[In vivo study of spontaneous and therapy-induced apoptosis in patients with chronic lymphocytic leukemia treated...

The efficiency of Chlorambucil in the induction of apoptosis was investigated in the study, and measurable apoptosis parameters were compared to the other prognostic factors with the aim of possible prediction of clinical response to the therapy in the patients with CD5 + B-cell chronic lymphocytic leukemia (B-CLL). Seven newly diagnosed patients, initially treated with daily high-doses of Chlorambucil (HD-CLB) were analyzed. Quantitative analysis of apoptosis parameters on semi-fine sections obtained from peripheral blood was performed prior and during the first five days of therapy. The level of spontaneous apoptosis (SA) was determined, as well as the maximal response by apoptosis (MAR), and the time needed to establish maximal response by apoptosis (TMAR), respectively. The results revealed that the level of SA in the studied group of patients was 11.39%-20.50%. In three patients with achieved criteria for complete remission (CR) was observed high level of SA, TMAR 2-4 days and MAR 23.42-26.36%, respectively. All patients with CR were with negative LDT, non-diffuse involvement of bone marrow and clinical stage B. Criteria for partial remission (PR) were achieved in 4 patients. Within this group, all three measurable parameters of apoptosis could have been determined in only one patient, while in the rest was noticed the increased percentage of apoptotic cells on the last day of follow-up. In all patients was observed negative LDT, diffuse bone marrow involvement, and 2 out of 4 patients had CLPL of cytomorphological type and clinical stage B. By comparing the obtained values of measurable apoptotic parameters with the clinical response to the applied therapy with HD-CLB, it is possible to divide our patients into two groups: patients who have achieved CR have the highest percentage of cells dying due to the therapy-induced apoptosis, as well as the higher values of measurable parameters compared to the certain parameters of the patients with the criteria for PR. Our preliminary results of therapeutic response to the apoptosis might be useful for the timely decision upon the duration of therapy and change of modality of treatment for every patient during the follow-up period.