Figure 3

CD27⁺ B cells with a memory phenotype are less susceptible to cyclophosphamide treatment in patients with systemic lupus erythematosus (SLE) (n = 20). Severely active SLE patients undergoing monthly intravenous cyclophosphamide bolus therapy were followed for a period of 3 to 6 months. Whereas CD27^- B cells and CD27⁺⁺ plasmablasts/plasma cells showed a decrease, the absolute numbers of CD27⁺ memory B cells did not change significantly. n.s., not significant.