Increase of CD21⁻ B cells in CVID patients of group Ia.

PBMCs were stained for the expression of CD19, CD21, IgM, and IgD and analyzed by FACS. Analysis was performed by gating on CD19⁺B cells, and dead cells were excluded by forward/side scatter gating. Representative FACS dot blots of the new CVID subgroups Ia, Ib, II, and one healthy control (HD) are shown. Indicated values represent percentages of gated CD19⁺ B cells. See “Patients, materials, and methods.”