Abstract: | In six patients undergoing allogeneic bone marrow transplantation granulocyte colony and cluster forming units were detectable in the blood up to 24 hours after intravenous marrow infusion. The mean surviving fraction 30 minutes after the end of the infusion was 0.3 for colonies and 0.42 for total aggregates. CFU-C declined logarithmically with time, but a small secondary rise in blood CFU-C occurred 2-6 hours after the end of the marrow infusion. Three patients were plasma-exchanged immediately before the marrow graft for major donor-recipient ABO incompatability. The proportion of total groups remaining in the blood at 30 minutes was significantly higher in the plasma-pheresed patients (P = < 0.05), and the secondary rise in CFU-C was less marked, but no correlation of the blood CFU-C decay curve with the subsequent fate of the graft was observed. |