Flow cytometric analysis of B lymphocytes. (A) Pedigree with those affected shown in closed symbols. (B) Analysis of circulating B cells. CD19⁺ CD27⁻ cells represent naive B cells; CD19⁺ CD27⁺ cells indicate memory B cells. (C) Summary of B-cell numbers relative to other CVID-affected patients. (D) Analysis of transitional B cells in family members. (E) Summary of CD10^hi CD24^lo cells in CVID patients and normal controls. I.1 and II.2 are indicated by red symbols. (F) Analysis of CD10 and CD24 expression by CD19⁺ cells obtained from cord blood, tonsil, and peripheral blood of a patient after treatment with rituximab. Plots are representative of 5 similar samples. (G) Bone marrow leukocytes of proband and control, gated on CD19⁺ cells to show CD10, CD45, and CD34. CD45⁺ CD10⁺ CD34⁺ cells are pro-B cells and CD45⁺ CD10⁺ CD34⁻ cells are pre-B cells. (H) Expression of indicated transcripts in bone marrow aspirate from proband relative to their expression in 2 normal control marrows. Ctrl, control.