title: Viable CD34+/CD133+ blood progenitor cell dose as a predictor of haematopoietic engraftment in multiple myeloma patients undergoing autologous peripheral blood stem cell transplantation.
abstract: Both CD34 (cluster of differentiation 34) and the more recently described CD133 are markers of primitive stem cells with haematopoietic repopulating ability. Most transplanting centres use a minimum number of CD34+ cells as the requirement for a transplant and consider this a predictor of haematopoietic engraftment. However, transplanted CD34+ cell dose does not always give a close correlation with time to engraftment nor explain delayed engraftment in some patients. We have retrospectively evaluated the potential of measuring viable CD133+ cell numbers in the autograft as an alternative predictor of haematological engraftment after autologous stem-cell transplantation in a cohort of patients with multiple myeloma (MM). We found an average 32% loss of viability of CD34+ cells in the post-thaw sample compared with the fresh sample. Of the original estimated CD34+ cell numbers transplanted per kg, 43% of the thawed samples were double positive for CD34+/CD133+. In this patient group, the CD34+/CD133+ subset gave the closest statistical correlation with time to neutrophil engraftment (p < 0.05), particularly for patients given above median (1.8 x 10(6)/kg) dose of the double-positive cells. The CD34+/CD133+ population was the only parameter to give a significant correlation with white cell engraftment in this patient cohort (p < 0.05). There was no significant correlation between CD34+, viable CD34+ or viable CD34+/CD133+ cells/kilogram with platelet engraftment. Determination of viable CD34+/CD133+ progenitor cell dose in the autograft may be a useful tool to predict neutrophil recovery after autologous transplantation than conventional assessment of CD34+ numbers. These results warrant further investigation of the role of CD133 in haematopoietic engraftment.
authors.affiliation: Department of Clinical Haematology, Bone Marrow Transplant Laboratory, St. George Hospital, Kogarah, 2217 Sydney, NSW, Australia. christine.hicks@unsw.edu.au
authors.forename: C
authors.initials: C
authors.lastname: Hicks
authors.forename: R
authors.initials: R
authors.lastname: Wong
authors.forename: A
authors.initials: A
authors.lastname: Manoharan
authors.forename: Y L
authors.initials: YL
authors.lastname: Kwan
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D000954:Antigens, Surface; D015415:Biomarkers; D001772:Blood Cell Count; D002452:Cell Count; D006023:Glycoproteins; D006085:Graft Survival / Q000276:immunology*; D006410:Hematopoiesis; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000473:pathology; D006801:Humans; D009101:Multiple Myeloma / Q000276:immunology / Q000628:therapy*; D010455:Peptides; D036102:Peripheral Blood Stem Cell Transplantation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D019172:Transplantation Conditioning; D014182:Transplantation, Autologous
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D000954:Antigens, Surface; D015415:Biomarkers; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides