"unacceptably high percentage of indeterminate results

PAULKING 2005-02-17 02:20:12

The medical literature lists dozens of reasons for positive HIV test
results: "transfusions, transplantation, or pregnancy, autoimmune
disorders, malignancies, alcoholic liver disease, or for reasons that are
unclear..."(Archives of Family Medicine. Sept/Oct. 2000).

"[H]uman or technical errors, other viruses and vaccines" (Infectious
Disease Clinician of North America. 7; 1993)

"[L]iver diseases, parenteral substance abuse, hemodialysis, or
vaccinations for hepatitis B, rabies, or influenza..." (Archives of
Internal Medicine. August. 2000).

"[U]npasteurized cows' milk... Bovine exposure, or cross-reactivity with
other human retroviruses" (Transfusion. 1988)

Even geography can do it:
"Inhabitants of certain regions may have cross-reactive antibodies to
local prevalent non-HIV retroviruses" (Medicine International. 56; 1988).

The same is true for the confirmatory test - the Western Blot.
Causes of indeterminate Western Blots include: "lymphoma, multiple
sclerosis, injection drug use, liver disease, or autoimmune disorders.
Also, there appear to be healthy individuals with antibodies that
cross-react...." (Archives of Internal Medicine. August. 2000).

"The Western Blot is not used as a screening tool because...it yields an
unacceptably high percentage of indeterminate results." (Archives of
Family Medicine. Sept/Oct 2000)

Pregnancy is consistently listed as a cause of positive test results, even
by the test manufacturers. "[False positives can be caused by] prior
pregnancy, blood transfusions... and other potential nonspecific
reactions." (Vironostika HIV Test, 2003).

This is significant in Africa, because HIV estimates for African nations
are drawn almost exclusively from testing done on groups of pregnant
women.

In Zimbabwe this year, the rate of HIV infection among young women
decreased remarkably, from 32.5 to 6 percent. A drop of 81% - overnight.
UNICEF's Swaziland representative, Dr. Alan Brody, told the press "The
problems is that all the sero-surveillance data came from pregnant women,
and estimates for other demographics was based on that." (PLUS News,
August, 2004)

When these pregnant young women are tested, they're often tested for other
illnesses, like syphilis, at the same time. There's no concern for
cross-reactivity or false-positives in this group, and no repeat testing.
One ELISA on one girl, and 32.5% of the population is suddenly HIV
positive.

The June 20, 2004 Boston Globe reported that "the current estimate of 40
million people living with the AIDS virus worldwide is inflated by 25
percent to 50 percent."

They pointed out that HIV estimates for entire countries have, for over a
decade, been taken from "blood samples from pregnant women at prenatal
clinics."

But it's not just HIV estimates that are created from testing pregnant
women, it's "AIDS deaths, AIDS orphans, numbers of people needing
antiretroviral treatment, and the average life expectancy," all from that
one test.

I've certainly never seen this in VH1 ad.

At present there are about 6 dozen reasons given in the literature why the
tests come up positive. In fact, the medical literature states that there
is simply no way of knowing if any HIV test is truly positive or negative:

"[F]alse-positive reactions have been observed with every single HIV-1
protein, recombinant or authentic." (Clinical Chemistry. 37; 1991). "Thus,
it may be impossible to relate an antibody response specifically to HIV-1
infection." (Medicine International. 1988)

And even if you believe the reaction is not a false positive, "the test
does not indicate whether the person currently harbors the virus."
(Science. November, 1999).

The test manufacturers state that after the antibody reaction occurs, the
tests have to be "interpreted." There is no strict or clear definition of
HIV positive or negative. There's just the antibody reaction. The reaction
is colored by an enzyme, and read by a machine called a spectrophotometer.

The machine grades the reactions according to their strength (but not
specificity), above and below a cut-off. If you test above the cut-off,
you're positive; if you test below it, you're negative.
So what determines the all-important cut-off? From The CDC's instructional
material: "Establishing the cutoff value to define a positive test result
from a negative one is somewhat arbitrary." (CDC-EIS "Screening For HIV,"
2003 )

The University of Vermont Medical School agrees: "Where a cutoff is drawn
to determine a diagnostic test result may be somewhat arbitrary... .Where
would the director of the Blood Bank who is screening donated blood for
HIV antibody want to put the cut-off?...Where would an investigator
enrolling high-risk patients in a clinical trial for an experimental,
potentially toxic antiretroviral draw the cutoff?" (University of Vermont
School of Medicine teaching module: Diagnostic Testing for HIV Infection)

A 1995 study comparing four major brands of HIV tests found that they all
had different cut-off points, and as a result, gave different test results
for the same sample: "[C]ut-off ratios do not correlate for any of the
investigated ELISA pairs," and one brand's cut-off point had "no
predictive value" for any other. (INCQS-DSH, Brazil 1995).

I've never heard of a person being asked where they would "want to put the
cut-off" for determining their HIV test result, or if they felt that
testing positive was a "somewhat arbitrary" experience.

In the UK, if you get through two ELISA tests, you're positive. In
America, you get a third and final test to confirm the first two. The test
is called the Western Blot. It uses the same proteins, laid out
differently. Same proteins, same nonspecific reactions. But this time it's
read as lines on a page, not a color change. Which lines are HIV positive?
That depends on where you are, what lab you're in and what kit they're
using.

The Mayo Clinic reported that "the Western blot method lacks
standardization, is cumbersome, and is subjective in interpretation of
banding patterns." (Mayo Clinic Procedural. 1988)

A 1988 study in the Journal of the American Medical Association reported
that 19 different labs, testing one blood sample, got 19 different Western
Blot results. (JAMA, 260, 1988)

A 1993 review in Bio/Technology reported that the FDA, the CDC/Department
of Defense and the Red Cross all interpret WB's differently, and further
noted, "All the other major USA laboratories for HIV testing have their
own criteria." (Bio/Technology, June 1993)

In the early 1990s, perhaps in response to growing discontent in the
medical community with the lack of precision of the tests, Roche
Laboratories introduced a new genetic test, called Viral Load, based on a
technology called PCR. How good is the new genetic marvel?

An early review of the technology in the 1991 Journal of AIDS reported
that "a true positive PCR test cannot be distinguished from a false
positive." (J.AIDS, 1991)

A 1992 study "identified a disturbingly high rate of nonspecific
positivity," saying 18% antibody-negative (under the cut-off) patients
tested Viral Load positive. (J. AIDS, 1992)

A 2001 study showed that the tests gave wildly different results from a
single blood sample, as well as different results with different test
brands. (CDC MMWR. November 16, 2001)

A 2002 African study showed that Viral Load was high in patients who had
intestinal worms, but went down when they were treated for the problem.
The title of the article really said it all. "Treatment of Intestinal
Worms Is Associated With Decreased HIV Plasma Viral Load." (J.AIDS,
September, 2002)

Roche laboratories, the company that manufactures the PCR tests, puts this
warning on the label:
"The AMPLICOR HIV-1 MONITOR Test... .is not intended to be used as a
screening test for HIV or as a diagnostic test to confirm the presence of
HIV infection."

But that's exactly how it is used - to convince pregnant mothers to take
AZT and Nevirapine and to urge patients to start the drugs.

The medical literature adds something truly astounding to all of this. It
says that reason HIV tests are so non-specific and need to be interpreted
is because there is "no virologic gold standard" for HIV tests.

The meaning of this statement, from both the medical and social
perspective, is profound. The "virologic gold standard" is the isolated
virus that the doctors claim to be identifying, indirectly, with the test.

Antibody tests always have some cross-reaction, because antibodies aren't
specific. The way to validate a test is to go find the virus in the
patient's blood.

You take the blood, spin it in a centrifuge, and you end up with millions
of little virus particles, which you can easily photograph under a
microscope. You can disassemble the virus, measure the weight of its
proteins, and map its genetic structure. That's the virologic gold
standard. And for some reason, HIV tests have none.

In 1986, JAMA reported that: "no established standard exists for
identifying HTLV-III [HIV] infection in asymptomatic people." (JAMA. July
18, 1986)

In 1987, the New England Journal of Medicine stated that "The meaning of
positive tests will depend on the joint [ELISA/WB] false positive rate.
Because we lack a gold standard, we do not know what that rate is now. We
cannot know what it will be in a large-scale screening program." (
Screening for HIV: can we afford the false positive rate?. NEJM. 1987)

Skip ahead to 1996; JAMA again reported: "the diagnosis of HIV infection
in infants is particularly difficult because there is no reference or
'gold standard' test that determines unequivocally the true infection
status of the patient. (JAMA. May, 1996)

In 1997, Abbott laboratories, the world leader in HIV test production
stated: "At present there is no recognized standard for establishing the
presence or absence of HIV antibody in human blood." (Abbot Laboratories
HIV Elisa Test 1997)

In 2000 the Journal AIDS reported that "2.9% to 12.3%" of women in a study
tested positive, "depending on the test used," but "since there is no
established gold standard test, it is unclear which of these two
proportions is the best estimate of the real prevalence rate... " (AIDS,
14; 2000).

If we had a virologic gold standard, HIV testing would be easy and
accurate. You could spin the patient's blood in a centrifuge and find the
particle. They don't do this, and they're saying privately, in the medical
journals, that they can't.

That's why tests are determined through algorithms - above or below
sliding cut-offs; estimated from pregnant girls, then projected and
redacted overnight.

By repeating, again and again in the medical literature that there's no
virologic gold standard, the world's top AIDS researchers are saying that
what we're calling HIV isn't a single entity, but a collection of
cross-reactive proteins and unidentified genetic material.

And we're suddenly a very long way from the public face of HIV.

But the fact is, you don't need to test HIV positive to be an AIDS
patient. You don't even have to be sick.

In 1993, the CDC added "Idiopathic CD4 Lymphocytopenia" to the AIDS
category. What does it mean? Non-HIV AIDS.

In 1993, the CDC also made "no-illness AIDS" a category. If you tested
positive, but weren't sick, you could be given an AIDS diagnosis. By 1997,
the healthy AIDS group accounted for 2/3rds of all US AIDS patients.
(That's also the last year they reported those numbers). (CDC Year-End
Edition, 1997)

In Africa, HIV status is irrelevant. Even if you test negative, you can be
called an AIDS patient:

From a study in Ghana: "Our attention is now focused on the considerably
large number (59%) of the seronegative (HIV-negative) group who were
clinically diagnosed as having AIDS. All the patients had three major
signs: weight loss, prolonged diarrhea, and chronic fever." (Lancet.
October,1992)

And from across Africa: "2215 out of 4383 (50.0%) African AIDS patients
from Abidjan, Ivory Coast, Lusaka, Zambia, and Kinshasa, Zaire, were
HIV-antibody negative." (British Medical Journal, 1991)

Non-HIV AIDS, HIV-negative AIDS, No Virologic Gold standard - terms never
seen in an HIV ad.
But even if you do test "repeatedly" positive, the manufacturers say that
"the risk of an asymptomatic [not sick] person developing AIDS or an
AIDS-related condition is not known." (Abbott Laboratories HIV Test, 1997)

If commerce laws were applied equally, the "knowing is beautiful" ads for
HIV testing would have to bear a disclaimer, just like cigarettes:

"Warning: This test will not tell you if you're infected with a virus. It
may confirm that you are pregnant or have used drugs or alcohol, or that
you've been vaccinated; that you have a cold, liver disease, arthritis, or
are stressed, poor, hungry or tired. Or that you're African. It will not
tell you if you're going to live or die; in fact, we really don't know
what testing positive, or negative, means at all."