Manufacturer Disclaimers
Manufacturer Disclaimers
The fine print on the information provided with HIV test kits can be very
revealing for its warnings about limitations of the tests.
“The possibility of exposure to or infection with HIV cannot be excluded
by a negative [Coulter HIV-1 antigen] test result. ”
Antibody to Human Immunodeficiency Virus type 1 (human); HIV-1 p24 antigen
neutralization kit. Coulter. 1996 Apr.
“AIDS and AIDS-related conditions are syndromes that can only be
established by clinical diagnosis. ”
Antibody to Human Immunodeficiency Virus type 1 (human); HIV-1 p24 antigen
neutralization kit. Coulter. 1996 Apr.
“In comparison with antibody testing, antigen testing will only detect
approximately 50% of AIDS, 30% of ARC [AIDS Related Complex] and 10% of
asymptomatic HIV infections…the predictive value of a positive test is
strongly influenced by the prevalence of the condition in the population
tested. In low risk populations, where the rate of HIV-1 infection may not
exceed 0.1%, the rate of antigen positivity could be as low as 0.01%.
Assuming a test sensitivity of 100%, the positive predictive value of a
repeatably reactive test would be only 5.9%, i.e. only 6 tests per 100
would be true positives…The sensitivity and specificity of the HIVAG-1
blocking antibody procedure are not known…In clinical studies performed in
low risk populations, the neutralization test was negative for 137/137
repeatedly reactive (presumed false reactive) samples giving a 95%
confidence range for specificity of 97.8% to 100%…in known infected
individuals [assuming the accuracy of antibody tests], the HIVAG-1
blocking antibody test was positive in 67/67 repeatedly reactive (presumed
true positive) samples giving a 95% confidence range for sensitivity of
95.9% to 100% ”
HIVAG-1; Antibody to Human Immunodeficiency Virus Type 1. Abbott
Laboratories. 1989.
“The sensitivity and specificity of the Abbott HIVAG-1 blocking antibody
procedure are not known, however, estimates can be obtained from the
clinical data by applying the binomial distribution. ”
HIVAG-1; Antibody to Human Immunodeficiency Virus Type 1. Abbott
Laboratories. 1989.
“Manufacturers claim impressive levels of accuracy [of HIV tests] -
usually well in excess of 99% - but much depends on the context in which
the assays are being used, and any overall figure is likely to be
misleading. ”
Mortimer PP. The AIDS virus and the HIV test. Med Int. 1988;56:2334-9.
Discordance between HIV Tests
There are many examples of inconsistency between different HIV tests. This
may mean that all but one of the tests are giving false results. But,
which one? And, how do we know that any of the tests are giving valid
results (see section on validation)?
“Infant HIV infection status was determined for 1248 of 1270 deliveries…22
deliveries (11 in each treatment group) were classified as indeterminate
[based on culture and/or DNA PCR] ”
Dorenbaum A et al. Two-dose intrapartum/newborn nevirapine and standard
antiretroviral therapy to reduce perinatal HIV transmission: a randomized
trial. JAMA. 2002 Jul 10;288(2):189-98.
“In HIV carriers [those with an established HIV infection], the HIV RNA
load is elevated, but infectivity is low [as measured by the success of
cell cultures]. The low infectivity…could be due to neutralization by
antibody in serum, resulting in immune complexes (ICs)…[Our] findings
indicate that the HIV RNA in the plasma of carriers is frequently composed
of antibody-neutralized HIV as ICs [The big question is how HIV can still
cause disease when it has been neutralized!] ”
Dianzani F et al. Is human immunodeficiency virus RNA load composed of
neutralized immune complexes?. J Infect Dis. 2002 Apr 15;185(8):1051-4.
“The study was started using the FDA-approved Abbott ELISA. Halfway
through the study, however, this assay was removed from the market and the
Vironostika assay was used instead. A subset of the samples [240] was
retested with both assays to establish the comparability of the results.
Using a cutoff value of 0.45 for classification of recent seroconverters,
the two assays agreed on 95.4% of the total sample. ”
Gouws E et al. High Incidence of HIV-1 in South Africa Using a
Standardized Algorithm for Recent HIV Seroconversion. J Acquir Immune
Defic Syndr. 2002 Apr 15;29(5):531-535.
“A number of patients (31%) exhibited discordant responses with
immunologic improvement and virologic failure [in a group of children
receiving anti-viral medications] ”
Nikolic-Djokic D et al. Immunoreconstitution in Children Receiving Highly
Active Antiretroviral Therapy Depends on the CD4 Cell Percentage at
Baseline. J Infect Dis. 2002 Jan 8;184.
“[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] ”
Mylonakis E et al. Report of a False-Positive HIV Test Result and the
Potential Use of Additional Tests in Establishing HIV Serostatus. Arch
Intern Med. 2000 Aug 14/28;160:2386-8.
“Suppression of viremia [low viral load] was not associated with an
increase in T cell proliferative responses...However, an apparent paradox
lies in the fact that, although CD4+ T helper cell responses wane with
time, virus-specific CD8+ CTL responses that depend on T helper cells
remain active throughout chronic HIV-1 infection. ”
Binley JM et al. The Relationship between T Cell Proliferative Responses
and Plasma Viremia during Treatment of Human Immunodeficiency Virus Type 1
Infection with Combination Antiretroviral Therapy. J Infect Dis. 2000
Apr;181(4):1249-63
http://www.journals.uchicago.edu/JID...55/991055.html.
“In the CVL [cervico-vaginal lavage] samples, 9 (41%) of 22 yielded
culturable HIV-1, 16(67%) of 24 were PCR positive for proviral HIV-1 DNA,
7 (30%) of 23 were positive for cell-free HIV-1 RNA, and 11 (45%) of 24
were positive for cell-associated HIV-1 RNA. ”
Panther LA et al. Genital tract Human Immunodeficiency Virus Type 1
(HIV-1) shedding and inflammation and HIV-1 env diversity in perinatal
HIV-1 transmission. J Infect Dis. 2000 Feb;181:555-63.
“LTNP [long-term non-progressor (to AIDS)] status was defined as
asymptomatic HIV-1 infection for at least 8 years with stable CD4+ cell
counts and no antiretroviral therapy...A wide range of plasma viral loads
was observed among the LTNPs with HIV-1 RNA levels ranging from < 20 up to
860,000 RNA copies/ml plasma and a similar range was observed for the
controls [Median: 40,000; Range: 2,200 up to 1,860,000] (Table I)...Among
the 47 LTNPs with plasma viral load higher than 800 copies/ml, 30 had a
viral load higher than 10,000 copies/ml and 3 had a viral load higher than
500,000 copies/ml despite fulfilling the inclusion criteria. ”
Candotti D et al. Status of long-term asymptomatic HIV-1 infection
correlates with viral load but not with virus replication properties and
cell tropism. J Med Virol. 1999 Jul;58(3):256-63.
“a peripheral blood sample was positive for HIV-1 by culture and a second
sample from a separate blood draw was positive by either culture or HIV-1
DNA polymerase chain reaction (PCR) testing. Uninfected infants had at
least two peripheral blood samples that were negative for HIV-1 by both
culture and DNA PCR, with 1 of the 2 samples obtained at no earlier than
14 weeks of age. We did HIV-1 antibody testing on the infants at 12 and 18
months of age to confirm their HIV-1 infection status. We defined infants
with a confirmed infection as having an early infection if a peripheral
blood sample drawn within 24h of birth was positive for HIV-1 by culture
or DNA PCR testing. Likewise, infected infants were defined as having a
late infection if a peripheral blood sample drawn within 24h of birth was
negative by culture or DNA PCR testing. Infected infants who did not have
a blood sample obtained within the first 24h after birth were not further
classified. Results from cord blood samples were not used for the
determination of infection status nor for the timing of infection...Twelve
infants were positive by both tests at [the study visit at which each of
the 19 infected infants first had a positive virologic test], 5 were
positive only by PBMC culture, and 2 were positive only by DNA PCR. Nine
infected infants had plasma cultures done at the first positive visit, and
5 (56%) were positive. Likewise, 11 had quantitative RNA PCR testing done,
and all were positive. ”
Van Dyke RB et al. The Ariel Project: A Prospective Cohort Study of
Maternal-Child Transmission of Human Immunodeficiency Virus Type 1 in the
Era of Maternal Antiretroviral Therapy. J Infect Dis. 1999
Feb;179(2):319-28.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
1...had 3 negative HIV EIA [ELISA antibody test] results in the 2 years
before admission, and 5 other document negative EIA tests in the 8 years
before that. On one occasion, 9 years before admission, one reactive HIV
EIA test result was obtained, but the confirmatory Western blot result was
negative...After the diagnosis of HIV infection was confirmed by HIV RNA
PCR, the patient was prescribed zidovudine and lamivudine. Two weeks after
initiation of therapy, serum from the patient was strongly reactive with
all HIV EIA ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
2...HIV EIA result was negative during admission, but HIV infection was
identified by HIV p24 antigen testing and DNA PCR...His wife was tested
for HIV infection by HIV EIA and DNA PCR; the results of both tests were
negative ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
3...HIV-1 EIA and an HIV-1/2 combination test administered 1 month [after
hospital admission] were negative...HIV-1 p24 antigen tests were
positive...The diagnosis of HIV infection was confirmed by HIV-1 DNA PCR.
During the following 27 months, the patient had eight negative HIV EIA
results; 3 HIV-1 DNA PCR tests and 3 HIV-1 RT PCR tests were positive ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
4...first HIV EIA, performed at the time of diagnosis of oral thrush 4
months [after persistent high fever], was negative...[8 months later,
after worsening health problems] an HIV EIA result was negative...[but]
specimens were positive by DNA PCR and p24 antigen tests...In the 11
months following the positive PCR and antigen tests at CDC, the patient
had 3 negative HIV EIA results ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
5...results of two HIV EIA performed during the initial evaluation [for
acute respiratory distress] were negative, although two quantitative
RT-PCR tests were positive...Viral culture was positive; however, a later
blood sample...was negative by HIV EIA and positive by p24 antigen
EIA...The patient had 4 children...All were tested by HIV EIA, p24 antigen
EIA, and RNA PCR with negative results ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“This report describes the field and laboratory investigation of eight
patients who had clinical evidence of HIV infection, but repeatedly
negative HIV-1 antibody screening results in the course of their clinical
care. In all patients, HIV infection was proven [sic] by other diagnostic
methods [PCR/viral load, p24 antigen and culture techniques]...Patient
6...became acutely ill after vaccination for measles, mumps and
rubella...[she had a] negative HIV EIA on 2 occasions, a positive HIV-1
p24 antigen result, and a positive HIV-1 DNA PCR result. Prior HIV EIA
results were negative 2 years, 1 year and 2 weeks before
hospitalization...Of her 17 lifetime sexual partners, four were tested at
CDC by HIV EIA and HIV-1 DNA PCR; all test results were negative ”
Sullivan PS, Schable C. Persistently negative HIV-1 antibody enzyme
immunoassay screening results for patients with HIV-1 infection and AIDS:
serologic, clinical, and virologic results. AIDS. 1999 Jan
14;13(1):89-96.
“Two infants had repeated discordant [test] pairs in which PCR was
positive in one pair [and culture negative] and the culture result was
positive in the other pair [and the PCR negative] ”
Bremer JM et al. Diagnosis of infection with human immunodeficiency virus
type 1 by a DNA polymerase chain reaction assay among infants enrolled in
the women and infant's transmission study. J Pediatr. 1996
Aug;129(2):198-207.
“there is approximately 15% probability that an HIV-negative sample will
evidence nonspecific reactions to p24 on WB [Western Blot]...samples with
strong reactivity to gag antigens...including p17, p24, p32, p46...and
p55...can be misinterpreted as p17, p24, p31, gp41 and p55 bands, and this
results in an overall positive interpretation...The 4 donors we studied
all lacked HIV risk factors and were proven by HIV PCR and, in two cases,
culture and p24 antigen analyses not to be infected ”
Sayre KR et al. False positive HIV-1 Western Blot tests in noninfected
blood donors. Transfusion. 1996;36:45-52.
“The observed discrepancy between total virus levels determined by direct
RNA measurements [PCR/Viral Load] and those determined by culture [is]
generally 100-10,000 to 1 [i.e. only 1 out of every 100-10,000 HIV
particles measured by RNA PCR is confirmed by culture] ”
Saag MS et al. HIV viral load markers in clinical practice. Nat Med. 1996
Jun;2(6):625-9.
“HIV-1 RNA [viral load] concentrations in plasma samples obtained at study
entry (baseline) were normally distributed over a range of <500 to 294,200
molecules/ml…among individuals with 400 to 800 CD4+ T cells/microliter [at
study entry] there was an approximately 400 fold range in HIV-1 RNA
concentrations…Thus, the CD4+ T cell count in a subject within any CD4+ T
cell range was a grossly inaccurate indicator of the level of viremia. ”
Mellors JW et al. Prognosis in HIV infection predicted by the quantity of
virus in plasma. Science. 1996 May 24;272(5265):1167-70.
“In a prospective study conducted from September 1993 through September
1995, a total of305,889 donations were tested for p24 antigen…223 donors
had repeatedly reactive p24-antigen EIA screening-test results and
negative neutralization results…81 [of these] later returned to donate
blood again. 65 of these donors had negative test results for HIV-1/HIV-2
antibody and for antigen EIA and neutralization. However, 16 donors who
were HIV-1/HIV-2 antibody negative on subsequent donations continued to
have repeatedly reactive p24-antigen EIA screening tests that did not
neutralize. ”
US Public Health Service guidelines for testing and counseling blood and
plasma donors for Human Immunodeficiency Virus Type 1 antigen. MMWR. 1996
Mar 1;45(RR-2).
“A 47-year old woman…was accidentally pricked by a needle on May 10, 1993
at the clinic where she worked as a cleaner…Symptoms of possible acute
primary infection were observed at the…6th month after the accident…HIV
serology…was [first] positive at the 8th month. The first positive western
blot showed a full pattern of infection. Serum p24 antigen remained
negative on all studied samples. The qualitative HIV-RNA NASBA assay was
positive for the first time on the plasma sample collected during symptoms
of acute infection [6th month]. The subsequent plasma sample corresponding
to the appearance of HIV antibodies [8th month] was found once positive
and once negative…Later samples were all clearly NASBA positive. HIV could
not be isolated by culture on the successive blood samples, even on the
more recent sample, collected 1 year after seroconversion. ”
Meyohas MC et al. Time to HIV seroconversion after needlestick injury.
Lancet. 1995 Jun 24;345(8965):1634-5.
“HIV was isolated from 32 patients (54%) of 59 [HIV+] patients examined.
In the group with positive blood culture (group P), CD4+ cell count and
CD4/8 were significantly lower than those in the group with negative blood
culture (group N). p24 antigen was detected in 6 patients of group P and 2
patients of group N. There was no difference in beta 2-m and cytokine
levels between the two groups. HIV isolation had no influence on the
subsequent changes in the clinical state and immunological data. ”
Urano H et al. HIV isolation may not correlate with clinical state or
immunological function of respective HIV infected patients. Int Conf AIDS.
1994 Aug;10(2):255.
“71 of 72 specimens collected from random blood donors were negative for
both p24 antigen and plasma RNA. The remaining sample was repeatedly
positive for plasma HIV-1 RNA, although at a low level. This specimen also
had bordeline reactivity for p24 antigen…[and] reacted to gp160 only in WB
[Western Blot antibody test] [Note that this type of test result will
become a big problem when millions of samples are tested, as for blood
transfusions, and is close to being interpreted as a positive test] ”
Henrard DR et al. Detection of human immunodeficiency virus type 1 p24
antigen and plasma RNA: relevance to indeterminate serologic tests.
Transfusion. 1994 May;34(5):376-80.
“Culturable virus in plasma was reduced to undetectable levels coincident
with seroconversion in five of six patients, and was substantially reduced
in the sixth. Circulating p24 antigen also decreased with seroconversion,
even by use of immune complex dissociation tests. However, despite
decreases in total plasma virus levels by QC-PCR of up to 236-fold that
closely paralleled declines in culturable virus, plasma virion-associated
RNA remained readily detectable throughout the full follow-up in all six
patients. ”
Piatak M et al. Viral dynamics in primary HIV-1 infection. Lancet. 1993
Apr 24;341:1099.
“Circulating levels of plasma virus determined by QC-PCR also correlated
with, but exceeded by an average of nearly 60,000-fold..., titers
[amounts] of infectious HIV-1 determined by quantitative endpoint dilution
culture of identical portions of plasma. ”
Piatak M Jr et al. High levels of HIV-1 in plasma during all stages of
infection determined by competitive PCR. Science. 1993 Mar
19;259:1749-54.
“we identified a group of 6 subjects who had been infected [with HIV]
through a single common [blood] donor...Throughout follow-up (range
6.8-10.1 years after infection), 5 of the [HIV antibody positive]
recipients and the donor...remained clinically free of symptoms, with
normal CD4 cell counts and no p24 antigenaemia. HIV-1 was isolated [via
culture, which is not really isolation] from only 1 recipient [in other
words, the only evidence of HIV was antibodies, all other measures
indicated no HIV and no AIDS] ”
Learmont J et al. Long-term symptomless HIV-1 infection in recipients of
blood products from a single donor. Lancet. 1992 Oct 10;340(8824):863-7.
“[in two cases] exposure to HIV antigens was detected 5 to 14 months
before the persons became HIV-positive by PCR and 2 to 14 months before
seroconversion [positive antibody test]. ”
Clerici M et al. HIV-1 from a seronegative transplant donor. N Engl J Med.
1992 Aug 20;327(8):564-5.
“False-positive and false-negative results were observed in [7 French]
laboratories (concordance [of viral load] with serology [ELISA/Western
Blot antibody tests] varied from 40 to 100%) ”
Defer C et al. Multicenter quality control of polymerase chain reaction
for detection of HIV DNA. AIDS. 1992;6:659-63.
“There were 140 P1 children [HIV infected without any clinical signs], 96
were seropositive...44 had become seronegative but had viral markers...4
subjects had positive viral cultures (3 repeatedly), 6 had serum p24
antigen (3 consistently), 9 had proviral DNA sequences by polymerase chain
reaction [‘viral load’] (5 consistently), and 7 had expression of viral
antigens in peripheral-blood mononuclear cells by direct
immunofluorescence test (all confirmed); the remaining 18 subjects had two
or more of these markers ”
Tovo PA et al. Prognostic factors and survival in children with perinatal
HIV-1 infection. Lancet. 1992;339:1249-53.
“there were 16 sera from 30 viraemic patients which did not have
detectable p24 antigen (<5 pg/ml, Fig. 2). As a consequence, p24 antigen
concentration and HIV-1 RNA did not correlate well. ”
Semple M et al. Direct measurement of viraemia in patients infected with
HIV-1 and its relationship to disease progression and zidovudine therapy.
J Med Virol. 1991;35:38-45.
“HIV was isolated [using culture] from only 36% of plasma samples, and the
isolation rate was closely related to CD4 cell counts, increasing
gradually from 0% in subjects with >800 [million] CD4 cells [per liter] to
88% in those with < 100 [million] CD4 cells [per liter]...The comparison
of p24 antigenaemia with plasma viral cultures was not clear-cut.
Concordant data were found in 62 subjects...while discordant data was
observed in 37 ”
Venet A et al. Correlation between CD4 cell counts and cellular and plasma
viral load in HIV-1-seropositive individuals. AIDS. 1991;5:283-8.
“About 10%-20% of sera that are repeatedly reactive by HIV-1 EIA [antibody
tests] are interpreted as indeterminate by Western blot. Indeterminate
HIV-1 Western blot may be due to antibody production against viral core
antigens early in HIV-1 infection, loss of core antibodies late in HIV-1
infection, cross-reactive antibody to HIV-2, or cross-reactive antibody
due to autoantibodies or alloimunization...42 group 2 subjects (84%) had
repeatedly reactive EIAAs at all study visits and 8 had one or more
nonreactive EIAs at follow-up visits. Conversely, 29 group 3 subjects
(82.9%) were nonreactive by EIA at all study visits and 6 were again
repeatedly reactive at one or more study visits. There was 70% agreement
between Epitope and Dupont blots [two different brands]...In this cohort
study of 89 adults referred because of prior reactive HIV-1 EIAs and IWBs
[indeterminate Western blots] we found HIV-1 infection in only 4 (12.5%)
of 32 high-risk cases and 0 of 57 low-risk cases. ”
Celum CL et al. Indeterminate human immunodeficiency virus type 1 Western
blots: seroconversion risk, specificity of supplemental tests, and an
algorithm for evaluation. J Infect Dis. 1991;164:656-64.
“In blood donor studies in the developed world, about 20% of sera referred
to confirmatory laboratories give indeterminate western blot results,
almost all of which are on presumed negative specimens. ”
Mortimer PP. The fallibility of HIV Western blot. Lancet. 1991 Feb
2;337:286-7.
“The 9 infected children with discordant results [out of 27 classified as
HIV infected] are described in Table 2. Case 2.1 [patient identity], who
developed AIDS at 6 months of age, was positive in Ag [p24 antigen], V
[Viral culture] and PCR [‘viral load’] assays, but was negative on both
IVAP [in vitro antibody production]…The discordant intra- and inter-test
results observed in cases 3.1, 3.2, 4.1, 4.2 and 4.3 may reflect the
sensitivity of the procedures…Interestingly, cases 3.3 and 3.4 were
positive for IVAP and repeatedly negative for the other parameters, the
reliability of this result was subsequently confirmed by Ab [antibody]
persistence when both children were over 18 months of age [obviously used
as the ‘gold standard’ with no consideration of possible false results in
this test] It is worth noting that one child (case 1.0) who was negative
for all parameters had an opportunistic infection and developed cerebral
lymphoma at 6 months of age [i.e. this patient was classified as ‘AIDS’
because of clinical symptoms even though all tests were negative]…our data
demonstrate that none of the diagnostic assays can assure absolute
specificity [reacting only to HIV] and sensitivity [always reacting to
HIV] for early diagnosis of vertically transmitted HIV-1 infection. ”
De Rossi A et al. Antigen detection, virus culture, polymerase chain
reaction, and in vitro antibody production in the diagnosis of vertically
transmitted HIV-1 infection. AIDS. 1991 Jan;5(1):15-20.
