Granulocyte colony‐stimulating factor (G‐CSF)‐induced mobilization of circulating haemopoietic stem cells

Summary. We studied the utility of G‐CSF for harvesting circulating haematopoietic stem cells in patients with leukaemia or lymphoma based on a comparative study in a single patient. Two successive cycles of leukapheresis following cytotoxic chemotherapy were performed in 22 patients as follows: the first cycle was performed with cytotoxic mobilization in all patients while the second cycle was randomized into two groups: cytotoxic (n= 10) and cytotoxic plus G‐CSF (cytotoxic/G‐CSF) (n= 12) mobilization. Repetitive cytotoxic mobilization did not alter the yields of mononuclear cells (MNC), myeloid (CFU‐GM), and erythroid (BFU‐E) progenitors. In contrast, cytotoxic/G‐CSF mobilization produced significantly higher yields of MNC (2·6‐fold), CFU‐GM (5·5‐fold), and BFU‐E (3·9‐fold) than did cytotoxic mobilization alone (P<0·01). The ratio of CFU‐GM to BFU‐E was not affected by G‐CSF. Furthermore, G‐CSF led to an earlier peak of CFU‐GM following chemotherapy. G‐CSF is thus effective in expanding the pool of circulating haematopoietic progenitors.