The effects of inflammatory reflex activation on whole-blood LPS-induced TNF production and disease activity in RA patients. (A) Schematic of the RA study design. D −21 to D84 indicate study visit days. The stimulation schedule and timing of assessments are shown. (B) Mean LPS-induced TNF production in the combined RA cohort (n = 17) at study days −21, 0, 42, 56, and 84; visit means are designated by bars, and error bars indicate SEM. Differences in means were tested for significance by paired t test: *P < 0.05 vs. d −21; ⁺P < 0.01 vs. d 0; ^{^}P < 0.01 vs. d 42; ^#P < 0.01 vs. d 56. (C) The mean change in DAS2 8-CRP from baseline by study visit day for cohort I (patients failing methotrexate treatment), cohort II (patients failing treatment by multiple biologic agents), and combined cohorts. The significance of the mean change by paired t test between visits is shown: *P < 0.05 vs. d −21; ^//P < 0.01 vs. d −21; ⁺P < 0.001 vs. d −21; ^#P < 0.001 vs. d 42; ^P < 0.05 vs. d 42). (D) Linear regression analysis comparing the changes in the DAS28-CRP and the percent change in TNF release from study day −21 measured at each individual visit for each patient in the combined cohort. Changes in the DAS28-CRP and TNF release are significantly correlated by Pearson’s test (r = 0.384, P < 0.0001). (E) Mean change in the DAS28-CRP and mean LPS-induced TNF release over time by study visit day. Changes in the DAS28-CRP and TNF release follow a similar temporal pattern in response to initial simulation, stimulation withdrawal, and stimulation reinitiation.

Individual RA patient DAS28-CRP. Individual patient DAS28-CRP over time are shown for cohorts I (7 patients) (A) and II (10 patients) (B).

Clinical response and remission rates of RA patients with respect to screening day −21. (A and B) The ACR20, ACR50, and ACR70 response rates in cohort I, cohort II, and the combined cohorts are shown at study day 42 (A), and study day 84 (B). (C and D) The rates of EULAR moderate and good response and remission in cohorts I and II and the combined cohorts are shown at study day 42 (C) and study day 84 (D). The patient with Whipple disease excluded from efficacy analysis had an ACR20 response and a good EULAR response on day 42 and no ACR response and a moderate EULAR response on day 84.

Modulation of serum cytokines. Serum from each patient in the combined cohort was analyzed for multiple analytes at day 42. (A, C, and E) Individual patient values for EULAR nonresponders and responders are shown for IL-6 (A), IL-8 (C), and IL-17 (E) levels. The significance of differences between mean values at each time point was tested by unpaired t test (**P < 0.01). Horizontal bars indicate mean ± SEM. (B, D, and F) Linear regression analysis comparing analyte level at day 42 to the change in the DAS28-CRP from study day −21 to day 42. The change in the DAS28-CRP is significantly correlated to IL-6 release (r = 0.707, P = 0.002) (B) but not to IL-8 release (r = 0.261, P = 0.31) (D) or IL-17 release (r = 0.384, P = 0.07) (F).