Analysis of sensitivity of leukemic cells to drugs in acute lymphoblastic leukemia in children by results of MTT-test ex vivo.

MTT-test use for objective,assessment of some biological characteristics of tumor cells in acute lymphoblastic leukemia (ALL) in children is analysed. A. original technique of point assessment of MTT-test results is proposed which enables comparison of leukemic cell sensitivity to different drugs. Sensitivity of leukemic cells to antileukemic drugs was studied in 62 patients with newly diagnosed acute ALL using MTT-test. It was found that sensitivity of leukemic cells to therapy depends on the child's sex and age: in any ALL form leukemic cells from girls were more sensitive to therapy that those in boys; age over 10 years is unfavourable for a therapeutic action on leukemic cells in T-ALL, but most favourable in B-ALL. Coexpression of myeloid markers on leukemic cells in. B-ALL does not indicate lower sensitivity to most of the antileukemic drugs but changes selectively the sensitivity profile,raising cell sensitivity to mitoxantron and doxorubicin and lowering this sensitivity to vepezide, L-asparaginase, 6-mercaptopurine and corticosteroids.