IL6 and rheumatoid arthritis: The levels of IL-6 were significantly higher in the plasma of RA patients (25.0±33.6 pg ml−1 in B19+ group and 19.0±30.5 pg ml−1 in B19− group) in comparison with the persons in the control group (0.8±1.0 pg ml−1 in B19+ group and 1.6±3.4 pg ml−1 in B19− group) (Fig. 1a).