CXCR5 and rheumatoid arthritis: We observed a higher frequency of PD-1hiCXCR5− Tph cells in the peripheral blood of patients with early RA compared with healthy controls (HC) (figure 1B, C), consistent with previous observations in patients with established RA.7 PD-1hiCXCR5+ Tfh cells were comparable between RA and HC, as were PD-1int and PD-1− CD4+ T cells, regardless of CXCR5 expression (figure 1C).