Search PubMed⌕ Search

Biomedical subjects

E H Choy

Publications and source records attributed to E H Choy.

At least 19 recordsLinked to original sources
PubMed2006

Fatigue in rheumatoid arthritis reflects pain, not disease activity.

OBJECTIVE: We determined the amount of fatigue experienced by patients with RA, and its relationship to synovitis, pain and other common clinical features. We also examined to what extent RA fatigue is improved by disease-modifying antirheumatic drugs (DMARDs) and anti-tumour necrosis factor (TNF) therapy. METHODS: We studied two cohorts of 238 and 274 RA patients cross-sectionally and examined treatment responses in 30 RA patients starting anti-TNF and 54 starting DMARDs followed for 3 and 6 months. We measured fatigue using visual analogue scores (VAS) and Medical Outcomes Study Short Form 36 (SF-36) vitality scores. We recorded the disease activity score for 28 joints and its components (tender/swollen joint counts, patient global assessment, ESR), morning stiffness, health assessment questionnaire, physician global assessment, erosive disease, nodules, rheumatoid factor, concomitant medications and illnesses, and the SF-36 questionnaire. RESULTS: Fatigue was common in RA patients; over 80% had clinically relevant fatigue (VAS > or =20 mm), over 50% had high levels (VAS > or =50 mm). It was associated with pain and changes in mental health, particularly depression. In each of the two cross-sectional cohorts, this relationship was similar whichever measures of fatigue and mental health were used. Fatigue fell with DMARDs and anti-TNF: before treatment, 87% of patients had high fatigue, after treatment this fell to 50%. These treatment effects were mainly linked to improvements in pain. CONCLUSIONS: High fatigue levels characterize RA and are mainly linked to pain and depression. The association with disease activity is secondary. Fatigue falls with DMARD and anti-TNF therapy. The balance of evidence suggests that fatigue is centrally mediated in established RA.

Adult↗
PubMed2006

Joint inflammation and cytokine inhibition in rheumatoid arthritis.

The hallmark of rheumatoid arthritis (RA) is chronic synovial inflammation resulting in progressive joint damage. Cytokines are key mediators of inflammation and can be found in abundance both in the joint and blood of patients with active disease. They are responsible not only for the destructive synovitis but also for some of the systemic features. Research over the last 2 decades has highlighted the important role of cytokines such as tumour necrosis factor alpha (TNF-alpha) and interleukins (IL) 1, 6 and 15 in the pathogenesis of RA and these are potential therapeutic targets. Inhibitors of TNF-alpha and IL-1 are already licensed treatments for RA. Novel biologic agents targeting IL-6 and -15 are currently being developed and showed promise in early clinical trials. This article reviews the role of various cytokines in the pathogenesis of RA and the therapeutic effect of inhibiting these cytokines.

Animals↗
PubMed2005

A two year randomised controlled trial of intramuscular depot steroids in patients with established rheumatoid arthritis who have shown an incomplete response to disease modifying antirheumatic drugs.

BACKGROUND: In rheumatoid arthritis (RA), intramuscular (IM) pulsed depomedrone expedites an immediate response to disease modifying antirheumatic drugs (DMARDs). Although IM depomedrone is also widely used to treat disease flares in patients treated with DMARDs, its effect on radiological progression has not been assessed. OBJECTIVE: To evaluate the benefits of 120 mg IM depomedrone versus placebo in patients with established RA whose disease was inadequately controlled by existing DMARDs. METHODS: In a 2 year prospective randomised controlled trial patients were assessed using the ILAR/WHO core dataset, disease activity score (DAS28), x ray examination of hands and feet scored by Larsen's method, and bone densitometry. RESULTS: 291 patients with RA were screened, 166 were eligible, and 91 consented and were randomised. Disease activity improved more rapidly in the steroid treated patients than with placebo, but after 6 months no difference remained. A small but significant reduction in erosive damage in the steroid group compared with placebo was also found. More adverse reactions occurred in the steroid treated group than in the placebo patients (55 v 42), especially those reactions traditionally related to steroids (16 v 2), including vertebral fracture, diabetes, and myocardial infarction. Hip bone density fell significantly in steroid treated but not placebo patients. CONCLUSIONS: IM depomedrone improved disease activity in the short term and produced a small reduction in bone erosion at the cost of a significant increase in adverse events. Despite the initial benefit of IM depomedrone, when patients respond suboptimally to a DMARD they should not be given long term additional steroids but should be treated with alternative or additional DMARDs.

Adult↗
PubMed2005

Are clinical trials in rheumatoid arthritis generalizable to routine practice? A re-evaluation of trial entry criteria.

OBJECTIVE: Trials of disease-modifying anti-rheumatic drugs (DMARDs) enrol active rheumatoid arthritis patients identified using standard criteria (three out of four of: >/=6 tender joints, >/=6 swollen joints, ESR >/= 28 mm/h, >/=45 min morning stiffness). Concern has been expressed about generalizability, as many patients in routine practice have less active disease. Furthermore, these criteria do not map onto standard disease activity and treatment response measures. We examined how many routine patients were sufficiently active to meet trial recruitment criteria and whether alternative definitions of active disease were more appropriate. METHODS: We studied 504 patients in a cross-sectional study, 156 in a longitudinal study and 94 starting new DMARDs or biologics. Patients were classified as 'trial active' (met entry criteria), in remission or 'intermediately active' (between the two). We also evaluated the effect of amendments to criteria. RESULTS: Cross-sectionally only 38% patients were 'trial active', but longitudinally 68% were 'trial active' at least once. Thus, many clinic patients do have disease activity below the level required for trial entry, but over time most reach eligibility levels. More (62%) of the cohort starting new treatment were 'trial active', suggesting that recruitment criteria relate to clinical decisions. Criteria omitting morning stiffness and a disease activity score (DAS28) >/=5.4 replicated the classification given by current criteria. CONCLUSIONS: Trial results can be generalized to routine practice because most clinic patients are 'trial active' when their therapy is changed and most become 'trial active' over time. As DAS-based criteria are simpler and relate directly to response measures, their use should be considered in future.

Adolescent↗
PubMed2001

Control of rheumatoid arthritis by oral tolerance.

OBJECTIVE: Previous randomized controlled trials for treatment of rheumatoid arthritis (RA) with acid-soluble chicken and bovine type II collagen (CII) have produced conflicting results. This randomized, double-blind, controlled trial examined the therapeutic effect of bovine CII tablets in RA. METHODS: CII tablets were prepared by adsorption onto a lactose base. Patients with a duration of RA of > or = 2 years and who had failed treatment with at least 1 slow-acting drug were recruited, provided that they had active arthritis. Patients were randomly assigned to receive either 0.05 mg, 0.5 mg, or 5 mg of CII or placebo daily for 6 months. All slow-acting drugs were stopped at least 4 weeks before starting CII, although prednisolone was permitted at dosages < 10 mg/day. Clinical assessments were performed at screening and at 0, 1, 4, 8, 12, 16, 20, and 24 weeks of treatment. RESULTS: Fifty-five patients were recruited. Initially, there were no significant differences in mean Disease Activity Scores between groups. At 24 weeks, there was a significant difference (P = 0.041, by Kruskal-Wallis analysis of variance); the major components of this difference were attributable to relatively large decreases in the 0.5 mg CII group (19% of initial values) and to minimal decreases in patients receiving placebo (3% of initial values). Twenty patients had American College of Rheumatology 20% responses; 11 of these were in the 0.5 mg CII group and 3 were in each of the other groups, a significant difference (chi2 = 14.6, P = 0.002). There was no significant difference in any clinical measure between the placebo, 0.05 mg CII, and 5 mg CII groups. There were no side effects associated with CII treatment. CONCLUSION: Treatment with 0.5 mg/day of bovine CII is well tolerated and produces small, but significant, disease improvement in RA. However, the therapeutic window is narrow. The difference between our results and those of other trials may relate to the dose, species, and formulation of the CII.

Administration, Oral↗
PubMed2001

Use of two-dimensional gel electrophoresis to measure changes in synovial fluid proteins from patients with rheumatoid arthritis treated with antibody to CD4.

Synovial fluid proteins from microliter volumes of synovial fluid were resolved by two-dimensional polyacrylamide gel electrophoresis and detected by silver staining to investigate the feasibility of using two-dimensional (2D) electrophoresis in the clinical research setting and provide global disease information of disease progression. Several hundred proteins could be resolved as spots, many of which displayed the characteristic pattern of plasma-derived glycoproteins. The lowest level of detection was approximately 0.2 ng from a total of 50 microg of protein loaded. Most of the proteins could be identified on the basis of pI and molecular weight when compared with plasma protein maps on the World Wide Web. Unknown proteins were characterized by mass spectrometry of tryptic digests and by comparison with peptide databases. Synovial fluids from patients with rheumatoid arthritis were analyzed using this technique. Each subject received a fixed dose of antibody to CD4 as part of a phase II clinical trial to determine the efficacy of this immunosuppressive treatment in modifying disease activity. Synovial fluid was removed at day 0, followed by administration of antibody. Subsequent removal of synovial fluid and additional administration of antibody were carried out at different times thereafter. Changes in levels of acute-phase proteins were quantified by densitometry of silver-stained 2D polyacrylamide gels. Other parameters of disease progression such as serum C-reactive protein and physician's global assessment of clinical condition were used for comparison. In this way, changes in acute-phase proteins towards normal levels, as measured by 2D polyacrylamide gel electrophoresis, could be correlated with clinical improvement and conventional clinical chemistry measurements. Thus, the system can be used for quantitative analysis of protein expression in sites of autoimmune disease activity such as the synovial fluid of rheumatoid arthritis patients.

Acute-Phase Proteins↗
PubMed2000

Pharmacokinetic, pharmacodynamic and clinical effects of a humanized IgG1 anti-CD4 monoclonal antibody in the peripheral blood and synovial fluid of rheumatoid arthritis patients.

BACKGROUND: CD4(+) T cells are important mediators in the pathogenesis of rheumatoid arthritis (RA). In this open-label, dose-escalating study, we examined the pharmacokinetic (PK), clinical, biological and immunological effects of a humanized IgG1 anti-CD4 monoclonal antibody (mAb), 4162W94, in the peripheral blood (PB) and synovial fluid (SF) of RA patients. METHOD: Twenty-four patients in four cohorts (six patients in each cohort) were allocated to be treated with five consecutive daily doses of 4162W94 (10, 30, 100 or 300 mg i.v.). Disease activity was measured by the American College of Rheumatology (ACR) criteria and disease activity score (DAS). We also measured 4162W94 concentration, the percentage of 4162W94-coated CD4(+) lymphocytes, percentage down-modulation of CD4, interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFalpha) levels in the PB and SF. RESULTS: A direct relationship between 4162W94 dose, biological response and clinical outcome was seen. Treatment with 10 and 30 mg of 4162W94 for 5 consecutive days resulted in transient coating and down-modulation of CD4(+) lymphocytes, with little effect observed beyond the final dose. However, treatment with 100 and 300 mg resulted in sustained coating and/or down-modulation for 3 weeks and 4 weeks, respectively, in PB and >4 weeks in SF in one patient from the 300 mg cohort. There was a dose-related moderate but transient depression in the CD4(+) lymphocyte count in most patients, with all but three returning to >0.40 x 10(9)/l or >75% baseline by the end of the study period. Significant clinical improvement (ACR 20%) was seen in only 1/6 patients in each of the 10- and 30-mg cohorts; however, 3/6 and 5/5 patients in the 100 and 300-mg cohorts, respectively, were ACR 20% responders. In addition, there were significant reductions in PB acute phase reactants as well as SF IL-6 and TNFalpha concentrations in parallel to clinical improvement. CONCLUSION: Data from this pilot study suggest that 4162W94 is a clinically active novel immunotherapeutic agent that may suppress inflammation in RA.

Adult↗
PubMed2000

Oral toleragens in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common inflammatory and destructive arthropathy. Its precise pathogenesis remains unknown but there is evidence to suggest it is an autoimmune disease. Recently, a number of candidate autoantigens have been identified in RA. Modulating the immune response to the autoantigens by oral tolerance may lead to safer and more effective treatment. Oral tolerance is a state of systemic immune suppression to an antigen induced by oral feeding of the same antigen. In animal models, oral feeding with pathogenic antigens prevents and reduces the severity of autoimmune diseases. Even in diseases where the pathogenic autoantigens are unknown, bystander suppression can be induced using antigens present in the anatomical vicinity. Hence, oral tolerance has been advocated as a treatment strategy for autoimmune diseases including RA. Clinical trials of chicken and bovine type II collagen, a major constituent of articular cartilage, produced conflicting results in RA. This review examines the scientific basis of oral tolerance, discusses the apparent discrepancy in clinical trial results and looks at the future prospect.

Animals↗
PubMed1999

The engineered human anti-tumor necrosis factor-alpha antibody CDP571 inhibits inflammatory pathways but not T cell activation in patients with rheumatoid arthritis.

OBJECTIVE: We investigated the effect of an engineered human anti-tumor necrosis factor-alpha antibody, CDP571, on immune functions as well as bone and cartilage turnover in patients with rheumatoid arthritis (RA) in a placebo controlled trial. We also assessed the effects of repeated treatment with CDP571 in an open label continuation study. METHOD: Thirty-six patients were treated with either placebo or 0.1, 1, or 10 mg/kg of CDP571 given as an intravenous infusion. The followup period was 8 weeks. Lymphocyte phenotype, soluble CD4 (sCD4), soluble interleukin 2 receptor (sIL-2R), IL-6, and stromelysin levels in the blood were measured before and after treatment; bone and cartilage markers (pyridinoline, deoxypyridinoline, N-terminal telopeptide) were similarly assessed in the urine. Patients who completed a placebo controlled trial of CDP571 were offered further treatment with CDP571. They received a maximum of 2 further doses of 1 mg/kg (7 patients) or 10 mg/kg (9 patients) in an open study. RESULTS: Plasma IL-6 level was statistically significantly reduced in the 1 and 10 mg/kg groups. In the 10 mg/kg group, there were also reductions in plasma stromelysin and urine bone markers, although there was no change in sCD4 and sIL-2R levels. Repeat doses of CDP571 were well tolerated and continued to suppress the acute phase response and disease activity. CONCLUSION: Treatment with 10 mg/kg of CDP571 reduced IL-6 and surrogate markers of bone turnover in RA, suggesting that CDP571 might prevent joint damage in RA. Since there was no effect on lymphocyte markers despite the marked reduction in inflammation, CDP571 appears to have no effect on ongoing CD4 T cell activation.

Antibodies↗
PubMed1998

Monoclonal antibody therapy in rheumatoid arthritis.

Monoclonal antibodies bind to their targets with high specificity and therefore have excellent potential as therapeutic agents. Biotechnological advances have allowed the production of large quantities of engineered monoclonal antibodies for therapeutic use. Recent research in rheumatoid arthritis has identified important mediators of synovitis. Monoclonal antibodies targeting these have been tested in clinical trials over the last decade. Anti-cytokine therapies, in particular anti-tumour necrosis factor alpha monoclonal antibodies, suppressed inflammation and produced rapid symptomatic improvement. Anti-lymphocyte monoclonal antibodies produced long-lasting disease suppression in animal models of rheumatoid arthritis. The use of depleting anti-lymphocyte monoclonal antibodies in rheumatoid arthritis had been disappointing as they did not penetrate the synovial joint in sufficient quantity to suppress disease without producing severe and protracted peripheral blood lymphopenia. Consequently, their use in rheumatoid arthritis had been abandoned. In contrast, clinical trials of non-depleting anti-CD4 monoclonal antibodies in rheumatoid arthritis showed that they could suppress synovitis. However, it remains unclear whether they could lead to prolonged disease improvement.

Animals↗
PubMed1998

New prospects for the treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common inflammatory and destructive arthropathy. Current therapies fail to stop joint damage and reduce long-term disability. Greater understanding of disease pathogenesis has identified many inflammatory mediators as possible therapeutic targets. Novel therapeutic agents, such as monoclonal antibodies (mAbs), cytokine receptor-human immunoglobulin constructs, recombinant human proteins and antisense oligodeoxynucleotides targeting these inflammatory mediators have been tested in rheumatoid arthritis with some success. In particular, inflammation can be effectively suppressed using anticytokine therapies. However, the ideal treatment for RA, one that is immunomodulatory and induces prolonged disease remission after a single course of therapy, still eludes us. Strategies aiming to achieve this include TCR peptide vaccination and anti-CD4 mAbs, currently in clinical trials in RA.

Journal Article↗
PubMed1998

Clinical pharmacology and therapeutic potential of monoclonal antibody treatment in rheumatoid arthritis.

Many monoclonal antibodies (mAb) have been tested in rheumatoid arthritis (RA). Murine antibodies were antigenic and caused human antimouse responses in the recipients. As a result, re-treatments were less effective and were associated with an increased risk of anaphylaxis. Advances in biotechnology have allowed us to develop chimaeric and humanised mAb that are less antigenic than their murine equivalents. The specificity of mAb allows targeting of particular inflammatory mediators that are thought to be pathogenic in RA. In clinical trials, anti-cytokine antibodies such as anti-tumour necrosis factor-alpha mAb reduced inflammation rapidly and produced marked symptomatic improvement. The clinical improvement was related to the dosage and plasma concentration of the antibody. When depleting anti-lymphocyte mAb were used in RA, they produced variable clinical responses. One of the explanations for this is the poor penetration of anti-lymphocyte antibodies into the synovial joint. Therefore, depletion of lymphocytes was much greater in the blood than in the synovial joints. Consequently this approach has been abandoned and, recently, nondepleting anti-CD4 mAb have been tested in RA. When sufficient dosages were given, they produced clinical improvement, but more studies are required to assess whether they can lead to long term disease suppression.

Antibodies, Monoclonal↗