Among RA patients, a significantly reduced titer was observed mainly in those treated with IL-6 inhibitors (T1 median: 518.9 BAU/ml, IQR: 441.4–1,016 vs. T6 median: 53.5 BAU/ml, IQR: 32.1–101, p = 0.015), CTLA-4-Ig (T1 median: 507.3 BAU/ml, IQR: 212.3–986.9 vs. T6 median: 20.3 BAU/ml, IQR: 9.1–49, p = 0.002), and DMARDs ± CCSs (T1 median: 3,170 BAU/ml, IQR: 942.9–4,797 vs. T6 median: 129.3 BAU/ml, IQR: 44.9–244.7, p = 0.015) (Figure 4C). Here, IL6 is linked to rheumatoid arthritis.