Comparison of three methods of CD34 + cell enumeration in peripheral blood: dual-platform ISHAGE protocol versus single-platform, versus microvolume fluorimetry

Background: Quantitation of peripheral blood (PB) CD34+ cells is now an established method for timing PBPC harvesting. Recent refinements to the dual-platform ISHAGE gating strategy for CD34+ cells has seen the introduction of microbeads to enable absolute counting of cells on a single instrument platform. This eliminates the need for total WBCC performed on an automated hematology analyzer and potentially increases the analytical precision of the methodology. At the same time, alternative methods for CD34+ cell enumeration have started to emerge, notably microvolume fluorimetry, which forms the basis of the fully-automated STELLer CD34 method using the Imagn 2000. Methods: We performed a three-way evaluation of these methods. Sixty-eight samples of PB from 42 patients undergoing PBPC mobilization were analyzed by all three methods and correlations between all three calculated. The two-platform ISHAGE method was used as the reference method. Results: Precision and linearity of the single-platform and STEL...