Minimal Residual Disease (MRD) in AML using flow cytometry Adhra.Almawali at
Thu Nov 17 21:31:08 EST 2005

Dear Flowers,

I have	several questions about MRD in AML patients.
It will be highly appreciated if any one could help in these questions or had
any experience in this field.

as you know in AML, sometimes we can get more than one blast subset in which
some markers will appear positive in one blast subset and negative in the other
blast subset , so what is the best way of  gating on the blast population? Is it
by gating on the whole blast population or taking every blast subset as
individual gate.

The other thing is we always use the progenitor markers as CD34 and CD117 as
indication of blast population by back gating to identify the blast population
, however, there are some cases of AML where we can find CD34 negative or CD117
negative so what is the best way to identify the blast population in these

Another question is:  in cases of M4 or M5 , the blast population always merged
into the monocyte population and that is expected!! in these cases, however, we
always expect to find some of the markers positive for monocyte like CD64, CD65
or CD11b , so here what is the best way to identify the leukemia-associated
phenotpes (LAP), will we still look at the co-expression of the progenitors and
these markers, what if	in this case of negative CD34 or negative CD117??

The last question is : in the follow up samples where you expect to find very
few blasts, what is the best way of gating, I think it is very important to
identify the right blast population in this case which was in the same place at

Any help in these questions will greatly appreciated 
Thank you very much in advance

Kind regards,
Mrs. Adhra Al-Mawali
PhD student- University of Adelaide
Institute of Medical and Veterinary Science (IMVS)
Division of Immunology and Haematology
South Australia
Frome Road, Adelaide SA 5000

Tel (61) 8 8222 3491

Fax (61) 8 8222 3485

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