Expression of surface membrane markers on B-CLL cells and normal CD5⁺ B cells.

Surface membrane markers overexpressed on B-CLL cells as compared with normal CD5⁺ B cells. PBMCs from B-CLL cases and age-matched healthy donors were analyzed for marker expression on CD5⁺CD19⁺ cells by means of 3-color immunofluorescence. (A) Representative flow cytometric profiles of expression of these markers on B cells from a 67-year-old healthy donor (N39) and a B-CLL patient (CLL 308). (B) Paired bars depict the mean ± SE of the percentage of CD5⁺CD19⁺cells expressing these markers in 61 (51 IgM⁺ and 10 IgG⁺) B-CLL patients and 20 age-matched healthy controls studied. B-CLL cells express significantly higher percentages (P < .0001) of CD27, CD39, CD23, CD25, CD69, and CD71 than normal CD5⁺CD19⁺ cells. The expression of these markers was variable both in the patients and in the markers, with the greatest variability seen for CD25. The SE and the SD for these markers ranged from 1.7 to 3.6 and from 13.1 to 28.0, respectively.