title: Analysis of CD34+ cell subsets in stem cell harvests can more reliably predict rapidity and durability of engraftment than total CD34+ cell dose, but steady state levels do not correlate with bone marrow reserve.
abstract: In peripheral blood stem cell transplantation (PBSCT), the number of CD34+ cells transplanted has been shown to correlate well with both rapidity and durability of engraftment. However, it is clear that engraftment does not necessarily correlate with total CD34+ cell numbers in some patients. Consequently, there is increasing interest in evaluating the role of CD34+ subsets in haemopoietic recovery as a more accurate marker of harvest quality. We analysed the numbers of CD34+ cell subsets, namely Thy-1+, L-Selectin+ and CD38-, and correlated this with engraftment in 86 patients undergoing PBSCT. Adequate engraftment was defined as being a platelet count greater than 50 x 10(9)/l and a neutrophil count greater than 1.0 x 10(9)/l. CD34+L-Selectin+ provided the best prediction of engraftment rapidity, although the improvement over total CD34+ cell dose was minor. Only the dose of CD34+Thy-1+ cells transplanted correlated with durable engraftment. The probability of adequate 3-month engraftment increased with the dose of CD34+ cells transplanted, but 10% of patients receiving > 5 x 10(6)/kg still showed poor engraftment at 3 months. However, all patients receiving > 2.5 x 10(5)/kg CD34+Thy-1+ showed adequate engraftment at this time point. We also demonstrated that CD34+Thy-1+ progenitors were restricted to the bone marrow under normal conditions and, during stem cell mobilization, their kinetics generally paralleled total CD34+ numbers.
authors.affiliation: Institution HMDS, Department of Haematology, General Infirmary at Leeds, Calverley Street, Leeds, West Yorkshire LS1 3EX, UK.
authors.forename: G
authors.initials: G
authors.lastname: Pratt
authors.forename: A C
authors.initials: AC
authors.lastname: Rawstron
authors.forename: A E
authors.initials: AE
authors.lastname: English
authors.forename: R J
authors.initials: RJ
authors.lastname: Johnson
authors.forename: A S
authors.initials: AS
authors.lastname: Jack
authors.forename: G J
authors.initials: GJ
authors.lastname: Morgan
authors.forename: G M
authors.initials: GM
authors.lastname: Smith
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000368:Aged; D015703:Antigens, CD; D018952:Antigens, CD34 / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology; D001854:Bone Marrow Cells / Q000276:immunology; D001943:Breast Neoplasms / Q000276:immunology / Q000601:surgery; D018380:Hematopoietic Stem Cell Transplantation; D006689:Hodgkin Disease / Q000276:immunology / Q000601:surgery; D006801:Humans; D019041:L-Selectin / Q000276:immunology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000601:surgery / Q000628:therapy; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000276:immunology / Q000601:surgery; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000601:surgery; D008562:Membrane Glycoproteins; D008875:Middle Aged; D009101:Multiple Myeloma / Q000276:immunology / Q000601:surgery; D009244:NAD+ Nucleosidase / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D011379:Prognosis; D013234:Stem Cells / Q000276:immunology; D018800:Thy-1 Antigens / Q000276:immunology*; D014181:Transplantation Immunology
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D008562:Membrane Glycoproteins; D018800:Thy-1 Antigens; D019041:L-Selectin; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1