Assessing pilot vial material as a surrogate for functional and phenotypic stem cell markers in cryopreserved haematopoietic stem cell product: Bone Marrow Transplant

Cryopreservation is often used as a means of storing haematopoietic progenitor cell-apheresis (HPC-A) product when it is collected as part of high-dose therapy for the treatment of haematological malignancies. Processing and cryopreservation of HPC-A is known to reduce the viability and the absolute number of CD34+ cells available for reinfusion.1,2 Therefore, a pilot vial (PV) containing a small aliquot of the same HPC-A material is usually cryopreserved and stored under the same conditions enabling enumeration and viability assessment on post-thaw HPC-A material without disturbing the primary infusion bag required for the transplantation. However, whether PV material can be used to assess other functional or phenotypic stem cell markers in HPC-A material following cryopreservation has not been fully investigated. We aimed to assess whether markers of viability, early apoptosis, DNA damage signalling and oxidative damage, together with CD34+ subset analysis performed similarly between PV and HPC-A material following cryopreservation