reply re hematogones

Frederic Preffer (preffer@helix.mgh.harvard.edu)
Tue, 09 Sep 1997 15:38:39 -0400

No I dont peter..in fact in my experience hematogones generally _do_
express CD10 and CD34 as well as TdT and some CD20. Commonly, there also
tends to be a characteristic 'smear' of CD20 (CD20 is not necessarily on
all CD19+ cells) and CD45 staining as well (which i *imagine* connotes a
process of differentiation), vs most ALLs which are predominantly 'locked'
(no CD45+/20+ smearing) into a clonal immunophenotype. The CD19 staining
does tend to be 'clear cut' staining, if i understand your note- but this
wouldnt help me distinguish ALL from the hematogone. I will agree this is a
most difficult area for _just_ immunophenotyping; as you probably are aware
there is a characteristic 'smudged' look to the dense chromatin with scant
or absent nucleoli, and little cytoplasm. I always work this out with the
morphologists when possible, although they also can find these calls
challenging! fyi there is some information on pgs 258-9 in BONE MARROW
PATHOLOGY, 1995 by K. Foucar, ASCAP press.

At 05:35 PM 9/9/97 +1000, Peter Chapple wrote:
>
>Dear flow-ers,
>
>I have a couple of questions to ask of the list:-
>
>1. I have a patient with ALL (CD19+, CD10+, CD34+) who is post induction,
with 21 bone marrow
>which has a clear cut population of CD19+, CD10-, CD34- cells. In my book
these are
>haematogones. Does anyone know of a definative reference on this topic
that I can use
>to convince my collegues of this ??
>
>2. I am keen to start including CD79a in my panel for lymphoid
malignancies, unfortunately all the
>CD791 clones I can locate are directed at intracellular domains on the
antigen. What a pain to
>include intracellular fix/perm steps for just 1 marker. Does anyone know
of a CD79a clone directed at
>one of the extracellular domains of this antigen ??
>
>Thanks in advance
>
>Peter Chapple
>Melbourne AUSTRALIA
>
>
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Frederic I. Preffer
preffer@helix.mgh.harvard.edu
Department of Pathology- Warren 525A
100 Blossom St
Massachusetts General Hospital
Boston MA 02114
v(617) 726-7481 fax (617) 724-3164
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