Re: MEMORY/NAIVE CELLS

From: Mario Roederer (Roederer@Darwin.Stanford.EDU)
Date: Thu Dec 18 1997 - 13:38:20 EST


>   I am looking for normal reference ranges for:
>
>   CD4+/CD45RA
>   CD4+/CD45RO
>   CD8+/CD45RA
>   CD8+/CD45RO

Nick,

these values will not help you!  CD45RA and/or RO do not adequately distinguish
naive from memory cells.  RA/RO is only a reasonable approximation in CD4 cells
from HEALTHY individuals.  In CD4, about 90% of RA+ (RO-) cells are naive--but,
in pathologic states like advanced HIV infection or after immune reconstitution
(BMT etc), this is not necessarily the case, and most RA+ CD4 cells can
actually
be memory.

In the CD8 compartment, the story is even worse, with many healthy individuals
having a large fraction of RA+ memory cells.

The best way to distinguish naive and memory cells is to include CD62L (or
CD11a) together with CD45RA and either CD4 or CD8.  Note that CD45RO really
does
not help at all; it gives exactly the same information as CD45RA but is less
bright and therefore less useful.

mr



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