Laboratory Test Reference Guide

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Haematopoietic progenitor cells (HPC) are obtained either through a bone marrow harvest or from GCSF-mobilised peripheral blood of the identified donor. Over the years various modalities have been utilised to establish the adequacy of harvested stem cell product e.g. Colony-forming unit – granulocyte monocyte (CFU-GM) assay, total mononuclear cell count (MNC), and CD34+ cell count. Here in Waikato Hospital, the flow cytometry area of haematology department performs CD34+ to enumerate these stem cells. HPC is established, not to replace the CD34+ but to triage/filter the samples that will go through flow cytometry area.

HPC counts can be used to schedule the start of CD34+ measurements in patients mobilised after chemotherapy for autologous donation. Thus, expensive and time-consuming CD34+ enumerations can perhaps be minimised. HPC measurements cannot completely replace flow cytometric CD34+ enumeration. In particular healthy stem-cell donors should be monitored with both methods to exclude false negative HPC measurements.

Auto comments are added depending on the value of the result.

Comment code: HPCHCOM1

HPC =< 5.3 cells/mcL - Correlates with CD34 <10 cells/mcL thus predicts an inadequate stem cell yield. It is advised to not proceed with stem cell apheresis. It may be appropriate to optimise adjunctive mobilising medications. Dr. Helen Moore (Laboratory Haematologist)

Comment code: HPCHCOM2

HPC 5.4 - 17.2  cells/mcL - Indeterminate HPC result that did not meet negative or positive cutoffs in validation cohort. Correlate and be guided by CD34. Dr. Helen Moore (Laboratory Haematologist)

Comment code: HPCHCOM3

HPC >= 17.3 cells/mcL - Correlates with CD34>20 cells/mcL and predicts a good harvest. Proceeding with stem cell apheresis is recommended. Dr. Helen Moore (Laboratory Haematologist)

NOTE: HPC is currently reported simultaneously with CD34+ and not yet used to triage samples for flow cytometry (subject to final approval).

 1 mL whole blood EDTA