title: Unfractionated peripheral blood stem cell autografts and CD(34+)-enriched autografts have similar long-term culture initiating capacity in multiple myeloma.
abstract: CD(34+)-enriched peripheral blood stem cells (PBSC) are increasingly being used as an autograft in patients with multiple myeloma (MM). The rationale for the use of the CD34+-enriched fraction in MM is the ability to obtain a graft with a significant reduction of contamination by plasma cells. However, the effect of such a manipulation on the proliferating potential of the engrafted cells is not known. We wished to study, as part of a randomized trial comparing the outcome in MM patients transplanted with either CD(34+)-enriched cells or unfractionated PBSC, the primitive hematopoietic cell content of the autografts using long-term culture initiating cell (LTC-IC) assays in 7 MM patients. In 3 patients CD(34+)cell-enriched fraction was compared to unfractionated PBSC whereas in the remaining 4 patients the LTC-IC assay was performed on total PBSC. The mean percentage of CD34+ cells of the CD34+ selected fraction in three patients was 82% (range 71%-96%) whereas the same percentage in PBSC varied from 0.6% to 10% in 4 patients (mean: 4.2%). Out of three patients transplanted with CD34+ cell fraction, two patients were found to have a very similar LTC-IC generating potential in their CD34+ versus PBSC fractions as this was assessed by the clonogenic cell output at week+5 per 10(4) CD34+ cells initiating the culture (PBSC: 92 and 168 and CD34+ fraction: 102 and 16, respectively) whereas one patient had a slightly different values (PBSC: 51 and CD34+ fraction: 103). When the PBSC fraction was compared in all 7 patients, the LTC-IC generation potential was very heterogenous, varying from 1.4 to 168. To determine if the selection procedure influences the numbers of LTC-IC's in both fractions, we have performed limiting dilution assays to determine both the frequency of distribution of hematopoietic colonies and the frequency of LTC-IC's in two patients. The frequency of distribution of hematopoietic colonies was linear in both CD34+ and PBSC fractions as was the frequency of LTC-IC when the corrections were made with regard to the CD34+ cell-content of the cultures (1/20). Our results indicate that the CD34+ selection procedure used in all three patients (Ceprate) is not deleterious for the generation of LTC-IC's and these findings support the rationale for the use of this procedure in multiple for the purposes of tumor depletion.
authors.affiliation: Translational Research-Cell Therapy Laboratory, INSERM U362, Department of Medicine, Institut Gustave Roussy, Villejuif, France.
authors.forename: A G
authors.initials: AG
authors.lastname: Turhan
authors.forename: J H
authors.initials: JH
authors.lastname: Bourhis
authors.forename: M L
authors.initials: ML
authors.lastname: Bonnet
authors.forename: S
authors.initials: S
authors.lastname: Novault
authors.forename: C
authors.initials: C
authors.lastname: Bayle
authors.forename: A
authors.initials: A
authors.lastname: Bennaceur
authors.forename: W
authors.initials: W
authors.lastname: Vainchenker
authors.forename: J L
authors.initials: JL
authors.lastname: Pico
authors.forename: F
authors.initials: F
authors.lastname: Beaujean
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000097:blood* / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001521:Behavior Therapy / Q000379:methods; D018929:Cell Culture Techniques; D002455:Cell Division; D002999:Clone Cells; D016238:Cytapheresis / Q000379:methods*; D003907:Dexamethasone / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000628:therapy*; D014182:Transplantation, Autologous / Q000379:methods; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D018952:Antigens, CD34; D014750:Vincristine; D003907:Dexamethasone; D004317:Doxorubicin