 |
 |
 |
 |
We have recently started using CD45 PerCP vs Log SS as a gating strategy for
leukemia typing along the lines of Borowitz etal Am J Clin Pathol 1993.
In many cases we find the intensity of CD45 staining varies substantially
depending on whether other antibodies in the same tube are positive or
negative. In some cases a discrete sub-population of *blasts* is present
with slightly brighter labeling than the main group of cells. When the FITC
and/or PE conjugated antibodies are positive this sub-population *disappears*.
By *disappear* I mean that the mean channel of the brighter labeling
sub-population drops down so that this group of cells coalesce with the main
group of blasts.
This effect has been noted with dual positive blasts cells for combinations
such as CD13/PE & CD7/FITC or CD33/PE & CD19/FITC, but also occurs with only
a single additional positive antibody such as HLA-DR/PE.
My question is this ... do other people doing leukemia typing experience
this and if so, how do you;
(a) Set analysis gates - presumably the only option is to set a gate wide
enough to *catch* both populations of *blast* cells when/if they occur
(b) explain to your *superiors* why there is so much tube-to-tube variation
in the CD45 labeling.
(c) ??? Am I making a *terrible mistake*, is the main group of blast cells
not blasts at all ??? - I'm using Ficolled Peripheral blood at this stage so
I can't imagine what else they could be ... total confusion reigns :-(
Thanks for all replys
Peter Chapple
Senior Scientist - Haematology
Peter MacCallum Cancer Institute
Melbourne AUSTRALIA
|
|
|
|