Complement-mediated lysis of B-CLL cells.

CDC assays were performed on the PBMCs isolated from 33 patients with B-CLL and 5 with PLL. Percentage lysis in the presence of 10 μg/mL rituximab and 25% human serum is shown (black bars). The percentage of cells expressing CD20 was also evaluated by standard direct immunofluorescence (hatched bars). The PLL samples are identified by darker hatched bars.