Timing of Peripheral Blood Stem Cell Yield: Comparison of Alternative Methods with the Classic Method for CD34⁺ Cell Determination

Figure 6

Protocol for the investigation of HPC in the peripheral blood. The results of our study showed that if the number of HPC cells was higher than 32/μL, the quality of the PBSC concentrate was good (i.e., the yield of CD34⁺ cells was sufficient); because the results of HPC enumeration are reliable, there is no need to measure the number of CD34⁺ cells. In situations when the HPC number is between 10 and 32/μL, we recommend an additional CD34⁺ cell count to precisely determine the time suitable for the initiation of PBSC collection (because while the HPC numbers and CD34⁺ expression in peripheral blood correlated very well, the correlation, however, was found to be weak between the HPC numbers and the yield). If the HPC number is lower than 10/μL, there is no hope of a sufficient yield and it is not necessary to verify this situation by CD34⁺ cell enumeration; the collection in this case is not initiated.