Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving antigen-antibody binding – specific binding protein...
Patent
1995-09-12
2000-02-15
Knode, Marian C.
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving antigen-antibody binding, specific binding protein...
435 792, 435 5, 435 691, 435 693, 435968, 435971, 435975, 435974, 4241841, 4242041, 4241861, 4241871, 4241881, 4241891, 424806, 530403, 530350, 436513, 436800, G01N 3353, G01N 33537, G01N 33567, C12P 2106
Patent
active
060251417
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to an assay for the detection of various disease states which utilizes antigens in insoluble form and more particularly, for the detection of HIV infection. The assay of the present invention has a high sensitivity allowing for detection of antibodies to the HIV virus in the "window" period.
BACKGROUND OF THE INVENTION
Enzyme immunoassays (EIA) and Western Blot assays (WB) have been routinely used for detecting HIV infection for several years. The implementation of these tests has significantly reduced the risk of transfusion-related HIV infection. However, some recent studies based on the detection of HIV DNA have demonstrated that some HIV infected individuals do not have any detectable amount of anti-HIV antibodies when the approved tests are performed. Data from several studies indicate that there is a "window period" estimated to span from a few weeks to several months or even several years between initial HIV infection and seroconversion. Cases of post-transfusion HIV infection have been reported from seronegative blood donors. This is assumed to be a consequence of donation during the "window" period on the part of these donors.
To verify the presence of HIV-antibody in donors of reactive samples to EIA, the Western Blot assay has been used for confirmatory testings (Ulstrup, J. C. et al, Lancet i:1151-1152). In this assay, 6 to 9 characteristic bands indicating antibodies to HIV surface and core antigens are observed if antibodies to HIV-1 proteins are present (positive), and no bands if antibodies are absent (negative). However, a significant proportion of EIA repeatedly reactive samples react only to the HIV-1 gag-derived core proteins (p17, p24 and p55) on the WB test (Kleinman, S., 1990, Arch. Pathol. Lab. Med. 114:298-303, Tribe D. E. et al, 1988, J. Clin. Microbiol. 26:641-647). This reactivity does not meet the definition of HIV-1 positive or negative in the criteria for WB tests and as a result these samples are labelled as HIV-1 WB indeterminates. Studies have established that 30 to 40 percent of EIA repeatedly positive donors are HIV-1 WB indeterminates, a figure that is typical in North America. Follow-up studies performed in regions of high prevalence of HIV show that while 95 to 99 percent of these are not infected with HIV, the remaining 1 to 5 percent of blood donors with HIV-1 WB indeterminate results are true seroconverters, usually at an early stage of infection (Busch, M. P. et al., 1991, Transfusion 31:129-137; Gallo D. et al, 1986, J. Clin. Microbiol. 23:1049-1051). In order to optimize the safety of transfusion, all donors with HIV-1 WB indeterminate results are deferred. The majority of donors with HIV-1 WB indeterminate results undergo needless anxiety, their deferral represents a significant loss of donors and recipients are still worried about contamination of blood taken from "window" period of seroconversion donors. A highly sensitive assay is thus also desirable in order to properly classify these indeterminate results.
Partially purified disrupted virus is used as an antigen for most currently licensed screening and confirmatory tests. Human cells are always used for culturing the HIV-1 virus (Dodd, R. Y. and C. T. Fang, 1990, Arch. Pathol. Lab. Med. 114:240-245). Recombinant proteins and synthetic peptides have been recently licensed for screening tests (Busch M. P. et al., 1991, Transfusion 31:129-137; Das P.C. et al., 1992, Trans Med 2:249-250; Ramirez E. P., 1992, J. Clin. Microbiol. 30:801-805). In theory, these antigens can provide more sensitive and definitive assays. However, most recombinant proteins are produced in E. coli and denatured during the purification and processing of the antigens. Also, a certain proportion of donors still show cross-reactivity to HIV core antigens (such as antigen p24), and sensitivity is limited to detecting very early HIV antibodies.
A serious drawback to the use of synthetic peptides is related to the fact that in some HIV-1 infected patients and seroconverters in high ri
REFERENCES:
patent: 4118479 (1978-10-01), Prince et al.
patent: 4129644 (1978-12-01), McAleer et al.
patent: 4241175 (1980-12-01), Miller et al.
patent: 4722840 (1988-02-01), Valenzuela et al.
patent: 4734362 (1988-03-01), Hung et al.
patent: 4752565 (1988-06-01), Folks et al.
patent: 4870023 (1989-09-01), Fraser et al.
patent: 4925784 (1990-05-01), Crowl et al.
patent: 5041385 (1991-08-01), Kingsman et al.
patent: 5156949 (1992-10-01), Luciw et al.
patent: 5169784 (1992-12-01), Summers et al.
patent: 5175098 (1992-12-01), Watanabe et al.
patent: 5175099 (1992-12-01), Willis
patent: 5204259 (1993-04-01), Helting et al.
Shoeman et al. "Comparison of Recombinant Human Immunodeficeiency Virus gag Precursor and gag/env Fusion Proteins and a Synthetic env Peptide as Diagnostic Reagents". Analytical Biochemistry, vol. 161, pp. 370-379, 1987.
Wagner et al. "Studies on processing, particle formation, and immunogenicity of the HIV-1 gag gene product; a possible component of a HIV vaccine", Arch Virology, vol. 127, pp. 117-137, 1992.
Gaskin et al. "Use of chemical cleavage active HIV-1 proteinase from a fusion protein produced in the form of insoluble inclusion bodies", Biochemical Society Transaction, vol. 20, No. 2, pp. 162S, May 1992.
J.M. Hofbauer et al Journal of Clinical Microbiology, Jan., 1988, 26:116-120, "Comparison of Western Blot (Immunoblot) Based on Recombinant-Derived p41 With Conventional Test for Serodiagnosis of Human Immunodeficiency Virus Infections".
L. Luo et al., Proc. Natl. Acad. Sci. USA, Nov., 1992, 89:10527-10531, "Chimeric gag-V3 Virus-Like Particles of Human Immunodefiency Viorus Induce Virus-Neutralizing Antibodies".
J.M. Sligh et al., A.J.C.P.,Feb., 1989, 91:210-214, "Flow Cytometric Indirect Immunoflorescence Assay with High Sensitivity Specificity for Detection of Anitbodies to Human Immunodeficiency Virus (HIV)".
Knode Marian C.
Lee Datquan
The Canadian Red Cross Society
LandOfFree
Immunofluorescence assay for the detection of antibodies using r does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Immunofluorescence assay for the detection of antibodies using r, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Immunofluorescence assay for the detection of antibodies using r will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1904772