PMC6803509_01
PMC6803509_02
(A) Dot plots show the gates used to identify B cells (CD19pos), CD24posCD27pos memory B cells (MBCs), and inside MBCs the IgMpos and IgMneg (SW). (B) PBMCs were kept in culture (RPMI) or stimulated in vitro with CpG for 7 days (CpG). Staining with CD27 and IgM identifies IgM MBCs (IgMposCD27pos, indicated as IgM MBCs) and switched MBCs (IgMnegCD27pos, indicated as SW MBCs). Plasma cells have higher levels of CD27 and express either IgM (IgM PCs) or switched isotypes (SW PCs). CD27negIgMpos cells are mature B cells. (C) Levels of secretory immunoglobulin in cell medium of HD and patient (PT) after stimulation with CpG.
fped-07-00418-g0001.jpg
PMC6803509_02_fped-07-00418-g0001.jpg
F1
Three months later, clinical conditions remained good (the patient did not present severe infections or autoimmune manifestations), but immunoglobulin levels were persistently lower than the normal range and low switched memory B cells for age were detected (Figure 1) as well as persistent positivity of EBV VCA IgM and IgG with negative RT-PCR.
PMC6803509_03