Referenced Quotes about HIV/AIDS Tests and Measurements

Alberta Reappraising AIDS Society

David Crowe, President
Phone: +1-403-289-6609
Fax: +1-403-206-7717

Roger Swan, Treasurer
Box 61037, Kensington Postal Outlet
Calgary, Alberta T2N 4S6
Phone: +1-403-220-0129

Referenced Quotes about HIV/AIDS Tests and Measurements

Discordance between HIV Tests

There are many examples of inconsistency between different HIV tests – one positive and one negative, borderline or indeterminate. 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?

“Although a Positive result may [!] indicate infection with the HIV-1 virus, a diagnosis of Acquired Immunodeficiency Syndrome (AIDS) can be made only if an individual meets the case definition of AIDS established by the Centers for Disease Control. A repeat test on an independent sample should be considered to control for sample mix-up or operator error, and to verify a positive test result. Individuals may present incomplete banding patterns…A person who has antibodies to HIV-1 is presumed [!] to be infected with the virus…Do not use this kit as the sole basis of diagnosis of HIV-1 infection…[When tested on ‘Low Risk’ subjects 100 out of 495 people with a negative ELISA were indeterminate on the western blot and 0 out of 14 who had a positive ELISA were positive on the Western Blot (3 were indeterminate). One person with AIDS with a negative ELISA was indeterminate on the Western Blot and 5 out of 241 who had AIDS and were ELISA positive were indeterminate on the western blot. Of 1007 people who were HIV-negative by ELISA 207 were indeterminate on this test, of which 111 were negative by another test. Of the remaining 800 with negative ELISA and this Western Blot, 295 were indeterminate on another Western Blot]
Human immunodeficiency virus type 1 (HIV-1) Western Blot kit. OraSure. 2009 Sep
[Table B of this test kit label shows that of 278 Low Risk people with a positive ELISA antibody test, 123 had negative Western Blots (44%), 29 indeterminate (11%) and 126 positive (45%). Of 86 people classified as low risk with consistently negative ELISA tests 73 (85%) were western blot negative, 13 (15%) were indeterminate and 0 were positive.]
Human Immundeficiency Virus type 1 (HIV-1) Western Blot kit. Maxim Biomedical. 2009 Jun 1
“A total of 429 treatment-naive patients initiated HAART and had baseline viral loads and follow-up viral loads performed within the qualifying interval…The area under the ROC curve, which indicates the overall ability of CD4 cell count increase to differentiate those with and without an undetectable viral load, was 0.68 [quite low]. However, the predictive ability of CD4 cell count increase was better among patients with baseline CD4 cell counts ≤100 cells/microliter…CD4 cell count increase after initiating HAART has only moderate discriminative ability in identifying patients with an undetectable viral load, and the predictive ability is lower in patients with lower baseline CD4 cell counts.”
Bisson GP et al. Diagnostic accuracy of CD4 cell count increase for virologic response after initiating highly active antiretroviral therapy. AIDS. 2006 Aug 1;20(12):1613-1619.
“In LAVBLOT I [Western Blot] kit there are lots of differences in results when read with different interpretation criteria. To interpret the results WHO criterion was assigned by the manufacturer. There were 158 (64.7) specimens found to be positive out of 244 used in the kit. But on using the various other criteria for interpretation the number of positive results varied from 157 (64.3) to 176 (72.1), while the number of indeterminate varied between 44 (18) and 63 (25.8). No such variation was present among the negative, which implies that some of the indeterminate specimens would be considered positive if different centers used different criteria to interpret the results [but indeterminate western blots are usually treated as negative]. [The] CDC criterion was found to be very liberal to confirm positive results…Of the 23 specimens that were run on both the LAV BLOT I and the genetic systems kit, we found a lot of discrepancies in the results. Based on the criteria suggested by the manufacturer the LAV BLOT I kit identified 3 specimens as positive, 4 specimens as negative and 16 specimens as indeterminate. However, the genetic systems identified only 2 specimens as positive, 7 specimens as indeterminate but 14 of these 23 specimens as negative. This implies that the LAV BLOT I could be wrongly reporting 10 negative specimens as indeterminate. On further analysis 1 out of this 10 specimens could be read positive if CDC & CRSS criteria were used. This again proves the variations of results with respect to different criteria. Also 1 specimen indeterminate in genetic systems kit was found to be positive in LAV BLOT I kit. We also noticed that the most common band associated with an indeterminate report in the LAV BLOT I kit was the p25 band. Four of the five specimens on which the PCR was performed were reported as negative. The genetic systems kit reported three of these four as negative and one as indeterminate. The other specimen that was reported as positive by the PCR was reported as indeterminate by the genetic systems kit. The LAV BLOT I kit on the other hand reported all the five specimens as indeterminate.”
Syed IH et al. HIV-1 western blot assay: What determines an indeterminate status?. Indian J Med Sci. 2005 Oct;59(10):443-50.
“Samples from 457 randomly selected HIV-1 infected patients attending King's College Hospital were analysed using a subtype specific enzyme immunoassay. All serotyped non-Bs that provided unambiguous sequence and for which sufficient sample was available (n=100), which included three serotyped subtype B samples were further analysed by env sequencing and subtyping using neighbour joining phylogenetic analysis, the NCBI Retrovirus Genotyping tool and the Los Alamos BLAST search tool. Of the serotyped viruses, 45% (n=204) samples were subtype B. Specifically serotyped non-B strains (n=130) accounted for 28% of the total, of which the largest proportion were subtype C (n=66). Twenty-seven samples (6%) were classified as non-B, 9% (n=40) were multiply-reactive and 12% were non-reactive (n=56). Of the 100 samples subtyped by sequencing the majority were subtype C (n=32), followed by subtype A (n=20). There was little concordance between the two methods. Although a 100% match was found among the serotyped and sequenced non-B viruses (n=13), only 16 of the sequenced subtype C specimens matched the 29 obtained by serotyping. Of the 20 multiply-reactive samples analysed by serotyping, only 1 sample consisted of a subtype mixture by sequencing. Of the 14 serologically non-reactive samples analysed, all were successfully sequenced, with subtype B strains (57%) the most common. Sequencing 15 samples in both env and pol regions revealed differences in subtype assignment for the same sample in some cases. Only 1/6 env subtype A and 4/5 env subtype C samples were concordant in pol sequence subtype. Differences were also found in subtyping by the different methods used. The overall agreement between the three methods was 89%. Four out of 11 samples agreed between the phylogenetic and Los Alamos methods, 1/11 between phylogenetic and BLAST and 2/11 between Los Alamos and BLAST.”
Smith M et al. High levels of discordance between sequencing and serological subtyping in a predominantly non-B subtype HIV-1 infected cohort. J Clin Virol. 2005 Aug;33(4):312-8.
“We studied four individuals who tested positive in ELISA and Western blot for HIV-1 antibodies but who lacked detectable proviral DNA…CD4+ lymphocyte counts in subjects 1-3 were measured repeatedly since 1996 and were always in the normal range…[and] in subjected 4 were monitored since 2000 and were always stable and around 400 cells/microliter blood. None of the four individuals ever ever received antiretroviral therapy. HIV-1 RNA viral load and p24 antigen load in plasma were frequently measured using different methods and [were] always below the lower limit of quantification…Several attempts were made to isolate ['culture'] replication competent virus from subjects 1 and 3. However…[it] could not be isolated”
Kloosterboer N et al. Natural controlled HIV infection: Preserved HIV-specific immunity despite undetectable replication competent virus. Virology. 2005 Jun 27;339(1):70-80.
“No correlation was found between DNA proviral load and plasma RNA viral load in thirty consecutive unselected patient samples received for RNA viral load determinations…No correlation was found between DNA proviral load and CD4+ cell count in thirty consecutive unselected patient samples received for RNA viral load determinations.”
Kabamba-Mukadi B et al. Human immunodeficiency virus type 1 (HIV-1) proviral DNA load in purified CD4+ cells by LightCycler real-time PCR. BMC Infect Dis. 2005;5(1):15.
“We divided the 300 children into three groups: HIV negative (153), HIV positive (69), and HIV indeterminable (78)…The HIV-indeterminable group consisted of: (i) children under 18 months of age and/or being breastfed, with two positive antibody test results and a negative (36 children) or indeterminable (1) p24-antigen test result; (ii) 2 children with 2 non-corresponding [one positive, one negative] antibody test results and a negative p24-antigen test result; and (iii) 39 children [with insufficient testing data]
van Gend CL et al. Evaluation of the WHO clinical case definition for pediatric HIV infection in Bloemfontein, South Africa. J Trop Pediatr. 2003 Jun;49(3):143-7.
“1258 pregnant women participated in this study and provided sufficient plasma…44 (3.49%) of the women were found to be HIV-antibody-positive by at least two of the standard EIA assays…4 of 87 EIA and rapid test negative specimens were found to be EIA positive at the NARI laboratory, of which two were found WB [Western Blot] negative, one was WB positive and one sample was insufficient for WB testing…[Of] 21 specimens that were Cadila [rapid test] positive and two specimens that were Abbott Determine [rapid test] positive and one plasma specimen that was Oraquick positive, but negative by conventional EIA…[were all found negative] by repeat EIA testing at NARI. Two specimens were positive by all rapid tests, discordant by two conventional EIAs, but positive by NARI EIA and WB. 4 specimens were negative by all rapid tests, discordant by conventional EIA and negative by NARI EIA. One specimen was positive by Cadila and conventional EIAs, but negative by NARI EIA. 2 specimens were negative by all rapid tests, but positive by both conventional EIAs and NARI EIA and WB. Finally, 2 specimens that were initially EIA-positive, but negative by all of the rapid tests, were also EIA-negative at NARI. In addition, HIV PCR performed on these two specimens was also negative…[normally antibody tests are considered the most accurate indication of HIV infection, but these authors feel that the combination of a rapid test with PCR trumps the standard EIA+WB] Our finding of some false positive results with the 'gold standard' EIAs, confirmed by negative HIV-1 PCR, also suggests that the rapid tests may have greater specificity in some settings than the standard EIAs.”
Bhore AV et al. Sensitivity and specificity of rapid HIV testing of pregnant women in India. Int J STD AIDS. 2003 Jan;14(1):37-41.
“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.
“Between 1996 and 2000, a total of 12,124 samples were tested for HIV-1 antibodies. A total of 1,437 plasma specimens (11.9%) were HIV-1 antibody positive. Of these, 91 ( 0.8%) gave equivocal results, with discordant serological data and indeterminate WB profiles. The WB reactivities measured on 91 indeterminate test results are summarized in Table 1. Most of the indeterminate WB results were due to antibodies against the HIV-1 core antigen p24 (30.4%). In addition, reactivities to pol p51 (13.9%), pol p66 (14.6%), and env gp41 (15.2%) antigens were frequent. Isolated p17 reactivity was observed rarely (only 2.3% of the samples). A total of 12 samples (13.3%) displayed reactivity to two of the three proteins p24, gp41, and gp120/160 and thus can be considered positive by CDC criteria…Among 1,475 HIV-negative cohort participants, 31 (2.1%) had at least one indeterminate WB test result during follow-up, of which 19 (61%) were related to false-positive ELISA results only, 11 (36%) were related to false-positive HIVSPOT test results only, and 1 (3%) was related to both (Table 1). Most of the initially indeterminate WB assays (30 of 31 [97%]), including samples considered positive by the CDC criteria (6 of 6), were negative when retested. One subject with initial indeterminate WB profile was negative throughout 30 months of follow- up, at which time he seroconverted. Only two samples remained persistently indeterminate (as long as 18 and 48 months, respectively) without developing any WB reactivity that indicated seroprogression. In addition, 17 indeterminate WB assays, including the two samples that persistently gave indeterminate WB profiles, were assessed by NASBA for HIV-1 viremia. Plasma HIV-1 viremia was not detected in any of the above specimens.”
Meles H et al. Indeterminate human immunodeficiency virus Western blot profiles in ethiopians with discordant screening-assay results. Clin Diagn Lab Immunol. 2002 Jan;9(1):160-3.
“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.
“a number of patients, the majority being African, were found to have low viral loads by the Chiron branched-chain DNA assay in conjunction with low CD4+ cell numbers [in theory a low viral load means little virus, and therefore nothing to kill off the CD4+ cells]
O’Shea S et al. Problems in the interpretation of HIV-1 viral load assays using commercial reagents. J Med Virol. 2000 Jun;61(2):187-94.
“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.
“In the CVL [cervico-vaginal lavage] samples [from HIV antibody positive women], 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, Tucker L, Xu C 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.
“All three samples were reactive with our standard immunometric HIV antibody screening assay and were confirmed by competitive ELISA, gelatin particle agglutination assay, and enzyme-linked fluorescent assay. All three sera, however, failed to react by the manufacturer's criteria in the antiglobulin format ELISA…all three sera were tested by HIV-1 antibody Western blot…the serum from patient 2 did not contain detectable antibodies against either the transmembrane glycoprotein gp41 or the gag-precursor protein p55.”
Preiser W et al. False-negative HIV antibody test results. J Med Virol. 2000 Jan;60(1):43-7.
“Sixteen patients with a diagnosis of symptomatic PHI [Primary HIV Infection]] were prospectively enrolled…Eight subjects were positive by HIV-1 p24 antigen EIA and negative by HIV-1 antibody EIA and Western blot; 3 subjects had positive antibody EIA but <4 bands on Western blot; and 5 subjects were positive for EIA and Western blot (>4 bands) but had <4 bands on Western blot within the 30 days before screening. All subjects received zidovudine [AZT] (200 mg 33/day), lamivudine [3TC] (150 mg 23/day) and indinavir [a protease inhibitor] (800 mg 33/day).”
Zaunders JJ et al. Potent antiretroviral therapy of primary human immunodeficiency virus type 1 (HIV-1) infection: partial normalization of T lymphocyte subsets and limited reduction of HIV-1 DNA despite clearance of plasma viremia. J Infect Dis. 1999 Aug;180(2):320-9.
“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 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 [an] 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 of 305,889 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 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).”
Pantaleo G et al. Studies in subjects with long-term nonprogressive Human Immunodeficiency Virus Infection. N Engl J Med. 1995 Jan 26;332(4):209-16.
“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.
“TABLE 1. Comparison of the estimated mean number of RNA copies per milliliter of plasma with the mean titer of virus in plasma and the p24 antigen level in symptomatic and asymptomatic patients [for symptomatic, HIV-positive patients 100% had detectable RNA ‘viral load’ but only 34/41 of these had positive virus cultures and only 22/35 had p24 antigen detectable] [for asymptomatic HIV-positive patients 29/39 had ‘viral load’ detectable at low levels but only 5/39 had positive virus cultures and 5/38 detectable p24 antigen]
Van Kerckhoven I et al. Quantification of human immunodeficiency virus in plasma by RNA PCR, viral culture, and p24 antigen detection. J Clin Microbiol. 1994 Jul;32(7):1669-73.
“Although serologic assays are capable of identifying prior exposure to human immunodeficiency virus (HIV), they cannot alone demonstrate whether an individual is currently harboring the virus. The first method used to ascertain if a blood specimen contained HIV was co-cultivation with stimulated primary human lymphocytes or continuous human T cell lines and monitoring the culture supernatants for the presence of reverse transcriptase. Although viral isolation has proved to be a poor diagnostic tool because of its relative insensitivity [about half of HIV-antibody-positive people are culture negative], high costs, and lengthy time requirements, culture has served as the standard by which all other diagnostic tests have been judged and established. Furthermore, virus culture remains the steadfast route by which new variants are identified, isolated and initially characterised.”
Rayfield M et al. HIV culture. Chapter 7 in “AIDS Testing: a comprehensive guide to technical, medical, social, legal and management issues”. Springer Verlag. 1994;129.
“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(8852):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(7):659-63.
“No significant association was found between seminal or blood HIV-1 antibody titer or specificity and the ability to culture HIV-1 from either the cellular or seminal plasma fractions of semen. There were seven [of 28] culture-positive semen samples in this study; all had seminal plasma titers of 400 or 4,000 and prominent gp160 bands”
Wolff H et al. A comparison of HIV-1 antibody classes, titers, and specificities in paired semen and blood samples from HIV-1 seropositive men. J Acquir Immune Defic Syndr. 1992;5(1):65-9.
“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 May 23;339(8804):1249-53.
“A blood donor had consistently tested ELISA negative for anti-HIV since 1985. In 1989, after the second injection of an HB [Hepatitis B] surface antigen recombinant vaccine he tested HIV-false positive, being ELISA positive but negative by western blot and indirect immunofluorescence assay…to show that the false positivity was vaccine dependent, he was given a booster injection with another recombinant vaccine…Serum was monitored over 3 weeks…Both titres [levels of antibodies] rose in parallel. The 'HIV titre' was low…but it was more than 3SD [standard deviations] above the negative controls…Since HBV [Hepatitis B Virus] is much more prevalent than HIV, HBV-positive individuals with HIV crossreacting antibodies could outnumber true HIV positives.”
Lee DA, Eby WC, Molinaro GA. HIV false positivity after hepatitis B vaccination. Lancet. 1992 Apr 25;339(8800):1060.
“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 EIAs 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 Oct;164(4):656-64.
“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(1):38-45.
“The DNA equivalent of 200 microliters of blood was assayed using the pol, gag, and nef primer pairs in a single PCR, and by performing a nested gag PCR…[on] 11 Western blot anti-p24(gag)-indeterminate blood donors. No positive signal was found for any of these donors.”
Bruisten SM et al. Enhanced detection of HIV-1 sequences using polymerase chain reaction and a liquid hybridization technique. Application for individuals with questionable HIV-1 infection. Vox Sang. 1991;61:24-9.
“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 Mar;5(3):283-8.
“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.
“In the 74 children who became seronegative [lost antibodies by 18 months, accepted unquestioningly by these researchers as definitive proof of lack of HIV infection], a total of 145 Ag [p24 antigen], 86 V [viral culture], 104 PCR [‘viral load’] and 103 IVAP [in vitro antibody production] tests were performed before 18 months of age, and inconsistent results were found in 13 cases [18%]. 3 children were Ag-positive at 1 and 2 months, but negative for all the other parameters, repeated Ag testing on the same samples confirmed the positive result, and excluded a laboratory error. However, Ag was negative in the subsequent samples, so mother-to-fetus passage of viral proteins without ensuing viral infection could explain these findings, and these children were uninfected. [not bad for an ad hoc theory to explain away these results without questioning the fundamental validity of the tests]. In 2 cases positive IVAP results were obtained at 2 and 3 months, while all other tests were negative; these results, however, were not corroborated by a later persistence of HIV-1 Ab [antibody], and were considered as false positives…3 children had positive PCRs, with all the other parameters repeatedly negative; in only 1 case was PCR positivity reconfirmed in a subsequent sample. The other 2 cases, despite repeatedly positive PCR results in the same samples, were considered false positives…In 3 cases both V and PCR tests were positive; although these children became seronegative [lost antibodies] and were asymptomatic, they were regarded as possibly infected…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.
“Of the 225 repeatedly reactive [for p24 antigen] samples, 220 were negative for anti-HIV-1 [antibodies] and failed to neutralize in the neutralization assay for p24 antigen. The other 5 repeatedly reactive samples were both positive for anti-HIV-1 (on EIA and Western blotting) and neutralized in the confirmatory assay for p24 antigen…[they also] were all positive by the polymerase chain raction…Follow-up laboratory evaluation in the 4 donors with p24 antigen confirmed by neutralization [no indication of what happened to the fifth] showed that 3 remained positive for p24 antigen after a mean sampling interval of 81 days; 1 was negative for p24 antigen on retesting 56 days after the initial donation…HIV-1 was isolated in lymphocyte culture from 1 of the 4.”
Alter HJ et al. Prevalence of human immunodeficiency virus type 1 p24 antigen in U.S. blood donors--an assessment of the efficacy of testing in donor screening. The HIV-Antigen Study Group. N Engl J Med. 1990 Nov 8;323(19):1312-7.
“HIV DNA was detected by PCR in 58 (92%) of 63 HIV antibody-positive samples...5 persons had PCR-negative samples that were negative with all 3 primer pairs...Subsequent serum samples from four of these men were also HIV antibody-positive; the fifth was lost to follow up...HIV DNA was detected in 7 (3.4%) of 208 samples in which there was no detectable HIV antibody...Despite [extensive] precautions, 2 (3%) of 65 PCR-positive results were false-positives. It is also possible that the positive PCR results before seroconversion were false-positives, since exposure to HIV continued to occur”
Horsburgh CR et al. Concordance of polymerase chain reaction with HIV antibody detection. J Infect Dis. 1990 Aug;162(2):542-5.
“the specificity and sensitivity of PCR for detection of HIV DNA were 100% (225/225 seronegative, low-risk individuals tested negative) and 94% (67/71 seropositive individuals tested positive), respectively. In a second study ... 7/474 (1.5%) antibody-negative specimens were found to be positive [for HIV DNA], 149/151 (99%) antibody-positive specimens were positive [for DNA], and 12/13 (92%) antibody-indeterminate specimens were negative for HIV DNA”
Young KKY, Peter JB, Winters RE. Detection of HIV DNA in peripheral blood by the polymerase chain reaction: a study of clinical applicability and performance. AIDS. 1990 May;4(5):389-91.
“Five patients who did not yield virus isolates [via culture] in a total of 14 attempts all had virus present in 1 per 10,000 or more cells, while five from whom virus was isolated in 11 of a total of 16 attempts all had virus present in 1 per 3,000 or fewer cells.”
Simmonds P et al. Human Immunodeficiency Virus-infected individuals contain provirus in small numbers of peripheral mononuclear cells and at low copy numbers. J Virol. 1990 Feb;64(2):864-72.
“Among the 8 newborns…born to HIV1-infected mothers, 6 had detectable HIV1 DNA sequences…In group II [babies], 17 of 23 sera were available…HIV1 DNA was detected in PBL [peripheral blood leukocytes] of 14 of 23 babies. Among the 14 babies positive by PCR, 10 had positive or incomplete and 2 had negative Western blots. Among the nine babies negative by PCR, 3 had positive or incomplete and two had negative Western blots. Therefore, 2 of 4 babies, who were seronegative at the time of PCR test, had HIV1 DNA in PBL…8 (including the 4 with symptoms consistent with AIDS) of the 14 HIV1 DNA-positive and 1 of 9 HIV DNA-negative babies had clinical features likely to be related to HIV infection. The results obtained with the three sets of primers markedly differed; indeed 7 of 31 samples yielded positive results with all three sets of primers as compared to 7 of 31 which were positive with two sets of primers but negative with the third, and the remaining six of 31 samples were only positive with one set.”
Paterlini P et al. Polymerase chain reaction for studies of mother to child transmission of HIV1 in Africa. J Med Virol. 1990 Jan;30(1):53-7.
“Overall, plasma viremia [as measured by culture] developed during follow-up in 17 of 27 patients (63%) who initially did not have viremia, and was sustained in 35 (88%) of the 40 patients who initially had viremia...In only 45% of persons from whom we isolated plasma-associated HIV was p24 antigen detected in plasma or serum”
Coombs RW et al. Plasma viremia in human immunodeficiency virus infection. N Engl J Med. 1989 Dec 14;321(24):1626-31.
“100 ELISA-negative donors...were tested by WB [note that normally a negative ELISA will not result in a Western Blot ‘confirmatory’ test]. 20 were WBi [Western Blot Indeterminate, neither positive nor negative], with p24 being the predominant (70%) and generally the only band.”
Genesca J et al. What do Western Blot indeterminate patterns for Human Immunodeficiency Virus mean in EIA-negative blood donors?. Lancet. 1989 Oct 28;II:1023-5.
“23 of 25 biopsies from HIV seropositive individuals were positive for HIV DNA...An average of 0.0001 to 0.01 HIV DNA copies per cell was estimated to be present in biopsies with follicular hyperplasia or involution. The positive lymphoma biopsies contained approximately tenfold fewer HIV DNA. In contrast, 19 of 20 biopsies from seronegative or low risk individuals were negative for HIV DNA.”
Shibata D et al. Human immunodeficiency viral DNA is readily found in lymph node biopsies from seropositive individuals. Am J Pathol. 1989;135(4):697.
“5 out of 17 newborns [of HIV-positive, mostly IV drug using mothers] were found to be IgM [antibodies that do not cross the placenta] anti-HIV positive, 1 was also p24 Ag [antigen] positive. All but 1 infant...cleared IgM anti-HIV from the sera within 2-3 months…6 children negative for both IgM anti-HIV and p24 Ag at birth, developed an IgM response at the second to third month…[only 1] was still positive at the ninth month…2 children became p24 Ag positive at the fourth to sixth month; both showed persistent p24 antigenemia at follow-up…3 children never developed p24 antigenemia or IgM anti-HIV positivity during the follow-up [9-12 months]…For two of the children no serological pattern can be defined [due to short follow up]
D'Arminio Monteforte A et al. Early diagnosis of HIV infection in infants. AIDS. 1989 Jun;3(6):391-5.
“Among the 171,974 [US soldiers tested for HIV on tests at least two months apart] in the survey population, the initial serum samples of 939 were repeatedly reactive on ELISA and negative on Western blot testing. The remaining 171,035 were initially nonreactive on ELISA. During the survey period, 11 [who were initially ELISA reactive]…and 79 whose initial samples were nonreactive on ELISA were seropositive for HIV on Western blot testing of subsequent serum samples…Although the relative risk of seroconversion during the survey period was 27.58 times greater for those whose initial samples were reactive on ELISA, the positive predictive value of initial ELISA reactivity for subsequent seroconversion was only 1.2% (11 of 939).”
McNeil JG et al. Direct measurement of human immunodeficiency virus seroconversions in a serially tested population of young adults in the United States Army, October 1985 to October 1987. Walter Reed Retrovirus Research Group. N Engl J Med. 1989 Jun 15;320(24):1581-5.
“The currently licensed Du Pont Western blot test specifies that the test result should be interpreted as positive only when the detected bands include p24 and p31, and gp41 or gp120/160. Conversely, a negative Du Pont Western blot test result requires the absence of any and all bands–not just viral-bands…[Three] Alternative criteria have been proposed by various groups. ASTPHLD has proposed that a positive test result be defined by the presence of any two of the following bands: p24, gp41, and gp120/160 (13). The Consortium for Retrovirus Serology Standardization (CRSS) has defined a positive test result as the presence of either p24 or p31, plus a diffuse envelope band (i.e., gp41 or gp120/160) (14). The American Red Cross has defined a positive test result as greater than or equal to 1 band from each of the GAG, POL, and ENV gene-product groups (15). These three groups and DuPont all agree that an indeterminate result is the presence of any other band or bands that fail to meet the positive criteria, and that a negative result is the absence of all bands. The criteria for a negative Western blot interpretation specify “no bands.” This interpretation is essential because some observed bands may reflect the presence of antibodies to HIV regulatory proteins or may indicate partially processed or degraded viral structural proteins. Furthermore, different Western blots (commercial, as well as “in-house” preparations) and different virus-antigen preparations used to prepare Western blots may contain different numbers and concentrations of both viral-specific and contaminating cellular proteins that may have unpredictable molecular weights…the ASTPHLD definition gives the highest percentage of positive and the lowest percentage of indeterminate results…On the basis of the results described above, CDC concurred with the ASTPHLD criteria and recommends their use in public health and clinical practice.”
CDC. Interpretation and Use Of Western Blot Assay for Serodiagnosis of Human Immunodeficiency Virus Type 1 Infections. MMWR. 1989;38(S-7):1-7.
“In the Chicago cohort of the Multicenter AIDS Cohort Study 60 of 630 seronegative men had a WB[Western Blot]-confirmed positive ELISA result. 24 (40%) had antibody bands to one or more products of the three major gene-encoding regions 6 to 30 months before [being declared positive because of a positive ELISA test]…Only two had p24 antigen detected in serum at the same visit when bands were noted on WB. An additional 17 participants with persistently negative ELISA results have had one or two antibody bands detected by WB on two or more occasions during the course of the 48 months of the study. Whether or not these 17 individuals are infected with HIV or have antibody that cross-reacts with viral proteins is presently unknown”
Phair JP, Wolinsky S. Diagnosis of infection with the human immunodeficiency virus. J Infect Dis. 1989 Feb;159(2):320-3.
“The eight persons at risk who were positive for anti-nef protein antibodies were also positive for HIV DNA; five of the eight remained anti-nef antibody positive and HIV seronegative (by ELISA and Western blotting) and p24/25 antigen negative for eight months (one person...) and four months (four people), respectively, after the detection of HIV DNA”
Ameisen JC et al. Persistent antibody response to HIV-1-infected seronegative persons. N Engl J Med. 1989 Jan 26;320(4):251-2.
“17 of 18 DNA samples from seropositive subjects (94%) had positive [PCR] signals…13 of 21 (62%) RNA samples from seropositive subjects were positive for HIV RNA…RNA samples also gave varying intensities of PCR signal…The serum antigen assay [probably p24], carried out twice on each sample, was positive for 6 of the 21 (29%) samples from seropositive subjects…13 (76%) of the seventeen HIV-DNA-positive subjects were negative for serum antigen”
Hart C et al. Direct detection of HIV RNA expression in seropositive subjects. Lancet. 1988 Sep 10;2:596-9.
“approximately 1% of all initial screening ELISAs were reactive, 50% of repeat ELISAs were reactive, and 30% to 40% of first Western blot assays were reactive and diagnostic.”
Burke DS et al. Measurement of the false positive rate in a screening program for human immunodeficiency virus infections. N Engl J Med. 1988;319(15):961-4.
“patients have been described who are culture positive but seronegative for HIV”
Steckelberg JM, Cockerill F. Serologic testing for human immunodeficiency virus antibodies. Mayo Clin Proc. 1988;63:373-9.
“patients have been described who are culture positive but seronegative for HIV”
Steckelberg JM, Cockerill F. Serologic testing for human immunodeficiency virus antibodies. Mayo Clin Proc. 1988;63:373-9.
“The virological status of the 20% seropositive individuals who had negative cultures and no viral RNA detected remains unexplained.”
Richman DD et al. Detecting Human Immunodeficiency Virus RNA in peripheral blood mononuclear cells by nucleic acid hybridization. J Infect Dis. 1987 Nov;156(5):823-7.
“Of 61,90 donors tested by the [CDC] 0.8% were initially reactive [first ELISA] and 0.25% were repeated reactive [second ELISA]. Of these donors, 31% were strongly reactive. Approximately 86% of these strongly reactive samples were positive by Western Blot and 58% were viral culture positive…American Red Cross data on testing done on 2.58 million blood donors showed 1% of donors to be initially reactive, 0.27% repeatedly reactive and only 0.035% Western Blot positive. In West Germany, over 80,000 donors were tested between May 1985 and September 1985. Approximately 0.2% were found to be repeatedly reactive and 0.01 to 0.02% to be Western blot positive…The Puget Sound Blood Center used the ELISA test method to screen 15,680 donors during a six-week period and found 14 repeatedly reactive donors. Only three of the 14 donors were confirmed positive by Western blot. 8 of the 11 false-positive samples were from women who had at one time been pregnant.”
Houn HY et al. Status of current clinical tests for human immunodeficiency virus (HIV): applications and limitations. Ann Clin Lab Sci. 1987 Sep-Oct;17(5):279-85.
“For the initial 334 subjects, 165 (49%) were seropositive by both ELISA and Western Blot, 166 (50%) were seronegative by both tests, and the tests were discordant for three (1%) subjects. The best single predictor of seropositivity at the start of the follow-up period was the frequency of drug injection 2 to 5 years prior…One subject apparently went from seropositive to seronegative status.”
Des Jarlais DC et al. Development of AIDS, HIV seroconversion and potential cofactors for T4 cell loss in a cohort of intravenous drug users. AIDS. 1987;1:105-11.
“Infectious virus was recovered from the serum of 20 (25.6%) of [78 randomly selected, HIV+ individuals, of whom about 30% were asymptomatic] and was generally present in low titers. Only undiluted serum (not a tenfold dilution) yielded infectious virus...In one serum sample, 25,000 infectious particles per milliliter were detected as measured by end dilution of the serum. This sample came from a clinically healthy individual with very low levels of antibody to HIV[!]. Nine of the positive serum samples came from 39 individuals whose PMCs [peripheral blood mononuclear cells] were also tested. Virus was isolated [sic] from the PMCs of approximately 50% of these individuals and one third also yielded infectious virus in their serum. Three serum samples contained infectious HIV without any virus being recovered from the individuals’ PMCs...These studies demonstrate further that not all seropositive individuals have virus recoverable from their PMCs and that isolation from serum is not a common event”
Michaelis BA, Levy JA. Recovery of human immunodeficiency virus from serum (letter). JAMA. 1987 Mar 13;257(10):1327.
“39 [EIA/ELISA antibody-positive] specimens [26%] had a positive Western blot [antibody] test result; 38 (84.4%) of the 45 specimens highly reactive on EIA were Western blot (1.2%) of the 86 low reactive specimens [but still classified as ELISA antibody test positive]...had a positive Western blot result...[HIV] was isolated [note: this is a common misuse of the term isolation. Co-culturing does not isolate virus] from 23 (57.5%) of 40 cultured specimens [classified as highly reactive on EIA/ELISA]...[as well as] 2 (2.5%) of 80 specimens with low EIA reactivity...The Western blot was positive in 23 (92%) of the 25 culture-positive specimens. Conversely, 23 (63.9%) of the 36 Western blot-positive specimens...were [culture] positive...Of the 150 EIA-positive specimens from blood donors tested at the CDC, 40 (26.7%) had a Western blot or culture positive for [HIV]. If we assume [NOTE: there is no scientific reason to make this assumption] that these are the only true-positives, nor more than 125 of the 67,190 [blood] units tested were falsely positive [and, in normal life, 125 people would be falsely told that they had a fatal disease!]
Ward JW et al. Laboratory and epidemiologic evaluation of an enzyme immunoassay for antivodies to HTLV-III. JAMA. 1986 Jul 18;256(3):357-61.
“A total of 225 serums were tested by both IFA [Immunofluorescence Assay] and ELISA [antibody]. 180 (80%)...gave the same result. The 7 ELISA-positive and IFA-negative serums were from 4 healthy men. One of these samples also tested by Western blot assay [another antibody test] was negative. 4 ELISA-negative serums were IFA positive. These were all positive by Western blotting and were obtained from two AIDS patients, one man with lymphadenopathy, and one healthy man. In 3 of the 4 men, additional serums were positive by ELISA.”
Sandstrom EG et al. Detection of human anti-HTLV-III antibodies by indirect immunofluorescence using fixed cells. Transfusion. 1985 Jul;25(4):308-12.
“Among laboratory personnel and blood donors, 6 of 74 and 93 of 1014, respectively, demonstrated ELISA P/N ratios of 2 or greater [the arbitrary cutoff point used to define HIV-positivity]....2 of the blood donor specimens with ELISA P/N ratios of 2.7 and 3.2 were confirmed as positive by Western blot [but no reason is given for why Western Blot testing should be considered infallible]
Carlson JR et al. AIDS serology testing in low- and high-risk groups. JAMA. 1985 Jun 21;253(23):3405-8.
“The sera [from 6720 blood donors] were examined by various enzyme-linked immunoassay (ELISA) screening tests and, usually, by one of three types of confirmatory assay. 45 samples (0.21%) were confirmed as positive. Only 2 were positive in all three confirmatory tests.”
Hunsmann G. HTLV-III antibody Positive Blood Donors. Lancet. 1985 May 25;1:1223.
“the implications of seropositivity in asymptomatic individuals are not clear. The presence of antibodies to HIV-1 is indicative of previous exposure to HIV-1 but is not necessarily a diagnosis of AIDS…The lifetime risk of an asymptomatic person confirmed as having antibodies to HIV-1 developing AIDS or an AIDS-related condition is not known…HIV-1 has been isolated from asymptomatic seronegative individuals presumably prior to seroconversion following exposure…results of specimens that are repeatedly reactive by the SUDS HIV-1 Test and are indeterminate by a more specific test are unclear…The SUDS HIV- 1 Test alone cannot be used to diagnose AIDS, even if the recommended investigation of reactive specimens suggests a high probability that the antibody to HIV-1 is present…Of the 139 serum and plasma specimens from persons with potentially interfering medical conditions, one was repeatedly reactive by both the SUDS HIV-1 Test and the license HIV-1 EIA. This specimen was positive for HIV-1 antibodies by Western immunblot. The two specimens which were repeatedly reactive by the HIV-1 EIA but negative by the SUDS HIV-1 Test were uniformly negative for HIV-1 specific antibodies by an FDA license Western Immunoblot…[One] specimen which was scored as non-reactive at one clinical testing site was repeatedly reactive when tested at a second site using the SUDS HIV-1 Test.”
SUDS HIV-1 test. Murex.


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