Quite right Brian about the CD68 KP1 and mast cells. And to further confuse
us, the good folks at Kiel Germany tout their KiM1P that recognizes an
epitope of CD68 as well as some other nebulous epitopes. This one reacts
with subsets of the FXIIIa+ dendrophages and all types of more phagocytic
macrophages AND mast cells.
I think the CD34/FXIIIa fibrohistiocytic motif is conserved in mice, dogs,
and probably a lot of mammals.
I'll have to try that alcian blue when we finally break down and buy the
c-kit antibody.
regards
Jeff Silverman

-----Original Message-----
From: Bryan Hewlett [mailto:bhewlett@cogeco.ca]
Sent: Wednesday, January 08, 2003 7:05 PM
To: Jeff Silverman; ian.montgomery@bio.gla.ac.uk
Cc: histonet@pathology.swmed.edu
Subject: Re: Mast cells fibroblasts, macrophages


 Ian and Jeff ,

We all seem to be assuming that Ian is staining Human tissues, is that true?
If so, then I concur with Jeff's suggestions. Mast cell tryptase is
absolutely specific, but have to add that Mast cells stained with a
combination of Alcian blue pH1.0 and CD117 are truly spectacular.
FYI, Mast cells only immunolabel for CD68 if one uses the clone KP1, they do
NOT stain for CD68 with the PG-M1 clone!

Best regards,

Bryan
(Old retired guy)


----- Original Message -----
From: "Jeff Silverman" 
To: 
Cc: 
Sent: Wednesday, January 08, 2003 4:27 PM
Subject: Mast cells fibroblasts, macrophages


> Hi Ian. Just putting the finishing touches on a paper studying just that
> combination of three cells- a triumverate that cooperate and interdigitate
> to make fibrovascular mesenchyme as part of the microvascular unit.
> Anyway--
> fibroblasts, undifferentiated dendritic interstitial type in dermis and
most
> collagenous mesenchyme use  CD34.  Fibroblasts- functional collagenous
type,
> use:  collagen type 1 aminopropeptide from U Nebraska Hybridoma bank or
> prolyl-1-hydroxylase from a number of vendors. Myofibroblasts- alpha
smooth
> muscle actin. The first type gives rise to the latter two and sometimes
CD34
> is retained along with the functional epitope, especially in
myofibroblastic
> neoplasms. Usually once a fibroblast differentiates, CD34 disappears.
>
> Macrophages or as I prefer to call them stromal assembly histiocytes-use
> Factor XIIIa.  For phagocytic macrophages I use CD68 KP1 clone. The
FXIIIa+
> dednritic cells are histiocytes I believe and are precursors to more
> functional phagocytic macrophages which are rich in lysosomes and hence
> CD68+. Mast cell granules must also incorporate the CD68 epitope in their
> matrix because Mast cells- also express CD68 but mast cell tryptase or
> c-kit/CD117 are more in vogue now and tryptase is most specific.
>
> Hope this helps. I have many references if you need.
>
>
> Jeff Silverman HT HTL QIHC (ASCP)
> Pathologists' Assistant
> Southside Hospital
> Bay Shore NY USA
>
>
>
>