I have two questions for the group to consider:-
1. I have just reviewed flow on a very interesting lymph node. We use =
CD45 vs SS gating on all diagnostic flow. The lymph node in question =
showed two distinct populations of cells in this strategy, one being an =
unremarkable population of lymphoid cells (30% of total) and the other =
population with precisely the same SS as lymphocytes but completely CD45 =
negative (3 decades lower than lymphocytes on the CD45 scale).
I assumed these to be non-haematologic cells (possibly carcinoma), on =
reviewing the histology of the node it looks like TB (ZN stain to =
follow) - so is the non-haematologic cell population the histocyte =
component of the disease process ??
The important question is ... what is the CD45 expression of histocytes, =
in particular do monocytes/macrophages loose their CD45 as they =
differentiate into the more epitheloid differentiation of histocytes ???
2. The second question arises from a recent response to the *clinical =
question*. One respondent suggested, among other things, the use of the =
CD45 v SS gating strategy. We use this strategy always; it's the =
backbone of all our clinical flow; and I'm always extolling colleagues =
to do the same - often without success because *it's too expensive* so =
how many other clinical labs use this routinely ???
Peter Chapple
Melbourne AUSTRALIA