Increased levels of megakaryocyte progenitors in peripheral blood mobilised by chemotherapy and/or haemopoietic growth factor protocols.
We have quantitated colony-forming unit megakaryocyte, (CFU-Mk), burst-forming unit megakaryocyte, (BFU-Mk), colony-forming unit granulocyte-macrophage (CFU-GM), and CD34+ cells in 98 mobilised PB samples from 53 patients mobilised by one of six protocols, including myelosuppressive chemotherapy alone (n = 22), or in combination with recombinant haemopoietic growth factors (n = 32), and growth factors alone (n = 17) or in combination (n = 27). The frequency of megakaryocyte progenitors (total Mk = CFU-Mk + BFU-Mk) in mobilised PB (mean 356, range 0-3240/10(6)) was similar to that in steady-state BM (mean 429, range 0-3315/10(6) n = 45). The levels of total Mk in mobilised PB (mean 1509, range 0-36 099/ml) showed a mean 75-fold increase compared with steady state PB (mean 20, range 0-86/ml, n = 15). In mobilised PB the levels of CFU-Mk were significantly correlated with levels of BFU-Mk (rs = 0.71, P < 0.0001) and the levels of megakaryocyte progenitors correlated significantly with those of myeloid progenitors (rs = 0.59, P < 0.0001) and CD34+ cells (rs = 0.69, P < 0.0001). The mobilisation of megakaryocyte progenitors into the circulation in response to high-dose chemotherapy and/or haemopoietic growth factors contributes to an understanding of the rapid platelet recovery following PBSC transplantation and suggests that the measurement of megakaryocyte progenitors may be a useful indicator for platelet reconstitutive capacity.
Dyson
P G
PG
Transplantation Laboratory, Hanson Centre for Cancer Research, Adelaide, South Australia.
Jackson
K A
KA
McClure
B J
BJ
Rawling
T P
TP
To
L B
LB
D000328:Adult; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage; D001772:Blood Cell Count; D002985:Clinical Protocols; D003114:Colony-Forming Units Assay; D003520:Cyclophosphamide / Q000008:administration & dosage; D005260:Female; D016298:Hematopoietic Cell Growth Factors / Q000008:administration & dosage; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D008297:Male; D008533:Megakaryocytes / Q000166:cytology / Q000187:drug effects*; D009369:Neoplasms / Q000097:blood / Q000628:therapy; D010976:Platelet Count
D018906:Antineoplastic Agents, Alkylating; D016298:Hematopoietic Cell Growth Factors; D003520:Cyclophosphamide