Interleukin-1β measurement in stimulated whole blood cultures is useful to predict response to anti-TNF therapies in rheumatoid arthritis
Kayakabe K et al. – IL–1β measurement in lipopolysaccharide (LPS)–stimulated WBC is useful to predict responsiveness to anti–TNF agents. Cytokine production capacities in LPS–stimulated whole blood cultures (WBCs) are up–regulated by biologics.Methods
- The authors measured the concentration of TNF–α, IL–1β and IL–6 in supernatants of lipopolysaccharide (LPS)–stimulated WBCs obtained from RA patients (n = 41) before anti–TNF therapy (infliximab, 13; etanercept, 26; and adalimumab, 2) and from healthy controls (n = 12).
- At 24 weeks after biologics, whole bloods were again drawn from 14 of 41 patients.
- Response was defined by the European League Against Rheumatism response criteria after 24 weeks of therapy.
- Among 41 patients, 32 were responders (good 14/moderate 18), while 9 were non–responders.
- All cytokines measured were significantly lower in RA patients than in controls.
- In RA, IL–1β production was lower in non–responders than in responders [median (interquartile range): 3.5 (1.5–9.4) vs 10.0 (5.1–93.1) pg/ml, P = 0.048].
- The area under the curve from a receiver operating characteristic curve analysis for the prediction of response using IL–1β was 0.717 (95% CI 0.520, 0.914).
- The sensitivity and specificity of IL–1β (cut–off value 4.84 pg/ml) was 78.1 and 77.8%, respectively.
- All cytokines were significantly higher 6 months later compared with their respective baseline.