POLYCHEMOTHERAPY-INDUCED CHANGES IN HEMAT OPOIESIS OF CHILDREN WITH ACUTE LYMPHOBLASTIC-LEUKEMIA

Bone marrow granulocytic-macrophagal precursors (GMP) and fibroblastic precursors (FP) were measured in 235 children with acute lymphoblasti c leukemia (ALL) receiving polychemotherapy (PCT) in progression of th e disease. A total of 408 culture investigations were conducted. PCT p roved to exert different effects on hemopoiesis during the first acute ALL period and remission. In the former period the target for PCT wer e blast cells, the course of induction therapy increased the number of GMP, FP and early granulocytic cells. In recurrent ALL the sensitivit y of GMP to PCT grew, while FP remained intact. PCT performed in remis sion resulted in gradual suppression of granulocytopoiesis, GMP beginn ing from the second remission year. The treatment discontinuation on r emission year 3.5 produced enhancement of granulocytosis by all parame ters.