CD4 and systemic lupus erythematosus: As several studies suggested that circulating Tfh cells were associated with autoimmunity, we first compared the frequency of CD4+CD45RA–CXCR5+ cells in total CD4+ T cells in patients with SLE (14 with a SLEDAI ≤ 4 and 13 with a SLEDAI > 4) with that in healthy controls (20 age- and sex-matched).