INTENDED USE

HIV Ag/Ab 4th Gen. Rapid Test is a lateral flow immunoassay for the qualitative detection of anti-HIV-1 (including O) and anti-HIV-2 virus antibodies (IgG, IgM, IgA), and HIV-1 p24 antigen in human serum, plasma or whole blood. It is intended to be used by healthcare professionals to aid in the diagnosis of infection with HIV.
Any use or interpretation of this preliminary test result must also rely on other clinical findings and the professional judgment of health care providers. Alternative test method(s) should be considered to confirm the test result obtained by this device.

SUMMARY

Human immunodeficiency virus type I and type II (HIV-1 and HIV-2) are enveloped, single- stranded, positive-sense RNA viruses. The causative relationship between HIV-1 and HIV-2 viruses and acquired immunodeficiency syndrome (AIDS) has been established over decades. HIV-1 has been isolated from patients with AIDS and AIDS-related complex and from healthy individuals with a high risk for developing AIDS1. HIV-2 has been isolated from West African AIDS patients and from sero-positive asymptomatic individuals. HIV-1 is much more prevalent than HIV-2 worldwide. Recent studies have shown that over 30 million people have been infected with HIV-1.
Both HIV-1 and HIV-2 viruses can elicit strong immune responses including the production of antiviral antibodies. Presence of specific anti-HIV-1 or HIV-2 virus antibodies in whole blood, serum or plasma indicates the exposure of an individual to HIV-1 or HIV-2 which is of great value for clinical diagnosis. Tests that detect HIV p24 antigen may be useful for the early diagnosis of HIV as p24 antigen is one of the earliest markers of HIV infection. It has been suggested that HIV infection is detectable with an HIV p24 antigen test 6 days earlier than an antibody test.
The HIV Ag/Ab 4th Gen. Rapid Test utilizes recombinant gp-120-4th, gp36 and anti-p24 antibodies to qualitatively detect antibodies (IgG, IgM, IgA) to anti-HIV-1 (including O) or HIV-2 viruses and HIV-1 p24 antigen in patient serum, plasma or whole blood. The test can be performed within 15 minutes by minimally skilled personnel without cumbersome laboratory equipment.

PRINCIPLE

The HIV Ag/Ab 4th Gen. Rapid Test is a lateral flow immunochromatographic assay. The test strip in the cassette consists of: 1) a colored conjugate pad containing recombinant HIV- gp120-41 and gp-36 antigens conjugated with colloidal gold (HIV conjugates), monoclonal anti-HIV-p24 antibody conjugated with colloidal gold (p24 conjugates) and a control antibody conjugated with colloidal gold, 2) a nitrocellulose membrane strip containing two test lines (Ag line and Ab line) and a control line (C line). The Ab line is pre-coated with HIV-gp120-41 and HIV-2 gp-36 antigens for the detection of antibodies to HIV-1 including O or HIV-2, the Ag line is pre-coated with another monoclonal anti-HIV-p24 antibody for the detection of p24 antigen, and theCline is pre-coated with a control line antibody.
When an adequate volume of test specimen is dispensed into the sample well of the test cassette, the specimen migrates by capillary action across the cassette. IgG, IgM or IgA antibodies to HIV- 1 or HIV-2, if present in the specimen, migrate through the conjugate pad where they bind to the HIV conjugates. The immunocomplex is then captured on the membrane by the pre-coated HIV- 1+2 antigens forming a colored Ab line, indicating a positive test result. Absence of the Ab line suggests an HIV-1 and HIV-2 antibody negative result.
HIV-1 p24 antigen, if present in the specimen, migrates through the conjugate pad where it binds to the p24 conjugates. The immunocomplex is then captured on the membrane by the pre-coated HIV-p24 antibody, forming a colored Ag line, indicating a positive test result. Absence of the Ag line suggests a HIV-p24 antigen negative result.
The test contains an internal control (C line) which should exhibit a colored line of the immunocomplex of control antibodies regardless of the presence of any colored test lines. If the C line does not develop, the test result is invalid and the specimen must be retested with another device.