CD4 and systemic lupus erythematosus: Only the absolute number of CD4+CD45RA+FoxP3low T cells was significantly decreased in SLE patients with low HDL cholesterol compared with those with normal HDL cholesterol (0.609 ± 2.362 cells/μl vs. 1.802 ± 4.647 cells/μl; p = 0.009 and 15.358 ± 11.608 cells/μl vs. 28.274 ± 34.139; p = 0.012, respectively).