Frequencies and absolute numbers of ASC subsets und IgG serum levels. (A) Frequencies and numbers of HLADRhigh antibody-secreting cells (ASC) were significantly lower in systemic lupus erythematosus (SLE) patients taking mycophenolate mofetil (MMF) compared to patients on azathioprine (AZA) and patients without immunosuppressive medication (no IS). (B) The absolute number of HLADRlow ASC was significantly lower in patients on MMF compared to patients without immunosuppressive therapy, whereas the frequency was not. (C) IgG serum levels (in mg/dl) were also significantly lower in patients taking MMF compared to patients on AZA or without IS. Lower limit of normal range is marked. Median values are shown: statistically significant differences were detected comparing patients on AZA and MMF (*P < 0.05, **P < 0.01, ***P < 0.001) or patients on AZA (§P < 0.5, §§P < 0.01, §§§P < 0.001) or patients on MMF (#P < 0.05, ##P < 0.01, ###P < 0.001) to patients without immunosuppressive therapy (Dunn's multiple comparison test).