Correlations between hematopoietic progenitor cell counts as measured by Sysmex and CD34+ cell harvest yields following mobilization with different regimens.
OBJECTIVE
The Sysmex SE-9000 cell counter provides an estimate of immature cells referred to as hematopoietic progenitor cells (HPC). HPC counts should correlate with CD34+ counts in mobilized peripheral blood and apheresis to allow optimization of apheresis timing.


METHODS
We correlated the HPC counts as measured in the immature information channel with CD34+ cell levels as determined by FACS (HPCA-2 antibody, Becton Dickinson) from mobilized peripheral blood in 40 samples (27 patients and three healthy donors) and in aphereses ( n=113, 41 patients and 20 healthy donors).


RESULTS
In mobilized blood, HPC counts were correlated with CD34+ cells ( r=0.78, P<0.0001, n=40). The HPC counts were about 1.5-fold higher than CD34+ cell counts with a median (range) of 84 (1-747)/microl and 57 (1-370)/microl, respectively. In CD34+ selected cell preparations ( n=8), HPC counts were about fourfold lower than CD34+ cell counts with a median (range) of 179 (67-693)/microl and 760 (191-4309)/microl, respectively. In apheresis preparations, linear regression analyses were performed for the group of stem cell donors ( n=44), the group of lymphoma patients ( n=23), the multiple myeloma group ( n=21), and the group of solid tumors ( n=25). Interestingly, no correlation between HPC counts and CD34+ cell counts was found in the G-CSF-mobilized healthy donor group ( r=0.23, P=0.13). Pairing of HPC counts and CD34+ counts was effective in the group of patients receiving chemotherapy + G-CSF for stem cell mobilization: lymphoma group ( r=0.67, P=0.0005), multiple myeloma group ( r=0.56, P=0.008), and the group of solid tumors ( r=0.52, P=0.007).


CONCLUSIONS
Lymphoma and multiple myeloma patients who were moderately pretreated and mobilized with chemotherapy and G-CSF showed the best results in correlation analyses even at low HPC counts. Therefore, HPC measurement can be used for timing of apheresis in these patients.
Vogel
W
W
Department of Hematology, Oncology, Rheumatology, and Immunology, Medical Center II, Eberhard Karls University, Otfried-Müller-Str. 10, 72076 Tübingen, Germany.
Kopp
H G
HG
Kanz
L
L
Einsele
H
H
D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000097:blood*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002452:Cell Count; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D006801:Humans; D000078224:Lenograstim; D008223:Lymphoma / Q000097:blood* / Q000188:drug therapy; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000188:drug therapy; D009369:Neoplasms / Q000097:blood* / Q000188:drug therapy; D011237:Predictive Value of Tests; D011994:Recombinant Proteins / Q000627:therapeutic use*; D012016:Reference Values; D012044:Regression Analysis
D018952:Antigens, CD34; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D000078224:Lenograstim