Can anyone tell me when they started to look at the cd4-cells of HIVpos? Who
else get their cd4cells evaluated? When did they start to use the Western
Blot test? What is the difference of this and ELISA? I am new infected.
03
Sep
cd4
posted by admin in Uncategorized and have Comments (2)
"linea" <travi…@hotmail.com> wrote in message
news:lwrH9.6919$8E1.129268@news4.e.nsc.no…
> Can anyone tell me when they started to look at the cd4-cells of HIVpos?
I am not 100% certain, but I think that researchers noticed the decline
in CD4 cells
without a similar decline in CD8 cells before anyone even knew exactly what
the "Gay
Related Immune Deficiency" (GRID) was caused by, back in 1981-1982 .
N Engl J Med 1982 Sep 16;307(12):729-31
T-lymphocyte subpopulations in homosexual men.
Kornfeld H, Vande Stouwe RA, Lange M, Reddy MM, Grieco MH.
PMID: 6213860
Wallace JI, Coral FS, Rimm IR, Lane H, Levine H, Reinherz EL,
Schlossman SF, Sonnabend J.
T-cell ratios in homosexuals.
Lancet. 1982 Apr 17;1(8277):908.
PMID: 6122124
The methods of counting numbers of different T-cell and B-cell types were
just beginning to
beworked out in the 1978-1984 time period:
J Immunol Methods 1979;26(1):47-60
Identification and quantitation of B and T cells by cytofluorographic
analysis.
Beveridge RA, Super BS, Chretien PB.
With cytofluorographic analysis (CFGA) of cells stained with the fluorescent
dye acridine orange (AO), the major peripheral white cell
populations–lymphocytes,
monocytes, and polymorphonuclear cells–display different characteristics
and
appear as distinct populations which can be quantitated. In this study we
present a method for determining percentages of human T and B cells
lymphocyte
subpopulations by CFGA and display of the data on a computer-generated
3-dimensional grid. Lymphocytes were depleted of either B, T, or both B and
T cells by rosetting with erythrocytes and separated by centrifugation. The
B cell
and T cell depleted and non-rosetting cell subpopulations localized on
constant,
distinct areas of the display grid. The percentages of T and B cells in
peripheral
blood samples from 6 normals analyzed by CFGA did not differ from the
results
obtained by light microscope counting (LMC).
PMID: 312304
> Who else get their cd4cells evaluated?
Normal people who participate in reseach studies aimed at understanding
the normal immunse system. People infected with various bacteria and
viruses, as part of understanding the disease process. People with
leukemia. People with any sort of immune dysfunction that is suspected
of involving subsets of T-cells or B-cells.
> When did they start to use the Western Blot test?
Very soon after a virus was discovered (named LAV, or HTLV-III at
that time) that was suspected of either causing or being directly linked
to the cause of AIDS.
JAMA 1985 Jun 21;253(23):3405-8
AIDS serology testing in low- and high-risk groups.
Carlson JR, Bryant ML, Hinrichs SH, Yamamoto JK,
Levy NB, Yee J, Higgins J, Levine AM, Holland P,
Gardner MB, et al.
The performance characteristics of the acquired immunodeficiency
syndrome (AIDS)-retrovirus serological tests including enzyme-linked
immunosorbent assay (ELISA), Western blot, and immunofluorescence
assay were defined in a clinical laboratory setting by testing 1,257
serum specimens from low- and high-risk groups for AIDS. The three
prototype AIDS retroviruses (lymphadenopathy-associated virus,
human T-lymphotropic virus III, and AIDS-associated retrovirus) were
equally suitable as target antigen for these assays. Sera from six of
74 laboratory and health care personnel and 91 of 1,014 unselected
blood donors were falsely positive by ELISA (positive to negative
ratio [P/N], greater than or equal to 2) based on the lack of Western
blot confirmation. Only two true-positives (two [0.2%] of 1,014 blood
donors) were detected in these low-risk groups. In contrast, 106 of
108 specimens with ELISA P/N ratios of 2 or greater from the high-risk
groups including asymptomatic homosexual men, hemophiliacs,
AIDS-related complex patients, and AIDS patients were positive by
Western blot and immunofluorescence assay. Four false-negative
ELISA results based on positive immunofluorescence assay and
Western blot were found in the AIDS patient group. Ten of 69 AIDS
patients were negative by all three serological tests. The consequence
of maintaining high sensitivity for the ELISA (P/N ratio, greater than or
equal to 2) as a screening test was a loss of specificity. The number
of false-positive results necessitated the use of a confirmation test with
greater specificity.
PMID: 2987558
> What is the difference of this (Western BLot) and ELISA?
Both use HIV proteins bound to a surface, to which human antibodies
will bind. Early versions of both tests used HIV proteins purified
from crude preparations of whole virus, more modern versions of both
tests use cloned viral genes to make viral proteins in bacteria which
can be more carefully purified. ELISA tests use several HIV proteins
all bound together to the bottom of a well in a plate. Western Blot tests
have each HIV protein seperated and bound to different places on
a membrane. Thus the ELISA can only tell if there are antibodies that
bind to any one of the HIV proteins in the ELISA well, whereas the
Western Blot can detect exactly which one(s) of the many HIV proteins
the subject has antibodies to.
> I am new infected.
I am sorry to hear that. I hope you take some time to learn about
what your options are for treatment. You should also learn about such
things as CD4 and CD8 counts, viral load measurements, and
other indicators of what infection means to you as an individual.
If you know exactly when you became infected, it can help to determine
whether or not the infection is "progressing" in you. Some people
are long term non-progressors, or virtually unharmed by the virus,
even without any treatment. Most people do better with treatment than
without, but no individual is a statistic, each individual has to decide
what is best for them, based on the "odds" that the statistics help
to provide.
On Wed, 4 Dec 2002, linea wrote:
> Can anyone tell me when they started to look at the cd4-cells of HIVpos? Who
> else get their cd4cells evaluated? When did they start to use the Western
> Blot test? What is the difference of this and ELISA? I am new infected.
Both WB and ELISA have a number of similarities….both are designed to
detect antibodies in the patient serum. Both rely on the ‘antibody
sandwich’ sort of detection…I’ll try with ASCII art
____________________ - Some sort of surface
$ * & – Some selection of HIV proteins bound to surface.
Y - Antibody in patient blood serum bound to protein
Y – Antibody that recognises human antibodies
** - Detection system stuck to anti-human antibody
that is visible.
In an ELISA (Enzyme Linked ImmunoSorbent Assay) the Surface in the bottom
of a plastic dish (usually a 96 well plated that is U shaped and about
half a centimetre across). A mix of proteins are bound to the surface, and
so a number of antibody species from the patients blood will bind to
them….The detection system is usually a bunch of enzymes that cause a
color change in the well – and that colour change and its strength is
measured optically….the result you get is the dilution that is needed to
remove that colour change happening. Once you have your ELISA working you
can refine it by adjusting exactly what that protein mix is…
In a Western blot you also have a protein preparation, but it is put at
the top of a gel and pushed through it with an electric current separating
the proteins by size….this is then transferred sideways to a membrane of
some sort which is the surface in the ASCII art….the patients serum is
then exposed to it and then the detection system run…again you get a
clour change of some kind but you also get a series of bands at specific
sizes so you get more information on what sticks to what.
Tim
When playing rugby, its not the winning that counts, but the taking apart
ICQ: 5178568