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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sera of 173 haemodialysis patients treated in two dialysis centers in Hungary were tested for the presence of HIV (HTLV III/LAV) antibodies. Four different commercial enzyme immunoassay (EIA) kits and two types (CEM/LAV, and H9/HTLV III) of indirect immunofluorescence assay (IFA) were used. The Western blot technique was applied as confirmatory test in the study. No confirmed positive results were found in any of the cases. However, in 15 patients (8.7%) false positive (not confirmable by the Western blot assay) results were obtained in at least one but mostly in all of the three type 1 EIA kits (ORGANON, ELECTRONUCLEONICS, SORIN) applied. In 4 patients, the IFA assay also gave false positive results which could be repeated in sequential samples taken from the same patients. Increased reactivity in the control plate (coated with a concentrate of cellular material shed by uninfected H9 cell line) of the SORIN kit was found only in a few false positive samples and no fluorescence with the uninfected H9 or CEM cells was observed in any of the sera showing a false positive IFA. These results indicate that the false positive anti-HIV results frequently observable in haemodialysis patients are not simply the consequence of the presence of antibodies reacting with the uninfected H9 and/or CEM cells but they are most probably due to antibodies against antigens expressed on these cells only after infection with the human immunodeficiency virus.
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PMID:[False positive results of HIV virus tests in patients undergoing chronic hemodialysis]. 264 79

Using confirmed positive and false-positive serum samples stored in deep frozen state we studied the reproducibility of the results obtained by different anti-HIV enzyme immunoassay (EIA) kits. Experiences obtained with 3 kits are presented. Two types of observations were made: (a) significant inter-lot, intra-lot and even inter-box sensitivity difference was found with some kits and (b) reactivity of the plates for true-positive and false-positive sera independently changed among different lots of the same kit: while reactivity for true positive sera was constant, a significant decrease or increase in reactivity for false-positive sera was found. These observations point to poor reproducibility of some commercial anti-HIV EIA kits that can cause serious difficulties in screening laboratories.
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PMID:Pitfalls in HIV serology: reagent-dependent changes in sensitivity and specificity of ELISA kits. 264 55

The Westmead HIV-1 antibody testing strategy showed that, regardless of ELISA screening kit manufacturer, sera which were repeatedly positive by two ELISA screening assays (one indirect and the other competitive format) had a 97-98% chance of being confirmed positive by Western blot for HIV-1 antibody or a less than 3% chance of either being identified as a seroconverter (1%) or a late stage AIDS patient (1.2%). Sera which were discordant by two ELISA screening assays had a less than 4% chance of either being confirmed positive by Western blot (2.5%) or identified as a seroconverter (1.3%). The incidence of non-specific indeterminate Western blot profiles were shown to be inversely proportional to the specificity of the ELISA screening kits used. The use of a recombinant envelope ELISA was able to confirm the viral specificity of HIV-1 envelope bands (gp160, 120 or 41) on Western blot. Guidelines suggested by the Australian National HIV Reference Laboratory, Fairfield Hospital, Melbourne, which categorized indeterminate or typical Western blot profiles into four reaction groups were found to be useful for the interpretation of Western blot patterns. A Western blot profile which is reactive for HIV-1 viral glycoproteins (gp160, 120 and 41) alone or in combination with not more than two other viral proteins (Indeterminate Group 4) and which is confirmed viral envelope specific by a recombinant envelope ELISA can be used as a predictor of seroconversion.
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PMID:HIV-1 antibody testing strategy: evaluation of ELISA screening and western blot profiles in a mixed low risk/high risk patient population. 269 39

A standardized pool of human sera that was positive for human immunodeficiency virus type 1 (HIV-1) antibody was developed. This positive control serum was used to analyze test differences among eight laboratories, among the HIV-1 antibody test kits of three different manufacturers, among different lots of the same test kit, and among pipetting devices and techniques. The standardized pool of human sera was tested 327 times by the different laboratories. In terms of positive tests, a reproducibility of 99.69% was achieved; however, significant test variance among laboratories, among test kit lots, and among pipetting devices and techniques could be demonstrated if the tests were compared on the basis of the net positive optical density (OD) value. This value was calculated by subtracting the cutoff OD value (i.e., the value below which an OD value was considered negative for HIV-1 antibody) from the observed OD value of the standardized pool of human sera. The results obtained suggest that this strategy can be used for proficiency testing, for monitoring the quality of HIV-1 antibody enzyme-linked immunosorbent assay reagents, and for evaluating pipetting devices and techniques.
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PMID:Development of quality control procedures for the human immunodeficiency virus type 1 antibody enzyme-linked immunosorbent assay. 275 3

Since the institution of routine testing for antibodies to Human Immunodeficiency Virus (HIV) using the enzyme-linked immunosorbent assay (ELISA), the specificity and sensitivity of this assay system has received significant scrutiny. During previous use of this methodology, we have quantified rates of false biological positive results using commercial kit assays in a normal donor population. In this study, we have identified a potential source for false negative results. Using multiple lots of two different commercial ELISA kits, the absorbance readings at the test end point could not differentiate between normal non-reactive donor samples and blanks containing no sample. These results occur using normal donor samples, even though the assays could distinguish between blank wells and the manufacturers' "normal controls", provided with the assay. Our findings suggest that a technical pipetting error is presently undetectable, either visually or by statistical methods, and could permit an untested, potentially HIV-1 positive, unit to be released into the transfusable blood supply. A possible solution is suggested.
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PMID:An undetectable source of technical error that could lead to false negative results in enzyme linked immunosorbent assay of antibodies to HIV-1. 291 65

A method previously used for studying the specificity of antibody components of circulating immune complexes in different diseases has been applied to analyse circulating immune complexes in HIV-infected patients. Antibodies against HIV antigens hidden in circulating immune complexes were studied in 14 sera from 13 patients with asymptomatic HIV infection (group 1) and in 11 sera from seven patients with HIV symptoms (group 2). HIV antigen-coated wells from the Vironostika kit as well as core and envelope antigen-coated beads from the Abbott confirmatory kit were used as solid-phase antigen. Using the Vironostika plates, HIV antibodies were demonstrated in circulating immune complexes in three and five sera in groups 1 and 2, respectively. Anti-core antibodies hidden in circulating immune complexes were present in three out of eight and two out of nine sera, respectively, in groups 1 and 2, whereas anti-envelope antibodies were present in circulating immune complexes in one out of eight and six out of nine sera in the same groups. These findings demonstrate that not only core-anti-core but also envelope-anti-envelope immune complexes are present in the sera of HIV infected patients.
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PMID:A simple method for detecting HIV antibodies hidden in circulating immune complexes. 312 57

Enzyme-linked immunosorbent assays (ELISA) were developed for the demonstration of antibodies to HIV-2 using disrupted virions of the SBL-6669 isolate of HIV-2 and the so-called human T-lymphotropic virus type IV (HTLV-IV), recently found to be identical with the simian immunodeficiency virus (SIVmac), as antigens. Three hundred sera from West African subjects, attending an outward clinic in Bissau for examination of suspected tuberculosis, were tested by these two assays as well as by a commercially available anti-HIV-2 ELISA (ELAVIA II). Fifty of these sera were positive in all three ELISAs as well as in Western blot tests against HTLV-IV. Thirty-eight of these positive sera were also tested by an anti-HIV-2 Western blot kit (LAV-Blot II) with positive results. The ELISAs based on SBL-6669 and HTLV-IV antigens had a specificity of 99.6% (one false positive among 250 negative sera) whereas the specificity of ELAVIA II was 94.6% using the recommended cut-off value and 98.4% using a higher cut-off value. Another 58 sera from West African patients, clinically suspected of having AIDS or HIV-related disease, were tested for HIV-2/HTLV-IV antibodies by Western blot and by ELISA against SBL-6669 and HTLV-IV antigens; all of the 30 sera which were positive by Western blot were found to be positive in both ELISAs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enzyme immunoassays for the demonstration of antibodies to HIV-2SBL-6669 and HTLV-IV (SIVmac). 313 13

2597 serum samples from individuals belonging to various groups were screened for antibodies to human immunodeficiency virus (HIV). The majority of the sera screened were from residents of India; 16 were from foreigners. Screening was done using ELISA kits from 4 different commercial sources. Samples which were reactive initially were retested using the same kit. 4 samples were reactive repeatedly in all the kits used. 2 of these were from patients with Acquired Immune Deficiency Syndrome (AIDS), 1 from a patient with AIDS-related complex, and 1 from an apparently healthy female prostitute living in Bombay. These 4 samples were confirmed to be positive by Western Blot, immunofluorescence, and the Karpas AIDS test. Among the sexually promiscuous persons screened for antibodies to HIV in India, female prostitutes appear to be the only risk group in whom antibodies to HIV virus have been detected. This also has been reported from Tamil Nadu. Positive reactors among blood donors screened even in areas of high incidence of AIDS has been very low. There were no positive reactors among the tribals, naval personnel, and individuals from jails. Overall, the data and an earlier report from Delhi suggest that the activity of AIDS retrovirus remains low in India, but the possible threat of spread of this disease should be considered. As prostitutes have been the only risk group with positive serological evidence of HIV infection, surveillance of this group is indicated.
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PMID:Seroepidemiological investigations on human immunodeficiency virus infections in some parts of India. 316 84

A consistently positive ELISA reaction and a band in the gp41-region of the HIV-1 western blot were found in repeated serum samples from a healthy pregnant woman. The band was more clearly defined than the HIV gp41 band. Additional ELISA testing and repeated western blot analyses using different test kit batches confirmed our suspicion of a false-positive reaction.
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PMID:False-positive band in the gp41 region in anti-HIV western blotting. 319 Sep 16

Eighty-three chronic hemodialysis patients were tested for human immunodeficiency virus (HIV) infection. Testing included screening enzyme immunoassay (EIA) for HIV antibodies, competitive EIA for envelope and core antibodies, EIA for HIV antigen, and lymphocyte culture. Five (6%) of the patients had positive screening EIA at low reactivity. Four of these five had antibodies to H-9 cellular antigens. Comparison of the five seropositive patients to matched controls showed no significant differences in number of lymphocytes or helper/suppressor ratio. Six months later, the five patients had negative screening EIA results using a kit with a manufacturing change approved by the Food and Drug Administration that provided improved specificity. In addition, their Western blot analysis was negative. We conclude that (1) false-positive screening EIA results are more common in chronic hemodialysis patients than other populations; (2) evaluation of chronic hemodialysis patients for HIV infection requires confirmatory tests; and (3) newer EIA screening kits appear to have improved specificity.
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PMID:False-positive results of screening for antibodies to human immunodeficiency virus in chronic hemodialysis patients. 328 69


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