CLINICAL IMPLICATION OF GENE MDR-1 EXPRESSION IN HEMATOPOIETIC-CELLS FROM PATIENTS WITH ACUTE-LEUKEMIA IN VARIOUS PHASES

Aim. Analysis of cytostatic therapy effects on expression of gene MDR- 1 in hemopoietic cells of patients with acute leukemia (AL) in complet e clinicohematological remission (CCHR). Materials and methods. The st udy included 48 AL patients. 27 of them were untreated 25 were resista nt to or had recurrent AL. 4 patients were followed lip. Bone marrow m ononuclear fraction was investigated. Expression of MDR-1 gene in the cells was evaluated at hybridization. Results, High expression of MDR- 1 gene occurred in leukemic blast cells either upon achievement of CCH R or at least 6 months after ifs onset. When using schemes of chemothe rapy containing two potential inductors of gene MDR-1, expression of t his gene was registered significantly more frequently than in using sc hemes based on one inducting drug (p < 005). Frequency of occurrence o f enhanced expression of gene MDR-1 in leukemic blasts significantly c orrelated with frequency of CCHR (p < 0.05). Correlation between occur rence of the gene's expression in normal hemopoietic cells in CCHR and occurrence of early AL recurrences was not found. Conclusion. The fin dings may facilitate design of new AL treatment programs.