Influence of a new relapse treatment for acute myeloid leukemia (AML) on in vitro granulopoiesis.

Twelve AML patients in relapse were treated with cytosine arabinoside (Ara-C), VP 16-213, vincristine, and vinblastine (A-triple-V). For bone marrow (BM) evaluation, in vitro granulopoiesis by agar and liquid cultures was investigated. In 15 treatments, 12 complete remissions (CR) were observed. Three patients, treated with 2 A-triple-V cycles achieved CR twice. One to four months after treatment normal colony formation and cell differentiation was found in remission patients. Evidence of sustained recovery was obtained in sequential studies of BM cultures of patients in CR. These results indicate that-A-triple-V treatment does not irreversibly deplete normal myeloid progenitor cell population.