Changes in plasma
IL-6, plasma
VEGF and serum YKL-40 were determined in
rheumatoid arthritis (RA) patients during treatment with
etanercept alone or in combination with
methotrexate. Twenty-five patients with active RA (DAS28 >/= 3.2) were randomized to receive
etanercept (25 mg sc. biweekly) plus
methotrexate (n = 12) or
etanercept alone (n = 13). Plasma
IL-6, plasma
VEGF and serum YKL-40 were determined by ELISA. The 3
biomarkers and DAS28 scores were evaluated at baseline and after 4, 8, 12 and 16 weeks of treatment. At inclusion all patients had significantly (p < 0.001) elevated plasma
IL-6, plasma
VEGF and serum YKL-40 compared to healthy subjects. Eighteen patients responded to treatment (pooled data from both treatment groups), and they had significant (p < 0.05 to p < 0.001) decreases in plasma
IL-6, plasma
VEGF, serum YKL-40, ESR and DAS28 after 4 weeks of treatment and throughout the study (except serum YKL-40 at week 16). Plasma
IL-6 showed the largest reductions. Non-responders had unchanged
biomarkers. At week 16 the patients with DAS28 < 3.2 had lower levels compared to baseline values in plasma
IL-6 (p = 0.005), plasma
VEGF (p = 0.014), and ESR (p = 0.024).Plasma
IL-6, plasma
VEGF and serum YKL-40, which reflect different aspects of the inflammatory process, may provide useful information regarding early differentiation of responders from non-responders.