B-cell chronic lymphocytic leukemia (B-CLL) is a lymphoproliferative disease caused by impaired apoptosis regulation that leads to an abnormal survival and an accumulation of B-lymphocytes. Anti-apoptotic Bcl-2 and pro-apoptotic Bax proteins are involved in the highly regulated mechanism of cell death. Bax and Bcl-2 intracellular levels were analyzed both in CD19+ and CD3+ cells from 28 B-CLL de novo patients and compared with cells from healthy donors. Our results were expressed as a ratio (Bax/Bcl-2) obtained by dividing Bax mean fluorescence intensity (MFI) and Bcl-2 MFI; obviously, a lower ratio is associated with an anti-apoptotic status, while a higher index correlates to apoptosis activation. In CD19+ B-CLL cells, the Bax/Bcl-2 ratio was lower than in the CD19+ normal counterpart (1.3 versus 3.51; P <.05), mainly due to a Bcl-2 over expression (17.65 versus 9.02; P <.001). In CD3+ cells from B-CLL patients, the Bax/Bcl-2 ratio was lower than in normal CD3+ cells (7.89 versus 8.96; P <.005), most importantly as a result of Bax suppression (77.22 versus 96.63; P <.001). These study data show an apoptosis inhibition not only in CD19+ cells, but also in CD3+ cells, suggesting a pivotal role of T-cells in B-CLL pathogenesis.
- B-Cell chronic lymphocytic leukemia
- Intracellular level
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