Figure 2: Sarcoidosis patient exhibited reduced peripheral blood B cell memory cell populations B lymphocytes were analysed in whole blood using forward and side scatter with surface CD19 staining (A). Total B cell memory was analysed using CD19+CD27+ staining (B). Class switched memory (CSM) B cells were identified using CD19+CD27+IgD-IgM- surface staining (D). Unswitched memory cells were identified using CD19+CD27+IgD+ (IgM+) (C & E). Naive B cells were identified as CD19+CD27- IgM+IgD+ cells (F). CD19+ B cells were further analysed for CD21 and CD38 surface expression to identify CD38loCD21lo B cells (G). B cells were also analysed for IgM and CD38 surface expression to identify CD38++IgMhi transitional B cells (H) and CD38++IgM- plasmablasts (I). B cell populations were expressed as either a percentage of lymphocytes (%L) or as a percentage of CD19+ B cells (%B).