Patients non-responding to etanercept obtain lower etanercept concentrations compared with responding patients.

OBJECTIVE: To investigate the relationship between serum etanercept levels and clinical response. METHODS: In 292 etanercept-treated patients with rheumatoid arthritis clinical and pharmacological data were determined at baseline and after 1, 4 and 6 months of etanercept treatment. Differences in etanercept levels between good, moderate and European League Against Rheumatism (EULAR) non-responders were assessed after 6 months of therapy. RESULTS: After 6 months of therapy etanercept levels were significantly higher in good responders (median (IQR) 3.78 (2.53-5.17)) compared with both moderate 3.10 (2.12-4.47) and EULAR non-responders 2.80 (1.27-3.93) (all p<0.05). There was a significant association between clinical response and serum etanercept levels (regression coefficient 0.54, 95% CI 0.21 to 0.86, p=0.001). When patients were categorised into quartiles according to the height of etanercept levels, the lowest quartile (etanercept level <2.1 mg/l) comprised 40% of all non-responders. The highest quartile (etanercept level >4.7 mg/l) comprised 35% of all good EULAR responders. Anti-etanercept antibodies were detected in none of the sera. CONCLUSION: The authors demonstrated that lower etanercept levels were associated with non-response. Therapeutic drug monitoring and the possibility of the adjusted dosing regimes in the selected groups of patients should be investigated further as a possible tool to optimise treatment with etanercept.

Beneficial effect of 1-year etanercept treatment on the lipid profile in responding patients with rheumatoid arthritis: the ETRA study.

BACKGROUND: Effective anti-inflammatory treatment with tumour necrosis factor α (TNFα) inhibitors may have favourable effects on the lipid profile. Available evidence is derived from short-term studies, and it is not clear whether TNFα inhibitors have a similar effect on the lipid profile in responders and non-responders to the treatment. OBJECTIVES: To investigate the effect of long-term etanercept treatment on the lipid profile in a large sample of patients with rheumatoid arthritis (RA), stratified for European League Against Rheumatism (EULAR) response. METHODS: Between 2004 and 2008, 292 consecutive patients with active RA (DAS28 >3.2) and a new etanercept prescription were included in an observational cohort. Clinical response variables and lipid samples were collected at baseline and after 4 months and 1 year of etanercept treatment. Generalised estimating equation analyses were used to investigate the longitudinal course of lipid levels in relation to clinical response variables. RESULTS: According to the EULAR response criteria, 76% of the patients were good or moderate responders at 4 months, and 85% of the remainder at 1 year. Significant changes in apoA-I (increased by 3.5% (p=0.002) at 4 months and 3.1% (p=0.005) at 1 year) and apoB/apoA-I ratio (decreased by 6.2% (p<0.001) at 4 months and 3.6% (p=0.025) at 1 year) were observed in EULAR responders. No significant differences were observed in EULAR non-responders at all time points. CONCLUSIONS: Treatment with etanercept resulted in a significant and sustained decrease in the apoB/apoA-I ratio in patients with good or moderate EULAR response. This may have a beneficial effect on the cardiovascular risk in patients with RA.

[Behçet's disease and the possibilities of modern tumour necrosis factor inhibiting medication]. / De ziekte van Behçet en de mogelijkheden van moderne tumornecrosisfactor-remmende medicatie.

A 25-year-old woman was admitted after having had a fever for one month, headache, nausea, vomiting, dysarthria and right-sided hemiparesis. A 35-year-old man was admitted because of severe loss of vision and a history of focal retinochoroiditis. Both were suffering from Behçet's disease. Behçet's disease can present with systemic symptoms that might be related to aberrant T-cell functions. It is treated with a variety of immunoregulatory drugs. Recently, treatment with tumour necrosis factor (TNF) alpha-inhibiting molecular designed drugs such as infliximab or etanercept has improved the therapeutic prospective of Behçet patients. Both of the patients described above developed refractory disease and responded to treatment with these new drugs.