Simple, fast method of detection apoptosis in lymphoid cells

To facilitate the analysis of apoptotic cells, the present study proposes a new quantitative method based on the changes of light scatter properties of lymphoid cells undergoing apoptosis measured with a hematology analyzer. Peripheral blood lymphocytes from 40 chronic B-lymphocytic leukemia samples, five acute T-lymphoblastic leukemia samples, three healthy donors and from T-cell lines Jurkat, SUB-T1 and SUP T8) were cultured during 72 hours in medium alone or in the presence of chlorambucil, fludarabine or theophylline, all compounds known to be apoptosis inducers, with or without adjunction of interleukin 4. Samples were run on a Bayer-H1 system and the percentage of apoptotic cells was evaluated by monitoring the lobularity index corresponding to the polymorphonuclear population. Results compared to the dUTP-fluorescein method by flow cytometry and dUTP-peroxidase labeling on slides (TUNEL) showed an excellent correlation (chi-square test: P < 0.01). This method is reliable and simple and allows one to measure routinely the percentage of apoptotic lymphoid cells at short notice in a laboratory of hematology. This is especially valuable, particularly in testing the predictive value of in vitro drug-induced apoptosis before starting a chemotherapy protocol.