B cell precursors
calomata at facstaff.wisc.edu
Thu Aug 21 12:03:55 EST 1997
according to our experience in the FlowCytometry Group of BIOMED Concerted
Action for Minimal Residual Disease there are three major B-cell (CD19+)
populations (=maturational stages) in the normal bone marrow differing in
expression of CD10, CD22, CD45 and CD20:
1. CD10 bright/CD22dim/CD45 dim/CD20 neg
2.CD 10 pos./CD22dim/CD45dim-pos/CD20dim
The population you describe does not fit in any of the above, unless the
antibody played up and you deal with the population 2....
Anna Porwit-MacDonald MD, PhD
Karolinska Hospital, Stockholm
>A question to the those on the list with experience in early B cells in
>normal bone marrow:-
>Would you expect SURFACE CD22 to appear before CD20 in normal B cell
>The reason I ask is we had a BM specimen in the other day in which we found
>a population of CD19+/10+/20+/22neg/45dim cells which is a phenotype we
>have seen on some of our NHL's with marrow involvement (& of course 22 is
>neg on most of our CLL's).
>I ran out of specimen before I could do any more CD's.
>The percentage of these cells is too low to give a definitive diagnosis and
>I don't want to mix up lymphoma cells with normal precursors.
>Sorry for such a basic question but I deal almost exclusively with ALL's
>where CD22 almost invariably appears before CD20 on the surface - at least
>with our leuks, which tend to be different from "western" types
>We have asked them (another hospital) to send us a suspension from a node
>Oman (for the time being!)
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