[Effect of stromal cells of the bone marrow on hematopoiesis in culture].

The authors studied the effect of medullary fibroblasts on granulomonocytopoiesis in a semi-solid agar gel. Seventy-three untreated patients with the blood system diseases and 18 hematologically healthy subjects were entered into the study. The medium conditioned with fibroblasts and fibroblasts themselves are capable of stimulating granulomonocytopoiesis. In addition, fibroblasts can exert an inhibitory effect on granulomonocytopoiesis, with the degree of this effect being dependent on the agar layer thickness. Patients with chronic lympholeukemia and acute lymphoblastic leukemia showed a decrease in the stimulating activity of fibroblasts, whereas in patients with chronic myeloleukemia, that activity was elevated. In patients with neutropenic conditions, the stimulating activity of fibroblasts depended on a factor that produced neutropenia. The role of the alterations in question in the pathogenesis of the blood system diseases and other possible influences of fibroblasts on myelopoiesis are discussed.