Peripheral blood stem cells (PBSCs) collected after recombinant granulocyte colony stimulating factor (rhG-CSF): an analysis of factors correlating with the tempo of engraftment after transplantation.

Factors affecting mobilization and engraftment were analysed in 54 patients undergoing transplant using autologous PBSCs mobilized with high-dose recombinant granulocyte stimulating factor (rhG-CSF). Patients received 5-7 d of rhG-CSF, 16 micrograms/kg/d, administered subcutaneously. PBSCs were harvested by leukapheresis using automated continuous-flow blood cell separators beginning on day 4 of rhG-CSF, processing 10 litres of whole blood, for 2-6 consecutive days. Transplants were performed for the following diseases: breast cancer (n = 22), non-Hodgkin's lymphoma (n = 18), multiple myeloma (n = 7) and other (n = 7). Engraftment was rapid with patients reaching a neutrophil count of 1 x 10(9)/l a median of 12 d (range 9-22) after transplant. Platelets > 20 x 10(9)/l independent of transfusion support were achieved a median of day 10 (range 7-60) after infusion. Multiple factors potentially influencing engraftment were examined using a Cox regression model. The number of CD34+ cells per kg was highly correlated with the time to achievement of granulocyte and platelet recovery (P < 0.012, 0.0001). The use of a post-infusion growth factor and a radiation preparative regimen was important for neutrophil recovery, and a diagnosis of breast cancer was important for platelet recovery. In an analysis by linear regression of the logarithm of CD34+ cells collected, lower age, marrow without disease, no prior radiation, and lower number of prior chemotherapy regimens, were important factors influencing larger numbers of CD34+ cells in collections.