Studies of hemopoietic stromal fibroblastic colonies in patients undergoing bone marrow transplantation

We report here the results of serial bone marrow fibroblast cultures from recipients of histocompatible allogeneic bone marrow transplants (37 patients with acute leukemia, and seven with severe aplastic anemia). The mean value of marrow CFU-F growth for recipients at day 21 after transplant was significantly lower than that for normals and for patients before transplant. There were no obvious differences in the morphologic, ultrastructural, and cytochemical characteristics of the CFU-F between the normals and the patients who received transplants. The number of stromal CFU-F cells in S phase was increased during the early period after transplantation, as demonstrated by a significant reduction of CFU-F growth after short exposure to hydroxyurea. However, the return to normal was rapid, within six weeks. The presence of graft-vs-host disease (greater than or equal to grade II) and the choice of immunosuppressive drug, i.e., methotrexate or cyclosporine, did not affect the CFU-F recovery. The findings in the present study show that the marrow stromal compartment is compromised after marrow transplantation, but its regeneration is rapid. No in vitro CFU-F growth was obtained from peripheral blood of donors and patients, either before or after bone marrow transplant.