Fig. 4.

Obinutuzumab induced stronger effects than rituximab. a, b PBMCs from GPA patients were treated with soluble antibodies like in Fig. 3. Experiments with PBMCs without relevant amounts of B cells (< 1% of PBL, n = 9) are depicted separately. > 1% of PBL, n = 15. a CD16 expression on NK cells from an example donor; this donor is characterized by an open circle in b. b As MFI values strongly varied between donors, data were normalized to the sample w/o antibody and logarithmized (change log) in order to simplify comparisons. RTX had a significant effect only in PBMCs with > 1% B cells (Wilcoxon test, p < 0.0001). c–e Using corresponding methods, PBMCs from healthy donors were cultured with either INX and RTX (n = 16, d) or RTX and obinutuzumab (OBI) (n = 7, e). c Example CD16 expression; this donor is characterized by an open circle in e. d, e Wilcoxon tests revealed significant differences (p < 0.0001 and p = 0.0156, respectively). f, g PBMCs from five rituximab-naive GPA patients were cultured overnight with RTX or OBI. In addition, IgG1 containing abatacept (ABA) was used as control. f B cell percentages. g Degranulation and expression of activation markers on NK cells. Geometric means after gating on NK cells are shown. p values determined by Friedman tests for B cells (f), CD107a, CD69, and CD16 (g) were < 0.0001, = 0.0002, = 0.0006, and < 0.0001 respectively. Significant post tests as indicated