Growth factors in bone marrow transplant recipients.

Normal human plasma samples usually support the growth of hemopoietic progenitors in the presence of exogenous growth factors. In contrast, plasma samples collected serially from bone marrow transplant recipients after administration of their preparative regimen demonstrate activities that routinely stimulate the growth of granulocyte-macrophage progenitors (CFU-GM) and precursors for megakaryocytes (CFU-Meg). The peak activities are usually observed between day 7 and day 21. Occasionally growth promoting activities for erythroid bursts are also observed. Activities for the growth of multilineage colonies are only rarely seen. These growth promoting activities for CFU-GM and CFU-Meg usually return to pretransplant values by day 30 in patients with prompt engraftment. Patients with delayed engraftment sustain high levels of growth promoting activities for long periods of time.