CD27 and systemic lupus erythematosus: Further analysis of the expression of surface IgD and CD27 in B cell subsets in 17 active SLE patients and 10 healthy subjects showed no difference in CD27+ B cells and IgD+ B cells between SLE and normal control (CD27+ B cells: median 45.1% (range: 10.9–80.5) versus median 38.9% (range: 27.5–70.1), P = 0.941; IgD+ B cells: median 52.8% (range: 15.6–88.8) versus median 64.1% (range: 47.7–72.4), P = 0.711).