title: Pre infusion, post thaw CD34+ peripheral blood stem cell enumeration as a predictor of haematopoietic engraftment in autologous haematopoietic cell transplantation.
abstract: BACKGROUND
  By convention, peripheral blood stem cell products for autologous transplantation are evaluated for quality by CD34(+) cell dose at the time of harvesting. A CD34(+) cell dose in excess of 2.0 × 10(6)/kg of recipient body weight is considered adequate for haematopoietic engraftment. Viable CD34(+) cell numbers are enumerated in most laboratories using the ISHAGE single platform flow cytometric method which utilizes monoclonal antibodies to CD45, CD34 and 7 amino actinomycin D (7AAD) dye exclusion.
  
  
  METHODS
  One hundred and six consecutive autologous transplantation procedures underwent viable CD34(+) cell enumeration at the time of harvesting and post thaw prior to re-infusion. Neutrophil and platelet engraftment and markers of haematopoietic support were analyzed.
  
  
  RESULTS
  Mean pre-cryopreservation viable CD34(+) numbers were 4.882 × 10(6)/kg. Mean post thaw viable CD34(+) numbers were 3.234 × 10(6)/kg. Mean loss of viable CD34(+) cells with processing and cryo-preservation was 1.648 × 10(6)/kg (33%). For neutrophil engraftment, there was no significant difference between high (⩾ 3.0 × 10(6)/kg) and low (<1.5 × 10(6)/kg) post thaw viable CD34(+) cell counts (p=0.545). For platelet engraftment, there was however a significant difference observed between the high and low pre infusion viable CD34(+) groups (p<0.001). Additionally, significant differences were seen between the post thaw viable CD34(+) cell count and the associated length of hospital admission, days of use of G-CSF post transplantation, use of antibiotics in the post transplantation period and transfusion support in the post transplantation period.
  
  
  CONCLUSIONS
  A significant loss of viable CD34(+) cells occurs during processing, cryopreservation and thawing. Low numbers of viable CD34(+) cells infused post thaw will still result in adequate neutrophil engraftment however may delay platelet engraftment. Low viable CD34(+) cell numbers have significant effects on admission duration and use of haematopoietic supportive measures with consequent effects on healthcare resources.
authors.affiliation: Bone Marrow Transplant Laboratory, ACT Pathology, Garran, ACT 2605, Australia; Australian National University Medical School, Canberra, ACT 0200, Australia; Bone Marrow Transplant Unit, Clinical Haematology Department, Canberra Hospital and Health Services, Garran, ACT 2605, Australia. Electronic address: james.drozario@act.gov.au.
authors.forename: James
authors.initials: J
authors.lastname: D'Rozario
authors.affiliation: Bone Marrow Transplant Laboratory, ACT Pathology, Garran, ACT 2605, Australia.
authors.forename: Robin
authors.initials: R
authors.lastname: Parisotto
authors.affiliation: Bone Marrow Transplant Laboratory, ACT Pathology, Garran, ACT 2605, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Stapleton
authors.affiliation: Bone Marrow Transplant Unit, Clinical Haematology Department, Canberra Hospital and Health Services, Garran, ACT 2605, Australia.
authors.forename: Alison
authors.initials: A
authors.lastname: Gidley
authors.affiliation: Australian National University Medical School, Canberra, ACT 0200, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Owen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000628:therapy; D018952:Antigens, CD34; D064592:Autografts; D015925:Cryopreservation; D005260:Female; D006085:Graft Survival; D006412:Hematopoietic Stem Cells; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000628:therapy; D009369:Neoplasms / Q000628:therapy; D009504:Neutrophils; D036102:Peripheral Blood Stem Cell Transplantation; D012189:Retrospective Studies
chemical_list: D018952:Antigens, CD34
keywords: Autologous transplantation; CD34(+) cell count; Neutrophil engraftment; Platelet engraftment