Flow cytometric analysis of nuclear DNA ploidy and proliferative activity in acute lymphoblastic leukemia

الملخص EN

Purpose : we have planned this work to determine DNA ploidy and S-phase fraction (SPF) in acute lympho-blastic leukemia using flow cytometry and also to correlate these parameters with FAB classification, immunopheno-typing, other prognostic factors and response to induction chemotherapy.

Materials and Methods : Twenty de novo ALL patients were selected and classified into 3 groups: L1, L2 and L3 according to FAB classification and into 4 groups: common ALL, pre B-ALL, B-ALL and T-ALL according to immu-nophenotyping.

All patients were subjected to the following: full history and clinical examination, laboratory investigations including: complete blood picture, bone marrow examination, cytochemistry, immunophenotyping of blast cells and the study of FCM DNA ploidy, DNA index and S-phase fraction (SPF) done on ALL blast cells.

All patients were treated with ALL induction protocol.

Results : the results were statistically analyzed and came to the following findings: aneuploidy was found in 5 cases of L1 group (45.5%) in one case of L3 (50 %), in 5 cases of common ALL group (45.5 %) and in one case of B-ALL (50 %).

A significant statistical difference was detected between the percentage of S-phase and both FAB and immunophenotyping subgroups.

There was a significant association between response to induction chemotherapy and FAB subgroups, immunophenotyping subgroups and percentage of S-phase fraction, whereas, there was no association between response to therapy and ploidy status or DNA index.

Conclusion : we can conclude that quantitative DNA analysis reflects the total chromosomal content of malignant cells and estimates the proliferative index of the blast cells which can now be determined rapidly and reliably using flow cytometry.

It can be used as an additive tool besides conventional methods helping in the diagnosis and in predicting patient's outcome in acute lymphoblastic leukemia.