In-vitro granulopoiesis in adult acute lymphoblastic leukemia at various phases of the disease.

We used the in-vitro agar culture technique to monitor the granulopoiesis in 68 adult patients with ALL during the course of their disease. Bone marrow cells were cultured from 42 patients at diagnosis, 26 patients in relapse, 36 patients in early remission and 31 patients in full remission. The results of culture growth were characterized by sparse or no growth at diagnosis. No inhibition of normal CFU-C by leukemic cells was demonstrated by co-culture experiments. In relapsed marrows with blasts exceeding 60%, the culture results were identical to those at first presentation. The colonies grown in ALL cultures showed normal morphology with a normal granulocytic and monocytic differentiation. The colony-forming potential gradually increased following induction therapy, but there was no relationship between the CFU-C number and the percentage of blasts. The impaired granulopoiesis usually recovered once a remission was obtained and remained normal throughout the remission period. In some instances, cultures were performed within a short period prior to relapse or carried out more than one occasion during stable remission, wide fluctuations in CFU-C incidences were observed. Our study indicates that the CFU-C assay in ALL is useful for monitoring the in-vitro granulopoietic activity at various phases of the disease, but is of limited value in predicting the response to treatment as well as in determining the remission-relapse status.