Fig. 4

JBCs are enriched among CD21^lo IgM⁺ memory cells. PBMCs from healthy controls (top) or Jo-1 ARS (bottom) patients were stained and analyzed based on IgD, IgM, IgG, and CD27 expression using flow cytometry. Live JBCs and non-JBCs (Jo-1 ARS) or total B cells (healthy donors) were identified as in Fig. 2. a, b Representative plots are shown for healthy control (top) or Jo-1 ARS (bottom) donors for the indicated markers. IgM and IgG expression was examined among CD27⁺ IgD⁻ cells gated as in panel a. c–h The indicated phenotypic subsets were examined in n = 5 stable Jo-1 ARS (triangles), n = 5 active Jo-1 ARS (circles), and n = 8 healthy controls (diamonds). Only those Jo-1 ARS patients that had > 20 JBC events were included for JBC sub-analysis of either CD21^lo (c–e) or all cells (f–h) for c, f IgD⁺ CD27⁺ IgM⁺, d, g IgD⁻ CD27⁺ IgM⁺, and e, h IgD⁻ CD27⁺ IgG⁺ subsets. Individual donors are plotted, and bars represent the mean ± SD. p values were determined using the Mann-Whitney U test, and significant values are indicated on each panel