Erythropoiesis and myelopoiesis in childhood leukemia and solid tumors

Purpose Hemopoiesis in childhood malignancies is mainly influenced by the a mount of neoplastic mass, the cytotoxic effect of treatment and the adminis tration of growth factors. In order to evaluate in vitro the hemopoietic ac tivity in childhood leukemia and solid tumors we studied the development of myeloid and erythroid colonies in semisolid cultures of bone marrow mononu clear cells. We also estimated the effect of metastatic infiltration of bon e marrow neuroblastoma cells on hemopoietic colonies' growth. Material-Methods Bone marrow mononuclear cells from fifteen children with A LL at the time of diagnosis and in remission at different stages of therapy and eight children with solid tumors at different stages of the disease (d iagnosis and following chemotherapy administration) were cultured in methyl cellulose in the presence of growth factors. Hemopoietic activity was estim ated by the development of BFU-E and CFU-GM colonies and compared with that of children without neoplastic disease used as controls. Results At the onset of leukemia diagnosis hemopoiesis is significantly aff ected. During remission granulopoiesis returns to normal whereas erythropoi esis remains impaired. The intensity of treatment does not seem to affect g ranulopoiesis but suppresses erythropoiesis which does not recover even wit hin six months following discontinuation of therapy. Hemopoiesis is defecti ve in children with solid tumors at diagnosis irrespectively of bone marrow neoplastic infiltration. Chemotherapy results in further reduction of gran ulopoietic activity. Conclusion Hemopoiesis in leukemia is being affected during treatment, but granulopoiesis returns to normal within six months after completion of ther apy. Erythropoiesis seems to remain defective not only throughout treatment , but also following cessation of therapy. Hemopoiesis in children with mal ignancy is defective both prior to chemotherapy and during treatment.