Dear Adrian,
First of all, on behalf of the entire world of civilized cytometrists and
hematopathologists, we apologize summarily for the incredibly rude response
given by the individual in Seattle. I would be afraid to ask a legitimate
question if I knew that my practice would be inappropriately insulted. While
such acts of "roundsmanship" are unfortunately commonplace in academic medicine,
they are a detriment to the scientific process and a danger to patient care, as
everyone ends up refusing to admit when they don't know something!
Secondly, try gating on the lymphocytes and any population of large
mononuclear cells. Usually clinicians are looking for involvement by lymphoma,
or blasts in the case of leukemia or transforming myelodysplasia. We use FITC
anti-CD45 and a combo of PE anti-glycophorin and PE anti-CD14 to check our gate,
the PE labeled antibodies are to help ascertain when we are merely looking at
normal monos or nucleated RBCs. If you find cells in the lymph or small
mononuclear cell gate that have an order of magnitude dimmer LCA (CD45), there
is a good chance that they may be abnormal. If there's no history available
(and even if there is), we usually make a smear of whatever we get to see what's
in there. Another way to go if you do 3-color work is to gate on dim LCA
positive cells with low light scatter, i.e., to the dim LCA side of the lymphs.
This will allow you to pick up small numbers of blasts, if you're looking for
minimal residual disease. Otherwise, with no history, we look for a B-cell
clone or abnormal antigenic expression in the lymphocyte gate, as flow is more
sensitive than morphology for picking up low levels of lymphoma involvement.
Third, one of my favorite references for these issues is the now 2nd edition
of Flow Cytometry and Clinical Diagnosis by Keren, Hanson and Hurtubise,
available from the American Society of Clinical Pathology Press. You can call
and order one from them toll free, 800-621-4142
Best wishes,
Brad Sherburne
Co-Director of Hematopathology
Beth Israel Deaconess Med Center
Boston, MA
_______________________________________________________________________________
Subject: CLINICAL question: bone marrow
From: Adrian O Vladutiu <vladutiu@acsu.Buffalo.EDU> at smtplink-nedh
Date: 5/15/97 11:47 PM
We receive more and more bone marrow aspirates for flow cytometry
analysis. How does the group feel about the value of bone marrow analysis?
How does one gate cells (or analyze ungated cells)? In what conditions is
the bone marrow analysis most useful? Finally, are there references of
general interest regarding clinical value of bone marrow analysis by flow
cytometry?
Thank you in advance for your help.
Adrian Vladutiu
The Buffalo General Hospital
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