Background Interleukin-17 (IL-17) and IL-17-induced CC-chemokine ligand 20 (CCL20) are increasingly implicated in the pathogenesis of rheumatoid arthritis (RA). A correlation has been reported to exist between serum levels of IL-17 and CCL20 and the disease activity following biologic treatment . However, such an effect has not been universally demonstrated .
Objectives The aim of the present study was to investigate if serum IL-17 and CCL20 reflect activity of the disease and whether they could be of prognostic value for predicting therapeutic response to biologic therapy in RA.
Methods Thirty RA patients qualified to receive biologic treatment were prospectively assessed before and 12 weeks of therapy with either TNFα inhibitors or anti-IL-6 receptor antibodies. Serum concentrations of IL-17 and CCL20 were measured with high sensitivity ELISA with estimated detection levels 0.01 pg/ml and 0.47 pg/ml, respectively. Successful response to therapy was defined by the EULAR criteria.
Results The patient baseline characteristics were summarized in Table 1.
Twelve weeks of biologic treatment resulted in a significant improvement in the majority of the patients with only 2 patients (7%) identified as non-responders. The favorable response to therapy was reflected both by clinical and standard biochemical criteria (Table 2). However, the mean serum concentrations of IL-17 and CCL20 did not change significantly over the course of therapy and they did not correlate with the disease activity, response to therapy, the type of biologic intervention and other medication used.
Serum IL-17 and CCL20 levels showed no correlation with DAS28, and standard inflammatory markers.
Conclusions Serum levels of IL-17 and CCL20 did not parallel changes in the clinical status and standard biochemical parameters in patients undergoing biologic treatment for RA. Thus, the measurement of IL-17 and CCL20 in serum does not seem to provide additional information that would help to monitor the response to biologic treatment in RA more effectively.
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Disclosure of Interest None declared