The frequencies of Th17 cells (CD3+CD4+CD45RA-CD25-CXCR5-CXCR3-CCR6+) and plasmablasts (PB) were significantly different in the three BMI groups among patients with RA, and were significantly increased in the RA group with BMI >25 (Table 2 and Fig. 1a). Here, CD4 is linked to rheumatoid arthritis.