Figure 6.

Minimal residual autoimmunity after RTX: presence of ANCA-specific memory B-cells. 1*10⁶ PBMCs/well from healthy controls (HCs) and AAV patients before, 24 and 48 weeks after RTX treatment, were stimulated for 10 days with CpG ODN class B, IL-2, and IL-21 to induce antibody-secreting cells (ASCs) in a 48-well plate (A). Representative bivariate dot plots of ASCs at day 0 and day 7 of PBMC cultures demonstrated the induction of CD27⁺⁺CD38⁺⁺ ASCs 7 days after polyclonal stimulation of PBMCs from a HC and an AAV patient (MPO-ANCA) (B). Absolute counts of total CD19⁺ B-cells were shown for each individual at baseline of the cultures (day 0) (C). Absolute counts of induced ASCs per well were shown for each individual after 7 days of culturing (D). Total IgG production was measured in the supernatants of each well after 10 days of culturing. Here the median of 5 wells is shown per individual (E). Total ANCA-IgG production was measured in the supernatants of each well after 10 days of culturing. Anti-PR3 IgG and anti-MPO IgG are, respectively, shown on the left and right y-axis. Each dot represents the median of 5 wells for each individual sample. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.