Fig. 1: IgG4-RD patients have altered B cell homeostasis in the peripheral blood.

A–D Flow cytometry analysis of subpopulations of B cells from PBMCs of HCs and patients. The percentages of B cell subsets (C) (HCs=24, patients=25) and MFI of CD19 (D) (n = 21) were analyzed in PBMCs from HCs and patients. E Relative mRNA level of CD19 was measured in total B cells, memory B cells and naive B cells from HCs and patients after sorting by RT-PCR (n = 3). F–H Analysis of the MFI of BAFF-R (F) (n = 6), the percentages of annexin V (G) (n = 8) and KI-67 (H) (n = 5) of the subpopulations of PBMCs from patients and HCs by Flow cytometry. I–K Memory B (CD27⁺) cells and naive (CD27⁻) B cells of HCs and patients were incubated with tethered to lipid bilayers for 3 and 5 min at 37 °C. Then cells were fixed, permeabilized and stained for AF647 anti-CD27, pBTK, and pY. The B cells were analyzed for the MFI of pY (K) and pBTK (J) by TIRFm (scale bar = 2.5 μm). L Western blot showing the levels of pBTK, pSHIP, BTK, and SHIP in B cells of patients and HCs. Representative results are shown. M–O B cells of patients and HCs were treated in the same way as in (I) except stained for pWASP and F-actin. The MFI of F-actin (N) and pWASP (O) were analyzed by TIRFm (scale bar = 2.5 μm). P Immunoblot showing the levels of pWASP and WASP in PBMCs of patients and HCs. Representative results are shown. Q–S Filopodia dilatation visualized using SEM (Q). Cells were analyzed for the number (R) (HCs=13, patients = 9) and length (S) (HCs = 33, patients = 34) of filopodia (scale bar = 5 μm). All images were representative images from 3 independent experiments. Data points in (C–H, J, K, N, O, R, and S) are represented as Mean ± SED. Statistical significance was based on two-tailed unpaired Student’s t-test. Relevant p values are given in the graph. *P < 0.05; **P < 0.01; ***P < 0.001. Source data are provided as a Source Data file.