? S phase or malignant aneuploid peak
Walter Sharp (102675.320@CompuServe.COM)
12 Jun 96 05:41:36 EDT
Dear All,
We have a child with generalised lymphadenopathy showing 70% peripheral
CD3+/8+/DR+ who demonstrates with PI an 11% "shoulder" to the right of the
diploid population, at first glance suggesting an increased early S phase.
Gating on the large FS cells, however, shows this shoulder to be a discrete and
tight population with a DNA index of 1.20 and occupying the first third of the
diploid S phase area.
Very few cells show in the remainder of the S phase region and none at all in
the G2/M - either of the left peak "normal" population or of the apparent
hyperdiploid "malignant" cells.
Two questions to all DNA'ers in Flowland.
1. Do you think this peak represent a de-novo neoplastic population
"transformed" from (? virally) activated T cells ?
We have read of EB virus causing malignancies of this phenotype, but nothing on
heterogeneity of DNA indexes in such neoplasms.
2. Has anyone seen a non-malignant S phase showing such a peak, which would
suggest an arrest of "normal" proliferating cells, all at exactly the same
stage of DNA synthesis.
No treatment was being administered at the time which could account for this
arrest so I guess it would have to be put down to apoptosis at a very specific
point in the cell cycle.
I stress that this PI peak is very tight, with the CV's one would normally
associate with a cohort population.
Unfortunately we do not yet have any method available here of proving clonality
in T cells.
Clinical signs are ambiguous
Any comments and hypotheses welcome - we're stumped and also divided in opinion
!
Wal Sharp
SQU
Oman
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