CRP and rheumatoid arthritis: However, the percentage of Th1 cells was not correlated with either CRP level or DAS28 (P  = 0.105 or P  = 0.205), and plasma level of IL-22 or IL-17 failed to show a statistical correlation with CRP level or DAS28 (P = 0.622 and P  = 0.357 or P = 0.317 and P = 0.872) in RA patients (Fig. S1j, k).