Michaeleen,
On the second case, are the CD5+ populations T-cells? We also need
more information about what you mean by dim and bright. As you are probably
aware, CLL and Mantle cell neoplasms are CD5+ but slightly dimmer than
normal T-cells. In addition, CLL can have very dim CD20 or CD22 that is
difficult to detect unless using the right fluorochrome. Therefore
CD20-,CD5 dim may be just CD20 very dim, CD5 dim. Some normal T-cells have
CD5 that is dimmer than the majority (e.g. gamma delta T-cells or LGL's).
You can also have dim CD5 on aute leukemias. The history of a T-cell clone
suggests they may be T-cells. Was this previously demonstrated T-cell clone
in the setting of lymphoma involving a lymph node or was it in the setting
of cytopenias and LGLs in the peripheral blood? Have you looked at
cytotoxic T-cell antigens? Are there any other T-cell abnormalities such as
CD2, CD7 or sCD3 negativity of a population equal to the dim CD5 T-Cells (I
am assuming the bright CD5 cells are not abnormally bright, just brighter
than the dim ones)? How do the dim CD5 ones cluster on FSC vrs SSC? LGLs
spread between llymphocytes and monocytes. These are interesting cases and
thank you for sharing them. Please post any comments sent directly to you
on the list for all to learn from.
Maryalice
>Cytometrists,
>I have two interesting cases that I would like some help with.
>1. The first patient appears to be a new acute leukemia with very
>large irregular cells. The bone marrow phenotypes CD13+,CD15+,CD33+,HLA DR+,
>CD45+(bright),CD14 My4+ but CD14 Mo2 negative.
>I would like to know others' experience with My4. Does it mark a
>more immature monocytoid cell? Would you call this myelomono-
>leukemia?
>2. The second case is a patient with normal numbers of all cell
>types in the peripheral blood but with two clearly different
>populations of CD5+ cells--one very bright and the other dimmer but
>still positive. They do not dual stain with B cell markers. In
>1993 the patient showed a T cell beta gene rearrangement. If we had
>not been aware of this we may not have worried so much about the
>staining. Has anyone noticed this pattern of CD5 reactivity?
>Thank you very much for your help.
>
>Michaeleen M. Collins
Maryalice Stetler-Stevenson
Director Flow Cytometry Unit
Laboratory of Pathology, NCI, NIH
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:50:00 EST