HIV 양성인이 HIV 테스트의 비과학성에 대해 법원에 소승을 내다. |
The Business 9/10 May 2004
Part 1. Why an HIV test may not provide proof positive at all. The critical flaws in the methods we use to detect the killer virus
By Neville Hodgkinson
Legal challenges to the validity of the HIV test, whose introduction 20 years ago led to the belief that millions of people are infected with a virus that will eventually cause them to die of Aids, are being mounted in the United States and France. In both cases, plaintiffs are citing the work of a group of scientists based in Perth, Western Australia, which has published evidence that contrary to widespread medical belief, none of the HIV test kits is capable of showing a person to be infected.
In Kansas, Calypte Biomedical Corporation (CBC) and Roche Diagnostics, two test kit manufacturers, are being sued for damages under that state’s Consumer Protection Act. In court papers filed on April 12, Kim Bannon says that 12 years ago, during routine medical testing, she was diagnosed “indisputably” HIV-infected at Kansas University School of Medicine. She was told that she would develop Aids within five to seven years and die soon afterwards.
Subsequent testing from 1996 to 2003 repeatedly reconfirmed the diagnosis. Today, she remains healthy and free of any symptoms of Aids.
Bannon says that two years ago, she discovered that the science, methodology and assumptions relied on by CBC and Roche as the basis for their tests are flawed. She is claiming civil penalties for misrepresentation and damages for the resulting “mental anguish, pain and suffering, shame and humiliation” as well as loss of earnings. She has sold her house to finance the law suit; with the support of her counsel, Dennis Webb, a Wichita, Kansas attorney, she is inviting others with an “HIV” diagnosis to join her, possibly in a type of class action.
In Paris, Philippe Autrive, a lawyer specialising in health and human rights, has taken up the case of Mark Griffiths, an Englishman living in France who was diagnosed HIV-positive in May 1986 while undergoing treatment for heroin addiction. He still tests HIV-positive but remains well. His complaint, against the Institut Pasteur and others, is for “administering dangerous substances, endangering life, falsification and using falsified material.”
Bannon and Griffiths both say their diagnosis led them to a journey of discovery in which they became outraged by misunderstandings over the tests for HIV and the failure of commercial and other interests to put them right. Griffiths, who has researched the issue for 16 years, said he hopes his case will lift the “fear, stigmatisation and ignorance” surrounding a positive test result. Bannon says she spent 10 years “doubting yet living with the stigma of conventional Aids dogma” before stumbling on an article by the Perth scientists.
“I realise that my life might be more peaceful if I just kept my HIV status under wraps and went on with the knowledge that I’m not going to die from Aids,” she says. “But my soul would not be at peace knowing that so many suffer from the orthodox viewpoint.”
In a series of papers published over more than a decade but ignored to date by most mainstream Aids experts, the Perth group has challenged the belief that the HIV test has ever been shown to relate to a specific virus. They say it is a non-specific test that detects raised levels of a variety of protein antibodies commonly found in the blood of Aids patients, but caused by a variety of conditions.
They cite evidence that in Africa and elsewhere, the main causes both of testing positive, and of the immune system deficiencies currently being interpreted as Aids. are poverty-linked diseases such as TB, malaria and other common infections. In the West the causes include the effects of drugs, infections such as hepatitis viruses picked up through needle-sharing and exposure to other people’s body fluids through promiscuous anal sex or repeated transfusions of blood products.
The group argues that genetic as well as biochemical signals interpreted as meaning the presence of “HIV” are a consequence rather than cause of immune system abnormality. Once this is understood, it says, the grounds for believing that Africans and other impoverished people are in the grip of a devastating new viral epidemic will fall away and help can be directed to fighting the real causes of immune deficiency.
HIV test kits were developed and marketed by US National Cancer Institute scientists at the same time as the HIV paradigm itself; the first kits were licensed in March 1985. France and the UK quickly followed. The kits were introduced as a means of protecting blood supplies, but their use in screening surveys gave rise to the idea that hundreds of thousands of Americans, and millions of Africans and others, were already infected.
The tests do not look directly for an AIDS virus but for HIV antibodies – proteins thought to be produced by the immune system in response to the presence of the virus. They do this by bringing a sample of blood serum (the fluid that separates from blood after it clots) from the person being tested into contact with proteins (antigens) that are believed to be virus components. This should then trigger an antibody-antigen reaction in people who are HIV-infected; but not in those who are not infected.
It could be a valid approach for establishing HIV infection if the proteins looked for by the test really do specify HIV’s presence; but this has never been shown to be the case. None of the proteins used in the tests has been shown to be specific for HIV and therefore to mean that a person is HIV-infected. They have been presumed but never demonstrated to come from HIV particles. Furthermore, all of the proteins used in the tests have been shown by the Perth group to have other potential sources, including normal cell constituents released when immune cells become over-stimulated and disordered.
Central to the Perth scientists’ re-examination of the foundations of the virus theory is their finding that, despite early claims to the contrary, it never proved possible to obtain pure particles of the purported virus, separate from everything else, with which to validate the tests.
Several steps are essential for identifying retroviruses, the type of virus HIV was supposed to be. The most fundamental is to purify the virus through the use of a filter (a high-speed centrifuge that separates materials of different densities), thus isolating the virus material from other cell constituents. Retroviral particles gather at a specific density. The purified particles can then be visualised and photographed with an electron microscope and their constituents analysed. A final step is to show that they replicate in other cells.
With HIV, none of those crucial steps has proved possible. Neither France’s Luc Montagnier nor America’s Robert Gallo, the two scientists who after a long dispute shared the credit for discovering HIV, was able to publish a photograph of purified virus. Nor has anyone else since. The photographs that have been published in numerous newspaper and magazine articles, labelled as showing HIV, are not from purified material. They are from cultures containing a variety of particles emerging from supposedly HIV-infected cells; but these particles are of unspecified character and similar particles appear in cultures of non-infected cells as well. When the next step is taken -- trying to filter particles to identify them and characterise them -- experts have never been able to obtain pure HIV.
Yet purification is essential to know which proteins as well as which stretches of genetic material (DNA and RNA) belong to a presumed virus. If the culture materials on which a test is to be based are not pure, test kits made from such materials will be liable to contain proteins of undetermined origin.
According to the Perth group, and growing numbers of scientists who support their position, that is exactly what happened with HIV. But because of political pressures, and a general sense of panic about Aids, regulators allowed the tests to come into use in ways that they knew were inappropriate. It was felt that the public health benefits outweighed the disadvantages.
The quandary was expressed clearly by Dr Thomas Zuck, from the US Food and Drug Administration’s office of biologics research and review, at a World Health Organisation (WHO) meeting in Geneva in 1986. He said the first test kits, using a technology known as Elisa, were licensed as a screen to protect blood and plasma donations, not as a screen for AIDS or people at risk of AIDS; their usage was intended to be limited by phrases to that effect in the package inserts. But “enforcing the intent of this language would be analogous to enforcing the Volstead Act, which prohibited alcoholic beverage sales in the United States in the 1920s – simply not practical.”
Dictated by public health needs, Zuck said, usage had expanded beyond the indications for which the tests were designed; broad application was evident among hospital patients, healthcare personnel and members of groups at high risk of AIDS.
The 100 experts from 34 countries who attended the meeting heard that, though the tests were sensitive enough to safeguard blood supplies, something more was needed to distinguish which people had genuinely been infected with HIV. Dr James Allen, assistant director for medical science in the US Centre for Disease Control (CDC) AIDS programme, said studies suggested some people were reacting to components of the cell line used to grow HIV for many of the test kits licensed in the US. Other reactions occurred because of antibodies to normal cell proteins, naturally occurring in the body. Allen warned that the problems could be magnified in areas of the world that did not have the sophisticated facilities of the United States.
Several delegates spoke of the need for a definitive, confirmatory test. They were clear that a commonly used confirmatory method, called western blot, was not up to the job. It reduced false positives: surveys in the US showed that, of blood donors who tested positive with the most commonly used Elisa kits, only about 4% were confirmed with western blot. But were any of those 4% truly infected?
The Elisa kits use a mixture of proteins attributed to HIV. When these react with antibodies in a patient’s serum, a colour change results. The first kits of this kind were made from materials filtered from cell cultures thought to be growing HIV and to be constituents of the virus. It soon became accepted that these materials were not pure virus. They contained normal cell proteins which confounded the test results, falsely producing large numbers of positive results.
The western blot kits are more refined. They use individual test proteins, separated along the length of a strip. These are incubated with the blood to be tested. If the blood contains antibodies to the test antigens, the reactions show up as a series of bands.
The problem is that without having pure virus particles to refer back to, nobody is sure which, if any, of the protein antigens selected for use in the tests really come from HIV and therefore signal HIV infection.
There has been a lot of argument over which proteins should be used and how to interpret the reactions. Even Montagnier and Gallo differ on this. The same uncertainty surrounds later versions of the Elisa test kits, using manufactured proteins rather than the “soup” of materials filtered from cell cultures. These kits overcome the earlier problem of not knowing which antigens were in the kits, but that is not much use when you do not know whether the antigens chosen really belong to HIV.
Dr MV O’Shaughnessy, head of viral surveillance at the Laboratory Centre for Disease Control, Ottawa, Canada, told the WHO meeting that when the proteins from an HIV preparation were separated and stained using ultra-sensitive techniques, “more than 30 individual proteins can be recognised.”
So, which were viral and which were normal cell components? Several large Canadian studies had shown extensive and generalised cross-reactivity, especially in haemophiliacs and in North American native populations.
Dr John Barbara, head of microbiology at the North London Blood Transfusion Centre in Britain, pointed out that both tests relied on the same principle, of antigen-antibody reactions. “It is important to remember that the western blot is itself an antiglobulin assay [a test for antibodies. It is liable, therefore, to the same kind of false-positive reactions as the screening test it might be confirming.” In other words, if there was uncertainty over whether the first test gave valid results, a second test based on the same principle could hardly be used to confirm the other.
Zuck, asked if better tests were in the pipeline, commented: “Don’t hold your breath. One of the difficulties we have in looking at claims for confirmatory tests or designing systems to validate what in fact is going to be ‘confirmatory’ is determining how you define and validate it.”
It was a muddle. At that point, little more than a year into widespread use of the tests, the delegates were frank with one another about the difficulties, though their uncertainties did not enter the public arena except in an expensive specialist textbook. As time went on, and the HIV paradigm won worldwide acceptance, increasingly complex procedures for trying to make a reliable diagnosis came into being. But the basic problem -- not being able to validate any of these procedures against pure virus preparations taken from patients -- still remains.
The Business 16/17 May 2004
Part 2. HIV diagnosis: a ludicrous case of circular reasoning. The concluding part of our investigation into a global healthcare scandal. Is the way we test for HIV more harmful than the disease itself?
By Neville Hodgkinson
From the start HIV tests had severe limitations. But these were disregarded, and their widespread use rapidly led to the idea that hundreds of thousands of Americans and millions of Africans are infected. Now a group of scientists based in Perth, western Australia, has claimed that no HIV test kit is capable of showing a person to be infected. Legal challenges are being mounted in the United States and France by people diagnosed as HIV-positive and told they would die from Aids. They remain healthy.
As long ago as 1986, Dr Thomas Zuck, a scientist with the US Food and Drug Administration (FDA) warned that the first test kits, using a technology called Elisa, were intended to screen blood donations – not to screen people at risk from Aids. He admitted that use had spread beyond the original intention but told a World Health Organisation meeting that it was “simply not practical” to stop it.
Other experts admit there were early problems with HIV tests, but say these were soon overcome. Not true, according to evidence cited in the 1994 edition of Aids Testing, a 400-page textbook edited by two US Centres for Disease Control experts. In a review of the various test methods used, they emphasise the need not to tell people they are HIV-positive or take medical decisions about them based on Elisa alone. "Testing by the sensitive EIA [Elisa] is done to identify those persons who need additional, more specific supplemental testing,” they say. “Counselling and medical decisions are made based on the results of the supplemental assay, not on those of the screening test alone."
Dr Jay Epstein, another FDA scientist, says in another chapter that western blot, a method used to check first results, remains by far the most widely used "confirmatory" procedure; but with this "the greatest concern has been the high prevalence of non-specific banding patterns, resulting in indeterminate test results”. Unfortunately, he says, this phenomenon is intrinsic to the technology.
The FDA has relaxed its criteria for a positive result on the western blot to get over the embarrassing fact that with the first kit licensed for confirmatory testing, which required a positive result on three different bands, fewer than half of AIDS patients tested HIV-positive. Other authors comment that production of the western blot strips is not a precise process. There had been extensive debate over how the tests should be interpreted. "Differences in protein concentrations, identities and positions are observed between manufacturers and even between lots from the same manufacturer."
Depending on the choice of proteins used as antigens, the tests give widely differing results in different patient groups. Elisa tests using genetically engineered or synthetic proteins bring the same problems.
If you cannot be told you are HIV-infected on the basis of the Elisa and there are such big problems with the western blot (in the UK, it is considered so unreliable as to be useful only as a research tool), which test does confirm you are infected?
In the early AIDS years, scientists often equated and described as “virus isolation” the detection in cultured cells of reverse transcriptase, an enzyme that enables a retrovirus to become integrated with the DNA of its host cell. It is now known that this enzyme has a much wider role in cell function and does not specify the presence of any retroviruses, let alone a specific one.
Similarly, detection of a protein of a particular molecular weight, believed but never proved to belong to HIV, also turned out to be of little diagnostic value. Both techniques “may be insensitive and/or non-specific”, according to guidance issued by UK Public Health Laboratory experts.
Today, a technique called the polymerase chain reaction (PCR), used to detect genetic sequences attributed to HIV by amplifying them millions of times over, is employed extensively in monitoring so-called “HIV disease”. Like the antibody tests, the method probably has value in indicating certain types of immune system activation or disturbance; but the segments of genetic material detected have not been shown to belong to a specific virus, HIV or any other.
Dramatically different results are obtained depending on the genetic "primers" chosen to start the reaction off, the probes used to analyse the results, the concentration of the various reagents used and the temperature and time over which the reaction is run. Such factors explain why results quoted in papers cited by US government scientists as having “confirmed the validity of the antibody tests” are not reproducible in other laboratories.
A meta-analysis by researchers from several institutions in the USA of relevant PCR studies published between 1988 and 1994 concluded: “The false-positive and false-negative rates of PCR that we determined are too high to warrant a broader role for PCR in either routine screening or in the confirmation of diagnosis of HIV infection. This conclusion is true even for the results reported from more recent, high-quality studies that used commercially available, standardized PCR assays …We did not find evidence that the performance of PCR improved over time.”
So, contrary to the impression most have lived with for years, the HIV test has never been proved to specify the presence of HIV. “The general belief that almost all individuals, healthy or otherwise, who are HIV-antibody-positive are infected with a lethal retrovirus, has not been scientifically substantiated,” the Perth group says.
There is a strong association between testing HIV-positive and the risk of developing AIDS. Evidence to this effect was and is the main reason why scientists believe HIV is the cause of AIDS. But the link is a consequence of the way the test kits were constructed, calibrated and clinically tested.
As described above, it never proved possible to validate HIV tests by culturing, purifying and analysing particles of the purported virus from patients who test positive, then demonstrating that these particles are not present in patients who test negative. This was despite heroic efforts to make the virus reveal itself in patients with AIDS or at risk of AIDS, in which their immune cells were stimulated in laboratory cultures with a variety of agents, sometimes over many weeks.
After the cells had been activated in this way, HIV pioneers selected some of the 30 or so proteins found in the filtered material that gathered at the density characteristic for retroviruses, and attributed some of these to various parts of the virus. But they never presented evidence that these so-called “HIV antigens” were constituents of a retrovirus particle of any kind, let alone a unique new retrovirus.
So, how did they define the proteins as being from HIV?
Amazingly, on the basis of selecting proteins most reactive with antibodies in blood samples from AIDS patients and those at risk of AIDS. This means that HIV antigens are being defined as such on the basis that they react with antibodies in AIDS patients, and AIDS patients are then diagnosed as being infected with HIV on the basis that they have antibodies reactive with those same antigens. The reasoning is entirely circular – which is probably why Zuck was so emphatic that none of the “HIV tests” was suitable for confirming HIV infection.
It gets worse. When Elisa test kits were developed, the priority was to protect blood supplies. For this, two limits were established. As a measure of the sensitivity of the kits in detecting unsafe blood, it was postulated that 100% of blood samples from patients with AIDS would be reactive and therefore test positive. So, if the actual proportion of samples from AIDS patients that prove reactive in clinical trials is 98%, that defines the sensitivity of that kit.
Second, as a measure of how specific the kits are in detecting unsafe blood – that is, in not causing healthy blood to test positive – it was postulated that 0% of healthy blood donors would be repeatedly reactive. Thus, if 2% of samples from healthy blood donors were found reactive during clinical trials, the specificity would be defined as 98%.
On the basis of such trials, the World Health Organisation and other agencies say that current HIV antibody tests have sensitivity and specificity in excess of 98% and are therefore extremely reliable. In reality, these measures tell us nothing about whether or not a person is infected with HIV.
The tests discriminate between healthy blood on the one hand and the blood of patients with AIDS or AIDS-like conditions on the other. That is why they are useful as a screen for the safety of blood supplies. Since AIDS patients suffer a range of active infections and other blood abnormalities, some of which will be transmissible through blood, the tests definitely help to safeguard blood quality.
Gay men leading “fast-track” sex lives, drug addicts, blood product recipients and others whose immune systems are exposed to multiple challenges and who are at risk of AIDS are much more likely to have raised levels of the antibodies looked for by the tests than healthy Americans – because the antigens in the tests were chosen on the basis that they were reactive with antibodies in AIDS patients. But this association does not prove the presence or otherwise of a lethal new virus.
In the absence of a specific test for HIV, the tests had to be calibrated so as to try to find a balance between detecting suspect blood samples and not causing healthy blood to be discarded. The safety of supplies was given priority, so the cut-off value for defining blood as reactive was set appropriately low. This ensures that the tests detect most samples of blood from people with AIDS.
But a low cut-off value also means that in screening surveys covering large numbers of people, many healthy individuals test positive. In early surveys covering 8m blood donors in the USA, it was found that of samples testing positive with a single Elisa, 96% were not reactive with the western blot test.
When the tests are used for the purpose for which they were originally designed – as a screen for blood safety – these flaws are not too big a price to pay. Repeated testing reduces the number of suspect samples and therefore the waste of healthy blood. But the flaws are deadly when it comes to screening for or diagnosing HIV/AIDS.
In wealthy countries that can afford repeated testing using a variety of approaches, and where the risks in a patient’s life are also taken into account in interpreting test results, the numbers of people falsely given to understand that they are infected with a lethal virus will be much lower than in poor countries where only a single positive result can be a sentence of death.
In the UK, for example, currently fewer than 200 deaths a year are designated HIV/AIDS, out of a nation of 60m people. Estimates for the total number of people infected with HIVstood at around 30,000 throughout the 1990s, though there has been a recent increase mostly accounted for by HIV-positivity among new immigrants from impoverished and war-torn countries.
Even so, in the light of the evidence and reasoning described above, to tell even one person that they are HIV-infected on the grounds that they have antibodies that react with the proteins in these unvalidated tests is an unwarranted assault. Manufacturers may be aware of this and some include cautious statements in their packet inserts, such as: “At present there is no recognized standard for establishing the presence or absence of antibodies to HIV in human blood.”
In countries where a single test is commonly all that can be afforded, screening surveys have given rise to the idea that millions are HIV-infected. The tests have caused countless individuals to be falsely diagnosed and nations to be deceived into believing that HIV/AIDS is set to decimate their population.
Dr Etienne de Harven, former professor of pathology, University of Toronto, who worked on retroviruses for many years at the Sloan Kettering Institute, New York, told a recent conference on AIDS at the European Parliament in Brussels: “There is a major problem with isolation and purification of HIV. The major problem being that, in spite of innumerable claims to the contrary, this retrovirus has never been isolated or purified in a scientifically acceptable manner that would satisfy the classic requirements of virology.”
He added that over the past 20 years, the medical literature “has been inundated with innumerable papers attempting to dodge the lack of electron microscope evidence for the presence of retroviral particles in samples directly collected from AIDS patients.”
Ann James, a Houston, Texas lawyer, writes in AIDS Testing: "No other disease, except perhaps leprosy from the beginning of the millennium to the 1800s, has brought so much societal pressure on its victims and caused such cataclysmic social consequences over such a long period."
Remarkably, this cataclysm may have been caused not so much by AIDS itself as by the concept of an epidemic of HIV disease, a concept that arose because in the atmosphere of emergency surrounding the idea that a deadly virus was spreading surreptitiously among sexually-active people, public health experts considered it “simply not practical” to stop the HIV test from being used for a purpose for which it was unsuited.
As Eleni Papadopulos-Eleopulos, who heads the Perth group of scientists, puts it: “In our view the greatest single obstacle to understanding and solving AIDS is HIV.”