I am interested in any experience with a strange phenotype of T-cells,
which we just found in a 27 old female with a history of repeated viral
infections and serology typical for chronic persistent EBV infection.
Immunophenotyping reveals monocytopenia (3 %) and only 1 % B cells
(mature, polyclonal). CD8+ T-cells show extremely bright and
homogeneous CD33 expression (nearly two decades above normal
monocytes). CD33 expression is also increased on monocytes and
neutrophils. CD4+ T cells show a highly heterogeneous CD33 expression.
All other findings are less dramatic (normal CD4/CD8 ratio, only low
expression of HLA-DR, CD25, CD45RO on T cell subsets, slight increase
of gamma/delta T cells, slight increase of CD57+CD8+ T cells).
Looking through literature, it has been described only twice (Blood
83:1442,1994; Br J Haematol 90:512,1995) that CD33 can be induced on T
cells (IL-2 + CD3 cross linking in vitro). I never have seen this at
this degree in vivo.
I am pretty sure that the phenotype is non-malignant. Also chronic
persistent EBV in my experience rather is an expansion of
CD3+CD8+CD57+HLADR+ cells.
Is there anything known about an in vivo association of CD33++ T cells
with disease? Is this an inborne case of immunedeficiency?
Any suggestions highly welcome.
Gregor Rothe
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Institute for Clinical Chemistry and Laboratory Medicine University of
Regensburg D-93042 Regensburg, F.R. Germany
Tel. +49 (941) 944-6204 Fax +49 (941) 944-6202
Internet: Gregor.Rothe@klinik.uni-regensburg.de
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