A.M.M. Eijsbouts

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

Background: Tumour necrosis factor α (TNFα) 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-TNFα 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.

Excess mortality emerges after 10 years in an inception cohort of early rheumatoid arthritis.

To investigate mortality rates, causes of death, time trends in mortality, prognostic factors for mortality, and the relationship between disease activity and mortality over a 23‐year period in an inception cohort of rheumatoid arthritis (RA) patients.

Validation Study of Existing Gene Expression Signatures for Anti-TNF Treatment in Patients with Rheumatoid Arthritis

So far, there are no means of identifying rheumatoid arthritis (RA) patients who will fail to respond to tumour necrosis factor blocking agents (anti-TNF), prior to treatment. We set out to validate eight previously reported gene expression signatures predicting therapy outcome. Genome-wide expression profiling using Affymetrix GeneChip Exon 1.0 ST arrays was performed on RNA isolated from whole blood of 42 RA patients starting treatment with infliximab or adalimumab. Clinical response according to EULAR criteria was determined at week 14 of therapy. Genes that have been reported to be associated with anti-TNF treatment were extracted from our dataset. K-means partition clustering was performed to assess the predictive value of the gene-sets. We performed a hypothesis-driven analysis of the dataset using eight existing gene sets predictive of anti-TNF treatment outcome. The set that performed best reached a sensitivity of 71% and a specificity of 61%, for classifying the patients in the current study. We successfully validated one of eight previously reported predictive expression profile. This replicated expression signature is a good starting point for developing a prediction model for anti-TNF treatment outcome that can be used in a daily clinical setting. Our results confirm that gene expression profiling prior to treatment is a useful tool to predict anti-TNF (non) response.

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” (⩽4.0) average DAS28 was 1.2 (95% CI 0.61 to 2.36). The odds ratio corrected for age, gender, BMI, baseline Health Assessment Questionnaire and baseline HDL was 0.91 (95% CI 0.39 to 2.12). Conclusion: Patients with RA who developed MI had more classical risk factors but not higher disease activity over time than control patients with RA. Low levels of inflammation may be sufficient for accelerated atherogenesis and an excess risk of cardiovascular disease in RA.

The tumour necrosis factor receptor superfamily member 1b 676T>G polymorphism in relation to response to infliximab and adalimumab treatment and disease severity in rheumatoid arthritis

Objective: To assess the effect of a functional polymorphism (676T>G, M196R) in the tumour necrosis factor receptor super family 1b (TNFSF1b) gene on disease activity, radiological joint damage and response to infliximab and adalimumab treatment in patients with rheumatoid arthritis (RA). Methods: Two cohorts of patients with RA were genotyped for the 676T>G polymorphism (rs1061622) in exon 6 of the TNFSF1b gene by restriction fragment length polymorphism analysis. One cohort (n = 234) included patients from the Dutch Rheumatoid Arthritis Monitoring register with detailed information on their response to anti-TNF therapy (infliximab and adalimumab), the other cohort comprised patients from a long-term observational early inception cohort at our centre (n = 248). Results: The 676T>G polymorphism was not associated with anti-TNF response after 3 or 6 months of treatment. Linear regression analysis showed no significant difference in the progression of radiological joint damage during the first 3 and 6 years of disease between the three genotype groups (TT, TG and GG). Additionally, no difference in mean disease activity between genotypes was seen after 3 and 6 years of disease. Conclusion: Despite its demonstrated functionality, the 676T>G polymorphism in the TNFSF1b gene does not have a major role in either the response to anti-TNF therapy or in the disease severity or radiological progression in RA.

Meta-analysis identified the TNFA -308G > A promoter polymorphism as a risk factor for disease severity in patients with rheumatoid arthritis.

IntroductionThe goal of this study is to investigate whether the -308G > A promoter polymorphism in the tumor necrosis factor alpha (TNFA) gene is associated with disease severity and radiologic joint damage in a large cohort of patients with rheumatoid arthritis (RA).MethodsA long-term observational early RA inception cohort (n = 208) with detailed information about disease activity and radiologic damage after 3, 6 and 9 years of disease was genotyped for the TNFA -308G > A promoter polymorphism (rs1800629). A longitudinal regression analysis was performed to assess the effect of genotype on RA disease severity and joint damage. Subsequently, a meta-analysis, including all publically available data, was performed to further test the association between joint erosions and the TNFA polymorphism. To learn more about the mechanism behind the effect of the polymorphism, RNA isolated from peripheral blood from RA patients (n = 66) was used for TNFA gene expression analysis by quantitative PCR.ResultsLongitudinal regression analysis with correction for gender and disease activity showed a significant difference in total joint damage between GG and GA+AA genotype groups (P = 0.002), which was stable over time. The meta-analysis, which included 2,053 patients, confirmed an association of the genetic variant with the development of erosions (odds ratio 0.78, 95% CI 0.62, 0.98). No significant differences in TNFA gene expression were observed for the different genotypes, confirming earlier findings in healthy individuals.ConclusionsOur data confirm that the TNFA -308G > A promoter polymorphism is associated with joint damage in patients with RA. This is not mediated by differences in TNFA gene expression between genotypes.

Circulating levels of the chemokine CCL18 but not CXCL16 are elevated and correlate with disease activity in rheumatoid arthritis

Background: Antigen-presenting cells (APC) and T cells are considered to play a significant role in the pathogenesis of rheumatoid arthritis (RA). CCL18 and CXCL16 are two chemokines that facilitate T cell attraction by APC, of which a role in the pathogenesis of RA has been suggested. Objective: To compare the circulating levels of CXCL16 and CCL18 in RA with controls and to investigate the relation of CXCL16 and CCL18 with RA disease activity and joint damage. Methods: Circulating CCL18 and CXCL16 levels were determined in 61 RA patients with a follow-up of 6 years and a group of 41 healthy controls with ELISA. Chemokine levels were correlated with demographic data, disease activity (DAS28) and joint damage (modified Sharp score). In addition, serum CCL18 and CXCL16 levels from a cohort of 44 RA patients treated with anti-TNF-α were correlated with disease activity. Results: CCL18 levels in serum were significantly elevated in RA patients compared with controls, while serum CXCL16 levels were not. In contrast to CXCL16, serum CCL18 was positively correlated with disease activity. Both CCL18 and CXCL16 levels decreased upon treatment with anti-TNF-α. Neither CCL18 nor CXCL16 correlated with joint damage and progression. Conclusion: Here, we show, for the first time, that circulating CCL18 and not CXCL16 levels are elevated in RA patients as compared with controls and correlate with disease activity in RA. More knowledge regarding the regulation and function of both CCL18 and CXCL16 is essential to value their role in RA.

Immune responses to stress in rheumatoid arthritis and psoriasis

OBJECTIVE Stress is one of the factors that may exacerbate the progression of chronic inflammatory diseases such as RA and psoriasis. We exploratively compared the effects of acute stress on levels of circulating cytokines involved in disease progression and/or the stress response in patients with RA, patients with psoriasis and healthy subjects. METHODS Patients with RA, patients with psoriasis and healthy controls underwent a standardized psychosocial stress test (Trier Social Stress Test). Levels of circulating cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IFN-γ and TNF-α) were measured before and after the stress test. RESULTS The baseline levels of all cytokines, except IL-8, were significantly higher in patients with RA. After correction for baseline levels, patients with RA showed higher stress-induced levels of IL-1β and IL-2 than patients with psoriasis and healthy controls. CONCLUSION The results suggest that patients with RA have a different immune response to stress than patients with psoriasis or healthy controls. More needs to be learned about the complex interaction between stress, immune parameters and chronic inflammation.

The psychophysiological stress response in psoriasis and rheumatoid arthritis.

Psychosocial stress can be a risk factor for the maintenance and exacerbation of chronic inflammatory diseases, such as psoriasis and rheumatoid arthritis (RA).

Effect of naproxen on the hypothalamic–pituitary– adrenal axis in healthy volunteers

AIM To study the effect of the nonsteroidal anti-inflammatory drug naproxen on the activity of the hypothalamic-pituitary-adrenal (HPA) axis in healthy volunteers. METHODS A double-blind, randomized study in two groups of 20 healthy volunteers was performed. The activity of the HPA axis was measured before and after the use of naproxen or placebo during a period of 2 weeks. Basal plasma adrenocorticotropic hormone (ACTH) and cortisol, 24-h urinary cortisol, and circadian cortisol rhythm in saliva were determined. Plasma ACTH and cortisol were also measured during submaximal physical exercise. RESULTS There were no significant differences between the placebo and naproxen groups in basal plasma ACTH [09.00 h 3.1 pmol l(-1), 95% confidence interval (CI) 2.0, 4.2, and 2.8 pmol l(-1), 95% CI 1.9, 3.7, respectively], cortisol levels (09.00 h 0.45 micromol l(-1), 95% CI 0.39, 0.51, and 0.40 micromol l(-1), 95% CI 0.35, 0.44, respectively), 24 h urinary cortisol excretion (67.5 nmol 24 h(-1), 95% CI 54.3, 80.7, and 86.8 nmol 24 h(-1), 95% CI 54.4, 119.2, respectively), circadian cortisol rhythm measured in salivary samples, or ACTH and cortisol concentrations after physical exercise. After the use of placebo or naproxen for 2 weeks, no significant change in any of the parameters occurred (ACTH 09.00 h 3.0 pmol l(-1), 95% CI 2.0, 3.9, and 3.0 pmol l(-1), 95% CI 2.2, 3.8, respectively; cortisol 09.00 h 0.45 micromol l(-1), 95% CI 0.37, 0.52, and 0.39 micromol l(-1), 95% CI 0.34, 0.44, respectively; cortisol urine 79.5 nmol 24 h(-1), 95% CI 59.5, 99.4, and 81.7 nmol 24 h(-1), 95% CI 64.0, 99.4, respectively), and no significant differences were found in these parameters between the placebo and naproxen groups. CONCLUSIONS The use of naproxen does not influence the activity of the HPA axis in healthy volunteers under basal circumstances or in response to physical stress.