REFRIGERATOR AIDS
hhscdc!reb4/O=CDC/OU=CINC/OU=NIOBBS1@mhs.attmail.com
22 Dec 92 20:23:45 GMT
Here is some more info from Jan Nicholson concerning the subject topic.
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FORWARDED FROM: Biagini, Raymond E. (Ray)
FROM: Nicholson, Janet
TO: Biagini, Raymond E. (Ray) DATE: 12-22-92
TIME: 09:32
CC:
SUBJECT: REFRIGERATOR AIDS
PRIORITY: R
ATTACHMENTS:
Ray,
This does seem to be a long way around to get a message to Marc Langweiler,
but we haven't had inquiries like this before. We (Immunology Branch,
Division of HIV/AIDS, NCID) does have access to the bulletin board you are
referring to through the VACS and some connection there. Carolyn Dawson in
my lab monitors messages there occasionally.
To reply to Marc's latest questions:
The reason that room temperature is recommended by the NCCLS is that most
studies are done on room temperature blood, and as you suggested, the nature
of the reduction in CD4 cells seen with ficolled blood is not known. We
sometimes get refrigerated blood for immunophenotyping, even in proficiency
testing specimens, and what we commonly do is to let them warm up to room
temperature before we process them. We haven't done any careful studies to
see if using them cold is just as good. In small studies in our lab as well
as others, cold specimens do not seem to present problems with the whole
blood lysis assay, but for no totally valid reason, we seem to think that
warm (room temperature) is better than refrigerator temperature.
For specimens that will be shipped, diluting them with medium was proposed in
a couple of journal articles. Certainly diluting them doesn't adversely
affect the results. My concern with diluting specimens is two-fold: 1) if
absolute numbers (including hematology) will be derived from the specimen,
the dilution obviously makes an accurate number (from hematology) impossible;
and 2) logistically, diluting specimens means that they must be transferred
out of the blood collection tube and pipetted into another tube containing
medium. Many blood collection settings do not have expertise or appropriate
conditions (pipettors, biological safety cabinets, etc.) to do this
appropriately. Just manipulating the specimen lends itself to microbial
contamination. If dilution can be done appropriately, diluted heparinized
blood is really the best specimen, in my opinion, for ficolling cells.
I'll have to find out exactly how we are connected to internet through the
VACS. Other than that, I don't know enough about our E-Mail to figure out if
there is a better connection there.
Thanks for transmitting this, Ray, and HAVE A MERRY, TOO!
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If you have any comments please direct them to Dr. J. Paul Robinson, Professor & Director, PUCL,
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