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Biomedical subjects

E Keystone

Publications and source records attributed to E Keystone.

At least 19 recordsLinked to original sources
PubMed2006

Safety of the selective costimulation modulator abatacept in rheumatoid arthritis patients receiving background biologic and nonbiologic disease-modifying antirheumatic drugs: A one-year randomized, placebo-controlled study.

OBJECTIVE: To assess the safety of abatacept, a selective costimulation modulator, in patients with active rheumatoid arthritis (RA) who had been receiving > or =1 traditional nonbiologic and/or biologic disease-modifying antirheumatic drugs (DMARDs) approved for the treatment of RA for at least 3 months prior to entry into the study. METHODS: This was a 1-year, multicenter, randomized, double-blind, placebo-controlled trial. Patients were randomized 2:1 to receive abatacept at a fixed dose approximating 10 mg/kg by weight range, or placebo. RESULTS: The abatacept and placebo groups exhibited similar frequencies of adverse events (90% and 87%, respectively), serious adverse events (13% and 12%, respectively), and discontinuations due to adverse events (5% and 4%, respectively). Five patients (0.5%) in the abatacept group and 4 patients (0.8%) in the placebo group died during the study. Serious infections were more frequent in the abatacept group than in the placebo group (2.9% versus 1.9%). Fewer than 4% of patients in either group experienced a severe or very severe infection. The incidence of neoplasms was 3.5% in both groups. When evaluated according to background therapy, serious adverse events occurred more frequently in the subgroup receiving abatacept plus a biologic agent (22.3%) than in the other subgroups (11.7-12.5%). CONCLUSION: Abatacept in combination with synthetic DMARDs was well tolerated and improved physical function and physician- and patient-reported disease outcomes. However, abatacept in combination with biologic background therapies was associated with an increase in the rate of serious adverse events. Therefore, abatacept is not recommended for use in combination with biologic therapy.

Abatacept↗
PubMed2004

Infliximab in active early rheumatoid arthritis.

OBJECTIVE: To examine the impact of the combination of infliximab plus methotrexate (MTX) on the progression of structural damage in patients with early rheumatoid arthritis (RA). METHODS: Subanalyses were carried out on data for patients with early RA in the Anti-TNF Therapy in RA with Concomitant Therapy (ATTRACT) study, in which 428 patients with active RA despite MTX therapy received placebo with MTX (MTX-only) or infliximab 3 mg/kg or 10 mg/kg every (q) 4 or 8 weeks with MTX (infliximab plus MTX) for 102 weeks. Early RA was defined as disease duration of 3 years or less; 82 of the 428 patients (19%) met this definition. Structural damage was assessed with the modified van der Heijde-Sharp score. The changes from baseline to week 102 in total modified van der Heijde-Sharp score were compared between the infliximab plus MTX groups and the MTX-only group. RESULTS: The erosion and joint space narrowing scores from baseline to week 102 in the cohort of patients with early RA decreased significantly in each infliximab dose regimen compared with the MTX-only regimen. Consistent benefit was seen in the joints of both hands and feet. CONCLUSIONS: Infliximab combined with MTX inhibited the progression of structural damage in patients with early RA during the 2 year period of treatment. Early intervention with infliximab in patients with active RA despite MTX therapy may provide long term benefits by preventing radiographic progression and preserving joint integrity.

Acute Disease↗
PubMed2001

Current and emerging therapies for rheumatoid arthritis, with a focus on infliximab: clinical impact on joint damage and cost of care in canada.

BACKGROUND: Rheumatoid arthritis (RA) is a physically debilitating disease that places an enormous burden not only on individuals and their families but also on the economy. Affecting -1% of the Canadian population, RA is characterized by pain and swelling of joints. Without effective treatment, RA results in joint destruction that often requires surgery. OBJECTIVE: This review summarizes the effect of current and new RA treatments on joint damage, with a focus on infliximab. The health-economic repercussions and potential impact of arresting the joint destruction of RA are discussed. METHODS: Information for inclusion in this review was identified through searches of the MEDLINE and HealthStar databases from 1995 to 2000. Search terms included rheumatoid arthritis, treatment guidelines, economics, and individual drug names. RESULTS: Standard initial RA drug therapy has been aimed at reducing pain and inflammation, whereas use of the more potent disease-modifying antirheumatic drugs (DMARDs) has been reserved for later stages of disease. More aggressive RA treatment involves introducing DMARDs at the earliest stage. The largest single direct cost of RA involves hospital admissions for the correction of joint deformities. Among newer therapies, the anti-tumor necrosis factor-alpha agent infliximab has been shown to arrest radiographic measures of disease progression. CONCLUSIONS: With early and aggressive treatment involving new drugs and drug combinations, it may be possible to ameliorate the physical, social, and economic effects of RA.

Adult↗
PubMed2000

Biologic agents in the treatment of rheumatoid arthritis.

Advances in the understanding of the pathogenesis of rheumatoid arthritis (RA) as well as improved biotechnology has enabled selective targeting of the pathogenic elements of disease. Targeting cell recruitment through adhesion molecules has been shown to be successful in pre-clinical murine models. Results of studies of an anti-ICAM-1 monoclonal antibody and anti-sense oligonucleotides have been encouraging. An alternate approach to inhibiting recruitment has been the targeting of chemoattractant molecules ie. chemokines. Important advances have been made in cytokine directed therapy targeting TNFalpha and IL-1. TNF antagonists (anti-TNF monoclonal antibody/soluble TNF receptor Fc fusion protein) have resulted in rapid and substantial improvement in signs and symptoms of disease as well as disease modification, shown by slowing of radiological progression. IL-1 receptor antagonist protein appears to have a significant effect on radiological progression despite a modest effect on symptoms and signs. Studies using anti-inflammatory cytokines such as IL-10 are in progress. A more recent therapeutic approach has been to target T-cell activation by interfering with co-stimulatory complexes such as CD40L/CD40 and CD28/CD80 and CD86. Both pre-clinical and preliminary clinical studies in human subjects support the concept. Another approach involving T-cell receptor peptide vaccination with VB peptides over-utilized in RA synovium has shown to be beneficial. Targeting the cytokines driving T-cells in the RA synovium ie. IL-12 & IL-15 has also proven beneficial in animal studies. Recent attention has also been directed toward the invading synovial fibroblast using Fas-FasL mediated apoptosis. Pre-clinical studies in which angiogenesis and osteoclast activation are targeted have been encouraging. In conclusion, the proof of principle has been established that selective targeting of pathogenic elements of disease results in substantial improvement in signs and symptoms as well as disease progression. Improved efficacy is expected with more aggressive targeting of the pathogenic elements.

Animals↗
PubMed2000

Granulomatous hypophysitis due to Wegener's granulomatosis.

We describe the MR image findings in a case of granulomatous hypophysitis due to Wegner's granulomatosis. A high index suspicion of hypophysitis based on imaging findings allowed successful medical management and helped avoid surgery. The MR imaging features included a thickened stalk, a diffusely and uniformly enlarged gland, a normal size or minimally enlarged sella, and enhancement of the optic chiasm.

Female↗
PubMed1999

Recapitulation of the round-table discussion--assessing the role of anti-tumour necrosis factor therapy in the treatment of rheumatoid arthritis.

Clinical trials specifically targeting and neutralizing the cytokine, tumour necrosis factor (TNF), have recently provided evidence of efficacy and a promise of a novel approach for the treatment and management of rheumatoid arthritis (RA). With the evolving emergence of anti-TNF therapeutics, several unresolved issues have come to light, including the assessment of safety and efficacy of current therapies, study design for new agents and cost-benefit issues. During an international meeting of leading rheumatologists and specialists, the majority opinion regarding the use of anti-TNF therapy was that these agents are most appropriate in patients with active disease who have insufficient response to methotrexate, which is presently considered the standard for RA treatment. Anti-TNF therapy was also recommended in patients with active disease unable to tolerate methotrexate therapy, or who have not responded to at least two other disease-modifying anti-rheumatic drugs (DMARDs). In patients with RA who have serious infection or malignancy, the use of anti-TNF therapies was not advised. Time, experience and clinical data from recently completed and currently ongoing studies of infliximab and etanercept, which will be available in the future, will help determine the ultimate role of such targeted therapeutics. Additional data on anti-TNF therapeutics as monotherapy or in various combinations are still needed to achieve maximum disease control safely with currently available DMARDs.

Antirheumatic Agents↗
PubMed1998

Biologic agents and immunotherapy in rheumatoid arthritis. Progress and perspective.

Advances in our understanding of rheumatoid synovitis have been coupled with increasingly refined methods from biotechnology to produce promising therapeutic agents. Monoclonal antibodies (MoAbs), recombinant cytokines, cytokine receptor fusion proteins and other biologics have been elevated from the status of novel reagents applied in phase I toxicity trials to, in some cases, substantially evaluated and validated tools awaiting federal regulatory approval. Biologic agents will soon be released for the treatment of patients with RA. We review some of the most promising preclinical work that supports a position of optimism regarding the future of RA. We also speculate on the potential role for biologics in future management of patients with RA.

Arthritis, Rheumatoid↗
PubMed1998

IL-10 as a therapeutic strategy in the treatment of rheumatoid arthritis.

IL-10 has anti-inflammatory and immunoregulatory properties that suggest a potential therapeutic role in RA. IL-10 inhibits proinflammatory cytokine and chemokine production in addition to blocking T-cell responses to specific antigens. It acts primarily through inhibition of costimulatory properties of macrophages. IL-10 stimulates proliferation and differentiation of antibody-forming B-cells. Preclinical studies in a variety of animal models, including collagen-induced arthritis, have shown that IL-10 is effective in preventing or inhibiting inflammation and autoreactivity. Although in RA, circulating and synovial levels of IL-10 are increased, accumulated evidence suggests that there may be a relative deficit of available IL-10. Moreover, exogenous addition of IL-10 in vitro has been shown to affect the immunopathological processes involved in RA. Preliminary studies of human recombinant IL-10 in patients with RA have demonstrated a trend towards efficacy with a good safety profile. Taken together, the data support a therapeutic role for IL-10 in the treatment of RA.

Arthritis, Rheumatoid↗
PubMed1996

Biologic agents for the treatment of rheumatoid arthritis.

Substantial progress has been made in our understanding of the immune system and immunopathogenesis of rheumatoid arthritis. This knowledge, combined with advances in biotechnology, has resulted in the development of biologic agents to selectively target elements of the immune system participating in the inflammatory response. This article reviews the available data from clinical trials of biologic agents for the treatment of rheumatoid arthritis. Randomized controlled trials comparing administration of a biologic agent to placebo are emphasized. Despite concerns raised by initial trials with these agents, they still offer the most promise as treatments for autoimmune diseases ++such as rheumatoid arthritis.

Antigens, Surface↗
PubMed1994

Outcome of polyarteritis nodosa and Churg-Strauss syndrome. An analysis of twenty-five patients.

OBJECTIVE: To compare outcome in patients with polyarteritis nodosa (PAN) and patients with Churg-Strauss syndrome (CSS) followed up at a single center. METHODS: A retrospective data review of 13 patients with PAN and 12 patients with CSS who were followed up at a vasculitis clinic. Outcome measures included a global damage index, disability and pain dimensions of the Health Assessment Questionnaire, and mortality rate. RESULTS: Compared with patients with CSS, patients with PAN had a significantly higher mean damage index score (5.15 versus 2.42; P = 0.011), a higher disability score (1.09 versus 0.16; P = 0.007), and a higher pain score (1.04 versus 0.01; P = 0.017). Patients with PAN had more relapses (relative risk = 5.07; P < 0.000) and a higher mortality rate (31%) compared with patients with CSS (8%). CONCLUSION: PAN and CSS differ in their morbidity and mortality; therefore, they should be considered as distinct clinical entities.

Adult↗
PubMed1994

A role for CD4+ T cells in the pathogenesis of skin fibrosis in tight skin mice.

The tight skin (Tsk/+) mouse represents a murine model of heritable fibrosis with some similarities to the skin fibrosis seen in human scleroderma. Tsk/+ animals display alterations in connective tissue in some internal organs. Skin fibrosis can be adoptively transferred to normal recipients with Tsk/+ bone marrow or spleen cells and older Tsk/+ animals develop autoantibodies against topoisomerase suggesting that some of the pathogenesis in the Tsk/+ mouse may be mediated by autoimmunity. To determine the role of T cell subsets in the pathogenesis of fibrotic disease, Tsk/+ mice were bred with CD4- and CD8-deficient (CD4-/- and CD8-/-) mice. Tsk/+ CD4-/- mice showed a marked reduction in skin fibrosis as well as decreased cellularity and only mild collagen disorganization as compared to Tsk/+ CD4+ CD8+ control mice yet did not differ from Tsk controls in the level of serum anti-topoisomerase activity. In contrast, Tsk/+ CD8-/- mice exhibited the same histology in the skin as Tsk/+ controls yet had significantly reduced levels of serum anti-topoisomerase activity. Lung pathology, i.e. emphysema, was unaffected by both the CD4 or CD8 mutations. These data show that only some of the pathological effects of the Tsk mutation are T cell dependent and that different T cell subsets affect different parameters in this multi-organ model of fibrotic disease.

Animals↗
PubMed1994

Is there a relationship between autoantibodies and silicone-gel implants?

The present study was conducted to determine if 200 patients with silicone-gel implants demonstrated elevated levels of autoantibodies, compared with a similar group of 100 age-matched control subjects without breast implants. These results were then compared with 29 patients who had demonstrated implant rupture. Differences in the frequency of autoantibody levels were determined by the chi-squared test. Differences in autoantibody titers were determined by Wilcoxon's signed rank test. Differences were considered significant with p > 0.05. The prevalence of a positive antinuclear antibody (ANA) test (dilution 1:100) in the 200 patients with breast implants was 26.5% compared with 28% in the 100 control subjects. In 29 patients with implant rupture, only 17.2% tested ANA positive. These values were not significantly different. In addition, there were no significant differences between the ANA titers of positive patients in each group. In each of the three groups, all patients who tested ANA positive were analyzed to assess the frequency and titer of other autoantibodies, including anti-DNA, anti-cardiolipin, anti-SSA, anti-SSB, anti-SM, anti-RNP, and anti-Scl-70. There were no significant differences between the frequency or titer of any of these autoantibody levels in each of the three groups of patients. These studies strengthen the concept that there is no conclusive evidence that silicone-gel implants are related to the development of connective tissue disease.

Adult↗
PubMed1994

Factors affecting the rupture of silicone-gel breast implants.

Between January 1990 and April 1993, over 500 patients with silicone-gel breast implants were clinically assessed regarding their implant status. Of these, 57 patients requested implant removal. Reasons for removal were capsular contracture (39 patients), possible implant rupture, suggested by ultrasound testing or mammography (7 patients), "silicone phobia" (7 patients), and asymmetry (4 patients). Of the 102 implants that were removed, 60% were intact, 33% were ruptured, and 7% were leaking. There was a positive correlation between duration of implantation time and the number of ruptured and leaking implants. Of the 45 implants that had been in place for 5 years or less, 93% were intact. Of the 29 implants that had been in place for 6 to 10 years, only 31% were intact (59% were ruptured and 10% were leaking). Similar results were obtained in 20 implants after 11 to 15 years (30% were intact, 55% were ruptured, and 15% were leaking). Of 8 implants that were in place for 16 to 26 years, 50% were intact and 50% were ruptured. In this study, the integrity of breast implants was not related to the degree of capsular contracture.

Adult↗
PubMed1993

Are antibodies reactive with chondrocyte proteins enriched in synovial fluids of patients with rheumatoid arthritis?

In this study we examined the reactivity of synovial fluid (SF) antibodies (Abs) from patients with rheumatoid arthritis (RA) against chondrocyte proteins. The levels of IgG, IgM and IgA in the synovial fluids varied from patient to patient, but were similar to the levels found in each individual's serum. Although the Abs in SF and serum of RA patients reacted with several molecular weight classes of chondrocyte proteins, this reactivity was very low. Synovial fluid and serum Abs from the same patients reacted with similar chondrocyte proteins and to a similar extent, suggesting that the level of Abs reactive with chondrocyte proteins is not enriched in the SF. These data demonstrate that SF from RA patients contain high levels of Abs, however, there is very little reactivity with chondrocyte proteins beyond that observed in serum of normal and RA patients.

Animals↗
PubMed1993

Antigen-specific human T-cell colony formation in a liquid culture system.

We have developed a limiting dilution microculture T-cell cloning technique to generate antigen-specific T-cell clones. Cultures contained peripheral blood T-cells, irradiated autologous mononuclear cells (feeders), human AB serum and recombinant IL-2. Colonies were enumerated at 14 days. Under these conditions the cloning efficiency expressed as the frequency of proliferating cells in response to PHA, ranged from 1/1.07 to 1/3.35. In response to tetanus toxoid, the frequency of proliferating cells ranged from 1/415 to 1/5655. Average colony size ranged from 0.7 x 10(5) to 6.2 x 10(5) cells with a mean T-cell recovery of 2.5 x 10(5) cells per microculture. Restimulation of 14-day tetanus toxoid T-cell colonies revealed marked proliferation to PHA and tetanus toxoid but only background responses to PPD. These studies document the development of a rapid, antigen-specific liquid culture T-cell cloning system which is likely to detect T-cell clones that are representative of the original T-cell population. The clones are of sufficient size to be useful in studies of antigen cross-reactivity.

Cells, Cultured↗
PubMed1991

Reconstitution of impaired autologous mixed lymphocyte reactivity in rheumatoid arthritis.

We examined the ability of recombinant IL-2 to reconstitute the autologous mixed lymphocyte reaction (AMLR) defect in peripheral blood mononuclear cells (PBM) from patients with rheumatoid arthritis (RA). Our results revealed an ability to fully reconstitute RA AMLRs with pharmacologic concentrations (100 units/ml), but not physiologic concentrations (10 units/ml) of IL-2. Full reconstitution of RA AMLRs was achieved whether IL-2 was added as the initiation of culture or at 48 or 72 hours prior to termination of the cultures. Impaired IL-2 production was noted throughout the time course of the RA AMLRs. Neither an inhibitor of IL-1 nor IL-2 was detected in AMLR culture supernatants. Moreover, IL-1 in pharmacologic concentrations up to 50 units/ml failed to reconstitute impaired AMLR reactivity. In 2 patients whose AMLRs failed to reconstitute fully with 100 units/ml IL-2, addition of 10 units/ml IL-1 in combination with IL-2 fully reconstituted the AMLR defect. The results may suggest that defective IL-2 generation alone cannot fully account for impaired AMLR reactivity in RA patients.

Arthritis, Rheumatoid↗