False Positives

“A city hospital nearly destroyed a New Jersey woman’s life and wrecked her marriage after misdiagnosing her with terminal HIV, hepatitis and herpes, according to a bombshell lawsuit. Maria Osorio, 54, of Passaic, said…a nurse offered her a free instant cheek swab and blood test [and] she accepted. That’s when she was told she had HIV. “It was horrible. I wanted to throw myself on the subway tracks,” she said. The shocked Osorio immediately turned on her husband of 37 years, Gabriel Lezcano, 60, who works as a janitor in New Jersey. “I started screaming violently at him. I pushed him. I pulled his hair. ‘Who were you with?’ I asked him. He kept denying that he was with anyone, but I kept raising my voice and pushing him. ‘You must have been with someone. You must have had too many beers and maybe now you just don’t remember,’ “ she recalled…A few days later, the hospital called again to say the disease was very advanced, according to court papers. “I wanted to kill him,” she said. “I began to mistrust him and hate him. I couldn’t believe that he had been with other women, that he had lied to me.” She also decided to commit suicide. “I kept thinking how I could kill myself. All I did was plan how I was going to end my life,” she said…She stopped sleeping. She threw up constantly. She couldn’t work. “I didn’t want to get out of bed,” she said. Her husband stopped sleeping, too. They both became addicted to sleeping pills and took to sleeping in separate beds, alone in their misery and distrust. Her two grown sons, who still live in Colombia, were hysterical. They would call, crying, insisting there was a mistake. When Osorio, a home health aide, pointed out to the nurses that she had no medical problems whatsoever, they replied, “This is a silent disease.” “They told me that this machine does not lie,” she said. But almost three weeks later, the hospital called to say she was perfectly healthy…But the damage to the marriage had already been done. “I met him when I was 17 years old. We were always very united as a couple,” Osorio said. “We work and we come home, and that is our life.” Now they still sleep in separate beds, and still rely on pills to sleep. “This has really hurt our marriage. We are afraid to have any sexual contact with each other. We are still very nervous,” Osorio said.”

“Rock wildman OZZY OSBOURNE ravaged his body so badly with drink and drugs, doctors wrongly diagnosed him with Aids. The Black Sabbath frontman was tested for the deadly virus during his heady heyday, and was left in shock when a blood test came back as HIV positive. He tells Britain’s Glamour magazine, “I went to the doctor and had an Aids test and he told me it was positive. “That was one of the worst days of my life.” But after undergoing another blood test, the star was relieved to hear he had been misdiagnosed because of the impact his hedonistic lifestyle had taken on his immune system. He adds, “When I used to f**king get loaded I would get myself into all kinds of situations. “It turned out that because I was drinking and using drugs so much, my immune system had dropped so that it was a borderline result. “When I went back to be tested again it was negative.””

“An HIV-positive homeless man convicted of biting a Miami police officer has been sentenced to 15 years in prison…Hall ultimately tested negative for HIV, the virus that causes AIDS, but only after months of taking precautionary medication that caused diarrhea, vomiting and nausea.”

“An HIV-positive man in northwest China’s Gansu province has apparently recovered from the disease, a local newspaper reported today…after taking two packets of a special Chinese medicine each day four years after the diagnosis, Li managed to fight off the disease [i.e. was tested and was found to be HIV-negative]”

“Expert evidence in a case [in Botswana] involving a woman who was wrongly diagnosed with HIV/AIDS has shown that she suffered a post-traumatic disorder. The woman, Kgakgamatso Sekgebetlela, was wrongfully diagnosed with the virus in 2003, which led to her being estranged from her husband and children.”

“In late 2005, an unexpected increase in the number of false-positive oral fluid tests occurred, but the increase subsided after several months. In December 2005, while the cluster of false-positive oral fluid test results was being investigated, the NYC DOHMH Bureau of STD Control suspended oral fluid testing in the clinics for 3 weeks…In late 2007, another larger increase in the incidence of false-positive oral fluid rapid test results was observed. The cause for the episodic increases in false-positive oral fluid tests has not yet been determined.”

“The study population included all patients seen at the Comprehensive Care Center [in Nashville, Tennessee] from August 1997 until 30 June 2007. Of 4,450 patients referred, 51 were subsequently determined to be HIV-uninfected by undetectable plasma HIV-1 RNA, CD4 positive lymphocyte count within normal limits, and repeat ELISA.”

“A farmer in northeast China’s Jilin Province has tested HIV negative, six years after being diagnosed as HIV-positive, according to the provincial Center of Disease Control (CDC). Wen Congcheng, from Erdaogou Village in Chuanying District, Jilin city, first tested HIV positive in 2001 at the Chuanying District disease prevention and control center when it was screening blood-plasma donors. Late in 2003, he was re-confirmed to have HIV/AIDS as a result of another test, this one by the CDC of Jilin province, which tested the same blood sample originally analyzed by the Chuanying District CDC…in July this year, Wen received a negative test result at the No. 1 Clinical Hospital of Beihua University in Jilin…Wen decided to seek another opinion and went to the First Hospital of the China Medical University and another three hospitals for HIV tests, which all proved to be negative…The Jilin municipal CDC carried out a follow-up test which confirmed the negative result, and later the provincial CDC also confirmed the result.…Professor Wu Min, a member of the HIV/AIDS experts’ committee under the Ministry of Health, is sceptical about the validity of the original positive test result…“I can not believe that such miracle could have really happened,” he said. “Some patients appear to be free of the virus after effective treatment, but the HIV antibody is always there, so the test result will still be positive.” [Wen was never treated with antiretroviral drugs]”

“The table shows the results of the rapid tests for HIV. In the total sample of 1517 tests the three rapid test algorithm had reasonable sensitivity (97.7%, 95% confidence interval 94.1% to 99.4%) and negative predictive value (99.7%), but the specificity was low (90.4%, 95% confidence interval 88.7% to 91.9%) and the positive predictive value was unacceptably low (56.3%). Overall, 129 of 295 positive test results were false positives (43.7%) and four of 1222 negative results were false negatives (0.3%). Of the 129 false positives, 123 (95%) resulted from the Determine and Uni-Gold tests.”

“Tommy Morrison had a seemingly boundless future in 1996. A former heavyweight boxing champion, he had had a starring role in “Rocky V” and was in line for his biggest payday, a showdown against Mike Tyson. All that came to an abrupt end, though, when he tested positive for H.I.V…In 1996, he tested positive for H.I.V. These days, he is back in the ring. He fought in West Virginia in February, and his return has raised questions of just how a fighter whose blood tested positive for H.I.V. in 1996 could test clean today.

This year, Morrison took two separate blood tests to support his assertion that he was not infected with H.I.V., West Virginia officials said last week. The test results provide new details on why they licensed him to return to the ring 11 years after he tested positive.

Two nationally renowned H.I.V. experts reviewed those and a third blood test for The New York Times, and said they suggested Morrison had been knocked out of the ring by false positive tests — if, indeed, the new tests are his blood…Morrison, 38, who has often derided conventional views on H.I.V. and AIDS, said he was pleased to hear some experts supported his assertion of a false positive.

“People are starting to wake up,” he said last week in a telephone interview. “There’s been a lot of careers destroyed along the way for no reason. Mine’s certainly been one of them.” The Times obtained copies of three documents, not previously made public, that purport to be tests of Morrison’s blood this year.

One of them, negative for H.I.V. antibodies, was a report from LabCorp in Phoenix on blood drawn Feb. 6 and was released by Peter McKinn, Morrison’s promoter. The second, which did not detect H.I.V. in DNA, was a LabCorp report on blood drawn Feb. 14 and was released by West Virginia. The state used those tests to license Morrison to box, said Michele Duncan Bishop, general counsel for the West Virginia Department of Revenue, which oversees the athletics commission. A third test, from Specialty Laboratories of Valencia, Calif., on blood drawn Jan. 5, indicates Morrison tested positive for H.I.V. antibodies but negative for H.I.V. in RNA. That report was released by Randy D. Lang, Morrison’s former legal adviser, who said the antibody result showed Morrison was still infected. But the experts said the RNA result in the same report raised the possibility that the antibody result was a false positive…The mixed result in the Jan. 5 test makes it “likely that the antibody result is a false positive,” according to Dr. Daniel R. Kuritzkes, a Harvard professor who directs AIDS research at Brigham and Women’s Hospital in Boston and is chairman of the board of the H.I.V. Medicine Association. Kuritzkes reviewed the test for The Times. Without additional blood work, he added in an e-mail message, “it’s hard to know for sure what’s going on, but I suspect he was never H.I.V.-infected.”

Dr. Michael P. Busch, director of the Blood Systems Research Institute and a professor of laboratory medicine at the University of California, San Francisco, said H.I.V. antibody screening was misinterpreted a small percentage of the time. He said the RNA and DNA tests, which measure the virus directly rather than through antibodies, would virtually prove that the person was not harboring even a latent infection. “If those results are really all from this person, I would tell you there is no way this person is infected, so something is wrong with those earlier results,” Busch said. Busch said there was a biological basis for some false positives on H.I.V. antibody tests, which makes some people repeatedly test false positive, although the reasons are not well understood.”

“The [new] Genscreen Plus HIV Antigen–Antibody is an EIA [Enzyme Immuno-Assay or ELISA] for the detection of HIV infection based on the detection (sandwich technique) of antibodies to HIV-1 and HIV-2, as well as the HIV-1 p24 antigen in human serum or plasma. These assays become valuable in diagnosing early HIV infection, reducing the window period by 4–5 days compared with third-generation assays [5]. Genscreen Plus is an assay with enhanced sensitivity for HIV antibody detection that does not differentiate between the antigen and antibody signal…In the first 6 months of its introduction we detected three acute HIV seroconversions in adults who tested antibody negative by the third-generation (antibody only) assays…Using this assay in 18 infants with three consecutive negative HIV-DNA PCR we found that eight were antibody negative (age range 18–24 months), and 10 were positive (age range 19–20 months). Of the 10 infants positive by the fourth generation assay, nine were negative by our previous third-generation HIV assay (performed simultaneously). Repeat fourth-generation EIA testing was negative for nine infants within a few months, confirming waning levels of maternal antibody and not emerging infection. In one infant it was not possible to obtain a repeat sample but it shows no clinical evidence of HIV infection [although a positive HIV test with no symptoms is usually accepted as a genuine infection].”

“He was positive, then negative, banished from boxing, and now in the middle of a comeback at age 38. The Tommy Morrison story defies logic. But a person who witnessed the first chapter in 1996 is sure of one thing: The HIV test Morrison took 11 years ago was accurate.…After his most recent blood test came back negative for HIV this week, Morrison was granted a boxing license in Texas and was to fight Dale Ortiz on Friday night in Houston. The fight was called off however, because the doctor who examined Morrison failed to file the paperwork with state boxing officials in time. After initially accepting what he called a "death sentence" in 1996, Morrison now believes that the test administered before his bout with Arthur Weathers 11 years ago was a false positive…But the odds of producing an inaccurate HIV diagnosis are very slim, two HIV specialists told ESPN.com…Jalali and Dr. Jeff Kirchner of the American Academy of HIV Medicine said the more plausible scenario in Morrison's comeback is that medicine suppressed his virus to undetectable levels. If Morrison were to go off of those drugs, Kirchner said, signs of the virus in the blood would return "within a very short period of time -- a week, two weeks [but] Morrison has said he stopped taking the medication years ago.…Morrison had several HIV theories in the months before his comeback. He wondered if he tested positive because of steroids, a theory Kirchner said is impossible.”

“After testing positive five different times, Nakalembe recently tested negative after two confirmatory tests at Mbuya Parish Outreach Clinic. Two initial tests were done at Mulago Hospital and the third at Mbuya Parish Outreach Clinic…Nakalembe tested positive in January 2003 at the age of 12. Her confirmatory test in July 2003, also posted positive…She suffered depression and stigma, failed to get antiretroviral drugs [luckily!] and her mother resorted to buying local herbs for her…when you test positive to a rapid test kit and the confirmatory test posts negative, a third test has to be done. It is called a tie-breaker kit — it resolves the uncertainty. If it turns out negative, then we know that person is negative…Betty Tibaleka, a journalist who hosted Nakalembe on her Untold Story programme on UBC Television recently, says she has had many stories like Nakalembe’s”

“Former World Boxing Organization heavyweight champion Tommy Morrison is staging a comeback, saying Tuesday that a positive HIV test that ended his career more than a decade ago was inaccurate. ”I’m negative and I’ve always been negative and that should be the end of it,” Morrison said in a telephone interview with The Associated Press.”

“Kenyan women who received prophylactic tetanus toxoid injections during pregnancy are 1.89 times more likely to be HIV-1 seropositive than women who did not receive this vaccination…The results are consistent with health care being a very important vector for HIV in sub-Saharan Africa [but they are also consistent with tetanus vaccinations directly generated antibodies that are misinterpreted as 'HIV']”

“[on an HIV test consent form] This test will tell if I have antibodies to HIV. Having antibodies, and therefore a positive test, does not mean I have AIDS or that I will necessarily get AIDS or any other disease…Like many things, the tests are not perfect…Sometimes the tests may be positive even if I do not have the infection because the test are complex and simply not perfect. This is called a"false positive." My health care professional will explain these facts to me and will advise me and offer me more counseling if the result is positive…The social risks of a positive test [whether true or false positive] are that I may be thought to be infected and I could be turned down for life or health insurance, housing, a job, or school even though such kinds of discrimination may be wrong or illegal”

“Six weeks after an occupational needle-stick injury, a 35-year-old man presented to a clinic in the Los Angeles area for testing to rule out acute infection with the human immunodeficiency virus (HIV). The patient had no other risk factors for HIV infection and reported having had no symptoms suggestive of an acute retroviral syndrome. His recent medical history was notable only for his having received an influenza vaccination 11 days before presentation…an enzyme immunoassay [ELISA] for HIV type 1 (HIV-1) was repeatedly reactive, and the result on a Western blot assay that was performed as part of the clinical protocol to confirm a reactive enzyme immunoassay was indeterminate, with a single band that was positive for glycoprotein 160 (GP160)…it is very important to remind patients and clinicians that influenza vaccination may cause cross-reactivity with HIV antibody assays. The time course for such crossreactivity remains uncertain.”

“A recent surge in false positive results produced by a much-heralded oral HIV test has caused at least six testing sites in Los Angeles, San Francisco and New York to shelve the test and prompted an inquiry by federal health agencies”

“in late 2005, HIV testing programs in multiple U.S. cities experienced apparent clusters of false-positive rapid HIV test results using oral fluid (but not whole blood) specimens. Counselors at these programs have expressed concern regarding the specificity and positive predictive value of the oral fluid rapid HIV test.”

“Health officials in New York and San Francisco said yesterday that a widely used rapid test for the virus that causes AIDS had been producing too many false-positive results…The test, called the OraQuick Advance H.I.V. test, is the same one the Food and Drug Administration has said it will consider approving for sale to the public for home use without a prescription. In New York, Dr. Susan Blank, an assistant health commissioner, said that city clinics performed 3,600 to 3,700 tests for the virus, H.I.V., each month, largely using OraQuick, and until recently they had about five false positives a month, a rate well within the maker's prediction. But in November, Dr. Blank said, the number shot up to 30, which was cause for concern…In San Francisco, Teri Dowling, manager of H.I.V. counseling and testing for the public health department, said the number of false positives there seemed to rise sharply in May. In 2005, 9,400 tests were done, and 250 were positive. Of those, 49 appeared to be false positives, though not all have yet been confirmed…Douglas A. Michels, president and chief executive of OraSure, said that over all the test was more than 99% accurate. In the last year, the company received complaints of only 107 false positives out of 28,436 tests, Mr. Michels said.”

“Health officials in New York and San Francisco said yesterday that a widely used rapid test for the virus that causes AIDS had been producing too many false-positive results…The test, called the OraQuick Advance H.I.V. test, is the same one the Food and Drug Administration has said it will consider approving for sale to the public for home use without a prescription. In New York, Dr. Susan Blank, an assistant health commissioner, said that city clinics performed 3,600 to 3,700 tests for the virus, H.I.V., each month, largely using OraQuick, and until recently they had about five false positives a month, a rate well within the maker's prediction. But in November, Dr. Blank said, the number shot up to 30, which was cause for concern…In San Francisco, Teri Dowling, manager of H.I.V. counseling and testing for the public health department, said the number of false positives there seemed to rise sharply in May. In 2005, 9,400 tests were done, and 250 were positive. Of those, 49 appeared to be false positives, though not all have yet been confirmed…Douglas A. Michels, president and chief executive of OraSure, said that over all the test was more than 99% accurate. In the last year, the company received complaints of only 107 false positives out of 28,436 tests, Mr. Michels said.”

“A MAN who tested positive for HIV, the virus that causes Aids, has subsequently shown up negative for the disease in a case that has mystified doctors…Stimpson was tested three times in August 2002 at the Victoria clinic for sexual health in central London and the results showed he was producing HIV antibodies to fight the disease…In October 2003, after impressing doctors with his good health, Stimpson was offered a new test, which came back negative. Further tests in December 2003 and March last year also proved negative.”

“A Texas woman won a civil suit against a Houston-area hospital Wednesday that she said wrongly diagnosed her as HIV-positive when she was about to give birth…Johnson claimed Methodist Hospital incorrectly diagnosed her with the virus when she was 8¸ months pregnant…"I felt like my whole world was crashing down," Johnson said. "I was scared for my children. I was scared for my husband. I didn't know if the baby was HIV-positive. I cannot tell you the emotions that went through my head."…she went into premature labor within 24 hours of hearing the news…Doctors and nurses pumped Johnson and her newborn son with drugs used to treat HIV…Her attorney, Stephen Buttram, said the lab technician did not properly label her blood sample…Johnson said doctors have told her that there is no conclusive proof that the heavy treatments her son was on will have any effect on him.”

“[South African] Zandile Magudulela had her world turned upside down when she was told mistakenly by nurses at KwaMashu PolyClinic that she was HIV-positive. She immediately contemplated suicide, but tests later showed that she did not have the virus. The KwaMashu woman was mistakenly treated as an HIV patient for more than six months. Married for nearly 20 years, Magudulela told the Daily News that she had been on the verge of committing suicide when she was told she was HIV- positive and that the medicine she used for more than six months was administered to HIV patients. A doctor, who wanted to remain anonymous, confirmed that Trimoxazole tablets [a potent 'sulfa' antibiotic], which were given to Magudulela, were mostly used by HIV patients who have a low CD4 count to prevent them from developing pneumonia.”

“The patient was diagnosed as HIV antibody positive (ELISA and WB) in 1995 during blood donation…two years later pericarditis was diagnosed and HIV viral load at that time was 29,000 and 24,000 copies/ml. CD4+ cell count was 856 cells/ml. HAART was initiated, and 4 months afterwards viral load became undetectable, CD4+ cell count was unchanged and pericarditis disappeared. Three years after initiating HAART, HIV antibody test was taken for enrollment to a clinical study, and was found to be negative. Since viral load measurements were undetected and CD4+ cell counts were high consistently, HAART was withheld…During the four years after stopping HAART, HIV antibody test remained negative, viral load is undetectable, HIV RNA is negative and viral cultures of blood and semen are negative.”

“HIV EIAs have become increasingly more sensitive and specific since HIV testing began in the early 1980s…The small disadvantage of such a highly sensitive test is that the test produces false positives, the number and type of which vary with the assay used and the HIV prevalence in the tested population.”

“The medical records of all rapid HIV-ELISA-positive gravidas [pregnant women] that delivered at our hospital between January 2000 and October 2001 were retrieved…The results of the Western blot tests were also retrieved and correlated to the ELISA results, across varying maternal characteristics.…A total of 69 patients had a positive rapid HIV-ELISA out of 9,781 deliveries. Of those, 26 were confirmed as HIV infected by Western blot (overall HIV prevalence: 0.27%, ELISA-positive predictive value: 37.7%). The subgroup prevalence of HIV and positive predictive value of ELISA were 1.53 and 75% among Caucasians; 2.43 and 82.6% among African-Americans; and 0.05 and 9.8% among Hispanics, respectively (p<0.05 for the comparisons between Hispanics and non-Hispanics only)…The positive predictive value of rapid HIV-ELISA during pregnancy varies widely, depending on maternal race/ethnicity and sexual behavior. The routine disclosure of rapid intrapartum HIV serum screening results prior to Western blot confirmation should be avoided in very low-risk populations.”

“Nearly eight years ago, just after Christmas in 1996, I tested H.I.V.-positive while I was on vacation in Los Angeles…it didn't surprise me when it did. My partner had passed away from AIDS. Before that I had been partying for about -- well, I'll be 60 on the 4th of July, so you do the math…I took the test results back home to Hayward, Calif., and gave them to my doctor at the V.A. clinic. He treated me for H.I.V. for the next seven and a half years. In July of this year, the V.A. [Veteran's Administration] clinic called because its new computer software had flagged my record for a missing diagnosis. I was asked to come in for another H.I.V. test. I found out that I was in fact negative and apparently had never been positive…I had been seeing my doctor for at least a decade for a bad back, a heart condition, ulcers, and I always trusted him. If he had said the sky was purple with pink polka dots, I would have had no reason to question him. The V.A. clinic eventually did another H.I.V. test. It was negative, but no one told me…I started telling my friends about my diagnosis because I'd had sexual relationships with many of them. At first, I still dated: dinner, a show, a bar, but the evenings always ended there. The minute I'd say I was positive it would be: ''It's late. I have to get up early for work.'' I started accepting that. Eventually I completely shut off…My big fear was that I'd have to die by myself. I tried to keep people around, even if it was as close as the telephone. People bailed out who at first said they were my friends and would always be there…I had the symptoms of AIDS -- weight loss, diarrhea, no appetite, vomiting. They call it being psychosomatic. I knew about the symptoms from my own lovers, from being right there, from cleaning up the mess…The eight years I thought I was positive cost me more than 45 pounds. I take medicine for depression and stress, even now…Two months after [my father] died, I found out I was negative. My doctor wrote me a letter saying he took full responsibility. It was human error. My lawyers filed a claim, and now we have to wait to see what happens. For years, I received free meals, help with rent, free counseling and therapy from AIDS organizations. It's going to be very tough financially now, but the relief is worth it. It feels as if somebody took an anvil off my shoulders. I'm planning trips. I haven't felt this good in 30 years, but that doesn't mean I'm not still mad as hell.”

“The currently used laboratory based and rapid HIV-tests show intolerably high numbers of false positive results when used in developing countries. This is mainly due to interfering effects of diseases virtually absent in developed countries. If this becomes widely known, such information could destroy the whole concept of the Knowledge Protects Program. People will prefer to seek refuge in the belief that they are among the 'false positives'. Therefore, it is not only an ethical but also a practical requirement for the success of the program that the reliability of the rapid tests being used is identical or even superior (i.e. more forgiving against handling errors) than those tests used in the developed world. Fortunately, such test systems have recently been introduced to the market. [by us!!]”

“For eight years, Hayward resident Jim Malone attended biweekly counseling sessions for men living with HIV…He had been told in 1996 that he was HIV-positive. Earlier this month, Malone, 59, was summoned to his doctor's office. He listened as the doctor delivered the stunning news: He is HIV negative…Malone had arrived at the clinic in 1996 with lab results from an outside testing firm in Southern California. Those results showed he was HIV positive. The VA did its own confirmatory HIV test on Malone and found he was negative [but due to a list of mixups did not inform him for another 8 years]”

“A Tanzanian man, who claims a wrong HIV diagnosis wrecked his wedding, has sued the hospital responsible for $50,000. Ramadhani Kaya was about to go on his honeymoon when he received his positive tests results. Mr Kaya, who says he is a very 'religious' man and could not have HIV/Aids, retook the test three times elsewhere with negative results. But his wife's family did not believe the new results and she returned to stay with them.”

“34 women tested HIV-1 positive with both rapid test and EIA, and all were confirmed by Western blot. There were 4 false positive and non false-negative rapid test results…positive predictive value [of the rapid test] was 90% [i.e. 10% of positive results were false]…The EIA had 11 false-positive results: 5 in women with an indetermineate Western blot result (usually a single p24 band) and 6 others with negative Western blot results.”

“Specificity [of this HIV test] is based on assay of blood donations from random donors [under the assumption that any positive result would be a false positive, yet when this test is used under normal circumstances such a positive would be treated as a true positive]…Specificity based on an assumed zero prevalence of antibody to HIV-1 and/or HIV-2 in random donors (17037 out of 17054) is estimated to be 99.90%…[but] in these calculations, one sample of the eighteen total repeatedly reactive specimens was confirmed by Western Blot and has been excluded…[Table II shows that out of 27 initially reactive test results from blood and plasma donors, only 18 were repeatedly reactive]”

“False Positive Results…Reocgnized Problems…1. HLA-antibodies [e.g. women with a prior pregnancy]…2.Repetitive Freeze/Thaws 3. Other retroviruses 4. Heating of sera 5. Autoantibodies…6. Hypergammaglobulinemia…7.Cross-reactive proteins…8.Non-specific IgM binding (e.g. after vaccination…)”

“Dimitrios Garnelis and his wife, Laura, sued the [Indiana, USA] Department of Health because of a false-positive test result Garnelis received in 1991. Until he was on a visit to Greece in July 1999, where health officials retested him before prescribing treatment, Garnelis lived under the impression that he was HIV-positive…Separately, the Garnelises also have filed complaints against the Bell Flower Clinic, 1001 W. 10th St., Indianapolis, where Dimitrios Garnelis had his blood drawn for the initial test, and a physician.”

“A cross-sectional study was conducted from January--December 1999 as screening of voluntary non-remunerated blood donor pool for HIV in the public sector blood banks, in all the six divisions of Balochistan. 5000 subjects were screened for the presence of antibodies against HIV-1/2. The subjects were all males between the age group 18-50 years…Strategy I was a rapid test and was performed on Capilus HIV I/2 by Cambridge, Ireland. Strategy II (ELISA) was performed on Lab System HIV I/2 Finland and Strategy III (ELISA) was undertaken as a confirmation test performed on Sanofi Pasture HIV I/2 France…Out of 5000 subjects, 48 (0.96%) were positive for HIV-1/2 on Strategy I, 37 (77% of 48) met the criteria of false positive, while only 11 (0.22% of 5000) were found to be true positive”

“The overall specificity of the Reveal™ Rapid HIV -1 Antibody Test for serum specimens in these studies was calculated to be 3608/3639 = 99.1%, combining the number of Reveal™ Rapid HIV -1 Antibody Test Non-Reactive results obtained from the study of previously screened HIV -1 antibody negative serum specimens with the number of Reveal™ Rapid HIV-1 Antibody Test Non-Reactive results obtained from the studies of high-risk populations [i.e. 1% false positives if we can assume that other antibody tests (ELISA and Western Blot) are 100% accurate and also completely independent from this rapid test]…The overall specificity of the Reveal™ Rapid HIV -1 Antibody Test for plasma [i.e. blood] specimens in these studies was calculated to be 2970/3011 = 98.6% [i.e. 1.4% of tests false positive] combining the number of Reveal™ Rapid HIV -1 Antibody Test Non-Reactive results obtained from the study of previously screened HIV -1 antibody negative plasma specimens with the number of Reveal™ Non-Reactive results obtained from the studies of low -risk populations [with the same caveats]”

“A Muslim couple is suing the department of health in the Western Cape for R5-million [about US$750,000] after their baby daughter became infected with HIV under mysterious circumstances at one of two leading paediatric hospitals…The parents, who are both HIV-negative, say…that their three-year-old daughter contracted the virus either at Mowbray Maternity hospital, where she was born, or at the Red Cross Children's hospital, to which she was transferred for surgery. [the possibility of a false-positive HIV test is not considered]…'Baby A', as the papers refer to her, is one of 14 children, all with HIV-negative parents, documented by the March 2004 South African Medical Journal as having contracted unexplained HIV infections in hospitals.”

“CASE 1: A 39-year-old married man presented to the Public Health-Seattle & King County sexually transmitted disease clinic in September 2000, seeking HIV serologic [antibody] testing. He gave a history of occasional orogenital sex with other men but denied insertive and receptive anal sex…His ELISA and Western blot results were interpreted as positive…He notified his wife of the result, revealed to her and to [others] that he had had sexual activities with other men, and sought spiritual counseling. However, further evaluation revealed an undetectable plasma HIV RNA level and a reasonably normal CD4+ lymphocyte count. Repeat HIV ELISA testing was negative in October 2000 and in January 2001. The patient expressed substantial distress and required repeated reassurance and psychological counseling. CASE 2: In October 2000, a 23-year-old woman sought HIV testing…because of vaginal irritation, a white discharge, pelvic pain, and fear that she had acquired a sexually transmitted disease. She reported having had multiple male sex partners in her teens, that she usually used condoms, and had been in a monogamous heterosexual relationship for 3 years before testing. The positive HIV ELISA result with Western blot confirmation was followed by findings of an undetectable HIV RNA level and a reasonably normal CD4+ lymphocyte count…In October 2001, after…confirmatory testing, her HIV ELISA results were negative, a result also found in March 2002. The patient described confusion, concern, and relief as well as uncertainty about which providers and test results to trust.”

“In a bizarre saga [in Soweto, South Africa] that has baffled medical doctors, an East Rand couple has a baby who has been diagnosed HIV-positive, while both parents have consistently tested negative…Doctors are baffled as to how the child got infected [and they would never consider the possibility of a false-positive test result]. One of them, Dr Johan Pretorius, a paediatrician who tested both the child and parents, said it was a mystery how and where the baby could have contracted the virus…"The parents are absolutely negative. I made tests on them after the baby was diagnosed and they are HIV-negative," he said…According to the parents, their son was born healthy, weighing 2,8kg. "He was growing well and his immunisation chart was satisfactory. He then developed flu symptoms and we took him to the hospital, where he was diagnosed with Bronchitis," the baby's father said…The baby's health started deteriorating and the parents decided to take him to Botselong Hospital, in Vosloorus on the East Rand, in July 2002. It was there that they were told that the baby had HIV symptoms [but, in Africa, fever, cough and diarrhea are taken as signs of AIDS].”

“A small but significant number of donor sera (0.1-0.3%) yield false-positive results in EIA, and these donors must be permanently deferred from the blood donor list, causing operational and public relations problems [This assumes that the Western Blot is completely accurate, as someone who was also false positive on Western Blot would be categorized as true positive]…In Canada, about 500 blood donors per year are found to have false-positive results in an HIV-1 and -2 EIA [i.e. repeatedly reactive on 2-3 EIA antibody tests but indeterminate on a single Western Blot]. Deferral of blood donors based on this criterion makes donor counseling extremely difficult, especially for regular donors. In addition, our inability to provide a scientific explanation to RR [repeatedly reactive]-but-uninfected donors concerning the cause of the false reactivity in EIA can be a source of great concern and anxiety to these individuals and their family…the SCN-EIA [a modified EIA antibody test that supposedly reduces non-specific reactivity] produced negative results for 69% of the 435 previously screened HIV RR blood donor sera without affecting the positive results of the five HIV confirmed-positive sera in the panel…In the past 10 years, several thousands of blood donors have been deferred [blocked from donating blood] in Canada because of false-positive reactivity in one of the EIAs used to detect exposure to viruses.”

“In Canada, about 500 blood donors per year are found to have false-positive results in an HIV-1 and -2 EIA…The logical explanation for the false-positive reactivity in the HIV-1/2 EIA is the binding of natural nonspecific polyreactive [antibodies] to the EIA plates…The cut-off values of EIAs are routinely determined by testing thousands of seronegative individuals and large panels of seropositive individuals [but people are 'seronegative' because they are below the current cutoff and 'seropositive' because they are above, so this is really a tautology, assuring at most that new tests are consistent with old tests]…it should be remembered that under current regulations, all donors with a RR [repeatedly reactive] EIA result are permanently deferred from the active blood donor list even if most of them (98.8% in our panel of 440 sera) are found negative or indeterminate in confirmatory testing [Western Blot]”

“Monoclonal antibodies used in diagnostic assays are produced using animal cells, usually from mice. The Achilles heel of this apparently highly specific assay principle is that many individuals, possibly up to 40% of the general population, possess naturally occurring antibodies to animal immunoglobulins (eg, to mouse, rabbit, cow, rat, goat), termed heterophilic antibodies. If an individual with heterophilic antibodies against mouse immunoglobulins has a test by an immunoassay that uses mouse monoclonal antibodies, then the heterophilic antibodies can also form links between the capture and signal antibodies, generating a false-positive signal”

“Among those [tested for HIV at various US STD clinics] reporting a previous positive test result (n=740), 91% had positive test results in the serosurveys [which means that 9% either had false negative test results this time, had previously had a false positive or had ‘forgotten’ their previous death sentence]…among those reporting a previous indeterminate result (n=52), 21% had positive test results”

“In a case that raises questions about the accuracy of HIV tests, an Oklahoma man has won a $1.4 million settlement nine years after a health clinic mistakenly told him he was infected with the virus that causes AIDS...In one of [Dr. Horberg’s] own cases a few years ago, he says, a woman insisted she could not have contracted HIV. She turned out to be right. She wasn't infected, despite a positive test result. "We did a mega work-up, kept following her every six months, and she was still negative," he says. "She never showed any sign of the virus, and her [immune system strength] was better than half the U.S. population."...Some people do worry that they got the wrong test results, Horberg says. Following the Oklahoma verdict, "I had tons of people calling and saying they wanted to be re-tested. You re-test them if that's what it takes to convince them that it's accurate," he says. [and they can be convinced without re-testing?]”

“During a prospective study of seronegative sexual partners of known HIV-1-infected patients [4], we identified two apparently transiently infected individuals (nos. 1 and 2) using a live-cell immunofluorescence assay (IFA) as a test for serum anti-HIV-1 antibodies, HIV-1 DNA amplification by PCR, and HIV-1 culture from the PBMC of the subjects (Table 1). These two were `early-infected' individuals previously reported (identified by their blood sample codes as R6 and R78) who possessed serum anti- HIV-1 antibodies that reacted with native HIV-1 antigens in live-cell IFA, but did not react in the standard Food and Drug Administration-approved denatured-antigen EIA or Western blot. These antibodies were later shown to react to conformational epitopes of HIV-1 Env (gp160) and Gag (p55) precursor proteins, and appear to be the first antibodies induced after HIV infection (submitted for publication) [this paper details how, for these two subjects, all evidence for the presence of HIV disappeared even after extensive re-testing]”

“100 adult patients (68 males; 32 females) with feverish illness were admitted to New Civil Hospital, Surat, India…peripheral blood smears showed malaria parasites in varying numbers. These patients did not have any risk factors for HIV infection. 25, age- and sex-matched healthy volunteers (17 males; 8 females) from the same community, geographical area and socioeconomic group were used as controls. None of the controls had any risk factors for HIV infection, and had had no febrile illness in the preceding six months…Two patients (6%) in the severe P. falciparum [malaria parasite infected] gropu tested positive for HIV-1 and -2 using ELISA…Western blotting proved persistently negative. No patient with low-level parasitaemia…tested positive…treating physicians should exercise extreme caution when interpreting such tests in a patient with PUO [fever of unknown origin] from an area where malaria is endemic, and in whom low level parasitaemia may have escaped detection.”

“Kaushalya greets visitors with a warm welcome, hot tea and biscuits, but her big dark eyes look sad. In the last three years, the 29-year-old woman has lost her husband and social life. ''They broke our lives four years ago,'' she says softly while other members of the family nod. The local hospital said that Kaushalya's husband died of AIDS. Doctors at the medical college in Rohtak city later explained that Kaushalya and her daughter too had tested HIV-positive. The doctors pressured Kaushalya, who was in her sixth month of pregnancy, to get an abortion because of her HIV-infection. ''By telling me a lie they made me lose my only son,'' the young widow mourns. But late last year, a second test [probably a Western Blot or a second ELISA] showed that neither Kaushalya nor her daughter had the AIDS virus. Other members of the family too have since been tested negative for HIV. Like most Indian hospitals, the Rohtak hospital carried out only a single HIV test [ELISA] on her husband. In most other nations, at least three tests with similar results [two ELISA and one Western Blot] are required before a patient is confirmed HIV-positive. However, her family is still well known as 'the family of Chochi's first AIDS case. ''For years we lived with the trauma that the whole family was finished. But it all was a big fraud,'' says Kaushalya's father-in- law Mangaram Joon.”

“Between January 1, 1989 and July 31, 1995, voluntary preoperative screening tests for human immunodeficiency virus (HIV) infection, using an enzyme-linked immunosorbent assay, were completed on 2,727 patients who underwent elective orthopedic surgical procedures. There were 2,719 (99.7%) negative, 4 (0.15%) positive, and 3 (0.11%) false-positive results; 1 test was indeterminate (0.04%)”

“We report the case of a sexually active woman with symptoms suggestive of ARS [Acute Retroviral Syndrome] who had a false-positive HIV-1 RNA assay result...Laboratory evaluation revealed negative results on HIV-1 ELISA and Western blot [antibody tests]. However, an HIV-1 RT-PCR [viral load] assay...revealed a viral load of 623 copies/ml, through p24, gp120, and gp160 antigens were not present. The HIV-1 RT-PCR assay was repeated and revealed a similar measurement...Subsequent studies 2 weeks later revealed an undetectable HIV-1 RNA viral load, as well as negative results on HIV-1 ELISA and Western blot serologies. Two months later, the patient’s symptoms [headaches, swollen glands etc.] had completely resolved...Four months after the onset of symptoms, the patient remained seronegative for HIV-1 infection”

“As the number of women being screened has increased, the proportion of false-positive and ambiguous (indeterminate) test results has increased and the positive predictive value (PPV) of the standard HIV test has decreased”

“[conditions associated with false positive ELISA are] autoimmune disease, renal failure, cystic fibrosis, multiple pregnancies, blood transfusions, liver diseases, parenteral substance abuse, hemodialysis, or vaccinations for hepatitis B, rabies, or influenza…Causes of indeterminate WB [Western Blot] results include…nonspecific antibody reactions (eg, due to lymphoma, multiple sclerosis, injection drug use, liver disease, or autoimmune disorders). Also, there appear to be healthy individuals with antibodies that cross-react with specific HIV-1 peptides or recombinant antigens…The Association of Public Health Laboratories now recommends that patients who have minimal positive results on WB, eg, p24 and gp160 only, or gp41 and gp160 only, be told that these patterns have been seen in persons who are not infected with HIV and that follow-up testing is required to determine actual infective status. The clinician must judge the test results within the context of other epidemiological and clinical information [i.e. gay men and IV drug users are likely to be defined as positive based on this prejudice in the presence of ambiguous test results]. In the appropriate clinical setting, positive ELISA and WB test results in patients with a normal CD4 + count and CD4/ CD8 ratio and undetectable HIV-1 RNA should be questioned, repeated, or confirmed with supplemented testing. A false-positive serological test result may be supported by normal CD4 + count and CD4/CD8 ratio and undetectable HIV-1 RNA, but is ultimately established by subsequent serological testing and, especially, close follow-up. [i.e. there is no test that can be absolutely relied on]”

“In 1984, I was informed that test results showed that I had an ‘HIV’ infection and I had at best five years to live...I am now 50 years old and have taken back control of my own health. For the past eight years, I’ve had no need for doctors, and have been on a diet of pure water, organic food and a positive belief system.”

“False reactivity with at least 1 of the 6 [rapid] HIV screening tests was found in sera from 21 of the 66 patients with malaria and from 4 of 9 patients with dengue. Specificity of individual kits ranged from 77% to 100%. Malaria antibody titers [levels] did not correlate with false-reactive HIV-1 results from test A, the least specific kit. 6 of the 12 malaria sera tested positive by IFA [immuno-fluorescence assay]. Test A was reactive in 4 of the 6 sera…and was negative by use of IFA in 5 of 14 sera. All dengue sera were negative on the basis of malaria IFA, but half were reactive by test A…false reactivity may occur with [HIV-1 rapid tests] and…it is important to define the cross-reactivity associated with endemic diseases, because resource-poor regions of the world rely more and more on these rapid, simple HIV tests.”

“Negative results (<50 copies/mL), were obtained in 30/32 (94%) [bDNA 3.0] assays [meaning that false-positive results were obtained in 2/32 or 6% of cases]”

“We describe here a case of heterophile antibodies that are cross-reactive with bovine and caprine proteins occurring in a 22-month-old child, causing false-positive immunoassay results to human immunodeficiency virus type 1 (HIV-1) and a number of other infectious serology tests...we believe the positive test results observed in this patient were due to heterophile antibodies reactive with BSA and caprine proteins. All of the positive tests observed used BSA [bovine serum albumin] as a blocking agent for the preparation of the microELISA reaction wells.”

“Abbott Laboratories state that their ELISA test is 100% sensitive and 99.9% specific and this would seem excellent, more reliable, in fact, than many other tests used elsewhere in medical practice…[However,] If…the incidence of HIV infection in the population was 0.1%, in a population of 1,000 there would be one true positive and one false positive, and the test would be considered very unreliable.”

“The Centers for Disease Control and Prevention (CDC) states that the two tests used to identify HIV - the ELISA and the Western blot (WB) - used in combination, have a better than 99% accuracy rate, but only if they are performed repeatedly. (The exact rate is unknown and the CDC states that it has no data on just how many false positives versus false negatives occur!)…The CDC estimates that 0.6% of Americans are HIV-positive…Using the CDC estimate that 0.6% of Americans are HIV-positive, in a population of 10,000, 60 Americans would test positive! This 60 must include all the false positives, 30, leaving only 30 people actually infected. This leads to the following conclusion: using a 99% accuracy, one finds as many false positives as true positives. Even if the results of both AIDS tests, the ELISA and WB, are positive, the chances are only 50-50 that the individual is infected.”

“18 subjects had 1 or 2 positive results with v.2.0 and an undetectable confirmatory test for a false positive rate of 4.4%. The rate is similar at baseline (9/183 subjects = 4.9%), wk. 4 (7/162= 4.3%) and wk. 26 (2/44 = 4.5%). Of the 18 pos. specimens, 9 tested pos. once and 9 twice. With version 3.0, 11 of 67 samples tested were pos. (16.4%). 6 were pos. once and 5 twice. The range of false pos. rates was 9.1% at wk. 4 (total of 22 specimens) to 26.7% at wk. 26 (total of 15 specimens). A week 4 sample with two values of 8,000 copies/ml on v.2.0 was neg. by DNA PCR, p24 antigen and Western Blot. Follow-up testing of this subject at wk. 26 was negative for HIV antibody and RNA. The emotional impact of a false positive screening RNA test in a recently exposed person is significant. With the high false positive rate, we do not advocate the routine use of HIV RNA tests to screen asymptomatic people. The high rate of repeat false positive tests in a given sample (50%) suggests a possible biologic mechanism”

“Of 421 donors who were positive for HIV-1 by Western blot, 39 (9.3%) met the criteria of possible false positivity because they lacked reactivity to p31. Of these, 20 (51.3%) were proven by PCR not to be infected with HIV-1. The false-positive prevalence was 4.8% of Western blot-positive donors and 0.0004% (1 in 251,000) of all donors (95% confidence interval, 1 in 173,000 to 1 in 379,000)...A review of the 5.02 million donations in the 1991-1995 REDS donation database revealed that 4,650 were anti-HIV EIA repeat-reactive and 421 were HIV-1 Western blot positive (0.008% of all donations, 9.0% of EIA repeat-reactives) using the 1993 FDA interpretive criteria. 39 (9.3%) of the Western blots with positive results lacked the p31 band.”

“A small number (15% to 20%) [!] of [ELISA and WB antibody] tests from low-risk patients will be indeterminate and remain so even if repeated over many months”

“A 5-month-old boy [of injection drug-using parents] was diagnosed with severe thrombopenia…The child’s plasma viral load was 3044 HIV RNA copies/ml, and he began to receive zidovudine plus didanosine…Unexpectedly, days later it was discovered that HIV antibodies [ELISA and WB] were not detected in sera collected from the child or from his parents. The plasma viral load was examined in a new specimen using the same technique (HIV Quantiplex, Chiron, Madrid, Spain) and again it gave a positive result of 5120 HIV RNA copies/ml.”

“Although nonspecific reactvity [false positives] may sometimes be attributed to autoantibodies, it is possible that in some cases the pattern may represent a cross-reaction with another human retrovirus…POSITIVE blot results using any specimen type (serum, plama, or urine) should be followed with additional testing. Such testing may rely on alternative test methods or specimen types. [yet this is a 'confirmatory test'!]…[Table P shows that 1 out of 63 tests on pregnant women who were HIV ELISA negative was positive on western blot]”

“No patient with liver disease showed reactivity to the HIV-1 gag and envelope proteins…Immunoblot reactivity was generally restricted to p24 and, in a few cases, p17 in the patients with liver disease. The frequency of HIV-1 p24 gag reactivity in the patients with primary biliary cirrhosis was not significantly different from that in the groups with systemic lupus erythematosus, chronic viral hepatitis, or other biliary disorders, but it was significantly higher than the frequencies among the healthy volunteers and patients with alcohol-related liver disease or alpha1-antitrypsin deficiency”

“Specimens were studied from a mother and her child, both with suspected transient viremia. The mother had 2 and the infant 3 positive HIV-1 cultures, but subsequently both individuals became negative for HIV-1 by nPCR, standard virus cultures, CD8+-depleted virus cultures, and enzyme-linked immunosorbent assay. HIV-1 RNA and DNA were not detected in two lymph nodes taken from the mother 3 and 4 years after the last virus-positive culture. PCR amplification and DNA sequence of HIV-1 env sequences from the...culture supernatants were performed in separate laboratories to eliminate the possibility of cross-contamination. Phylogenetic analysis found that none of the five isolates were genetically linked. Although it is improbable, these 5 virus isolates appear to have arisen from 5 separate incidents of specimen contamination or mislabeling. This case remains enigmatic, however, in that both the mother and infant had strong CD8+ cytotoxic lymphocyte proliferation to multiple HIV-1 antigens.”

“Initial testing of plasma by RNA RT-PCR was reported as positive. This result was not confirmed by viral cultures, nested DNA PCR, western blot, or EIA. Additional RNA RT-PCR assays gave positive results from earlier occasions in the vaccine trial. Eventually, testing of all previously reactive samples by RNA RT-PCR was repeated in a quality-controlled laboratory, and confirmed the negative HIV-1 status of the individual. Interpretation This case report exemplifies the difficulties with use of viral-genome measurement as a screening test to diagnose HIV- 1 infection, particularly in individuals who have ever participated in HIV-1 vaccine trials. Monitoring of large numbers of phase III vaccinees by RNA RT-PCR will not be feasible. The design of efficacy trials for new vaccines should be in parallel with development of antibody-based diagnostic tests that are capable of differentiating between immunisation and true HIV-1 infection.”

“the EIA [this test] was designed to be extremely sensitive. As a result, non-specific reactions may be seen in samples from some people who, for example, due to prior pregnancy, blood transfusion, or other exposure, have antibodies to the human cells or media in which the HIV-1 is grown for manufacturer of the EIA. The risk of an asymptomatic person with a repeatably reactive serum sample developing AIDS or an AIDS-related condition is not known.”

“For 859 specimens from uninfected infants [based on two negative cultures], 97% had PCR negativity, 2% had PCR positivity and 1% had indeterminate status”

“Not all persons infected with HIV-1 will test positive; not all persons testing positive are infected with HIV-1…inaccurate results may occur and a positive test result alone does not mean I have AIDS or will ever develop AIDS…an indeterminate result means the result is neither negative nor positive”

“False positive results may occur due to non-specific binding to assay materials and not from infection with HIV-1.”

“False positive results [with this HIV-1 antigen test kit] may occur due to non-specific binding to assay materials, and not from infection with HIV-1”

“Our previous data demonstrated that anti-gp41 MAb [monoclonal antibody] 781.4, as well as human serum antibodies against the same gp41 epitope, bound specifically to the surface of [HIV-uninfected] human astrocytoma cells…Antigens from U-138 MG human astrocytoma cells that cross-react with anti-gp41 MAb 781.4 were isolated by immunoaffinity chromatography. Two major bands of approximately 100 and 200 kDa in molecular mass were visible…Western blot analyses of the purified preparations demonstrated that both the 100- and 200-kDa proteins were immunoreactive with MAb 781.4 as expected, although the reactivity of the 100-kDa protein was much greater…When the N-terminal sequences obtained from peptides [generated by partial digestion of the 100-kDa protein] A, B and C were subjected to analyses…the amino acid sequence of each of the three peptides was found to be homologous to a human non-muscle isoform of alpha-actinin…we analyzed their immunoreactivity with the anti-gp41 MAb 781.4 and an anti-alpha-actinin specific MAb by Western blot. The two antibodies displayed the same reactivity…In addition we used an ELISA with the purified chicken alpha-actinin protein…The anti-gp41 as 598-609 MAb 781.4, as well as another antibody, designated MAb 781.3, which recognizes an epitope within gp41 aa 581-597 were immunoreactive with alpha-actinin”

“The causes of false-positives [on ELISA antibody tests] are listed in Table 1 [Hematologic malignant disorders, DNA viral infections, Autoimmune disorders, Multiple myeloma, Primary biliary cirrhosis, Alcoholic hepatitis, Influenza vaccination, Hepatitis B vaccination, Passively transferred antibodies, Antibodies to class II leukocytes, Renal transplantation, Chronic renal failure, Stevens-Johnson syndrome, Positive rapid plasma reagent test]”

“Considerable variation was observed in the number of repeatedly false-positive reactions observed for each assay. Only one assay (ELISA 1) was 100% specific. The highest rate of false-positive results was obtained with tests 2 (10 [false positive results]) and 4 (8 [false positive results])…the highest rate of false-positive results was obtained by testing serum samples from high-risk individuals, patients with autoimmune diseases or acute viral illness, organ transplant recipients and pregnant women. In contrast, sera which were repeatedly reactive by ELISAs, but negative in Western blot, did not affect the specificity of the 6 assays”

“A case was defined as a donor whose blood donation tested reactive in screening tests [usually ELISA] for antibodies to at least two of…HIV-1, HTLV-1, and hepatitis C and had negative or indeterminate results in confirmatory or supplemental tests…70.3% of the cases compared with 22.6% of [matched] controls reported a recent influenza vaccination. A history of recent acute illness was [also] more common…A history of allergies and a history of recent vaccination other than for influenza were also more common among the cases than among the controls.”

“HIV could not be isolated from the plasma of subjects with long-term nonprogressive HIV infection, but it could be isolated from lymph-node mononuclear cells (in seven patients) after coculture with phytohemagglutinin- activated mononuclear cells from an HIV-negative donor (data not shown).”

“We report a false-positive result on an enzyme immunoassay screening test for antibodies to human immunodeficiency virus in a 32-year-old nonpregnant woman who belonged to none of the usual risk groups. Because of the patient's employment in an animal care facility, she had received a series of three vaccinations for rabies, and 16 days after the last vaccination, she had donated a unit of blood. It was during routine screening on a sample drawn at the time of donation that the repeatedly reactive enzyme immunoassay screening test occurred. The results of a Western blot were indeterminant. A polymerase chain reaction assay was negative for proviral DNA.”

“WB was considered diagnostic for HIV-1 if there was reactivity with two of three envelope bands (gp160/120 and gp 41). The rate of HIV-1 false-positive ELISAs was…63.6%…among uninfected leprosy patients…Of the cohort of 500 pregnant women, HIV-positive results were obtained by Abbott ELISA in…5.6%, Organon ELISA in…5.4%, and on both tests for…5.2%…WB were indeterminate in…83.6%…of 55 leprosy patients and...3.9%...of HIV-negative pregnant women.”

“During a ten-month period 3 of 77 low-risk normal controls had positive ELISA tests. This gives a false-positive rate [on ELISA] of about 4% [manufacturer quotes 0.58%]…Case 1…a 38-year-old woman who had had unprotected anal intercourse twice in her life tested strongly positive for the presence of HIV antibodies. Further questioning revealed that she had had an outbreak of herpes simplex type 2 infection three weeks before…Case 2…a 23-year-old man with no known risk factors…he had been inoculated with the influenza vaccine two months before testing…Case 3…a 32-year-old man had no known HIV risk factors, but he had received the influenza vaccine two months before HIV testing. He also had had hepatitis C infection several years previously…we have screened another 50 subjects and have had two more false-positive ELISA results”

“False-positive HIV ELISAs have been observed with serum from patients with a variety of medical conditions unrelated to HIV infection [but claims that these can be eliminated by use of Western Blot test or synthetic peptides in the test kits]…False-positive HIV ELISAs [also] occur because of human or technical errors associated with doing the tests or because of antibodies that coincidentally cross-react with HIV or nonviral components in the tests…Notable causes of false-positive reactions have been anti-HLA-DR antibodies that sometimes occur in multiparous women and in multiply transfused patients. Likewise, antibodies to proteins of other viruses have been reported to cross-react with HIV determinants. False-positive HIV ELISAs also have been observed recently in persons who received vaccines for influenza and hepatitis B virus [but again claims that these can be eliminated by Western Blot tests or use of synthetic peptides in tests]”

“When the EIA [enzyme immunoassay antibody test] is used to screen populations in which the prevalence of HIV-1 infection is low (e.g., blood donors), nonspecific reactions may be more common…Reactivity at only slightly above the cut-off value is more frequently nonspecific”

“From October 31 through December 15, 1991, 10 blood donors to the American Red Cross Blood Services, Badger Region (ARCBS) , were found to have false-positive screening enzyme-linked immunosorbent assays (ELISAs) for antibodies to two or more of the following viruses: human immunodeficiency virus type 1 (HIV-1), human T-cell lymphotrophic virus type 1 (HTLV-I), and hepatitis C virus (HCV)”

“The specificity of immunoassays for detecting HIV antibodies has major shortcomings. Almost all reactions, especially in low risk populations, represent false-positive results. This has been observed with Western blot (WB), which is widely used as a confirmatory test…A serum panel of 21 blood-bank donors and two serum samples from patients with primary Sjögrem's syndrome were analysed…All sera were positive on two commercial WB assays, as well as on home-made blots using recombinant p24 proteins. All sera appeared to be HIV-negative on a third-generation ELISA. Specimens of these sera were also HIV-1-antigen negative and [by] PCR. Infection could not be detected after cocultivation of donor-derived lymphocytes with permissive cells. Furthermore, in a retrospective study of blood donations, seroconversion was not observed in any of the recipients of this blood. We performed a radioimmunoprecipitation assay (RIPA) using recombinant p24 proteins…No reaction was observed…herpes simplex virus type 1 (HSV-1), strain 17, may be the agent that caused the cross-reactivity in…two cases.”

“A 30 year old male Hispanic college student with no history of intravenous drug abuse, blood tranfusion, or high risk sexual behavior was admitted to hospital in October 1990. He had had fever, myalgias, dyspnoea, weight loss, mouth ulcers, and arthritis in his leg for four months before admission…Antibodies to HIV were twice positive by ELISA at a one month interval. The western blot analysis gave positive results for the gp41 band…Six months later the ELISA and western blot results were negative…A 26 year old male Hispanic construction worker as diagnosed as having SLE in 1988 based on malar [cheek] rash, photosensitivity, persistent leucopenia and positive antibodies to DNA. He also developed sensitive polyneuropathy due to peripheral nerve vasculitis [so far this sounds like pesticide or heavy metal poisoning]…He did not report a history of intravenous drug abuse, blood transfusion, or high risk sexual behavior. He was being treated with prednisone 40 mg/day and monthly intravenous cyclophosphamide. In 1989 he was treated for pulmonary tuberculosis…admitted to hospital in August 1990 with fever, abdominal pain, weight loss, myalgias [muscle pain], and proximal and distal muscle weakness…The patient tested positive twice for antibodies to HIV by ELISA with a two month interval, but was negative by Western blot analysis. Six months later both tests were negative]”

“9 of the 10 case donors received influenza vaccine, compared with 3 of 30 control donors. Among 9 case donors, the mean time between vaccination and blood donation was 26 days (range, 9 to 68 days). Follow-up ELISAs of serum samples from seven case donors obtained 52 to 130 days after vaccination demonstrated reversion to HIV and HTLV-1 seronegativity in all but one specimen, with persistence of positive HCV ELISAs in four specimens. We estimate between 0.6% and 1.7% of blood donors who received influenza vaccine this season had multiple false-positive viral ELISAs.”

“In 1990, of 20.2 million HIV tests done in Russia only 112 were confirmed and about 20,000 were false positives, 1991 saw some 30,000 false positives out of 29.4 million tests, with only 66 confirmations...in 1991 alone some 8000 false-positive results were reported in pregnant women, with only 6 confirmations [presumably with the Western Blot test]”

“In India, nearly 5000 blood donor specimens have shown serological evidence of HIV infection by [ELISA] but there are only a few reports of clinical evidence of [AIDS]. Majority continue to remain asymptomatic…During the period between March, 1989 and February, 1991, a total of 74 specimens were identified as positive for anti-HIV antibody by the method of competitive ELISA technique employing recombinant reagents. Out of 74 sera, 40 showed positivity by confirmatory Western Blot technique by the criteria of positivity laid down by CDC as well as WHO. Out of the remaining 34 specimens, 16 showed total absence of any band in Western Blot (false positive) while the remaining 18 specimens showed a few band(s) that could not qualify the interpretive criteria of positivity ('indeterminate' category)…our study did not point out any association between malarial infection and serological reactivity for HIV infection whether 'true' or 'false'.”

“The initial study group consisted of 1,129 addicts (949 men and 180 women) consecutively admitted to the National Institute of Mental Health’s former Clinical Research Center at Lexington, KY, between May 15, 1971, and May 14, 1972...The WB results from the earlier study, which had employed a technique enhanced by the use of an avidin-biotin system, were reanalyzed. The Centers for Disease Control issued diagnostic criteria in 1985 recommending that a WB be considered positive if either band p24 or band gp4l was present alone or in combination with other bands. On rereading, blots with isolated p24 bands were considered to be indeterminate. One 1985 WB, with bands at both the 24 and 55 kilodalton regions, was included among the positives, since the interpretation of this pattern had previously been unclear. The 1971-72 serum specimens were not available for retesting... The two former patients whose 1971-72 WB results were most strongly reactive had current ELISA and WB assays that were negative. Their immune function parameters were inconsistent with immune suppression... The results of the ELISA and WB assays performed on the 1971-72 specimens remain an enigma. Some were interpretable as positive, although only weakly reactive. One explanation is that the results observed in 1985 were true positives, that PDAs in the early 1970s had antibodies to an HIV-like agent that was nonpathogenic, and that the WBs subsequently converted from positive to negative. Loss of HIV antibodies in asymptomatic homosexual men has been reported. It is possible that antibodies to a nonpathogenic virus would have disappeared during the 17 to 18 years between admission to Lexington and the 1989 followup. Although this potential cannot be ruled out, it is more likely that the earlier results were false positives. The reasons for false positivity are unclear, but cross reactivity with related retroviruses may be one possibility. The HIV Western blot assay may cross-react with antibodies to HTLV-I in the p24 and p55 antigen regions, but not the gp4l region. These serum specimens were tested for the presence of HTLV-I/HTLV-II antibodies by other investigators, and a 6.3 percent seropositivity rate for the entire cohort was observed. It is not known if these 10 persons were seropositive for this related retrovirus; however, it is unlikely that this type of cross reactivity accounted for the previous results, given the distribution of the bands and the fact that reactivity was not detected during selected 1989 followup WB screening. The earlier false positivity could be the consequence of either the state of the serum specimens or the test kit or assay employed. It has been suggested that artifactual findings may occur as a consequence of frequent thawing and refreezing of serum aliquots, and that frequent refreezing might affect the physical properties and serologic characteristics of the serum protein moieties. The available evidence would suggest that long-term storage and repeated thawing and refreezing does not affect subsequent testing for serum constituents”

“HIV-1 p24 is the HIV-1 protein most prone to "false-positive" reactions…false-positive reactions have been observed with every single HIV-1 protein”

“In this study we have shown that normal human serum contains antibodies capable of recognizing the carbohydrate moiety of HIV envelope glycoproteins…These antibodies are thought to have been naturally elicited as a result of exposure of various pathogens including bacteria, fungi, and human viruses with envelope glycoproteins such as herpes viruses. It is unlikely that individuals whose sera posses anti-oncovirus antibodies are infected with animal retroviruses…Antibodies reactive to HIV glycoproteins described here may also have been elicited naturally rather than as a consequence of HIV exposures.”

“A 25-year-old nurse injured her hand on the edge of an operating-table. She was given a prophylactic injection of tetanus immune globulin. The following day a blood sample was taken to test for hepatitis B markers and HIV antibody…HBV markers were negative but she was anti-HIV positive with both ELISA tests used in our laboratory, and the same sample was western blot positive, showing reactivity against all viral proteins…A second blood sample, taken 12 days later, was anti-HIV negative by ELISA but showed reactivity for gp120 and p24 by western blot. A third sample, taken 1 month after the first, was negative by both ELISA and western blot”

“The possibility of false-positive results in the Ag [p24 antigen], IVAP [in vitro antibody production] and PCR [‘viral load’] assays seems worth stressing. False-positive results in Ag and IVAP occurred only in the first 2-3 months of life [in this relatively small study]…false positive PCR results were unrelated to the child’s age.”

“As part of a phase 1 trial of a candidate AIDS vaccine, blood specimens were collected from 168 healthy adult volunteers at minimal or no risk for becoming infected with human immunodeficiency virus type 1 (HIV-1). These specimens were screened for evidence of HIV-1 infection by enzyme immunoassay (EIA) and the Biotech/Du Pont Western blot (168), culture (122), and polymerase chain reaction assay (20). None of the subjects had a positive test result by any of these assays, but 32% had indeterminate Western blot tests, most of which demonstrated a single band of low intensity. The most common bands were p24 (47%), p55 (34%), and p66 (36%); envelope bands were unusual (gp41, 2%; gp120, 2%) [meaning that none of these bands are unique to HIV, yet multiple bands would be interpreted]. No serum specimen collected after 2-11 months from individuals with indeterminate Western blot results was positive by EIA or Western blot. There was 91% agreement in the test results of the first and second serum samples when the same lot of Western blot kit was used but only 36% agreement when different lots were used.”

“144 dog sera were tested on Chiron Western blot strips. Of these, 72 sera (50%) reacted with one or more HIV recombinant proteins”

“A 31-year-old heterosexual male, who was not a drug abuser, was admitted with a history of an influenza-like illness followed some 6 weeks later by a painful neuropathy progressing from legs to hands…autoantibodies were noted to be positive on one or more occasions (double-stranded DNA, smooth muscle, and ANCA). ANCA was detected by routine immunofluorescence with alcohol-fixed neutrophils; staining was perinuclear with some focal intracytoplasmic positivity. Subsequently HIV antibody was detected in three sera, confirming the diagnosis of HIV-induced neuropathy. The history and clinical findings followed the pattern described with HIV seroconversion. [The doctors concluded that the auto-antibody tests were false-positive, but since neuropathy is not an AIDS-defining illness (but a side-effect of AIDS drugs) and flu-like symptoms are vague, it’s equally possible that the positive HIV tests were false]”

“Clinical follow-up of patients with indeterminate Western blot results may require many months of observation, interviewing, and testing…Some indeterminate results may be obtained with serum samples from persons who are in the process of seroconverting…A person whose Western blot test results continue to be consistently indeterminate for at least 6 months–in the absence of any known risk factors, clinical symptoms, or other findings–may be considered to be negative for antibodies to HIV-1. Such persons should be reassured that they are almost certainly not infected with HIV-1. However, no large-scale studies have been done to provide virologic data to confirm independently the serologic findings from the studies of clients whose Western blot test results are consistently indeterminate. n contrast, an asymptomatic person who has an indeterminate Western blot test result and a history of possible exposure to or symptoms compatible with HIV infection requires additional diagnostic follow-up. This should include conducting serial Western blot testing, assessing the function of the individual’s immune system, and eliciting the cooperation of the person’s sexual and needle-sharing partners to determine whether they are infected. Individuals with a pattern of indeterminate Western blot test results should not donate blood or plasma for either transfusion or use in manufactured blood products.”

“We describe a patient with acute leukemia in whom both antibodies against HLA-DR4 and a false-positive HIV ELISA transiently occurred while he was receiving red-cell and platelet transfusions…The patient’s serum first became reactive with H9 ELISA reagents in September 1985. ELISA values rose until November and then fell. The immunofluorescence assay was also positive during this period, but reactivity was similar with both infected and noninfected H9 cells…none of the serum samples tested reacted the CEM-cell ELISA kit, and Western blot analyses of serum samples obtained in November were negative…Serum samples obtained in November 1985 were retested…and were again positive”

“Two newborns of mothers carrying hepatitis B and at high risk for human immunodeficiency virus (HIV) infection developed HIV-positive test results by enzyme-linked immunosorbent assay and Western blot tests after birth. Both had been administered hepatitis B immune globulin within 48 hours of birth. Serological tests detected HIV antibody as long as 17 days after birth. Both newborns had received lots of hepatitis B immune globulin containing antibody to HIV.”

“Two newborns of mothers carrying hepatitis B and at high risk for human immunodeficiency virus (HIV) infection [but actually HIV negative] developed HIV-positive test results by enzyme-linked immunosorbent assay and Western blot tests after birth. Both had been administered hepatitis B immune globulin within 48 hours of birth. Serological tests detected HIV antibody as long as 17 days after birth. Both newborns had received lots of hepatitis B immune globulin containing antibody to HIV. While hepatitis B immune globulin cannot transmit HIV infection to recipients, physicians should be aware that administration of older lots of this preparation may result in transiently positive tests for HIV antibody in the recipients”

“5 recipients [of organ transplants] not reported above each had only a single serum positive by EIA [ELISA antibody test] but negative by Western Blot [antibody test]…3 patients who had positive Western blot tests are not listed…because later serum samples did not contain HIV-1 antibodies”

“we describe a patient whose serum showed false-positive reactions with HIV proteins detected by ELISA and immunoblot assay with an unusual reaction pattern…The patient…was heterosexual, married and had one child. The wife and the child were seronegative on HIV ELISA. To obtain anti-Rhesus immune plasma the patient was given six 5 ml injections of Rh+ serum, administered at 4-day intervals, Rh+ serum was shown to be negative on HIV antibody and antigen ELISA…Blood taken after the first immunization was shown to be negative on HIV antibody ELISA and immunoblot assay [Western Blot]. After the second immunization a weak signal on ELISA, slightly above the cut-off level, was monitored. After the third immunization the signal was strong and immunoblot revealed distinct interaction with p17 and p55 proteins. An even stronger signal was monitored after the fifth immunization. Interaction with p17, p31, gp41, p55 and some other proteins was evident. However…immunofluorescence…gave negative results. The samples were also probed in immunoblot based on HIV gag and env encoded proteins expressed by recombinant vaccinia viruses. They demonstrated no reaction with recombinant HIV proteins…A specimen is considered to be immunblot-reactive by the presence of bands at the 24-kilodalton [p24] and/or 41-kilodalton [gp41] molecular weight regions with or without the presence of other bands. Reaction with isolated p17, p24 or p55 proteins may be false-positive while interaction with gp41 is considered indicative of HIV infection. Here we present evidence that this may be untrue. What is more, analysis of sequential samples of the serum demonstrated blot progression imitating real HIV infection.”

“At the time of study (1978-1983), 36 (33%) of the 110 patients had been exposed to HIV, based on positive Western blot analysis…False-positive ELISA reactions for anti-HIV in relation to Western blot were seen in five (7%) of the 70 patients with negative Western blot analyses [and significant discrepancies between the two ELISA types used…Compared with the patients with a true-negative ELISA for anti-HIV, patients with false-positive tests had significantly more years of alcohol abuse and commenced their alcohol use at younger ages…no specific liver pathology was associated with a false-positive ELISA test for HIV”]

“we found cross-reacting antibodies...to HIV-1 in patients with multiple sclerosis. Among 150 healthy Finnish persons, 1 (a woman) had antibodies to p24 and p55 of HIV-1. Some patients with multiple sclerosis, cutaneous T-cell lymphoma, or dermatologic disorders had antibodies that also reacted with the viral proteins of an HIV-2 isolate”

“Most patients (68 to 89%) from low risk groups (prevalence of 0.1% or less) who show reactivity on screening tests will have false-positive results…The predictive value of a positive ELISA varies from 2 to 99%…One notable association with false positive ELISA reactivity in some commercial preparations has been patients with anti-HLA-DR4 antibodies, most often multiparous [having experienced one or more births] or multiply transfused patients”

“if a specimen is reactive in several assays based on independent methodologies [since ELISA and Western Blot are both antibody tests, they cannot be considered independent, nor can several repeated ELISA even if done by different personnel], it is very likely [but not certain, is that good enough for you?] to be truly positive.”

“Four asymptomatic homosexual men reverted from positive to negative serologic [antibody] results for…HIV-1…over 2.5 years as shown by …ELISA…and Western Blot…No HIV-1-p24 antigenemia was detected; cryopreserved [frozen] peripheral blood mononuclear cells [PBMCs] were negative for HIV-1 by standard culture assay. Polymerase chain reaction…assays were done on [PBMCs] and showed the HIV-1 provirus in all subjects 6 to 18 months after the last positive antibody test…[this is in the abstract, but in the body of the paper they say]…The [PCR]-amplified gag gene product was found [in patient A] at visits one to four…[and] at visits two, three and four [in patient B]…[and] at visits one and two but not at three and four [in patient C]…[and] at visits one and three but not at visits four and five [in Patient D]…[But, in the table of data they show the actual data for the four tests they took at 6 month intervals. Omitting times when they did not test a sample, for patient A the results were at 6mo–2 of 4 determinations positive, 1yr–1 of 4, 1.5yr–3/4 positive, 2yr–4/4 +. Patient B: 1yr–2/4, 1.5yr–1/4, 2yr–2/4. Patient C: 6mo–1/4, 1yr–2 of 4, 1.5yr–0/4, 2yr–0/4. Patient D: 6mo–4/4, 1.5yr–1/4, 2yr–0/4, 2.5yr–0/4]”

“8 of the 11 false-positive samples were from women who had at one time been pregnant…other reported causes of false positive ELISA tests for HIV screening include anti-hepatitis A IgM, anti-hepatitis B core IgM, anti-thyroid microsomal, antinuclear, anti-smooth muscle, anti-parietal cell, anti-liver/kidney microsomal, and anti-mitochondrial…Causes of false positive Western blot tests for antibodies to HIV are…1. Presence of antibody to another human retrovirus…2. Presence of another human retrovirus in the H9 cells that the reagent antigen is obtained from. 3. Cross reactions with cell derived ribonucleoproteins or other non-viral proteins…Monoclonal [artificial] antibodies can be a pure, well defined and characterized reagent used to detect the HIV virus. These antibodies do, however, show cross reactivity with other antigens…1. Proteins found in HIV particles may be part of normal cellular polypeptides that are expressed only under particular circumstances, such as rapid cell proliferation where cellular polypepetides are entrapped with genuine HIV components. 2. Whole polypeptides which are unrelated but share short amino acid sequences with HIV sequences with HIV can give rise to immunologic cross reactions…3. Proteins encoded by the HIV genome and gene products of the human endogenous gag sequences are related to the extent that monoclonal antibodies react with both.”

“Three chimpanzees were inoculated with AIDS plasma [i.e. plasma from someone with AIDS, not purified virus] and one was inoculated only with normal human plasma. Blood was sampled biweekly from each animal and sperm was tested in the standard indirect ELISA for HTLV-III [HIV] antibodies...all four of the animals were positive for passively transferred HTLV-III”

“These results, supported by previous reports of false seropositivity in asymptomatic blood donors, emphasize the need to be certain of viral antigen specificity when screening for HIV antibodies. We suggest that blood banks use both HIV-infected and noninfected cell lines when confirming seropositivity by the Western Blot test and that the presence of bands on such tests not be automatically considered to indicate positive status”

“we tested 151,667 blood units by ELISA. 130 (8.6%) were confirmed positive by WB (in that they reacted with different HIV proteins, including gp41 and/or gp 110). 8 of these were false positive for gp18 and 23 were false positive for p25 [now known as p24]; in other words there was 1 false positive by WB for about 4 true positives in our population of blood donors and under our work conditions”

“the C+ M- [child HIV-positive, mother negative] children were significantly more likely to be boys, to have received medical injections, and to have had previous blood transfusion or hospital admission than C- M- children…Gastrointestinal illness and malnutrition were associated with seropositivity among ill children”

“The frequencies of false-positive reactions in a tricky panel of samples from patients with autoimmune and acute viral diseases...were Abbott 9.5%...Organon 1.7%...Litton 1.0%...Behring 2.7%...Wellcome 0%...and Pasteur 0%...The results of a 7th EIA (Dupont) were excluded from the study at the company’s request.”

“Reactivity with [HIV proteins] p24 and/or gp41 has been suggested as a minimum requirement for HIV seropositivity by WB [Western Blot]. While testing ELISA positive serum from Swedish blood donors we detected 3 sera with false-positive WB reactions to p24 and p55...The 3...had no risk factors for HIV infection”

“we recently sent 5 identical proficiency panels to 5 large commercial firms that offered HTLV-III Western blot testing…Each panel consisted of 15 samples from healthy, low risk adults whose serum was repeatedly negative for HTLV-III antibodies and 5 samples from HTLV-III-infected (culture-documented) patients…4 of the 5 laboratories reported at least one false-positive test result. The 6 false positive results were all on different normal specimens…The single most common error was detection of a band at 24 kd using normal samples.”

“We recently completed a study of 1129 serum samples obtained from parenteral [IV] drug abusers throughout the United States and 89 control samples from nonabusers of drugs, all collected during 1971-1972…A total of 45 serum samples from addicts were repeatedly positive according to at least one of the ELISA procedures, whereas the 89 control samples were uniformly negative…these samples and 196 other selected samples, including 3 randomly selected control samples, were tested by the Western blot technique. 17 of the serum samples from addicts demonstrated reactivity to specific HTLV-III [HIV] proteins. The 3 control samples were negative…14 of the samples from addicts demonstrated reactivity to multiple viral proteins on the blot, and 3 reacted with only the p24 protein…On the basis of our positive Western blot data, it appears possible that parenteral drug abusers may have been exposed to HTLV-III or a related virus as early as 1971. An alternative but equally viable explanation is that the HTLV-III seropositivity detected in these specimens represents false positive or nonspecific reactions. Parenteral drug abusers are known to present a high rate of both false positive and false negative results on ELISA…often have hypergammaglobulinemia, higher titers of immune complexes, a high prevalence of positive tests for rheumatoid factor, and high rates of false positivity on a number of routine laboratory tests.”

“We evaluated serum samples from a group of 12 patients with acute Plasmodium vivax infection [malaria] who lived in…southwestern Venezuela…Our second group, 12 patients with Plasmodium falciparum infection…None of the patients were receiving antimalarial drugs…and none belonged to any of the recognized AIDS risk groups or had any AIDS-associated disorders…3 of the patients with P. falciparum infection (25%) and 5 with P. vivax (41%) were found to be positive for HTLV-III/LAV [HIV] antivodies by [3 antibody test types]”

“Initial testing...revealed that [a 34-year old woman from rural Alabama] was positive for HTLV-III [HIV] antibody by ELISA tests on two separate occasions. Here serum was then sent for verification to the designated commercial laboratory, where three repeat ELISAs were strongly positive...as was a Western blot assay...In July 1985, the patient was informed that her serum was positive for HTLV-III antibody...Her physical examination was normal. Both she and her husband of 14 years denied any homosexual or extramarital sexual encounters, intravenous drug abuse, blood transfusions, or foreign travel. The patients T4:T8 [immune cell] ratio was 2.1:1, with a normal lymphocyte count. Her husband and their two-year-old son were both antibody negative by ELISA. More blood was drawn from the patient...Western blot, radioimmunprecipitation, and HTLV-III virus isolation studies were all negative. HTLV-III ELISAs were repeated in two laboratories, and results from both were positive...Western blot tests with positive bands at 24 and 41 kd [which this woman had, plus two others] have been used as the ‘gold standard’ by which other test results are judged to be falsely positive. Several articles refer to the inevitability of false positive Western blots.”

“We tested serum samples from 224 [Venezuelan] Indians belonging to four different ethnic groups…5 of 150 Yanoama Indians, 2 of 54 Makiratare Indians, and 2 out of 15 Pemon Indians were positive for HTLV-III/LAV [HIV] antibodies by all three assays used…all the Indians tested were apparently healthy…Amazonian Indians have no contact with surrounding non-Indian populations…[they are located] in the most inland and remote part of the country, thereby making transmission of agents from outside of the Continent unlikely; blood donors in Caracas and other coastal cities facing the Caribbean islands, on which AIDS is endemic, lack antibodies against HTLV-III/LAV; no AIDS case from Venezuela has yet been reported…Despite a prevalence [in aboriginal populations]…of up to 13%, no clinical symptoms of AIDS-like illness were observed during the latest blood collection round in 1984/85.”

“The prevalence of malarial parasitaemia was 13% [in a serological survey of 250 outpatients in rural Zaire]. However, 72% of patients had antibodies against P falciparum [the malaria parasite]…The proportions of subjects positive in the ELISA test for HTLV-I, HTLV-II and HTLV-III [HIV] were 14%, 25% and 12%, respectively…When the titer [level] of antibodies against P falciparum was considered…this single factor dominated all others…If the human retrovirus reactivity observed in the ELISA tests is frequently non-specific among Africans, the causes of the non-specificity need to be clarified.”

“68% to 89% of all repeatedly reactive ELISA tests are likely to represent false positive results...each year we might expected to find 175 to 209 truly antibody-positive donors [in Minnesota] and between 371 and 1701 falsely positive donors among those who have repeatedly positive screening tests”

“the proportion of HTLV-III [HIV] seropositive patients was notably high among those with idiopathic splenomegaly [enlarged spleen with no known cause] and schistosomiasis [parasitic infection]…Among Kenyans, the Turkana have the highest and the [closely related] Masai have the lowest prevalence of antibodies against both viruses [HTLV-I and HTLV-III(HIV)]…the Turkana inhabit a desolate area of desert and scrub-brush and are the poorest and most isolated of the groups that we studied…the Turkana have many other parasitic and viral infections [apart from seasonal malaria], including one of the highest rates of hydatid [tapeworm] disease in the world and a high prevalence of hepatitis markers…In view of the high prevalence of HTLV-III antibody, AIDS illness might have been expected to be frequent, yet no cases have been documented in Kenya [to 1985]. We are aware of only 3 cases suspected of being AIDS-related…it is unlikely that AIDS-illnesses of the recognized varieties are occurring at a rate commensurate with the prevalance of antibody against HTLV-III”

“We have tested HLA antisera in the Abbott ELISA [HIV antibody test]…of 310 HLA-DR antisera 10 gave positive HTLV-III antibody results. The HTLV-III [HIV] antibody ELISA [antibody test] from Electro-Nucleonics Inc.…also gave positive results with [10 out of 310] HLA-DR4 antisera except for 9w594…the recognition of DR4 antibodies in the sera of homosexuals (immunised by sperm and white blood cells), haemophiliacs, and patient on haemodialysis is important in the interpretation of [potentially false] positive HTLV-III antibody ELISA results.”

“The Ugandan serum tested was primarily from clinically healthy donors randomly selected as controls [for an unrelated study]…All [blood] samples were collected between August 1972 and July 1973…The data show that antibodies recognizing a virus related to or identical to HTLV-III [HIV] were present in most of the Ugandan subjects tested…our samples were taken from a sparsely populated subsistence-farming environment where AIDS is not known to occur, while the recent spread in African AIDS appears to be in more densely populated urban environments [but apparently the thought that the antibodies were non-specific for HIV never crossed the minds of these researchers]”

“False positive and false negative results are to be expected [in HIV antibody testing] as with all screening tests”

“[during validation tests for HIV ELISA antibody tests] any positive ELISA screening result among the blood donors could be assumed to represent “false-positives” [but, if this same person later had the same test outside the context of a validation study, it would be assumed to be a true positive!]”

“non-specific reactions may be seen in samples from some people who, due to prior pregnancy, blood transfusion, or other exposure, have antibodies to the human cells or media in which the HIV-1 virus used for the manufacture of [this test] is grown…”

“Clinical samples have also been described have…been described that are reactive in the screening assays but do not contain HIV-1 antibody. Some of these samples possess antibody to certain Class II HLA histocompatibility antigens that are found in some cell lines used to produce the virus. Other persons, who have had no known exposure to HIV-1, produce reactive results in the screening test for still unknown reasons. Such nonspecific results are found commonly when screening tests are used in large populations. Since the psychosocial and medical implications of a positive antibody test may be devastating, it has been recommended that additional testing be performed on such samples [such as this test]…A sample that is reactive in both the EIA screening test and the Western blot is presumed [!] to be positive for antibody to HIV-1, indicating infection with this virus except in situations of passively acquired antibody or experimental vaccination…Sensitivity and specificity of the HIV-1 Western Blot Kit was determined in comparative studies with a previously licensed HIV-1 Western blot using EIA repeatedly reactive samples from high AIDS risk and low risk populations respectively [i.e. without a ‘gold standard’ such as virus purification] [Specificity can only be tested with EIA negative specimens, of which there were none].”