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Biomedical subjects

Piet L C M van Riel

Publications and source records attributed to Piet L C M van Riel.

At least 19 recordsLinked to original sources
PubMed2007

The role of TNF-alpha in chronic inflammatory conditions, intermediary metabolism, and cardiovascular risk.

The recent insight that inflammation contributes to the development of atherosclerosis and type 2 diabetes mellitus constitutes a major breakthrough in understanding the mechanisms underlying these conditions. In addition, it opens the way for new therapeutic approaches that might eventually decrease the prevalence of these public health problems. Tumor necrosis factor-alpha (TNF-alpha) has been shown to play a key role in these processes and thus might be a potential therapeutic target. Increased concentrations of TNF-alpha are found in acute and chronic inflammatory conditions (e.g., trauma, sepsis, infection, rheumatoid arthritis), in which a shift toward a proatherogenic lipid profile and impaired glucose tolerance occurs. Although therapeutic blockade of TNF-alpha worsens the prognosis in patients with abscesses and granulomatous infections, this strategy is highly beneficial in the case of chronic inflammatory conditions, including rheumatoid arthritis. Current investigations assessing the impact of anti-TNF agents on intermediary metabolism suggest that TNF-alpha blockade may improve insulin resistance and lipid profiles in patients with chronic inflammatory diseases.

Cardiovascular Diseases↗
PubMed2006

MIF production by dendritic cells is differentially regulated by Toll-like receptors and increased during rheumatoid arthritis.

Macrophage migration inhibitory factor (MIF) is clearly associated with rheumatoid arthritis (RA) disease severity. However, the regulation of MIF during the course of RA has not been subjected to similar scientific scrutiny. The aim of our study was to investigate the role of various Toll-like receptors (TLRs) and inflammatory mediators on MIF production by dendritic cells (DCs) in healthy controls and RA patients. DCs were cultured from 12 healthy donors and 12 RA patients. Triggering via TLR mediated pathways was achieved using various TLR specific ligands alone or in combination: Pam3Cys for TLR2, LPS and recombinant extra domain A containing fibronectin for TLR4 and Poly(I:C) and R848 for TLR3 and TLR7, respectively. In addition, iDCs from healthy controls were incubated with various cytokines, RANKL and CD40L for 48 h. MIF levels were measured using an ELISA assay. Stimulation of DCs by TLR4 ligands resulted in higher MIF production compared to immature DCs from healthy controls (p<0.002) and RA patients (p<0.002). DCs from RA patients produced higher MIF levels than healthy controls both at the immature stage (p<0.04) as well after full maturation via TLR2 (p<0.04) and TLR4 (p<0.001) triggering. Incubation with TLR3 and TLR7 ligands resulted in a significantly decreased secretion of MIF in RA patients and controls. Simultaneous incubation of TLR4 with either TLR3 or TLR7 ligands resulted in a decrease of MIF secretion when compared to TLR4 stimulation alone. The secretion of MIF increased when DCs were stimulated with TNF-alpha, RANKL and CD40L. The secretion of MIF by dendritic cells is differentially regulated by TLRs. In addition, TNF-alpha, RANKL, and CD40L augment MIF production by DCs and thus play a potential role in the amplification of the inflammatory loop in RA.

Arthritis, Rheumatoid↗
PubMed2006

Novel insights in the regulation of CCL18 secretion by monocytes and dendritic cells via cytokines, toll-like receptors and rheumatoid synovial fluid.

BACKGROUND: The T cell attracting chemokine CCL18 is produced by antigen presenting cells and a role for CCL18 has been suggested in the pathogenesis of a variety of diseases. Rheumatoid arthritis (RA) is one of these conditions, in which abundant CCL18 production is present. Although Th2 cytokines and IL-10 are known to have an effect on CCL18 production, there are several gaps in our knowledge regarding the exact regulation of CCL18 secretion, both in general and in RA. In this study we provide new insights in the regulation of CCL18 secretion by monocytes and dendritic cells. RESULTS: In contrast to a large panel of pro-inflammatory stimuli (IL-1beta, TNF-alpha, IL-10, IL-13, IL-15, IL-17, IL-18, IFN-gamma), T cell mimicking molecules (RANKL, CD40L) or TLR driven maturation, the anti-inflammatory IL-10 strongly stimulated DC to secrete CCL18. On freshly isolated monocytes, CCL18 secretion was induced by IL-4 and IL-13, in strong synergy with IL-10. This synergistic effect could already be observed after only 24 hours, indicating that not only macrophages and dendritic cells, but also monocytes secrete CCL18 under these stimulatory conditions. A high CCL18 expression was detected in RA synovial tissue and incubation of monocytes with synovial fluid from RA patients clearly enhanced the effects of IL-4, IL-13 and IL-10. Surprisingly, the effect of synovial fluid was not driven by IL-10 of IL-13, suggesting the presence of another CCL18 inducing factor in synovial fluid. CONCLUSION: In summary, IL-10 synergistically induces CCL18 secretion in combination with IL-4 of IL-13 on monocytes and monocyte derived cells. The effects of IL-14, IL-13 and IL-10 are strongly enhanced by synovial fluid. This synergy may contribute to the high CCL18 expression in RA.

Arthritis, Rheumatoid↗
PubMed2006

CXCL16 is elevated in the cerebrospinal fluid versus serum and in inflammatory conditions with suspected and proved central nervous system involvement.

In neuro-inflammatory diseases, activated T cells are thought to drive the inflammatory process. In this study, we investigated the potential role of three T cell attracting chemokines (CK) in neuro-inflammation. For this purpose, we measured levels of CXCL16, CCL17 and CCL18 in matched serum and cerebrospinal fluid (CSF) samples of patients with different neurological diseases. Interestingly, CXCL16 levels were significantly elevated in the CSF and were higher in inflammatory disease than in controls, whereas CCL17 and CCL18 were absent in the CSF. CCL18 was only elevated in serum of SLE patients. These data suggest that attraction of activated memory type T cells by CXCL16 might play an important role in the orchestration of immune responses in the central nervous system.

Case-Control Studies↗
PubMed2006

The functional variant of the inhibitory Fcgamma receptor IIb (CD32B) is associated with the rate of radiologic joint damage and dendritic cell function in rheumatoid arthritis.

OBJECTIVE: Fcgamma receptors (FcgammaRs) recognize immune complexes (ICs) and coordinate the immune response by modulating the functions of dendritic cells (DCs). The purpose of this study was to unravel the role of the inhibitory FcgammaRIIb in rheumatoid arthritis (RA) by studying the effect of the FCGR2B 695T>C polymorphism on susceptibility to RA, severity of the disease, and DC function. METHODS: Genotyping was performed in RA patients (n = 246) and healthy blood donors (n = 269). The patients' demographic data, disease severity, and disease progression were assessed over a followup of 6 years. DCs were cultured for flow cytometry to determine the expression of FcgammaRs. For detection of FcgammaRIIb (CD32B), a unique anti-FcgammaRIIb antibody (2B6-fluorescein isothiocyanate [FITC]) was used. The capacity for antigen uptake by DCs was studied by assessing the uptake of FITC-labeled ICs. Levels of cytokine production by DCs were measured during lipopolysaccharide-mediated cell activation in the presence and absence of ICs. RESULTS: Although no role of the FCGR2B variant in RA susceptibility was demonstrated, this variant was associated with a nearly doubled rate of radiologic joint damage during the first 6 years of RA. Multiple regression analysis showed that FCGR2B was by far the strongest predictor of joint damage identified to date. DCs from patients carrying this variant failed to display the inhibitory phenotype normally observed upon IC-mediated triggering of inflammation and displayed diminished FcgammaRII-mediated antigen uptake compared with wild-type DCs. However, the levels of FcgammaRs were not affected, suggesting that the FCGR2B variant alters the function rather than regulation of proteins. CONCLUSION: This study is the first to show that a single genetic variant, the FCGR2B 695T>C polymorphism, is a critical determinant of disease severity in RA and radically changes DC behavior. Our results underscore the key role of DCs in the progression of RA and reveal FcgammaRIIb as an important potential therapeutic target in RA and other autoimmune conditions.

Antigens, CD↗
PubMed2006

The initial validation of a Markov model for the economic evaluation of (new) treatments for rheumatoid arthritis.

OBJECTIVE: Markov models are increasingly used in economic evaluations of (new) treatments for chronic diseases. In this study we propose a Markov model with health states defined by the disease activity score (DAS) to be used to extrapolate efficacy data from short-term clinical trials in rheumatoid arthritis to longer term cost-effectiveness results. Moreover, we perform an initial validation of this model. METHODS: To test the validity of the model, the expected disease course (according to the model) was first compared with the observed disease course in an inception cohort of newly diagnosed rheumatoid arthritis patients. Then the relationship of the health states with utility and costs was investigated. Finally, costs and QALYs were calculated for usual care of patients in the first 5 years of their disease using the model and compared with the literature. RESULTS: The model seemed to be able to extrapolate 1-year efficacy data as seen by a comparable distribution over the Markov states between the model results and the observational data. The health states had a significant relationship with costs and utility, and population characteristics had only a moderate effect on the cost and utility values of the Markov states. The distribution over the Markov states resulted in 3.266 expected QALYs per patient over 5 years. The expected medical and total costs per patient over 5 years were 6754 euro (1997 values) and 12,641 euro, respectively, for standard rheumatoid arthritis care in The Netherlands. CONCLUSION: The developed Markov model seems a valid model for use in economic evaluations in rheumatoid arthritis. The model produced similar utilities, but lower total costs, to those in previously published studies. Although the steps to develop and validate this Markov model were applied in the context of rheumatoid arthritis, they can be generalised to other chronic diseases.

Arthritis, Rheumatoid↗
PubMed2006

Intranasal administration of recombinant human cartilage glycoprotein-39. A phase I escalating cohort study in patients with rheumatoid arthritis.

OBJECTIVE: To investigate safety and tolerability and pilot efficacy of repeated single doses of Org39141 in patients with active rheumatoid arthritis (RA). Org 39141 is recombinant human cartilage glycoprotein-39, intended to induce mucosal tolerance upon intranasal administration. METHODS: RA patients with moderate disease activity were treated for 4 weeks and followed for another 8 weeks. The trial had a sequential cohort design: RA patients in the first cohort received 4 intranasal doses (one per week) of either 25 microg Org 39141 or placebo; in subsequent cohorts, treatment with 125microg, 625 microg, or 3125 microg Org39141 was compared to placebo. Safety was evaluated by means of reporting adverse events, standard laboratory testing, and nose examination. The primary efficacy endpoint was RA disease activity as measured by the Disease Activity Score 28 (DAS28). RESULTS: A total of 36 patients were randomized. Org39141 was well tolerated, and no severe or serious adverse events (AE) were reported. In the pooled placebo group, a decrease in DAS28 was observed, but to a lesser extent than in the Org 39141 treatment groups. After 4 weeks of treatment, the mean decrease in DAS in the 625 microg Org 39141 treatment group (-24%) was statistically (p = 0.02) and clinically (EULAR criteria) significantly larger than in the pooled placebo group (-3%). Once-weekly intranasal treatment with Org39141 was well tolerated, and no serious or severe AE were reported. A trend towards efficacy was observed. Our results are encouraging for further clinical development of Org39141.

Adipokines↗
PubMed2005

DAS28: a useful instrument to monitor infliximab treatment in patients with rheumatoid arthritis.

The Disease Activity Score using 28 joint counts (DAS28) has been developed in a cohort of patients with rheumatoid arthritis in which only conventional anti-rheumatic treatments were used. It has extensively been validated to monitor disease activity in daily clinical practice as well as in clinical trials. The study of Vander Cruyssen and colleagues showed that the DAS28 correlated best with the decisions of rheumatologists to increase the infliximab dose because of insufficient response. This result once more confirms the validity of the DAS28 to monitor disease activity in patients with rheumatoid arthritis and to titrate treatment with biologicals.

Antibodies, Monoclonal↗
PubMed2005

Dermatological conditions during TNF-alpha-blocking therapy in patients with rheumatoid arthritis: a prospective study.

Various dermatological conditions have been reported during tumor necrosis factor (TNF)-alpha-blocking therapy, but until now no prospective studies have been focused on this aspect. The present study was set up to investigate the number and nature of clinically important dermatological conditions during TNF-alpha-blocking therapy in patients with rheumatoid arthritis (RA). RA patients starting on TNF-alpha-blocking therapy were prospectively followed up. The numbers and natures of dermatological events giving rise to a dermatological consultation were recorded. The patients with a dermatological event were compared with a group of prospectively followed up RA control patients, naive to TNF-alpha-blocking therapy and matched for follow-up period. 289 RA patients started TNF-alpha-blocking therapy. 128 dermatological events were recorded in 72 patients (25%) during 911 patient-years of follow-up. TNF-alpha-blocking therapy was stopped in 19 (26%) of these 72 patients because of the dermatological event. More of the RA patients given TNF-alpha-blocking therapy (25%) than of the anti-TNF-alpha-naive patients (13%) visited a dermatologist during follow-up (P < 0.0005). Events were recorded more often during active treatment (0.16 events per patient-year) than during the period of withdrawal of TNF-alpha-blocking therapy (0.09 events per patient-year, P < 0.0005). The events recorded most frequently were skin infections (n = 33), eczema (n = 20), and drug-related eruptions (n = 15). Other events with a possible relation to TNF-alpha-blocking therapy included vasculitis, psoriasis, drug-induced systemic lupus erythematosus, dermatomyositis, and a lymphomatoid-papulosis-like eruption. This study is the first large prospective study focusing on dermatological conditions during TNF-alpha-blocking therapy. It shows that dermatological conditions are a significant and clinically important problem in RA patients receiving TNF-alpha-blocking therapy.

Adult↗
PubMed2005

Is the disease course of rheumatoid arthritis becoming milder? Time trends since 1985 in an inception cohort of early rheumatoid arthritis.

OBJECTIVE: Based on comparisons of short-term cohort studies or cross-sectional samples of patients from different calendar times, it has been suggested that present patients with rheumatoid arthritis (RA) have a milder disease course compared with that of patients in past decades. This study was undertaken to investigate whether the course of disease activity and functional disability in patients with RA has become milder over the past several years. METHODS: We used the Nijmegen inception cohort of early RA, which included all patients with newly diagnosed RA who had attended the department of rheumatology at Radboud University Nijmegen Medical Centre since 1985. Patients were assessed for disease activity by the Disease Activity Score in 28 joints (DAS28) every 3 months and for functional disability by the Health Assessment Questionnaire (HAQ) disability index (DI) every 6 months. Within the total cohort, 4 subcohorts were defined, based on the date of inclusion of the patients (1985-1990, 1990-1995, 1995-2000, 2000-2005). To investigate whether the course of disease activity and functional disability (over time) was different between the subcohorts, longitudinal regression analysis (linear mixed models) was used, with the DAS28 and HAQ DI over time as outcome variables, respectively, and subcohort as the independent variable, correcting for baseline demographic and clinical characteristics. The treatment strategy was compared between the subcohorts. RESULTS: The DAS28 at baseline and over the first 5 years of disease was lower in the more recent subcohorts. The HAQ DI did not show improvement but instead a trend toward worsening functional disability. Using longitudinal regression it was shown that disease activity improved early in the disease course and stabilized thereafter, and that this improvement was greater in patients in the more recent subcohorts and in patients with a higher baseline DAS28. Initially, the HAQ DI also improved but stabilized thereafter, and this initial improvement was less pronounced in patients in the more recent subcohorts and was greater for patients with a higher baseline HAQ DI. The treatment strategy was more aggressive in the more recent subcohorts, as shown by a shorter duration from diagnosis to the start of treatment with prednisone or disease-modifying antirheumatic drugs (DMARDs), and a greater prevalence of DMARD therapy. CONCLUSION: The course of disease activity in RA patients has become milder in more recent years. The reason for this improving trend remains to be elucidated, although the trend coincides with a more aggressive treatment strategy.

Arthritis, Rheumatoid↗
PubMed2005

Correlation of rheumatoid arthritis severity with the genetic functional variants and circulating levels of macrophage migration inhibitory factor.

OBJECTIVE: To study whether genetic variants of macrophage migration inhibitory factor (MIF), the MIF -173G>C and CATT(5-8) alleles, are associated with disease severity and levels of circulating MIF in patients with rheumatoid arthritis (RA). METHODS: Genotyping was performed in patients with early RA and in healthy controls. Demographic data, disease activity, and outcome measurements were compared between patients with and without the MIF variants. MIF -173G>C and CATT(5-8) polymorphisms were genotyped, and a newly developed enzyme-linked immunosorbent assay for human MIF was used. Allele and genotype distributions of the MIF -173G>C and CATT(5-8) polymorphisms were compared between patients and controls by chi-square test. Multiple regression analysis was performed to assess the independence of the MIF functional genetic variants as risk factors for radiologic joint damage. RESULTS: Genotyping of the -173G>C and CATT(5-8) polymorphisms of MIF in RA patients and healthy individuals (n = 277 each) revealed similar frequencies of genotypes and haplotypes in both groups. No significant differences in demographic or clinical features were observed between RA patients carrying the MIF -173C allele or the MIF CATT7 allele or both and non-carrier RA patients. Radiologic joint damage was significantly higher in patients carrying risk alleles of the MIF -173G>C or the MIF CATT(5-8) functional variants. No synergistic effects between both genetic variants were observed. Multivariate regression analysis revealed that presence of the MIF -173C/C and MIF CATT(7/7) genotypes and having 1 MIF -173C allele were independent prognostic variables. Carriership of the MIF -173C allele (P = 0.002) or MIF CATT7 allele (P = 0.004) was associated with significantly higher circulating MIF levels compared with those in subjects having none of the risk-conferring alleles, and greater circulating MIF levels correlated with more severe radiologic joint damage (r = 0.64, P = 0.001). CONCLUSION: The MIF polymorphisms are not associated with RA susceptibility but are associated with high levels of radiologic joint damage. High circulating MIF levels were shown to correlate strongly with radiologic joint damage, suggesting that MIF expression is genetically determined and can be used as a novel prognostic tool in RA.

Adult↗
PubMed2005

Minimal disease activity for rheumatoid arthritis: a preliminary definition.

Agreement on response criteria in rheumatoid arthritis (RA) has allowed better standardization and interpretation of clinical trial reports. With recent advances in therapy, the proportion of patients achieving a satisfactory state of minimal disease activity (MDA) is becoming a more important measure with which to compare different treatment strategies. The threshold for MDA is between high disease activity and remission and, by definition, anyone in remission will also be in MDA. True remission is still rare in RA; in addition, the American College of Rheumatology definition is difficult to apply in the context of trials. Participants at OMERACT 6 in 2002 agreed on a conceptual definition of minimal disease activity (MDA): "that state of disease activity deemed a useful target of treatment by both the patient and the physician, given current treatment possibilities and limitations." To prepare for a preliminary operational definition of MDA for use in clinical trials, we asked rheumatologists to assess 60 patient profiles describing real RA patients seen in routine clinical practice. Based on their responses, several candidate definitions for MDA were designed and discussed at the OMERACT 7 in 2004. Feedback from participants and additional on-site analyses in a cross-sectional database allowed the formulation of 2 preliminary, equivalent definitions of MDA: one based on the Disease Activity Score 28 (DAS28) index, and one based on meeting cutpoints in 5 out the 7 WHO/ILAR core set measures. Researchers applying these definitions first need to choose whether to use the DAS28 or the core set definition, because although each selects a similar proportion in a population, these are not always the same patients. In both MDA definitions, an initial decision node places all patients in MDA who have a tender joint count of 0 and a swollen joint count of 0, and an erythrocyte sedimentation rate (ESR) no greater than 10 mm. If this condition is not met: * The DAS28 definition places patients in MDA when DAS28 < or = 2.85; * The core set definition places patients in MDA when they meet 5 of 7 criteria: (1) Pain (0-10) < or = 2; (2) Swollen joint count (0-28) < or = 1; (3) Tender joint count (0-28) < or = 1; (4) Health Assessment Questionnaire (HAQ, 0-3) < or = 0.5; (5) Physician global assessment of disease activity (0-10) < or = 1.5; (6) Patient global assessment of disease activity (0-10) < or = 2; (7) ESR < or = 20. This set of 2 definitions gained approval of 73% of the attendees. These (and other) definitions will now be subject to further validation in other databases.

Arthritis, Rheumatoid↗
PubMed2004

Modeling the 5-year cost effectiveness of treatment strategies including tumor necrosis factor-blocking agents and leflunomide for treating rheumatoid arthritis in the Netherlands.

OBJECTIVE: To determine the cost effectiveness of treatment strategies for rheumatoid arthritis patients satisfying the indication for tumor necrosis factor (TNF)-blocking treatment. METHODS: A Markov model study was performed. The following treatment strategies were considered: 1) usual treatment; 2) treatment with leflunomide, in the case of nonresponse after 3 months, switch to usual treatment; 3) TNF-blocking treatment, in the case of nonresponse after 3 months, switch to usual treatment; 4) treatment with leflunomide, in the case of nonresponse, switch to TNF-blocking treatment, in the case of nonresponse to TNF-blocking treatment, switch to usual treatment; 5) TNF-blocking treatment, in the case of nonresponse, switch to leflunomide treatment, in the case of nonresponse to leflunomide, switch to usual treatment. Expected patient-years in the different Markov states, costs, and quality-adjusted life years (QALYs) were compared between the treatment strategies; incremental cost-effectiveness ratios (ICERs) were calculated. RESULTS: Over the 5-year period, the expected effect on disease activity and QALYs was better for treatment strategies that included TNF-blocking treatment than for the other treatment strategies. The greater effectiveness of these treatment strategies reduced medical and nonmedical costs compared with usual treatment by about 16% and 33%, respectively, omitting the costs of medication. When the costs of medication were included, the costs of strategies that started with TNF-blocking treatment were higher than those of the other treatment strategies. Treatment strategy 4 had the most favorable ICER of the treatment strategies that included TNF-blocking treatment: 163,556/QALY compared with usual treatment. CONCLUSION: Among strategies that include TNF-blocking agents, one starting with leflunomide and, in the case of nonresponse, switching to TNF-blocking treatment probably results in the most favorable ratio between incremental costs and effects.

Antibodies, Monoclonal↗