The comparison of the notations for quantitative evaluation of adhesive molecules’ expression on CD34 positive cells.

Abstract

There are various quantitative notations for molecule expression on cells, such as the percentage of positive expressing cells (PPC) and the mean fluorescence intensity (MFI). As to MFI, some evaluate only MFI-PF among cells in positive fraction (PF), which express blighter fluorescence than that of iso-type control anti-bodies, the others do MFI PF&NF among cells in PF and negative fraction (NF). We had published that the MFI-PF&NF of CD11a and CD11b on CD34 positive cells (CD34+) in peripheral blood (PB) were inversely correlated to the yields of total collected CD34+ before administration of granulocyte-colony stimulating factor (G-CSF). Although some authors have reported similar analysis, they represented the expressions of these adhesion molecules by PPC or MFI-PF. Thus, the direct comparison of these results was impossible. We have analyzed the significance of the change of PPC, MFI-PF and MFI-NF of CD11a and CD11b, and the correlations of the yield of PB graft (YPBG). No significant changes ware indicated with 2-way ANOVA in PPC neither by the number of days administrating G-CSF (Days), nor the YPBG, while there were significant changes in MFI-PF&NF. The same test indicated not only significant change of MFI-PF of CD11a by Days, but also that of MFI-NF of CD11a by YPBG. The significant correlation between the PPC and the YPBG was not shown. MFI-PFs of CD11a and CD11b on day 1 indicated significant inverse correlations with the YPBG. MFI-NFs of CD11a and CD11b indicated no significant correlations with the YPBG. PPC does not represent the quantity of expression on each cell, thus isn’t suitable for the evaluation of changes of each cell. The value of the lower fluorescence, which derived from non-specific binding of anti-bodies, was commonly recognized as meaningless. The presenting results suggested that the value of the lower fluorescence area had some important mean in a certain situation.