James D'Rozario1, Robin Parisotto2, Jennifer Stapleton2, Alison Gidley3, David Owen4. 1. 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. 2. Bone Marrow Transplant Laboratory, ACT Pathology, Garran, ACT 2605, Australia. 3. Bone Marrow Transplant Unit, Clinical Haematology Department, Canberra Hospital and Health Services, Garran, ACT 2605, Australia. 4. Australian National University Medical School, Canberra, ACT 0200, Australia.
Abstract
INTRODUCTION: 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. CONCLUSION: 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. Crown
INTRODUCTION: 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. CONCLUSION: 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. Crown