BACKGROUND AND OBJECTIVES: For timing the onset of apheresis, parameters obtained by flow cytometry and by a haematological cell analyser were compared. MATERIALS AND METHODS: Haematopoietic cell counts (n = 159) were performed by two different methods; CD34 analyses by flow cytometry, immature myeloid information (IMI) and human progenitor cell counts (HPC) by a haematological cell analyser. RESULTS: Comparing the IMI total results with CD34+ analyses (n = 159) revealed a correlation of r = 0.46 (P <0.05). Similar results were obtained for HPC (r = 0.44; P <0.05). CONCLUSION: The haematology analyser-based method does not allow the precise determination of absolute haematopoietic stem cell numbers and is thus not able to replace flow cytometry for the monitoring of peripheral blood stem cell counts.
