Fibromyalgia: management strategies for primary care providers.

AIMS: Fibromyalgia (FM), a chronic disorder defined by widespread pain, often accompanied by fatigue and sleep disturbance, affects up to one in 20 patients in primary care. Although most patients with FM are managed in primary care, diagnosis and treatment continue to present a challenge, and patients are often referred to specialists. Furthermore, the lack of a clear patient pathway often results in patients being passed from specialist to specialist, exhaustive investigations, prescription of multiple drugs to treat different symptoms, delays in diagnosis, increased disability and increased healthcare resource utilisation. We will discuss the current and evolving understanding of FM, and recommend improvements in the management and treatment of FM, highlighting the role of the primary care physician, and the place of the medical home in FM management. METHODS: We reviewed the epidemiology, pathophysiology and management of FM by searching PubMed and references from relevant articles, and selected articles on the basis of quality, relevance to the illness and importance in illustrating current management pathways and the potential for future improvements. RESULTS: The implementation of a framework for chronic pain management in primary care would limit unnecessary, time-consuming, and costly tests, reduce diagnostic delay and improve patient outcomes. DISCUSSION: The patient-centred medical home (PCMH), a management framework that has been successfully implemented in other chronic diseases, might improve the care of patients with FM in primary care, by bringing together a team of professionals with a range of skills and training. CONCLUSION: Although there remain several barriers to overcome, implementation of a PCMH would allow patients with FM, like those with other chronic conditions, to be successfully managed in the primary care setting.

Enhanced and persistent levels of interleukin (IL)-17⁺ CD4⁺ T cells and serum IL-17 in patients with early inflammatory arthritis.

Prognosis of patients with early inflammatory arthritis (EIA) is highly variable. The aim of this study was to compare, longitudinally and cross-sectionally, the levels of cytokine-expressing cells in peripheral blood (PB) from patients with EIA to those in established rheumatoid arthritis (RA) and healthy controls (HC). PB mononuclear cells from HC (n = 30), patients with EIA (n = 20) or RA (n = 38) were stimulated with phorbol myristate acetate (PMA)/ionomycin for 3 h, and stained for cell markers and cytokines. Serum cytokines and chemokines were measured by Luminex. Patients with EIA were reassessed at 6 and 12 months. The percentage of interleukin (IL)-17⁺ interferon (IFN)-γ⁻ CD4⁺ T cells [T helper type 17 (Th17)] was increased in RA and EIA versus HC. Serum IL-1ß, IL-2, IL-4 IL-17 and macrophage inflammatory protein (MIP)-1α were increased in RA and EIA versus HC. IL-1Ra, IL-15 and IFN-α were increased in EIA versus HC. IL-6 and tumour necrosis factor (TNF)-α was increased in RA but not EIA versus HC. Disease activity scores in EIA patients improved over 12 months' treatment. Th17 percentage at baseline was correlated with both rheumatoid factor (RF) titre and functional deficit at 12 months. Baseline levels of serum granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6 and IL-8 were correlated with Larsen score at 12 months. There were no significant changes in cytokine-expressing CD4⁺ T cells over time, although the percentage of IL-6⁺monocytes increased. IL-17⁺ CD4⁺ T cells and serum IL-17 levels are increased in EIA. IL-6-expressing monocytes increase during the first year of disease, irrespective of disease-modifying anti-rheumatic drug (DMARD) therapy. We observed incomplete clinical responses, suggesting EIA patients need more intensive early therapy.

Defective CD8+CD28+ regulatory T cell suppressor function in rheumatoid arthritis is restored by tumour necrosis factor inhibitor therapy.

Balanced immunoregulatory networks are essential for maintenance of systemic tolerance. Disturbances in the homeostatic equilibrium between inflammatory mediators, immune regulators and immune effector cells are implicated directly in the pathogenesis of autoimmune diseases, including rheumatoid arthritis (RA). In this study we characterize the peripheral blood CD8(+) CD28(-) regulatory T cells (Treg) contribution to the immunoregulatory network in health and in RA. In health, CD8(+) CD28(-) Treg are suppressive but, unlike CD4(+) Treg , they function predominantly through the action of soluble mediators such as interleukin (IL)-10 and transforming growth factor (TGF)-ß. Neutralization of TGF-ß consistently reduced CD8(+) CD28(-) Treg suppressor function in vitro. RA, CD8(+) CD28(-) Treg are increased numerically, but have reduced expression of inducible co-stimulator (ICOS) and programmed death 1 (PD-1) compared to healthy or disease controls. They produce more IL-10 but autologous T cells express less IL-10R. This expression was found to be restored following in-vitro addition of a tumour necrosis factor inhibitor (TNFi). Deficiencies in both the CD8(+) CD28(-) Treg population and reduced sensitivity of the T responder cells impact upon their regulatory function in RA. TNFi therapy partially restores CD8(+) CD28(-) Treg ability in vivo and in vitro, despite the defects in expression of functionally relevant molecules by RA CD8(+) CD28(-) Treg compared to healthy controls. This study places CD8(+) CD28(-) Treg cells in the scheme of immune regulation alongside CD4(+) Treg cells, and highlights the importance of understanding impaired responsiveness to regulation that is common to these suppressor subsets and their restored function in response to TNFi therapy.

Selective modulation of T-cell co-stimulation: a novel mode of action for the treatment of rheumatoid arthritis.

Disease-modifying antirheumatic drug therapy, including biological treatments that act via tumour necrosis factor (TNF)-alpha blockade, have benefited numerous patients suffering from rheumatoid arthritis (RA). However, a portion of the patient population is unresponsive to initial therapy, experience a decline in response over time or may develop side effects to treatment. These factors illustrate the requirement for additional therapy options, with novel modes of action, in order to treat this chronic and disabling disease. Activated T cells predominate in the disease processes of RA. Therefore, one rational approach to therapy is to modulate or target T cells. Abatacept is a first-in-class agent that targets T-cell modulation via the co-stimulatory CD80/CD86:CD28 pathway. Preclinical studies and clinical trials have demonstrated both the rationale and efficacy of using T-cell modulation as a therapeutic approach and, as a result, abatacept is currently approved in the European Union for the treatment of RA in adults with moderately to severely active disease who have not responded to TNF-alpha antagon-ist therapy. This review will highlight abatacept as an important treatment option in the therapeutic repertoire for RA that selectively modulates T-cell co-stimulation.

EULAR evidence-based recommendations for the management of fibromyalgia syndrome.

OBJECTIVE: To develop evidence-based recommendations for the management of fibromyalgia syndrome. METHODS: A multidisciplinary task force was formed representing 11 European countries. The design of the study, including search strategy, participants, interventions, outcome measures, data collection and analytical method, was defined at the outset. A systematic review was undertaken with the keywords "fibromyalgia", "treatment or management" and "trial". Studies were excluded if they did not utilise the American College of Rheumatology classification criteria, were not clinical trials, or included patients with chronic fatigue syndrome or myalgic encephalomyelitis. Primary outcome measures were change in pain assessed by visual analogue scale and fibromyalgia impact questionnaire. The quality of the studies was categorised based on randomisation, blinding and allocation concealment. Only the highest quality studies were used to base recommendations on. When there was insufficient evidence from the literature, a Delphi process was used to provide basis for recommendation. RESULTS: 146 studies were eligible for the review. 39 pharmacological intervention studies and 59 non-pharmacological were included in the final recommendation summary tables once those of a lower quality or with insufficient data were separated. The categories of treatment identified were antidepressants, analgesics, and "other pharmacological" and exercise, cognitive behavioural therapy, education, dietary interventions and "other non-pharmacological". In many studies sample size was small and the quality of the study was insufficient for strong recommendations to be made. CONCLUSIONS: Nine recommendations for the management of fibromyalgia syndrome were developed using a systematic review and expert consensus.

A systematic review and meta-analysis of efficacy and toxicity of disease modifying anti-rheumatic drugs and biological agents for psoriatic arthritis.

OBJECTIVE: Treatments for psoriatic arthritis (PsA) range from high-cost agents such as tumour necrosis factor (TNF) inhibitors evaluated in large randomised control trials (RCTs) and low-cost disease-modifying anti-rheumatic drugs (DMARDs) studied in less detail. We compared their efficacy and toxicity in a systematic review. METHODS: We searched Medline, PubMed and EmBase (1966-2006) for RCTs in PsA. We included RCTs that were randomised, placebo-controlled, in English, involved current treatments and only enrolled PsA patients. Efficacy was assessed by the numbers of patients withdrawn for lack of effect; toxicity by withdrawals for adverse events. RCTs were compared using risk ratios (RR) with 95% confidence intervals (CI). RESULTS: We identified 32 potentially relevant RCTs; 14 were excluded because they involved unused agents, were unblinded, were not placebo-controlled and enrolled patients with other diseases. 18 studies were included in the meta-analysis assessing DMARD monotherapy (11), DMARD combinations (one), TNF inhibitors (five) and alefacept (one). Treatment was more effective than placebo (RR = 0.35; 95% CI 0.25, 0.49) but caused more toxicity (RR = 2.33; 95% CI 1.61, 3.37). There was evidence that gold, sulfasalazine, leflunomide and TNF inhibitors were effective; gold and TNF inhibitors showed the largest effect sizes; TNF inhibitors had the best efficacy/toxicity ratio (number needed to harm/number needed to treat = 0.25); tolerability was least with gold and leflunomide. CONCLUSIONS: Efficacy/toxicity ratios were highest with TNF inhibitors followed by leflunomide, gold and sulfasalazine. Gold, though effective, has excessive toxicity and sulfasalazine, though of low toxicity, was also relatively ineffective.

Non-steroidal anti-inflammatory drugs and myocardial infarctions: comparative systematic review of evidence from observational studies and randomised controlled trials.

OBJECTIVE: The comparative risk of myocardial infarction (MI) with cyclo-oxygenase-2-specific drugs and traditional non-steroidal anti-inflammatory drugs (NSAIDs) was determined. METHODS: The results of studies of a suitable size in colonic adenoma and arthritis-that had been published in English and from which crude data about MIs could be extracted-were evaluated. Medline, Embase and Cinahl (2000-2006) databases, as well as published bibliographies, were used as data sources. Systematic reviews examined MI risks in case-control and cohort studies, as well as in randomised controlled trials (RCTs). RESULTS: 14 case-control studies (74 673 MI patients, 368 968 controls) showed no significant association of NSAIDs with MI in a random-effects model (OR 1.17; 95% CI 0.99 to 1.37) and a small risk of MI in a fixed-effects model (OR 1.32; 95% CI 1.29 to 1.35). Sensitivity analyses showed higher risks of MI in large European studies involving matched controls. Six cohort studies (387 983 patient years, 1 120 812 control years) showed no significant risk of MI with NSAIDs (RR 1.03; 95% CI 1.00 to 1.07); the risk was higher with rofecoxib (RR 1.25; 95% CI 1.17 to 1.34) but not with any other NSAIDs. Four RCTs of NSAIDs in colonic adenoma (6000 patients) showed an increased risk of MI (RR 2.68; 95% CI 1.43 to 5.01). Fourteen RCTs in arthritis (45 425 patients) showed more MIs with cyclo-oxygenase-2-specific drugs (Peto OR 1.6; 95% CI 1.1 to 2.4), but fewer serious upper gastrointestinal events (Peto OR 0.40; 95% CI 0.31 to 0.53). CONCLUSION: The overall risk of MI with NSAIDs and cyclo-oxygenase-2-specific drugs was small; rofecoxib showed the highest risk. There was an increased MI risk with cyclo-oxygenase-2-specific drugs compared with NSAIDs, but less serious upper gastrointestinal toxicity.

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.

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.

A meta-analysis of the efficacy and toxicity of combining disease-modifying anti-rheumatic drugs in rheumatoid arthritis based on patient withdrawal.

INTRODUCTION: Combinations of disease-modifying anti-rheumatic drugs (DMARDs) are increasingly used to treat rheumatoid arthritis (RA). Early trials showed their toxicity while recent trials suggest superior efficacy. Trials of DMARD combinations have enrolled different types of patient (early or established RA), used different designs (step-up, parallel or step-down) and utilized a range of outcome measures. We undertook a systematic review of combination DMARD therapy for RA and carried out a meta-analysis to evaluate the evidence for efficacy and toxicity. METHOD: Medline, PubMed and EmBase were searched using MESH headlines 'arthritis, rheumatoid', 'drug therapy, combination' and 'randomized controlled trial' (RCT) for papers published from 1975 to April 2004. References from published articles were also searched. Three independent assessors evaluated abstracts and selected trials for detailed examination. Trials were excluded if their quality was poor, were not published in English or studied DMARDs not licensed to treat RA. Two independent assessors extracted data. Efficacy was assessed by the numbers of patients withdrawn due to lack of efficacy. Toxicity was assessed by the numbers of patients withdrawn due to adverse events. Risk ratios (RR) with 95% confidence intervals (CI) were calculated and meta-analysis was carried out based on a random effects model. Sensitivity analyses evaluated different treatment combinations, trial designs, study populations and outcome measures. RESULTS: Fifty-three potentially relevant RCTs were identified. Twelve were excluded due to: using unlicensed DMARDs (n = 3); reporting in journal supplements of RCTs already included (n = 2); follow-up of an earlier RCT, report of biological outcomes or pharmacokinetics (n = 5); and non-English language publications (n = 2). Forty-one RCTs were evaluated in detail and another five excluded (three open-labelled studies and two with high patient attrition); 36 studies were included in the meta-analysis. These comprised 13 step-up, 16 parallel and 7 step-down trials. Nine assessed early RA and 27 established RA. Seven added steroids to DMARD monotherapy and one study added steroids to DMARD combinations. Six assessed methotrexate (MTX) plus tumour necrosis factor (TNF) inhibitors. Overall, combination DMARD therapy was more effective than monotherapy (RR 0.35; 95% CI 0.28, 0.45) although the risk of toxicity was also slightly higher (RR 1.37; 95% CI 1.16, 1.62). Combinations of MTX with TNF inhibitors and MTX with sulphasalazine or anti-malarials showed good efficacy/toxicity ratios. CONCLUSIONS: DMARD combinations vary in their efficacy/toxicity ratio. MTX plus sulphasalazine and/or anti-malarials and MTX plus TNF inhibitors have particularly favourable benefit/risk ratios.

Therapeutic benefit of blocking interleukin-6 activity with an anti-interleukin-6 receptor monoclonal antibody in rheumatoid arthritis: a randomized, double-blind, placebo-controlled, dose-escalation trial.

OBJECTIVE: To investigate the safety and efficacy of MRA, a recombinant human anti-interleukin-6 (anti-IL-6) receptor monoclonal antibody of the IgG1 subclass that inhibits the function of IL-6, in patients with established rheumatoid arthritis (RA). METHODS: A randomized, double-blind, placebo-controlled, dose-escalation trial was conducted in 45 patients with active RA, as defined by the American College of Rheumatology (ACR) revised criteria. Patients were sequentially allocated to receive a single intravenous dose of either 0.1, 1, 5, or 10 mg/kg of MRA or placebo. The primary efficacy end point was meeting the ACR 20% response criteria at week 2 after treatment. RESULTS: Demographic features were similar between treatment groups. At week 2, a significant treatment difference was observed between the 5 mg/kg of MRA and placebo, with 5 patients (55.6%) in the MRA cohort and none in the placebo cohort achieving ACR 20% improvement. There was no statistically significant difference in the ACR 20% response between the other 3 MRA cohorts and placebo at week 2. The mean disease activity score at week 2 in those who received 5 mg/kg and 10 mg/kg of MRA was 4.8 and 4.7 (P < 0.001 and P < 0.001 by analysis of variance), respectively. These mean scores were statistically significantly lower than those in the 0.1- and 1-mg/kg MRA and the placebo cohorts (6.4, 6.2, and 7.0, respectively). The erythrocyte sedimentation rate and C-reactive protein values fell significantly in the 5- and 10-mg/kg MRA cohorts and normalized 2 weeks after treatment. Seventeen patients (5, 4, 6, 2, and 0 patients in the placebo, 0.1-, 1-, 5-, and 10-mg/kg MRA cohorts, respectively) required corticosteroid or disease-modifying antirheumatic drug treatment because of active disease before study end. They were regarded as nonresponders from the time they received these treatments. Diarrhea was the most common adverse event, occurring in 8% of patients. Seven patients (15.6%) reported a severe adverse event (3, 1, 2, and 2 patients in the placebo, 0.1-, 1-, and 10-mg/kg MRA cohorts). There were no serious adverse events that were thought to be related to the study drug. CONCLUSION: This is the first randomized controlled trial showing that inhibition of IL-6 significantly improved the signs and symptoms of RA and normalized the acute-phase reactants. Further research with multiple dosing is necessary to define the most appropriate therapeutic regimen of MRA in RA.

Efficacy of a novel PEGylated humanized anti-TNF fragment (CDP870) in patients with rheumatoid arthritis: a phase II double-blinded, randomized, dose-escalating trial.

OBJECTIVE: Biological products that neutralize tumour necrosis factor alpha (TNF-alpha) are beneficial in rheumatoid arthritis (RA). We studied the effects of CDP870, a novel anti-TNF-alpha antibody fragment modified to obtain a prolonged plasma half-life ( approximately 14 days). METHODS: Thirty-six patients were randomized in a double-blind, ascending-dose group study to a single intravenous infusion of placebo (n = 12) or 1, 5 or 20 mg/kg CDP870 (each n = 8). The patients were predominantly female (30/36), had a mean age of 56 yr and a mean duration of RA of 13 years. They had received a mean of five DMARDs or experimental therapies (with 1 month washout before the study started) and had active disease. Continuation of NSAIDs and up to 7.5 mg prednisolone daily was allowed. Following the blinded dosing period, 32 patients received a single open-label infusion of either 5 or 20 mg/kg CDP870. RESULTS: In the blinded dosing period, 6/12 placebo patients withdrew from the study (for deteriorating RA < or =4 weeks after dosing). Two of 24 CDP870-treated patients withdrew, both in the 1 mg/kg group (for deteriorating RA or lost to follow up >4 weeks after dosing). The proportion of patients with ACR20 improvement for the per-protocol population with the last observation carried forward was 16.7, 50, 87.5 and 62.5% after 0, 1, 5 and 20 mg/kg CDP870 respectively (combined treatment effect, P = 0.012, primary analysis) at 4 weeks and 16.7, 25, 75 and 75% (P = 0.032) at 8 weeks. The proportion of patients with ACR50 improvement for the per-protocol population with the last observation carried forward was 0, 12.5, 12.5 and 50% after 0, 1, 5 and 20 mg/kg CDP870 respectively (combined treatment effect, P = 0.079) at 4 weeks and 0, 12.5, 12.5 and 50% (P = 0.079) at 8 weeks. Following the open-label dose of CDP870, similar beneficial effects were achieved. CONCLUSION: CDP870 is effective, was very well tolerated in this small study, and has an extended duration of action following one or more intravenous doses.

Repeat-cycle study of high-dose intravenous 4162W94 anti-CD4 humanized monoclonal antibody in rheumatoid arthritis. A randomized placebo-controlled trial.

OBJECTIVE: Results of an earlier open-label pilot study showed that 4162W94 was a relatively non-depleting anti-CD4 monoclonal antibody that induced >80% down-modulation of CD4 molecules from the surface of T lymphocytes. This placebo-controlled repeat-cycle study was conducted in active rheumatoid arthritis (RA) patients to determine the duration of CD4 blockade required to achieve lasting clinical benefit. METHODS: Following DMARD washout, 48 patients (i.e. three cohorts of 16 patients) with ACR-defined RA were to be dosed with 1 (cohort 1), 2 (cohort 2) or 3 (cohort 3) cycles of 5x300 mg 4162W94 or placebo (12 and 4 patients per cohort respectively) at monthly intervals. There was at least 3 months of follow-up after dosing. Clinical outcome was assessed in evaluable patients (receiving at least 80% of each dose course) using ACR20 criteria (required on two consecutive visits). CD4 lymphocyte counts and adverse events were also monitored. RESULTS: Sixteen patients were dosed in each of the first two cohorts; however, the dose was reduced in cohort 3 after five patients had received up to two dose cycles due to accumulating evidence of a high frequency of skin rash. These patients were analysed according to the number of cycles received. A further eight patients received 5x100 mg for one to three cycles prior to stopping the study for administrative reasons. Four of 13 (P=0.119 vs placebo) and 7/13 (P=0.015 vs placebo) in cohorts 1 and 2 respectively achieved ACR20 response on at least two consecutive occasions. No patient receiving 5x100 mg/day or placebo achieved ACR20. Four patients were still responding at the end of the 3-month follow-up period. CD4 lymphocyte suppression (<0.2x10(9)/l on at least two successive occasions) occurred in 11/34 patients who received 4162W94 vs none on placebo. Rash occurred in 21/34 monoclonal antibody-treated patients, including one case of biopsy-confirmed cutaneous vasculitis and 1/11 placebo patients. CONCLUSION: 4162W94 demonstrated significant clinical efficacy in this study. However, because of unacceptable CD4 lymphopenia and rash, the original hypothesis that prolonged CD4 blockade would give lasting clinical benefit was not tested.

Treatment of dermatomyositis and polymyositis.

Since idiopathic inflammatory myositis is relatively uncommon, randomized placebo controlled trials are rare. Although corticosteroids have not been tested in randomized controlled trials, general clinical consensus among physicians has accepted it as effective therapy. However, corticosteroid toxicity leads to significant disability in many patients. For patients with refractory dermatomyositis, intravenous immunoglobulin is an effective short-term treatment but its long-term effect remains unknown. Immunosuppressants are commonly used in refractory inflammatory myositis; evidence for their efficacy, with very few exceptions, has been derived from case reports and open studies with small numbers of patients. Even in randomized trials, the lack of validated and generally accepted outcome measures makes it difficult to compare the effect of interventions in different studies. Although the balance of evidence suggests that immunosuppressants are equally effective in dermatomyositis and polymyositis, there are no randomized controlled trials to show if any of these drugs, individually or in combination, is best. For uncommon diseases, such as inflammatory myositis, only multicentre randomized controlled trials involving rheumatologists and neurologists will define the optimal therapy.

Modulation of blood glucose by melatonin: a direct action on melatonin receptors in mouse hepatocytes.

Melatonin receptors were studied in isolated mouse hepatocytes using the 2[(125)I]iodomelatonin binding assay. The binding of 2[(125)I]iodomelatonin to hepatocytes isolated from the mouse using collagenase was stable, saturable, reversible and of high affinity. The equilibrium dissociation constant (K(d)) obtained from saturation studies was 10.0 +/- 0.4 pmol/l (n = 16), which was comparable to the K(d) obtained from kinetics studies (6.9 +/- 1.2 pmol/l, n = 3), and the maximum number of binding sites (B(max)) was 2.9 +/- 0.4 fmol/mg protein (n = 16). The relative order of potency of indoles in competing for 2[(125)I]iodomelatonin binding was 2-iodomelatonin > 2-phenylmelatonin > 6-chloromelatonin > melatonin > 6-hydroxymelatonin > N-acetylserotonin, indicating that the binding was mediated by the ML(1) receptor subtype. The linear Rosenthal plots, the close proximity of the Hill coefficient to unity and the monophasic competition curves suggest that a single class of 2[(125)I]iodomelatonin binding sites is present in the mouse hepatocytes. Guanosine 5'-O-(3-thiotriphosphate) dose-dependently inhibited 2[(125)I]iodomelatonin by lowering the affinity of binding, while no inhibitory effects of adenosine nucleotides were observed, suggesting that the binding sites are G-protein linked. Western immunoblotting was used to identify the melatonin receptor subtype in mouse hepatocytes using anti-Mel(1a) and anti-Mel(1b). Hepatocyte membrane extract reacted with anti-Mel(1b) but not anti-Mel(1a) giving a peptide-blockable band of 36 kD, supporting the hypothesis that the melatonin receptors in mouse hepatocytes are of the Mel(1b) subtype. Melatonin injection and a high plasma glucose level affected 2[(125)I]iodomelatonin binding in the whole mouse liver homogenates. Plasma glucose was elevated by mid-light intraperitoneal injection of melatonin (4 and 40 mg/kg body weight) in a dose-dependent manner with maximum elevation achieved 1 h after injection. 2[(125)I]Iodomelatonin binding at this time showed increased K(d) with no changes in B(max). When the plasma glucose returned to normal within 2 h, the binding remained lowered with increased K(d) but no changes in B(max). Elevation of plasma glucose by 2-deoxyglucose injection (500 mg/kg), on the other hand, decreased the binding by decreasing the B(max) without affecting the K(d). Suppression of plasma glucose by insulin injection (3 IU/kg) did not change the binding. Thus, melatonin may act directly on the liver to elevate the plasma glucose level, and changes in plasma glucose level itself may in turn affect hepatic melatonin binding.

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.

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.

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.