Summary of apoptosis data in a series of 15 CLL cases.

Freshly isolated CLL B cells from 15 unselected cases were cultured with media only or stimulated using anti-CD40 mAb, anti-IgM, or dexamethasone. Apoptosis in each circumstance was measured after 48 hours by annexin V–FITC binding and FACS analysis. As outlined in “Materials and methods,” “apoptosis inhibition” reflects the difference between the apoptosis percent in the experimental circumstance and that measured in the same cells after 48 hours with media only. Each symbol represents the results for a particular case, and the horizontal bars represent the mean for specific apoptosis inhibition in each circumstance. P values were determined by application of the Student t test, based on comparison of results in each experimental circumstance with those for media only.