title: Clearance kinetics of CD34+ cells from peripheral blood: an independent predictor of hematologic recovery after high-dose chemotherapy and hematopoietic stem cell transplantation.
abstract: We measured the concentration of CD34+ cells in peripheral blood (PB) (1/2) h prior to and (1/2), 1, 3, 6, and 12 h following hematopoietic stem cell (HSC) infusion in 34 breast cancer patients treated with high-dose chemotherapy (HDC). The decrease in these concentrations over time enabled us to determine the clearance kinetics of CD34+ cells from PB. The absolute number of CD34+ cells in PB generally peaked at (1/2) h after infusion, then rapidly declined from 1 to 3 h post infusion and continued to fall until 12 h post transplant, but more slowly. In univariate analysis, CD34+cells/kg infused, CFU-GM/kg infused, the CD34+ count at (1/2) h, and the 12-h clearance of CD34+ cells from PB were predictors of hematologic recovery, as were each of the two phases of clearance when the slope was divided into rapid and slow phases (from (1/2) to 3 and from 3 to 12 h post transplant, respectively). We then stratified our population by the number of CD34+ cells/kg infused. In group 1, patients received </=7.5 x 10(6) CD34+ cells/kg; in group 2, >7.5 x 10(6) CD34+ cells/kg. After adjusting for CD34+ cells injected, age, and purged or unpurged graft in multivariate analysis, the 12 h clearance remained a predictor of hematologic recovery in group 1. In addition, the second phase of clearance (from 3 to 12 h after infusion) was an even better predictor than the 12 h clearance. In group 2, however, no statistically significant correlation was observed, even with the number of HSC injected. Results suggest that rapidity of clearance of CD34+cells from PB is an independent indicator of hematologic recovery in patients receiving lower doses of CD34+ cells. When the cell dose injected is over a threshold, PB clearance correlations with hematologic recovery are masked.
authors.affiliation: Laboratory of Experimental Oncology and Hematology, Catholic University of Louvain (UCL), Brussels, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: D'Hondt
authors.forename: J
authors.initials: J
authors.lastname: Wuu
authors.forename: M
authors.initials: M
authors.lastname: André
authors.forename: C
authors.initials: C
authors.lastname: Lerberghe
authors.forename: T
authors.initials: T
authors.lastname: Guillaume
authors.forename: A M
authors.initials: AM
authors.lastname: Feyens
authors.forename: Y
authors.initials: Y
authors.lastname: Humblet
authors.forename: A
authors.initials: A
authors.lastname: Dromelet
authors.forename: B
authors.initials: B
authors.lastname: Chatelain
authors.forename: J
authors.initials: J
authors.lastname: Longueville
authors.forename: F
authors.initials: F
authors.lastname: Stewart
authors.forename: V
authors.initials: V
authors.lastname: D'Hondt
authors.forename: M
authors.initials: M
authors.lastname: Symann
mesh_terms: D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001772:Blood Cell Count; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000628:therapy; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000008:administration & dosage; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006801:Humans; D007700:Kinetics; D015993:Life Tables; D008875:Middle Aged; D016879:Salvage Therapy; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D018952:Antigens, CD34; D015251:Epirubicin; D003520:Cyclophosphamide; D005472:Fluorouracil