Integrating Mendelian randomization and enzyme-linked immunosorbent assay validation identifies candidate mediators across the rheumatoid arthritis disease continuum

Figure 3 Comparison of serum inflammatory cytokine levels between patients with active rheumatoid arthritis and healthy controls. Serum concentrations were measured by enzyme-linked immunosorbent assay in 41 patients with rheumatoid arthritis and 41 matched controls. All 4 cytokines were significantly elevated in the rheumatoid arthritis group compared with the control group: CD40: 341.78 ± 69.99 pg/mL vs 207.12 ± 72.46 pg/mL, mean difference = 134.66 pg/mL [95% confidence interval (CI): 103.35-165.97; P < 0.0001]; C-C motif chemokine ligand 28: 3562.13 ± 699.25 pg/mL vs 1891.77 ± 523.32 pg/mL, mean difference = 1670.36 pg/mL (95%CI: 1398.91-1941.80; P < 0.0001); matrix metalloproteinase-1: 8.67 ± 1.68 ng/mL vs 5.42 ± 1.29 ng/mL, mean difference = 3.26 ng/mL (95%CI: 2.60-3.92; P < 0.0001); interleukin-18 receptor 1: 238.37 ± 47.47 pg/mL vs 140.40 ± 40.41 pg/mL, mean difference = 97.97 pg/mL (95%CI: 78.59-117.34; P < 0.0001). A: CD40; B: C-C motif chemokine ligand 28 (CCL28); C: Matrix metalloproteinase-1 (MMP-1); D: Interleukin-18 receptor 1 (IL-18R1). RA: Rheumatoid arthritis.