Collection of Large Quantities of Granulocyte/Macrophage Progenitor Cells (CFUc) in Man by Means of Continuous‐Flow Leukapheresis

Abstract
Continuous-flow leukapheresis using the AMINCO Celltrifuge was performed in 35 adult volunteers for the procurement of large quantities of granulocyte/macrophage progenitor cells (CFUc) as part of the mononuclear leucocytes. The donor blood volume processed was 12 1 at a flow rate of 50 ml per min. The centrifuge speed was 800 rpm. The mean yield of mononuclear cells (MNC) per run was 12.0 x 10(9) and that of CFUc, 8.7 x 10(5). The leukapheresis did not much affect the donor blood cell concentration except the platelet concentration; this must be considered as a limiting factor for leukapheresis. The mean granulocyte contamination of the leukapheresis-derived leucocytes was only about 10%. Successive leukaphereses (with short-term intervals) in 7 donors led to significant increases in CFUc yield. The possible therapeutic application of blood stem cells in the treatment of haemopoietic failure in man is discussed.