Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the HIV Seroprevalence Survey among Childbearing Women (SCBW), antibodies to human immunodeficiency virus type 1 are detected using enzyme immunoassays (EIA) and Western blot (WB) methods modified to accommodate samples of blood dried on special collection paper. Dried blood spot (DBS) eluates positive by EIA are tested by one of two WB methods, the miniblot technique using equipment from Immunetics Corporation and the PBS Integra assay (pageblot) from Genetic Systems. In this report we compared the performance of the two WB methods. The identity and position of the viral proteins on the WB were identified using monoclonal antibodies and monospecific antisera. The blots differed substantially in their composition and concentration of viral glycoproteins. Performance of the WB assays with DBS elution buffers from different EIA kits was equivalent except for samples eluted in the Abbott buffer, which reduced detection of antibodies to the p31, p51, p55, and p66 viral proteins. Case classification of DBS, positive sera, dilution curve samples, and seroconversion panels was equivalent by both tests in the presence of all elution buffers. Proficiency evaluation panels sent to SCBW participating laboratories over a 3-year period were used to note the differences between the two WB methods in detection of antibodies to the viral glycoproteins.
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PMID:Factors influencing HIV-1 banding patterns in miniaturized western blot testing of dried blood spot specimens. 140 56

Transfusion of whole blood or blood components is the mainstay of treatment in patients with beta-thalassemia and hemophilia. Owing to the scarcity of reports regarding the frequency of transfusion-transmitted hepatitis virus infections in thalassemia patients, the frequency of such infections was studied in India in 40 multi-transfused thalassemia patients (26 males, 14 females; mean age 8.1 +or- 5.3 years, range 1-35) with no clinical or biochemical evidence of liver disease. The enzyme-linked immunosorbent assay (ELISA) technique (Abbott) was used for all tests. The patients had received an average of 80 units (range 10-250) of blood. A majority of these units had been screened for hepatitis B surface antigen (HBsAg) using RPHA. HBsAg antibodies were present in 18 (45%), antihepatitis C virus (HCV) in 7 (17.5%), and antihuman immunodeficiency virus in 1 (2.5%) case, respectively. Of 18 HBsAg positive patients, antidelta and anti-HCV antibodies were present in 3 and 4 patients, respectively; 1 patient had both the antibodies. 4 of 40 (10%) patients had evidence of both hepatitis B virus (HBV) and HCV infection. In a US study, the frequencies of HBsAg and anti-HBs positively among thalassemics were 4.5% and 43.5%, respectively. In contrast, 90% of hemophiliacs show serological evidence of HBV infection. Routine screening of blood donors by CEP or RPHA technique was started in the hospital blood bank 7 years ago. The sensitivity of these techniques is much lower than that of RIA and ELISA and a majority of the patients has received initial blood transfusions before HBsAg screening was started. The study indicated that more than 50% of multi-transfused thalassemia patients showed serological evidence of one or more HBV, HCV, HDV, and HIV infection. Thus, screening of blood units for HBV, HCV, and HIV infections to be used for thalassemic patients and vaccination of thalassemic patients against hepatitis B is imperative.
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PMID:Frequency of hepatitis B, C and D and human immunodeficiency virus infections in multi-transfused thalassemics. 142 37

A new, modular Western blot (immunoblot) system for human immunodeficiency virus (HIV) antibodies (ABN WesPage; Wellcome) was compared with enzyme immunoassays (Wellcome, Behringwerke, and Abbott) and with a U.S. Food and Drug Administration (FDA)-licensed Western blot (DuPont) in a multicenter study. A total of 649 serum samples from HIV patients at different stages of the disease, as well as from high-risk patients, from patients with conditions unrelated to AIDS, and from healthy blood donors, were used in the evaluation along with nine seroconversion panels. For evaluation of Western blot reactivity, both Centers for Disease Control (CDC) and FDA criteria were used. With the DuPont Western blot as the reference assay, the overall sensitivity and specificity of the ABN WesPage were 100 and 99.1%, respectively, when indeterminate results were not taken into account and when both tests were interpreted in accordance with CDC criteria. The DuPont Western blot detected significantly more antibodies to pol and gag gene products than the ABN WesPage. The ABN WesPage showed a higher positive rate of detection of viral envelope band gp160. When both Western blots were interpreted in accordance with CDC criteria, the ABN WesPage and the DuPont Western blot yielded 9.3 and 10.4% indeterminate results, respectively. When the DuPont Western blot was interpreted in accordance with the manufacturer's instructions (FDA criteria), 25.7% of the samples tested were regarded as indeterminate. The choice of interpretation criteria is of paramount importance for the evaluation of HIV Western blot patterns.
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PMID:Multicenter evaluation of the novel ABN Western blot (immunoblot) system in comparison with an enzyme-linked immunosorbent assay and a different Western blot. 155 87

Our objective was to examine the utility of the human immunodeficiency virus (HIV-1) antigen test as an early predictor of HIV-1 infection among children born to infected mothers and to collect information about its performance as a diagnostic test. The Abbott HIVAG-1 Enzyme Immunoassay was used to analyze serial serum samples from patients enrolled in a longitudinal cohort study of children born to mothers infected with HIV-1. There were 85 subjects who were followed from birth whose HIV-1 infection status could be definitely determined as of March, 1990. Of these 22 (26%) were infected with HIV-1 and 63 (74%) were uninfected. Overall the sensitivity of the test was 77% (95% confidence interval (CI), 55 to 92%) and the specificity was 97% (95% CI, 89 to 99%). The positive predictive value of a single positive test was 89% (95% CI, 67 to 99%) and of two or more positive tests was 100% (95% CI, 50 to 100%). The sensitivity of the test varied greatly with age. For 36 children from whom sera were collected during the first month of life the specificity of the antigen test was 100% but the sensitivity was only 20%. Overall in the first 6 months of life the sensitivity was less than 50%. The Abbott HIV-1 antigen test is useful as an early predictor of HIV-1 infection in children whose mothers are infected.
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PMID:Predictive value of the human immunodeficiency virus 1 antigen test in children born to infected mothers. 160 78

Quality-assurance sera (QAS) are prepared from pooled sera composed of thousands of individual donations. Previous studies documented that a substantial percentage of individual QAS test positive for viral disease markers, including antibodies to human immunodeficiency virus and to hepatitis B surface antigen. We tested 239 QAS from various proficiency programs and commercial sources to determine the prevalence of hepatitis C virus (HCV) antibody. We tested samples for anti-HCV by using an enzyme immunoassay (EIA; Abbott Labs.) and an enzyme-linked immunosorbent assay (ELISA; Ortho Diagnostics). We observed an overall positive rate of 49% by one or both assays in all categories of sera tested. In addition, we found a greater rate of positivity (58%) in proficiency program samples than in commercial samples (43%). We found discrepant results between the two assays for 15 of 239 samples (6%). In the discrepant samples, the EIA result was positive, whereas the ELISA result was negative. Anti-HCV positivity in QAS has important implications for laboratory personnel handling these samples.
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PMID:Prevalence of non-A, non-B hepatitis/hepatitis C virus antibody in laboratory quality-assurance sera. 164 89

An enzyme immunoassay (EIA) was developed to measure serum antibody responses of healthy adult volunteers vaccinated with 40 or 80 micrograms of human immunodeficiency virus type 1 (HIV-1) recombinant gp160 (rgp160) vaccine at 0, 1, 6, and 18 months. This assay, which used purified rgp160 as antigen, was compared with the Biotech/Du Pont HIV-1 Western blot and the Abbott HIV-1 EIA. Of 33 volunteers who received three doses of rgp160 vaccine, seroresponses were detected in 91% by rgp160 EIA, 97% by Western blot, and 30% by HIV-1 EIA. The level of IgG rgp160 EIA antibody (mainly IgG1) peaked after the third immunization; 64% of 33 vaccinees still had detectable antibody by 12 months. The fourth immunization induced anamnestic IgG EIA antibody in 23 of 24 vaccinees, with titers ranging from 1:200 to 1:25,600. Neutralizing antibody was not detected in postvaccination sera by microtiter syncytium formation inhibition assay. Additional testing of sera by EIA indicated that the immune response to the vaccine was directed toward epitopes on both gp120 and gp41. Seroresponses to the immunodominant epitopes on gp41 were infrequent and none were detected to the neutralization epitope in the V3 region of gp120. This highly sensitive EIA is useful for characterizing HIV-1-specific antibody responses induced by an HIV-1 gp160 subunit vaccine.
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PMID:Characterization of serum antibody responses to recombinant HIV-1 gp160 vaccine by enzyme immunoassay. NIAID AIDS Vaccine Clinical Trials Network. 170 7

An antigen capture enzyme immunoassay was developed for the demonstration of human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus (SIV). The assay (HIV-2 CE) has a sensitivity of approximately 250 pg/ml of HIV-2/SIV antigen. The HIV-2 CE was 4-16 times more sensitive than the Abbott HIV-1 antigen assay for detection of HIV-2/SIV antigen in cell culture supernatant. The sensitivity for detection of HIV-2/SIV antigen in serum or plasma was 98.5% in the HIV-2 CE and 95.5% in the Abbott HIV-1 antigen assay. The specificity of the HIV-2 CE was 99.2% (one false positive among 119 negative sera) whereas the Abbott assay was 100% specific. The HIV-2 CE detected antigen in supernatants from cultures of peripheral blood mononuclear cells of macaque monkeys infected with HIV-2 or SIV about 1 week before a reverse transcriptase (RT) microassay was positive and remained positive for at least 1 week after the RT assay had become negative. Three cultures from persistently infected monkeys were positive only in the HIV-2 CE, reflecting a higher sensitivity compared to the RT microassay. Thus, the HIV-2 CE was more sensitive than the Abbott HIV-1 antigen assay for detection of HIV-2/SIV antigen in culture supernatants as well as in serum/plasma. Furthermore, the HIV-2 CE showed a higher sensitivity than the RT microassay for detection of HIV-2/SIV in cell culture supernatants.
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PMID:A capture enzyme immunoassay for detection of HIV-2/SIV antigen. 170 69

Alternatives to confirmation of human immunodeficiency virus (HIV)-1 seropositivity by Western blot analysis were evaluated retrospectively using combinations of six anti-HIV-1 screening assays, including four enzyme-linked immunosorbent assays (ELISA) and two simple tests (a rapid dot immunoassay and an agglutination assay), according to an algorithm where sera are first screened by one assay and those repeatedly reactive on this assay are tested repeatedly by a second assay. Two panels of sera collected in Dar es Salaam, Tanzania, were used. Panel 1 was composed of 1,465 consecutive blood donor sera of which 99 (6.8%) were confirmed HIV-1 antibody positive, and panel 2 was composed of sera from 396 consecutively admitted patients at two medical wards of which 116 (29.3%) were confirmed HIV-1 antibody positive. Sera reactive on any of the six screening assays were also tested by a confirmatory Western blot assay. The sensitivity of the assays at the initial valid testing were as follows: Abbott 99.5%, Behring 99.5%, Organon 97.7%, Wellcozyme 100%, HIV CHEK-1 95.8%, and Serodia 95.8%. After repeat testing of sera that initially gave false-negative results all assays showed 100% sensitivity except HIV CHEK-1 (98.6%). The specificities after repeat testing were between 99.6 and 99.9% for all assays except for the Behring ELISA (98.1%). Several combinations of screening assays were found to give the same diagnostic accuracy as the screening assay followed by Western blot analysis. We conclude that an alternative confirmatory strategy can be fully satisfactory for some testing purposes.
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PMID:Alternative confirmatory strategies in HIV-1 antibody testing. 173 10

One hundred and twenty reactive sera were selected from specimens studied by enzyme immunoassay (EIA, Abbott Laboratories, Abbott Park, North Chicago, IL) for antibodies against human immunodeficiency virus (HIV-1). Using these sera, the 'WesPage' system (American Bionetics, Inc., Haywood, CA), was compared to the Western blot evaluation performed by a commercial reference laboratory (Abbott Laboratories, Abbott Park, North Chicago, IL). Using criteria established by the Food and Drug Administration, all major bands representing specific antigens of HIV-1 and their corresponding antibodies were identified on the immunoblot membrane when the strongly reactive control serum was used in the assay. The weakly reactive control serum demonstrated antibodies to the p24 core antigen and the gp120/160 envelope antigen of the virus in addition to others. The non-reactive control serum did not react with any antigen on the immunoblot sheet. All results obtained by our evaluation agreed with the reference laboratory results. The WesPage assay offers a combination of advantages which include rapid turn around time, less direct contact with potentially infectious materials, good resolution of bands and high reproducibility of results.
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PMID:Performance characteristics of a rapid western blot assay system for antibody to human immunodeficiency virus type 1. 178 75

Only "fair" agreement has been shown between the Abbott and DuPont enzyme linked immunosorbent assays when used for the detection of human immunodeficiency virus (HIV) antigen in serum samples from asymptomatic HIV antibody positive homosexual men. To investigate the discrepancies between the two ELISA results, further experiments were performed. The rabbit detector antibody solutions of both tests were western blotted and showed that the DuPont test was specific for p24; the Abbott detector antibody had bands for p18, p41-43, gp120 as well as p24. By using dilutions of a known amount of HIV antigen, the Abbott test could detect 20 pg/ml p24; the DuPont test could detect 30 pg/ml p24. The DuPont test was also more sensitive than the Abbott test at detecting a synthetic 104mer peptide of p24. Within the 104mer sequence two regions (294-318, 334-348 amino acids) inhibited the binding of the DuPont detector antibody, but no blocking was observed with the Abbott antibody. Although the Abbott test was slightly more sensitive at detecting HIV protein than the DuPont test, the major difference between the tests was in the molecular specificity, in that the Abbott test detected proteins other than p24. This may not be important for detecting antigen in cell culture, but it may affect the detection of antigenaemia in patients' sera.
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PMID:Molecular specificity of two commercial enzyme linked immunosorbent assays for human immunodeficiency virus antigens. 179 Dec 2


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