RTX effectively depletes naïve circulating B cells but not memory B cells. (A) Flow cytometric contour plots of CD19 and CD20, and numbers of CD20⁺ B cells, (B) CD19⁺ B cells, and (C) on peripheral blood lymphocytes taken from patients who have not (control patients, top) or have been (lower) treated with RTX. (D) Flow cytometric contour plot of naïve, IgD⁺ memory, IgD⁻ memory, plasma cell, and CD27⁻IgD⁻ subsets of CD19⁺ cells and MFI of CD38 on these subsets in a representative untreated patient. (E) Flow cytometric contour plot and MFI of CD38 of the same subsets in a representative RTX-treated patient. Bar graphs of (F) peripheral blood IgD⁺CD27⁻CD19⁺ naïve B cells, (G) IgD⁺CD27⁺CD19⁺ memory B cells, (H) CD38^hiIgD⁻CD27^hiCD19⁺ plasma cells, (I) IgD⁻CD27⁺CD19⁺ memory B cells, and (J) IgD⁻CD27⁻CD19⁺ B cells. For all bar graphs one symbol represents one individual, and the height of the bar represents the mean.