Prediction of cardiovascular risk in rheumatoid arthritis: performance of original and adapted SCORE algorithms.

OBJECTIVES: Predictive performance of cardiovascular disease (CVD) risk calculators appears suboptimal in rheumatoid arthritis (RA). A disease-specific CVD risk algorithm may improve CVD risk prediction in RA. The objectives of this study are to adapt the Systematic COronary Risk Evaluation (SCORE) algorithm with determinants of CVD risk in RA and to assess the accuracy of CVD risk prediction calculated with the adapted SCORE algorithm. METHODS: Data from the Nijmegen early RA inception cohort were used. The primary outcome was first CVD events. The SCORE algorithm was recalibrated by reweighing included traditional CVD risk factors and adapted by adding other potential predictors of CVD. Predictive performance of the recalibrated and adapted SCORE algorithms was assessed and the adapted SCORE was externally validated. RESULTS: Of the 1016 included patients with RA, 103 patients experienced a CVD event. Discriminatory ability was comparable across the original, recalibrated and adapted SCORE algorithms. The Hosmer-Lemeshow test results indicated that all three algorithms provided poor model fit (p<0.05) for the Nijmegen and external validation cohort. The adapted SCORE algorithm mainly improves CVD risk estimation in non-event cases and does not show a clear advantage in reclassifying patients with RA who develop CVD (event cases) into more appropriate risk groups. CONCLUSIONS: This study demonstrates for the first time that adaptations of the SCORE algorithm do not provide sufficient improvement in risk prediction of future CVD in RA to serve as an appropriate alternative to the original SCORE. Risk assessment using the original SCORE algorithm may underestimate CVD risk in patients with RA.

Performance of four current risk algorithms in predicting cardiovascular events in patients with early rheumatoid arthritis.

OBJECTIVE: This study was undertaken to assess the predictive ability of 4 established cardiovascular (CV) risk models for the 10-year risk of fatal and non-fatal CV diseases in European patients with rheumatoid arthritis. METHODS: Prospectively collected data from the Nijmegen early rheumatoid arthritis (RA) inception cohort was used. Discriminatory ability for CV risk prediction was estimated by the area under the receiver operating characteristic curve. Calibration was assessed by comparing the observed versus expected number of events using Hosmer-Lemeshov tests and calibration plots. Sensitivity and specificity were calculated for the cut-off values of 10% and 20% predicted risk. RESULTS: Areas under the receiver operating characteristic curve were 0.78-0.80, indicating moderate to good discrimination between patients with and without a CV event. The CV risk models Systematic Coronary Risk Evaluation (SCORE), Framingham risk score (FRS) and Reynolds risk score (RRS) primarily underestimated CV risk at low and middle observed risk levels, and mostly overestimated CV risk at higher observed risk levels. The QRisk II primarily overestimated observed CV risk. For the 10% and 20% cut-off values used as indicators for CV preventive treatment, sensitivity ranged from 68-87% and 40-65%, respectively and specificity ranged from 55-76% and 77-88%, respectively. Depending on the model, up to 32% of observed CV events occurred in patients with RA who were classified as low risk (<10%) for CV disease. CONCLUSIONS: Established risk models generally underestimate (Systematic Coronary Risk Evaluation score, Framingham Risk Score, Reynolds risk score) or overestimate (QRisk II) CV risk in patients with RA.

An increased risk of non-melanoma skin cancer during TNF-inhibitor treatment in psoriasis patients compared to rheumatoid arthritis patients probably relates to disease-related factors.

BACKGROUND: Concerns exist about a risk of non-melanoma skin cancer (NMSC) in psoriasis patients and rheumatoid arthritis (RA) patients treated with TNF-inhibitors. However, current data also show that in some psoriasis patients, NMSC is diagnosed relatively short after the start of TNF-inhibitors, which suggests that these NMSC can be explained by previous therapies instead of by TNF-inhibitor therapy. OBJECTIVE: To investigate whether there was a difference in time until first NMSC and the rate of NMSC between psoriasis and RA patients on TNF-inhibitors. METHODS: Time until first NMSC and the rate of NMSC were compared between psoriasis and RA patients from the same region treated with TNF-inhibitors and followed up for at least one year in prospective cohort studies, by using Cox regression and Poisson regression. Both analyses were corrected for confounders (age, gender, disease duration, prior NMSC, duration of anti-TNF and other systemic therapies). RESULTS: The NMSC risk was significantly higher in the psoriasis group [fully adjusted HR 6.0 (1.6-22.4 95%CI)] with a shorter time until first NMSC in psoriasis compared to RA. By Poisson regression, psoriasis patients had a 5.5 (2.2-13.4 95%CI) higher rate of NMSC. CONCLUSION: The time until first NMSC was significantly shorter and the rate of NMSC was significantly higher in psoriasis compared with RA. This indicates that disease-related factors like phototherapy may be important contributing factors to NMSC diagnosed in psoriasis patients treated with TNF-inhibitors.

The psychophysiological stress response in psoriasis and rheumatoid arthritis.

BACKGROUND: Psychosocial stress can be a risk factor for the maintenance and exacerbation of chronic inflammatory diseases, such as psoriasis and rheumatoid arthritis (RA). OBJECTIVES: To gain insight into the specificity of the psychophysiological stress response during chronic inflammation, we assessed autonomic and neuroendocrine responses to stress in different chronic inflammatory diseases. METHODS: Thirty patients with psoriasis (nine women, mean age 58·5 years ± 12·4), 34 patients with RA (16 women, mean age 60·8 years ± 9·2) and 25 healthy controls (16 women, mean age 55·6 years ± 8·7) underwent a standardized psychosocial stress task (Trier Social Stress Test). Salivary levels of α-amylase and cortisol and self-reported tension levels were measured before and after the stress test. RESULTS: The cortisol response to stress was heightened in patients with psoriasis compared with patients with RA and healthy controls, whereas there were no differences in the autonomic and self-reported measures. CONCLUSIONS: The altered neuroendocrine stress response in patients with psoriasis suggests that stressful events might have different physiological consequences for specific patient groups with chronic inflammatory conditions, possibly adversely affecting disease status.

The development of the disease activity score (DAS) and the disease activity score using 28 joint counts (DAS28).

In rheumatoid arthritis, disease activity cannot be measured using a single variable. The Disease Activity Score (DAS) has been developed as a quantitative index to be able to measure, study and manage disease activity in RA in daily clinical practice, clinical trials, and long term observational studies. The DAS is a continuous measure of RA disease activity that combines information from swollen joints, tender joints, acute phase response and patient self-report of general health. Cut points were developed to classify patients in remission, as well as low, moderate, and severe disease activity in the 1990s. DAS-based EULAR response criteria were primarily developed to be used in clinical trials to classify individual patients as non-, moderate, or good responders, depending on the magnitude of change and absolute level of disease activity at the conclusion of the test.

The effect of anti-TNF-α vs. DMARDs on fatigue in rheumatoid arthritis patients.

OBJECTIVES: Fatigue is experienced frequently by patients with rheumatoid arthritis (RA). Fatigue may be caused by high levels of pain and disease activity in RA but can remain present while disease activity is moderate to low. It is not clear whether RA patients receiving anti-tumour necrosis factor (TNF) treatment reach lower levels of acute fatigue than RA patients receiving disease-modifying anti-rheumatic drug (DMARD) treatment. The aim of our study was to analyse whether, in patients with RA, the effect of anti-TNF on fatigue is greater than the effect of DMARD treatment. METHOD: Sixty-seven RA patients receiving anti-TNF treatment and 104 RA patients receiving DMARDs were included. All patients were on stable treatment for at least 6 months prior to baseline measurement. Fatigue was measured monthly over 1 year with the fatigue severity subscale of the Checklist Individual Strength (CIS-fatigue). The association between persistent severe fatigue and medication group was analysed using multiple linear regression including confounders. RESULTS: In the anti-TNF group the mean (SD) level of persistent fatigue was significantly higher than in the DMARD group [32.2 (11.4) vs. 28.3 (10.9), p = 0.025] and more patients experienced persistent severe (CIS-fatigue score ≥ 35) fatigue (42% and 27% respectively, p = 0.043). However, when correcting for age, disease activity, haemoglobin, treatment duration, pain, physical disability, and clinical depression, medication type seemed to influence neither the mean level of persistent fatigue (p = 0.251) nor the percentage of patients with persistent severe fatigue (p = 0.745). CONCLUSIONS: When taking into account probable confounders including disease activity, medication type did not influence persistent fatigue in RA patients. It seems that, besides its anti-inflammatory effect, anti-TNF has no complementary effect on persistent fatigue.

Long-term follow-up of the cervical spine with conventional radiographs in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the prevalence of cervical spine damage due to rheumatoid arthritis (RA) in the long term and to investigate which disease-specific factors are related to this damage. METHOD: Patients with early RA from the Nijmegen inception cohort with 6 to 12 years of follow-up were included. Conventional radiographs of the cervical spine were obtained at baseline, 3, 6, 9, and 12 years and scored for erosions of C1 and C2, anterior atlantoaxial subluxation (AAS) and atlantoaxial impaction (AAI). Disease-specific factors, such as disease activity, functionality, and peripheral joint damage, at baseline, 3, 6, and 9 years, were compared between patients with and without cervical spine damage at 9 years. RESULTS: A total of 196 patients were included, of whom 134 had radiographs at 9 years. Cervical spine damage was present in 16% (22/134) of the patients at 9 years. During the total 12 years of follow-up, AAS and erosions of C2 were observed most frequently. Erosions of C1 and AAI were very rare. Patients with cervical spine damage at 9 years had a higher number of erosions of the peripheral joints and failed more disease-modifying anti-rheumatic drugs (DMARDs) at 3, 6, and 9 years. Patients without peripheral erosive disease at 3 years were unlikely to develop cervical spine damage within 9 years of disease duration. CONCLUSIONS: The prevalence of cervical spine damage due to RA was 16% at 9 years. Patients without peripheral erosive disease at 3 years were unlikely to develop cervical spine damage at 9 years.

Abatacept modulates proinflammatory macrophage responses upon cytokine-activated T cell and Toll-like receptor ligand stimulation.

OBJECTIVES: We investigated whether Abatacept might reduce proinflammatory cytokine production by macrophages upon contact with cytokine activated T cells and/or stimulation with TLR ligands. METHODS: Macrophages and cytokine stimulated T cells (Tck) were added together in the presence of Abatacept or a control Ig, with or without TLR ligands. The production of cytokines was determined by luminex. RESULTS: Abatacept reduced Tck-induced production of TNFa by macrophages. Tck and TLR ligands synergistically induced the production of proinflammatory cytokines by macrophages, especially IL-12p70. The production of IL-12p70 coincided with the production of IFNg, which were both reduced in the presence of Abatacept. CONCLUSIONS: Tck induce the production of TNFa by macrophages and facilitate the highly increased production of proinflammatory cytokines in the presence of TLR ligands. Abatacept was shown to potently suppress these pathways suggesting that its role may extend beyond antigen specific T cell mediated effector function.

Prevalence and predictors of health care use in patients with early hip or knee osteoarthritis: two-year follow-up data from the CHECK cohort.

OBJECTIVE: To describe health care utilization (HCU) and predict analgesic use and health professional (HP) contact at baseline and 2 years in individuals with early symptomatic hip and/or knee osteoarthritis (OA). DESIGN: Baseline and two-year data on HCU of the 1002 participants from the multi-centre Cohort Hip & Cohort Knee study were used. Six forms of health care services were described: analgesic use, supplement use, contact with a General Practitioner (GP), contact with a HP, contact in secondary care, and alternative medicine use. Multivariable logistic regression was performed in order to identify predisposing, enabling and disease-related variables that predict analgesic use and HP contact at 2 years; treatment modalities of first choice in early OA. RESULTS: For the hip (n=170), the knee (n=414) and the hip and knee (n=418) group analgesic use (38%, 29% and 47%, respectively), contact with a GP (32%, 38% and 36%, respectively) and contact with a HP (26%, 18% and 20%, respectively), were reported most often at baseline. Contact with a GP significantly decreased, supplement use increased (to about one third), and other treatment modalities remained stable at 2 years. In all three groups, analgesic use at baseline was the strongest predictor for analgesic use at 2 years, whereas contact with a HP at baseline was the strongest predictor of contact with a HP after 2 years. Belonging to a first generation minority was a predisposing risk factor [Odds Ratio (95%-CI), 8.72 (1.55-48.97)] for analgesic use in the hip and knee group. CONCLUSIONS: In early OA, familiarity with HCU and other predisposing factors are, apart from disease-related factors strongly associated with HCU at 2 years. Further research is necessary to examine whether our findings reflect sub-optimal management of early OA in terms of efficacy and equity.

Role of induced negative and positive emotions in sensitivity to itch and pain in women.

BACKGROUND: Itch and pain are common symptoms in skin disease. It has been suggested that negative emotions may play a role in itch and pain. To date, however, the role of emotions has only been studied for pain in experimental studies, not yet for itch. OBJECTIVES: To investigate the effects of negative and positive emotions on the sensitivity to itch and pain. METHODS: Film fragments were used to induce a negative or positive emotional state in healthy women. Itch and pain were induced using the following somatosensory stimuli: electrical stimulation, histamine iontophoresis and the cold pressor test. RESULTS: Results showed that the scores for itch and pain evoked by histamine and the cold pressor test, respectively, were significantly higher in the negative than in the positive emotion condition, whereas tolerance thresholds to electrical stimulation and the cold pressor test, and stimulus unpleasantness scores did not differ between the two conditions. CONCLUSIONS: These findings for the first time indicate in an experimental design that emotions play a role in sensitivity to somatosensory sensations of both itch and pain.

Tailored cognitive-behavioural therapy and exercise training improves the physical fitness of patients with fibromyalgia.

OBJECTIVES: Patients with fibromyalgia have diminished levels of physical fitness, which may lead to functional disability and exacerbating complaints. Multidisciplinary treatment comprising cognitive-behavioural therapy (CBT) and exercise training has been shown to be effective in improving physical fitness. However, due to the high drop-out rates and large variability in patients' functioning, it was proposed that a tailored treatment approach might yield more promising treatment outcomes. METHODS: High-risk fibromyalgia patients were randomly assigned to a waiting list control group (WLC) or a treatment condition (TC), with the treatment consisting of 16 twice-weekly sessions of CBT and exercise training tailored to the patient's cognitive-behavioural pattern. Physical fitness was assessed with two physical tests before and 3 months after treatment and at corresponding intervals in the WLC. Treatment effects were evaluated using linear mixed models. RESULTS: The level of physical fitness had improved significantly in the TC compared with the WLC. Attrition rates were low, effect sizes large and reliable change indices indicated a clinically relevant improvement among the TC. CONCLUSIONS: A tailored multidisciplinary treatment approach for fibromyalgia consisting of CBT and exercise training is well tolerated, yields clinically relevant changes, and appears a promising approach to improve patients' physical fitness. ClinicalTrials.gov ID NCT00268606.

Making the rheumatologist aware of patients' non-adherence does not improve medication adherence in patients with rheumatoid arthritis.

OBJECTIVES: We have developed an instrument that provides the physician structured information about medication use and patients' (non-)adherence. This study aimed to determine the effectiveness of this instrument on adherence and medication beliefs in outpatients with rheumatoid arthritis (RA). METHODS: In this within-subject controlled prospective cohort study, 50 outpatients were assessed during three consecutive visits to their rheumatologist. At these three points in time, patients' adherence, medication beliefs, satisfaction about information about medication, and physical functioning were measured using validated self-report questionnaires. An intervention was scheduled during the second visit. The intervention consisted of a written report informing the physician about medication use and adherence to medication for each patient. The effectiveness of the intervention was evaluated by comparing outcome measures at the third visit to the same measures assessed prior to the intervention. RESULTS: At baseline, 30% of the patients (n = 50) were non-adherent. No significant changes in adherence were found between the first and second visit prior to the intervention. Adherence did not change after the intervention, compared to both of the adherence assessments prior to the intervention. Beliefs about medication, patients' satisfaction about information on medication, and physical functioning were also not significantly altered. CONCLUSION: Supplying the rheumatologist a report with information about medication use and adherence did not change adherence or patients' beliefs about medication. Further research is necessary to ensure effective support for adherence for individual patients with RA.

Evidence-based tailored conservative treatment of knee and hip osteoarthritis: between knowing and doing.

OBJECTIVE: Insufficient data are available on the efficacy of combined conservative interventions recommended by treatment guidelines for knee/hip osteoarthritis (OA). The aims of this observational cohort study were (i) to estimate the results of an evidence-based 12-week tailored multimodal conservative treatment protocol for patients with knee/hip OA and (ii) to identify predictors for response. METHODS: After obtaining data on previous OA-related interventions, multimodal treatment was offered to patients with knee and/or hip OA at a specialized outpatient clinic. Treatment with analgesics was tailored using a numeric rating scale (NRS) for pain, aiming for NRS ≤ 4. The following outcome measures were assessed: (i) the proportion of patients fulfilling OMERACT-OARSI (Outcome Measures in Rheumatoid Arthritis Clinical Trials/Osteoarthritis Research Society International) responder criteria and (ii) the proportion of patients with NRS pain ≤ 4 after 12 weeks. RESULTS: A total of 183 out of 299 patients was included. OMERACT-OARSI responder criteria were fulfilled at 12 weeks in 47% of patients; 39% reached NRS pain ≤ 4. The only independent predictor for response was the number of previously used non-steroidal anti-inflammatory drugs (NSAIDs). The majority of patients had not been exposed adequately to conservative treatment modalities for knee and/or hip OA in the past (81%). CONCLUSION: Evidence-based multimodal conservative treatment using a standardized protocol for knee and/or hip OA is feasible and successful in 47% of patients. In general, response could not be predicted. Basic first-line recommended conservative treatment options have not been used adequately prior to referral to secondary care in the vast majority of patients.

Formation of antibodies against infliximab and adalimumab strongly correlates with functional drug levels and clinical responses in rheumatoid arthritis.

BACKGROUND: Tumour necrosis factor alpha (TNFalpha) neutralising antibody constructs are increasingly being used to treat rheumatoid arthritis (RA). OBJECTIVE: To determine potential differences in clinical responses, soluble drug levels and antibody formation between patients with RA receiving infliximab and adalimumab. METHODS: 69 patients with RA fulfilling the 1987 American College of Rheumatology criteria and about to start treatment with infliximab or adalimumab, were enrolled consecutively. All patients had active disease (28-joint count Disease Activity Score >3.2). Infliximab was given intravenously at 3 mg/kg at baseline and after 2, 6 and 14 weeks. Adalimumab was administered as 40 mg biweekly subcutaneously. Concomitant drug treatment was monitored and continued at constant dosage during the study. All serum samples were tested for infliximab/adalimumab levels and anti-infliximab/anti-adalimumab antibodies. RESULTS: 35 patients received infliximab, 34 received adalimumab. At 6 months, 15 (43%), 6 (17%) and 14 (40%) of the infliximab-treated patients fulfilled the EULAR criteria for good, moderate and non-responders, respectively, whereas the corresponding figures for adalimumab-treated patients were 16 (47%), 8 (24%) and 10 (29%). Clinical responses correlated with the levels of S-infliximab/adalimumab and the formation of anti-infliximab/anti-adalimumab antibodies. CONCLUSION: The clinical response to two anti-TNFalpha biological agents closely follows the trough drug levels and the presence of antibodies directed against the drugs. Further studies that focus on the underlying pathways leading to antibody formation are warranted to predict immunogenicity of these expensive biological agents and treatment outcomes.

Influence of age on the outcome of antitumour necrosis factor alpha therapy in rheumatoid arthritis.

OBJECTIVE: To investigate the influence of age on the effectiveness and tolerance of antitumour necrosis factor alpha (TNFalpha) therapy in rheumatoid arthritis (RA). METHODS: 730 patients of the Dutch Rheumatoid Arthritis Monitoring (DREAM) register were categorised into three groups according to their age at initiation of anti-TNFalpha therapy (<45, 45-65 and >65 years). Effectiveness of anti-TNFalpha therapy was primarily assessed by longitudinal analysis of the DAS28 during the first 12 months of treatment. RESULTS: Improvement in disease activity and physical functioning was significantly less in elderly patients, correcting for relevant confounders. Elderly patients reached the EULAR categories of good responders and remission less often than younger patients. Drug survival, co-medication use and tolerance were comparable between the three age groups. CONCLUSION: Anti-TNFalpha therapy significantly reduced disease activity in all age groups of patients; however, it appeared less effective in elderly compared with younger RA patients.

Validation of the 28-joint Disease Activity Score (DAS28) and European League Against Rheumatism response criteria based on C-reactive protein against disease progression in patients with rheumatoid arthritis, and comparison with the DAS28 based on erythrocyte sedimentation rate.

OBJECTIVE: To validate and compare the definition of the Disease Activity Score 28 based on C-reactive protein (DAS28 (CRP)) to the definition based on erythrocyte sedimentation rate (ESR). METHODS: Data were analysed from two randomised, double-blind, placebo-controlled trials of abatacept of 6-month and 12-month duration in patients with rheumatoid arthritis. European League Against Rheumatism (EULAR) response criteria and the proportion of patients in remission (DAS28 <2.6) based on the two DAS28 definitions were examined. Trends in radiographic progression (erosion score, joint space narrowing score and total score) and physical function (Health Assessment Questionnaire Disability Index (HAQ-DI)) across the EULAR responder states (none, moderate and good) were analysed. RESULTS: There was general agreement in determining the EULAR responder state using both DAS28 definitions (kappa = 0.80, 95% CI 0.76 to 0.83). Overall, there was 82.4% agreement on the EULAR response criteria; when disagreements occurred, the DAS28 (CRP) yielded a better EULAR response more often then DAS28 (ESR) (12.6% vs 4.9%, respectively). There was also agreement in determining remission: kappa = 0.69 (95% CI 0.60 to 0.78). Radiographic progression decreased in patients treated with abatacept across EULAR states (from none to moderate to good) based on both definitions. For patients treated with placebo, the trend was not as pronounced, with radiographic scores higher for moderate vs non-responders. For physical function, similar trends were observed across the EULAR states for both DAS28 definitions. CONCLUSIONS: The DAS28 (CRP) has been validated against radiographic progression and physical function. While the DAS28 (CRP) yielded a better EULAR response more often than the DAS28 (ESR), the validation profile was similar to the DAS28 (ESR), indicating that both measures are useful for assessing disease activity in patients with rheumatoid arthritis.

Disease activity as a risk factor for myocardial infarction in rheumatoid arthritis.

OBJECTIVE: Patients with rheumatoid arthritis (RA) are at greater risk of developing coronary heart disease than the general population. Systemic inflammation may contribute to this risk. This study investigated whether the level of disease activity is associated with the risk of developing myocardial infarction (MI) in patients with RA. METHODS: A case-control study was performed within a large prospective cohort of patients with RA. Cases were patients who developed their first MI after the diagnosis of RA, controls were patients with RA without MI. Cases and controls had similar RA disease duration. Traditional and disease-specific risk factors for MI were collected and a time-averaged disease activity score (DAS28) was calculated. The data were analysed using conditional logistic regression analysis. RESULTS: Cases of MI were significantly older, were more often male, with higher body mass index (BMI) and total cholesterol and lower high-density lipoprotein (HDL) serum levels than controls. Time-averaged disease activity was similar for cases and controls. The raw odds ratio for MI in patients with a "high" (>4.0) versus a "low" (

Development of quality indicators for monitoring of the disease course in rheumatoid arthritis.

OBJECTIVES: To suppress rheumatoid arthritis (RA) patients' disease activity, it should be periodically measured and patients should be treated on the basis of the disease activity outcomes. Insight into the actual care, by using quality indicators, is the first step in achieving optimal care. The objective of this study was to develop a set of quality indicators to evaluate RA disease course monitoring of rheumatologists in daily clinical practice. METHODS: A RAND-modified Delphi method in a five-step procedure was applied: a literature search for quality indicators and recommendations about disease course monitoring; a first questionnaire round; a consensus meeting; a second questionnaire round and drawing up the final set. RESULTS: The systematic procedure resulted in the development of 18 quality indicators: 10 process, five structure and three outcome indicators that describe seven domains of disease course monitoring: schedule follow-up visits; measure disease activity; functional impairment; structural damage; change medication; preconditions for measuring disease activity and outcome measures in terms of disease activity. CONCLUSIONS: This quality indicator set can be used to assess the quality of disease course monitoring of rheumatologists in daily clinical practice, and to determine for which aspects of disease course monitoring rheumatologists perform well, or where there is room for improvement. This information can be used to improve the quality of disease course monitoring.

Type I interferons might form the link between Toll-like receptor (TLR) 3/7 and TLR4-mediated synovial inflammation in rheumatoid arthritis (RA).

BACKGROUND: Rheumatoid arthritis (RA) has been associated with an increased risk of infections, but the underlying pathways have not yet been identified. Toll-like receptors (TLR) probably play a role in synovial inflammation and may also contribute to the understanding of the role of infections in RA. OBJECTIVES: To investigate if the synovial expression of TLR3 and TLR7 in RA correlates with that of inflammatory cytokines, and to assess whether this has functional consequences for local cytokine production and to study potential links between the TLR3/7 axis and TLR4 in RA synovium. METHODS: Immunohistochemistry was used to study the expression of TLR3, TLR7, interferon alpha (IFNalpha), tumour necrosis factor alpha (TNFalpha) and interleukins IL1beta, IL12, IL17 and IL18 in RA synovium obtained by arthroscopy from 34 patients with RA. Monocytes, monocyte-derived dendritic cells (MoDCs) and RA synovial fibroblasts were stimulated via TLR3 (poly-IC) and TLR7 (loxorubin), after which IL1beta, IL6 and TNFalpha were measured by Luminex bead array technology. Following preincubation with IFNalpha, IL1beta and IL18, TLR3 and TLR7 mRNA expression was assessed using real-time PCR. Cytokine production after preincubation with IFNalpha and subsequent TLR stimulation was measured. RESULTS: Synovial TLR3/7 expression was co-expressed with IFNalpha, IL1beta and IL18, but not with TNFalpha, IL12 and IL17. Stimulation of TLR3/TLR7 on monocytes, MoDCs or synovial fibroblasts led to secretion of type I IFN but no biologically active IL1beta or IL18 could be detected. Type I IFNalpha increased TLR3/7 mRNA expression whereas IL1beta and IL18 did not. In spite of the fact that the mRNA level of TLR4 remained unchanged, IFNalpha enhanced the response to TLR4 agonists, a phenomenon that was clearly more marked in patients with RA. CONCLUSION: Type I interferons are highly co-expressed with TLR3/TLR7 in RA synovium. They enhance TLR3/TLR7-mediated cytokine production and also TLR4-mediated responses.

Regulation of CXCL16 expression and secretion by myeloid cells is not altered in rheumatoid arthritis.

OBJECTIVE: Chemokine (C-X-C motif) ligand 16 (CXCL16) is secreted by macrophages and dendritic cells (DCs) to attract memory type T cells. CXCL16 expression is increased in arthritic joints of patients with rheumatoid arthritis (RA) and a role for CXCL16 has been suggested in the pathogenesis of RA. To date, little is known about the regulation of CXCL16 on monocytes/macrophages and DCs. The aim of this study was to elucidate how CXCL16 expression is regulated in healthy donors and patients with RA. METHODS: CD14+cells were isolated from the peripheral blood or synovial fluid of patients with RA and healthy controls, differentiated into different types of dendritic cells or macrophages and stimulated with various cytokines or lipopolysaccharide (LPS). Cell surface proteins, including surface CXCL16, were measured by flow cytometry and soluble CXCL16 was measured by ELISA. RESULTS: Distinct types of dendritic cells constitutively express and secrete CXCL16, which is not affected by maturation. Monocytes rapidly upregulate membrane-bound CXCL16 expression and release soluble CXCL16 upon culture. CXCL16 expression by monocytes is transiently inhibited by the Toll-like receptor (TLR)4 ligand LPS. Th2 type cytokines inhibit soluble CXCL16, whereas T helper (Th)1 cell stimulus enhances its release. In RA monocytes/macrophages, neither CXCL16 expression, nor CXCL16 regulation is different from healthy controls. CONCLUSIONS: Culture of monocytes is the main trigger for CXCL16 surface expression in vitro, which is not altered in RA. Together our data suggest that the increased CXCL16 expression in patients with RA is likely to be caused by increased influx of monocytes rather than intrinsic differences in CXCL16 regulation.