[The effect of fibronectin on hematopoiesis in long-term cultures of the bone marrow from patients with acute leukemias in the remission stage].

: Hemopoietic effects in bone marrow long-term cultures (BMLTC) of healthy subjects and patients with acute myeloid leukemia (AML) in remission were studied due to fibronectin (FN) and glycoprotein of extracellular matrix of stromal microenvironment. Twelve AML patients and 6 healthy donors of allogenic transplant were examined. Blood formation in the BMLTC was assessed by weekly production of cells in nonadhesive BMLTC fraction and the content of granulocytic-macrophagal colony-forming cells in it. The response of hemopoietic stroma on FN sublayer was evaluated by weekly measurements of BMLTC adhesive layer cellularity. FN is demonstrated to stimulate the growth of BMLTC adhesive cell sublayer, the cellularity increase being the same in the above groups. FN sublayer had no influence on cellularity of the nonadhesive fraction and on the number of granulocytic-macrophagal colony-forming cells in healthy subjects, whereas it increased these values in AML patients in remission. This rise, however, was not significant. BMLTC is capable of defining a favorable effect of FN sublayer on hemopoiesis in AML patients in remission. This effect may arise from higher quality of the sublayer and survival of cells-precursors at initial stages of the cultivation.