Induction of apoptosis in a representative CLL patient isolate. (A) Cells were incubated in the absence or presence of 10 μmol/L methylprednisolone with or without 25 μmol/L zAPFcmk for 48 hours, and apoptosis was quantified by PI staining and FACS analysis. Representative results are presented from one patient (not included in Table 1). (B) Glucocorticoid treatment induces exposure of phosphatidylserine. Cells were incubated in the absence or presence of 10 μmol/L methylprednisolone with or without 25 μmol/L zAPFcmk, and PS exposure was measured by binding of annexin V as described in Materials and Methods. Representative results from two experiments (patients 24 and 25 from Table 1).