70% response criteria. Among the 3 patients with systemic features of Still's disease (fever and rash), improvement in these features was seen in 1; the arthritis did not improve in any of these 3 patients. Except in the 2 patients who withdrew due to disease flare (rash, fever, and arthritis), no other significant adverse events occurred.

CONCLUSION

In this initial study of etanercept therapy for Still's disease in the adult, this treatment resulted in improvement in the arthritis and was well tolerated. Additional trials should be performed to elucidate the effects of tumor necrosis factor inhibitors in Still's disease.

Differential effects between marimastat, a TNF-alpha converting enzyme inhibitor, and anti-TNF-alpha antibody on murine models for sepsis and arthritis

We investigated the effects of marimastat, an inhibitor of TNF-alpha converting enzyme and matrix metalloproteinases, and anti-TNF-alpha antibodies on a murine model for sepsis, and on arthritis in human TNF-alpha transgenic mice. Marimastat (25-200 mg/kg) inhibited lipopolysaccharide (LPS)-induced soluble TNF-alpha production in mice in a dose-dependent manner. At an oral dose of 200 mg/kg, marimastat almost completely inhibited LPS-induced soluble TNF-alpha production, but only slightly delayed LPS lethality. On the other hand, anti-TNF-alpha antibodies completely abolished LPS-induced morbidity. In addition, anti-TNF-alpha antibodies, but not marimastat (200 mg/kg/day), inhibited the development of arthritis in human TNF-alpha transgenic mice. These results suggest that cell surface TNF-alpha may be important in the pathogenesis of murine models for sepsis and arthritis.

Therapeutic use of etanercept in polyarticular course juvenile idiopathic arthritis over a two year period

OBJECTIVE

To analyse the treatment response to etanercept in patients with polyarticular course juvenile idiopathic arthritis (JIA).

METHODS

22 patients with polyarticular course JIA (19 females, three males; mean age 13.9 years; mean disease duration 6.3 years; 15 with polyarticular onset, seven with systemic onset, one with residual systemic activity; eight rheumatoid factor positive; eight with erosive disease) were treated with etanercept for up to 24 months. Etanercept was given subcutaneously at 0.4 mg/kg twice a week. Treatment response was ascertained in an open prospective study.

RESULTS

All patients showed impressive clinical improvement, with a decrease in swollen joint count by an average of 10.1 joints (mean of 49% decrease), a decrease in tender joint count by 9.3 joints (mean of 94%), and decrease in total joint count by 11.2 joints (mean of 48%). Duration of morning stiffness decreased to less than 10 minutes. Furthermore, haemoglobin concentration increased on average by 14 g/l (mean of 15.3%) and packed cell volume increased by 0.035 (mean increase of 12%), and erythrocyte sedimentation rate decreased on average by 42.8 mm/1st h (mean decrease of 64%). No major side effects were noted.

CONCLUSION

Etanercept continues to be clinically effective and well tolerated in patients with polyarticular course JIA over a two year period.

Current treatment of juvenile rheumatoid arthritis

Prognostic factors in juvenile rheumatoid arthritis (JRA) include polyarticular onset, polyarticular disease course, and rheumatoid factor positivity; in the systemic onset subtype, persistence of systemic features at 6 months after onset confers a worse prognosis. Timely diagnosis and appropriate aggressive treatment of patients with poor prognostic features improve quality of life and outcome. After nonsteroidal anti-inflammatory drugs, methotrexate is the most commonly used second-line agent. However, approximately one third of patients do not respond to methotrexate adequately. Randomized, placebo-controlled, clinical trials in patients with JRA are few, but one such trial with the tumor necrosis factor inhibitor etanercept shows that this drug is effective and well-tolerated. Other recently approved agents for rheumatoid arthritis, including infliximab, leflunomide, celecoxib, and rofecoxib, have not been adequately studied in pediatric patients, and the role of these agents in children with JRA remains to be determined.

Chemokine Receptor CCR4 on CD4+ T Cells in Juvenile Rheumatoid Arthritis Synovial Fluid Defines a Subset of Cells with Increased IL-4:IFN-γ mRNA Ratios

To understand the mechanisms that promote recruitment and survival of T cells within the pediatric inflamed joint, we have studied the expression of CCR4 and CCR5 on synovial fluid T cells and matched peripheral blood samples from juvenile rheumatoid arthritis (JRA) patients using three-color flow cytometric analysis. Thymus- and activation-regulated chemokine and macrophage-derived chemokine, ligands for CCR4, were measured by ELISA in JRA synovial fluid, JRA plasma, adult rheumatoid arthritis synovial fluid, and normal plasma. IL-4 and IFN-gamma mRNA production was assessed in CD4+/CCR4+ and CD4+/CCR4(-) cell subsets. We found accumulations of both CCR4+ and CCR5+ T cells in JRA synovial fluids and a correlation for increased numbers of CCR4+ T cells in samples collected early in the disease process. Thymus- and activation-regulated chemokine was detected in JRA synovial fluid and plasma samples, but not in adult rheumatoid arthritis synovial fluid or control plasma. Macrophage-derived chemokine was present in all samples. CD4+/CCR4+ synovial lymphocytes produced more IL-4 and less IFN-gamma than CD4+/CCR4(-) cells. These findings suggest that CCR4+ T cells in the JRA joint may function early in disease in an anti-inflammatory capacity through the production of type 2 cytokines and may play a role in determining disease phenotype.

Corticosteroid-Sparing Effect of Etanercept in Idiopathic Panuveitis Resistant to Immunosuppressive Therapy

Uveitis, an inflammatory eye disease with varying immunopathogenic mechanisms, may be associated with autoimmune disorders, may be secondary to infection, or may be idiopathic. Response to treatment of uveitis is inconsistent. In this report we describe an adult with idiopathic panuveitis who attempted to lower his oral corticosteroid dose from intolerable levels but was unable to do so because of the reappearance of symptoms. His 8-year course was managed with ocular and systemic corticosteroids, methotrexate, and cyclosporine, which allowed only partially successful control of his ocular inflammation. Complete control was not achieved until the addition of etanercept. With this case report we are the first to describe the complete response of idiopathic panuveitis to etanercept. Our success with this patient strongly supports the critical role of tumor necrosis factor in the immunopathogenesis of some cases of idiopathic panuveitis. Furthermore, etanercept offers a relatively nontoxic, safe option in cases of panuveitis that are unresponsive to traditional immunosuppressive therapy.

The angiogenic pathway "vascular endothelial growth factor/flk-1(KDR)-receptor" in rheumatoid arthritis and osteoarthritis

Active angiogenesis, together with an up-regulation of angiogenic factors, is evident in the synovium of both rheumatoid arthritis (RA) and osteoarthritis (OA). The present study assessed, by immunohistochemistry, the microvessel density in the synovium of these arthritides and in normal controls, in relation to the expression of the angiogenic factors vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) and the apoptosis-related proteins bcl-2 and p53. More importantly, using the novel 11B5 MAb, the activated "VEGF/flk-1(KDR)-receptor" microvessel density was assessed. VEGF expression in fibroblasts was diffuse in both RA and OA. Diffuse PD-ECGF expression of fibroblasts was noted in all cases of RA, while fibroblast reactivity was focal in the OA material. The standard microvessel density (sMVD), as assessed with the anti-CD31 monoclonal antibody (MAb), was higher in RA (64+/-12) and in OA (65+/-16) than in normal tissues (52+/-8; p=0.008 and 0.0004, respectively). The activated microvessel density (aMVD), assessed with the 11B5 MAb, was significantly higher in RA (29+/-10) than in OA (17+/-4; p<0.0001) and than in normal tissues (14+/-2; p<0.0001). The "activation ratio" (aMVD/sMVD) was statistically higher in RA (0.46+/-0.17) than in OA and normal synovial tissues, the latter two having a similar ratio (0.28+/-0.08 and 0.26+/-0.03, respectively). Cytoplasmic bcl-2 expression was frequent in the synovial cells of OA, but rare in RA. Nuclear p53 protein accumulation was never observed. It is suggested that the angiogenic pathway VEGF/flk-1(KDR) may play an important role in the pathogenesis of RA and OA. Thus, failure of VEGF/flk-1(KDR) activation, in the presence of increased VEGF expression, may indicate a synovium with an impaired capacity to establish a viable vasculature, consistent with the degenerative nature of OA. On the other hand, the activated angiogenesis in RA shows a functional, still pathologically up-regulated VEGF/flk-1(KDR) pathway. Whether restoration of an impaired VEGF/flk-1(KDR) pathway in OA, or inhibition of this in RA, would prove of therapeutic importance requires further investigation.

Etanercept in juvenile rheumatoid arthritis

OBJECTIVE

To review the classification, pathophysiology, safety, and efficacy of treatment options for juvenile rheumatoid arthritis (JRA). Etanercept, the agent most recently approved by the Food and Drug Administration for use in JRA, is featured.

DATA SOURCES

Articles were identified from a search of the MEDLINE database (1966 to January 2000) and through secondary sources. Meeting abstracts and posters were also evaluated.

STUDY SELECTION AND DATA EXTRACTION

Articles identified and retrieved from data sources were evaluated and, if determined to be relevant, were included in this review.

DATA SYNTHESIS

JRA represents a major cause of functional disability in children. In contrast to traditional therapeutic agents for JRA, which act through generalized antiinflammatory activity or generalized immunosuppression, new therapeutic modalities have been developed that target specific molecules involved in the pathophysiology of JRA. Etanercept inhibits the activity of tumor necrosis factor and lymphotoxin-alpha. In a clinical trial of patients with polyarticular-course JRA, etanercept-treated patients experienced less pain and swelling in their joints, decreased incidence of disease activity, less frequent flare, and a longer time to flare than patients receiving placebo. Treatment with etanercept was generally well-tolerated.

CONCLUSIONS

Etanercept represents an exciting new therapeutic option for the treatment of JRA. The positioning of etanercept among other therapeutic options for JRA will be more clearly established as additional safety and efficacy data are made available.

T-cell and T-cell receptor abnormalities in the immunopathogenesis of juvenile rheumatoid arthritis

Several lines of indirect evidence suggest that the pathologic autoimmune responses in juvenile rheumatoid arthritis may be antigen-driven and T cell-mediated. These include (1) activation markers expressed on synovial T cells suggestive of previous activation in vivo; (2) persistent oligoclonally expanded T-cell populations accumulating preferentially in the synovial compartment; (3) some T-cell receptor complementarity-determining region 3 sequence similarities between different clones in an individual patient; and (4) T-cell derived cytokines of predominantly Th1 type. Whether T-cell contribution is limited to only early stages of the disease (as appears to be the case in collagen-induced arthritis) or T cells are required for the perpetuation of the inflammation at later stages as well, still remains to be determined.

Use of biologics in the treatment of childhood rheumatic diseases

Over the last two decades, progression in the knowledge of molecular biologic techniques has led to a better understanding of immunopathogenesis and identification of several cytokines, which propagate chronic arthritis in both adult and pediatric patients. A number of biologic agents have been developed in targeting different immune markers or mediators with the hope that they may help in controlling the inflammation in the group of patients who are resistant to disease-modifying antirheumatic drugs (DMARDs) and may alter the natural history of the diseases. Tumor necrosis factor (TNF)-alpha is the first to be targeted and its antagonists have been approved. Other biologic agents targeting different markers/mediators have followed and have been tested in clinical trials especially in adult rheumatoid arthritis (RA). Experiences in pediatric use are limited and agents proved to be effective in adult RA are not always transferred the same efficacy in different subtypes of juvenile idiopathic arthritis (JIA). It is reasonable to see the efficacy, and more importantly the safety profiles of each agent before the decision is made to use them in children. This article reviews the published and anecdotal reports of biologic agents that have been used in children with JIA and also focuses on the potential use of other biologic agents in JIA that have been used in trials to combat adult RA.

Etanercept in children with polyarticular juvenile rheumatoid arthritis. Pediatric Rheumatology Collaborative Study Group

BACKGROUND

We evaluated the safety and efficacy of etanercept, a soluble tumor necrosis factor receptor (p75):Fc fusion protein, in children with polyarticular juvenile rheumatoid arthritis who did not tolerate or had an inadequate response to methotrexate.

METHODS

Patients 4 to 17 years old received 0.4 mg of etanercept per kilogram of body weight subcutaneously twice weekly for up to three months in the initial, open-label part of a multicenter trial. Those who responded to treatment then entered a double-blind study and were randomly assigned to receive either placebo or etanercept for four months or until a flare of the disease occurred. A response was defined as an improvement of 30 percent or more in at least three of six indicators of disease activity, with no more than one indicator worsening by more than 30 percent.

RESULTS

At the end of the open-label study, 51 of the 69 patients (74 percent) had had responses to etanercept treatment. In the double-blind study, 21 of the 26 patients who received placebo (81 percent) withdrew because of disease flare, as compared with 7 of the 25 patients who received etanercept (28 percent) (P=0.003). The median time to disease flare with placebo was 28 days, as compared with more than 116 days with etanercept (P<0.001). In the double-blind study, there were no significant differences between the two treatment groups in the frequency of adverse events.

CONCLUSIONS

Treatment with etanercept leads to significant improvement in patients with active polyarticular juvenile rheumatoid arthritis. Etanercept is well tolerated by pediatric patients.

Cytokine, activation marker, and chemokine receptor expression by individual CD4(+) memory T cells in rheumatoid arthritis synovium

IL-10, IL-13, IFN-gamma, tumor necrosis factor (TNF)-alpha, LT-alpha, CD154, and TNF-related activation-induced cytokine (TRANCE) were expressed by 2-20% of rheumatoid arthritis (RA) synovial tissue CD4(+) memory T cells, whereas CD4(+) cells that produced IL-2, IL-4, or IL-6 were not detected. Expression of none of these molecules by individual CD4(+) cells correlated with the exception of TRANCE and IL-10, and TRANCE and TNF-alpha. A correlation between expression of IL-10 and CCR7, LT-alpha and CCR6, IFN-gamma and CCR5, and TRANCE and CXCR4 was also detected.

Autocrine induction of gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) and GLS-induced expression of matrix metalloproteinases in rheumatoid arthritis synoviocytes

OBJECTIVE

The purpose of this study was to examine how gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) is involved in the molecular mechanism of cartilage degradation in rheumatoid arthritis (RA) with special reference to the GLS-induced gene expression and protein synthesis of matrix metalloproteinase (MMP)-1 (collagenase-1) and MMP-3 (stromelysin-1).

METHODS

Fibroblast-like synoviocytes (FLSs) obtained from RA patients were cultured and stimulated by GLS. Changes in the expression levels of GLS, MMP-1 and MMP-3 were assessed by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) for GLS, and by RT-PCR and enzyme-linked immunosorbent assay for MMPs and tissue inhibitor of metalloproteinase 1.

RESULTS

GLS demonstrated a self-induction of mRNA in cultured RA FLSs. GLS evoked a dose-dependent induction of MMP-1 and MMP-3 mRNAs, and subsequently their extracellular secretion.

CONCLUSION

These findings suggest that GLS is a plausible pathogenic factor causing the extensive joint destruction in RA mediated via MMPs.

Fibroblast-Like Synoviocytes from Rheumatoid Arthritis Patients Have Intrinsic Properties of Follicular Dendritic Cells

The production of IgG rheumatoid factors in the inflamed synovium of many patients with rheumatoid arthritis (RA) implies that local sites exist where plasma cell precursors undergo isotype switching and affinity maturation by somatic mutation and selection. Lymphonodular infiltrates of the synovium-containing germinal centers (GCs), are candidates to fulfill such function in the rheumatoid patient. It has been suggested that these GCs are organized around, obviously ectopic, follicular dendritic cells (FDCs). The present study attempts to find out whether these putative FDCs 1) are specific for RA, 2) have the same phenotype and functional capacity as FDCs in lymphoid organs, and 3) may locally differentiate from fibroblast-like synoviocytes (FLS). Synovial biopsies from patients with RA versus non-RA, yet arthritic backgrounds, were compared. Cells with the FDC phenotype were found in both RA and non-RA tissues as well as in single cell suspensions thereof. When FLS were cultured in vitro, part of these cell lines could be induced with IL-1β and TNF-α to express the FDC phenotype, irrespective of their RA or non-RA background. By contrast, the FDC function, i.e., stable binding of GC B cells and switching off the apoptotic machinery in B cells, appeared to be the prerogative of RA-derived FLS only. The present data indicate that FDC function of FLS in RA patients is intrinsic and support the idea that synovial fibroblast-like cells have undergone some differentiation process that is unique for this disease.