Multiparametric analysis for the enumeration of CD34+ cells from bone marrow and stimulated peripheral blood

Determination of CD34+ cells was performed in bone marrow and G-CSF mobilised peripheral blood samples. We adopted three different protocols of analysis: the Milan/Mulhouse protocol, the ISHAGE guidelines for CD34+ cell determination and our own protocol based upon the use of PAINT-A-GATEPRO software analysis program. An excellent correlation was demonstrated between the three methods (r2 0.98); however the analysis of variance showed a statistically significant difference between the results generated with the three methods (P=0.001). The differences between the three procedures are discussed with a special focus on the value of CD34+dim cells and the role of CD45 in the setting of a double staining. We have in fact identified a minor subset (CD34+CD38+CD45-) which would go unrecognised based upon its CD45 negativity.