Some antibodies to the alpha beta T-cell receptor cross react with the
gamma delta T-cell receptor so that they look double positive. This can be
seen in gamma delta T-cell malignancies. However, other antibodies have
different specificities. I don't believe you can actually have coexpression
of the two and therefore the antibody studies have something wrong or the
results are due to cross reactivities. The immunophenotype of CD5-, CD4 -
and CD8- but CD56+ is consistent with our series of gamma delta T-cell
neoplasms. The J-Beta rearrangement is consistent with an alpha beta
T-cell. You need to figure out where the problem is. It is worth working
up. If you have a gamma delta T-cell malignancy with a J-Beta rearrangement
I think it is reportable.
Maryalice
>Hi everyone,
>We recently processed a hepatosplenic lymphoma in an 18 y/o BM which was very
>aggressive and which had the following phenotype:
>CD2+, CD3+, CD5-, CD7+, gamma/delta-TCR+, alpha/beta-TcR+, CD4-, CD8Ò, CD56+,
>and CD11c+. It showed J-Beta rearrangement bands, and this resembles the rare,
>but previously reported cases of aggressive gamma-delta T cell lymphomas.
>Checking several times, we confirmed the coexistence of the two forms of T
>cell
>receptor (a/b, g/d) on the cell surface. I have never seen any T cell
>tumor that
>coexpressed two TCR forms and I would appreciate any comments or advice from
>those of you who may have had previous experience with a similar tumor.
>
>Thanks,
>
>Phil Ruiz
>U. of Miami
Maryalice Stetler-Stevenson
Director Flow Cytometry Unit
Laboratory of Pathology, NCI, NIH
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