HIV testing: an update.HIV testing has significantly improved since the first diagnostic test in 1985. Increased understanding of HIV HIV (Human Immunodeficiency Virus), either of two closely related retroviruses that invade T-helper lymphocytes and are responsible for AIDS. There are two types of HIV: HIV-1 and HIV-2. HIV-1 is responsible for the vast majority of AIDS in the United States. transmission and the clinical course of the infection, together with the availability of new techniques, have changed the strategies used for HIV testing. Furthermore, now that HIV testing is recommended in the routine medical evaluation of patients, an increase in screening and the identification of HIV-infected patients is expected. To adequately understand HIV testing, a review of the virus, the natural course of the infection, and the test characteristics is helpful. Virology virology, study of viruses and their role in disease. Many viruses, such as animal RNA viruses and viruses that infect bacteria, or bacteriophages, have become useful laboratory tools in genetic studies and in work on the cellular metabolic control of gene expression and natural history HIV is a retrovirus retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for this RNA-to-DNA transcription. that consists of an envelope (outer membrane The outer membrane refers to the outside membranes of Gram-negative bacteria, the chloroplast, or the mitochondria. It is used to maintain the shape of the organelle contained within its structure, and it acts as a barrier against certain dangers. ) and a viral core. The viral envelope viral envelope n. The outer structure that encloses the nucleocapsids of some viruses. is taken from the membrane of a human cell during viral budding and carries Env, a complex viral protein. The Env protein consists of a cap (made from glycoprotein glycoprotein (glī'kōprō`tēn), organic compound composed of both a protein and a carbohydrate joined together in covalent chemical linkage. (gp) 120), and a stem (made of gp41). Within the envelope, the viral capsid capsid /cap·sid/ (kap´sid) the shell of protein that protects the nucleic acid of a virus; it is composed of structural units, or capsomers. cap·sid n. is made of thousands of copies of another viral protein, p24. These three proteins are highly immunogenic im·mu·no·gen·ic adj. Producing an immune response. immunogenic producing immunity; evoking an immune response. and are the antigens used in many diagnostic tests. The capsid surrounds two single strands of HIV RNA HIV RNA AIDS RNA of HIV origin, a serum marker of a Pt's 'HIV-ness,' now the standard by which Pt response to antiretovirals is evaluated; HIV RNA levels correlate with CD4+ count, response to antiviral therapy, clinical stage and disease progression. , each of which has a copy of the virus' nine genes. Three of these--gag, pol, and env--encode structural proteins. Three regulatory genes (tat, rev, and nef), and three auxiliary genes (vif, vpr, and vpu) contain information necessary for the production of proteins that control the ability of HIV to infect a cell, produce new copies of virus, or cause disease. The core of HIV also includes the HIV nucleocapsid nucleocapsid /nu·cleo·cap·sid/ (noo?kle-o-kap´sid) a unit of viral structure, consisting of a capsid with the enclosed nucleic acid. nu·cle·o·cap·sid n. protein (p7) and three enzymes: reverse transcriptase Reverse transcriptase Any of the deoxyribonucleic acid (DNA) polymerases present in particles of retroviruses which are able to carry out DNA synthesis using an RNA template. , integrase, and protease protease /pro·te·ase/ (pro´te-as) endopeptidase. pro·te·ase n. Any of various enzymes, including the proteinases and peptidases, that catalyze the hydrolytic breakdown of proteins. . Some of the new HIV tests (e.g. molecular RNA RNA: see nucleic acid. RNA in full ribonucleic acid One of the two main types of nucleic acid (the other being DNA), which functions in cellular protein synthesis in all living cells and replaces DNA as the carrier of genetic or DNA DNA: see nucleic acid. DNA or deoxyribonucleic acid One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. technologies) target some of these genes and enzymes. [FIGURE 1 OMITTED] Host and viral markers of infection change depending on the duration of the infection and will influence the selection of a test and its performance (see Figure 1). Soon after HIV infection, the virus starts active replication, enabling the detection of viral RNA at very early stages (first marker of infection). Within the first few weeks after the acute infection, the capsid protein p24 appears. Its presence in the serum is transient and its disappearance coincides with the development of specific antibodies (see Figure 1). A transient immunoglobulin M immunoglobulin M n. Abbr. IgM The class of antibodies found in circulating body fluids and the first antibodies to appear in response to an initial exposure to an antigen. antibody response against core and/or envelope proteins is usually the first to appear and is followed by a long-lasting IgG response. (1) Following a similar sequence to their respective inducing antigens, IgG antibodies against the gag (p24) and env (gpl60, 120, 41) appear first, followed by antibodies against HIV viral enzymes. (2) Most patients remain asymptomatic during the acute infection, but some others might develop a constellation of symptoms that include fever, rash, malaise and myalgias, diarrhea, and/or headache, among the most common. (3) At this time, the humoral hu·mor·al adj. 1. Relating to body fluids, especially serum. 2. Relating to or arising from any of the bodily humors. Humoral Pertaining to or derived from a body fluid. response is still at early stages and most patients will have negative antibody tests (regardless of the technology used). The acute infection is followed by a period of clinical latency Clinical latency is the state, or time period, in which an infectious agent produces no clinical symptoms in a host. This is particularly notable with viruses and bacterium with long periods of latency such as HIV and syphilis. Latency is not equivalent to dormancy. that last several months to years. During this time, viral replication Viral replication is the term used by virologists to describe the propagation of biological viruses during the infection process in the target host cells. When used in the strictest sense, the term refers specifically to the amplification of the viral genome remains active and is associated with a progressive decline in T-helper lymphocyte lymphocyte: see blood; immunity. lymphocyte Type of leukocyte fundamental to the immune system, regulating and participating in acquired immunity. Each has receptor molecules on its surface that bind to a specific antigen. (CD4+ T cell) counts. Both viral and host factors will determine the rate of decline in the CD4 T cell Noun 1. CD4 T cell - T cell with CD4 receptor that recognizes antigens on the surface of a virus-infected cell and secretes lymphokines that stimulate B cells and killer T cells; helper T cells are infected and killed by the AIDS virus count, which ultimately results in loss of immune function Immune function The state in which the body recognizes foreign materials and is able to neutralize them before they can do any harm. Mentioned in: Herbalism, Traditional Chinese, Stress Reduction and increased susceptibility to infection. HIV testing technologies The HIV testing assays are categorized in three main classes: tests that detect HIV antibodies, tests that detect antigens (in particular p24), and tests that detect or quantify viral nucleic acids Nucleic acids The cellular molecules DNA and RNA that act as coded instructions for the production of proteins and are copied for transmission of inherited traits. . Enzyme immunoassays (EIA (Electronic Industries Alliance, Arlington, VA, www.eia.org) A membership organization founded in 1924 as the Radio Manufacturing Association. It sets standards for consumer products and electronic components. ) detect HIV-1 specific antibodies by using HIV-1 antigens coated onto the wells of micro-well plates. EIA was the first technology developed for HIV diagnosis in 1985. Since then, serologic tests have been modified to include antigens for enhanced detection of viral variants (see Table 1) and to enable the diagnosis of HIV infection at earlier stages. In general, this technology has very high sensitivity and specificity, is inexpensive, simple, suitable for testing sizeable numbers of samples, and easily adapted to automatic platforms. These characteristics make it the ideal test for the diagnosis of patients with chronic infection. A partial list of test kits can be found in Table 1. Tests can be grouped in four generations by the antigens used. The first generation of EIAs was based on viral lysate-based immunoglobulin G immunoglobulin G n. Abbr. IgG The most abundant class of antibodies found in blood serum and lymph and active against bacteria, fungi, viruses, and foreign particles. Immunoglobulin G antibodies trigger action of the complement system. (IgG) test, and this was soon followed by a second generation of tests in which recombinant proteins Since human recombinants have replaced the animal version in human therapeutics, the prefix of "rh" for "human recombinant" appears less and less in the literature Human recombinants that replaced animal or harvested from human types The Western Blot Western blot A technique developed in 1979 that is used to confirm ELISA results. HIV antigen is purified by electrophoresis and attached by blotting to a nylon or nitrocellulose filter. (WB) assay is based on the recognition of the major HIV proteins (p24, gp41, gpl20/160) by fractionating them according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. weight by electrophoresis and then visualizing them by binding with specific antibodies over a nitrocellulose nitrocellulose, nitric acid ester of cellulose (a glucose polymer). It is usually formed by the action of a mixture of nitric and sulfuric acids on purified cotton or wood pulp. sheet. In contrast to EIAs that qualitatively detect antibodies without delineating the specific antigens to which the antibody reacts, WB shows the specific proteins to which the patient's antibodies are attached, making it a more specific test. When two or more of the three major bands (p24, gp41, and/or gp 120/160) are present, the test is called positive. The presence of any other combination of bands is called indeterminate. (5) Given its test performance, WB is probably the most widely accepted confirmatory assay and has been traditionally considered the "gold standard." Immunofluorescence Immunofluorescence A technique that uses a fluorochrome to indicate the occurrence of a specific antigen-antibody reaction. The fluorochrome labels either an antigen or an antibody. assay, or IFA Immunofluorescent assay (IFA) A blood test sometimes used to confirm ELISA results instead of using the Western blotting. In an IFA test, HIV antigen is mixed with a fluorescent compound and then with a sample of the patient's blood. , identifies HIV-1-specific antibodies by using immortalized human T-cells expressing surface viral antigens fixed on the surface of a glass. HIV antibodies from the specimen bind the HIV-1 antigens and the antigen-antibody complex is detected by using anti-human immunoglobulin conjugated conjugated adj. Conjugate. estrogens, conjugated Warning - Hazardous drug! C.E.S. to fluorescein isothiocyanate Noun 1. fluorescein isothiocyanate - a fluorochrome commonly conjugated with antibodies for use in indirect immunofluorescence fluorescein isocyanate fluorochrome - any of various fluorescent substances used in fluorescence microscopy to stain specimens , or FITC FITC fluorescein isothiocyanate; used as a fluorescent label for proteins, especially antibodies. , which is fluorescent when exposed to UV light. This technique can provide a definitive diagnosis in samples that test indeterminate with other confirmatory tests, but it requires a fluorescence microscope A fluorescence microscope is a light microscope used to study properties of organic or inorganic substances using the phenomena of fluorescence and phosphorescence instead of, or in addition to, reflection and absorption. and well-trained operators. Line immunoassay Immunoassay An assay that quantifies antigen or antibody by immunochemical means. The antigen can be a relatively simple substance such as a drug, or a complex one such as a protein or a virus. (LIA LIA Little Ice Age LIA Laser Institute of America LIA Labrador Inuit Association LIA Lock in Amplifier LIA Logistics Integration Agency LIA Live Impact Area LIA Licensed Insurance Advisor LIA Liability Insurance Administrators LIA Life Imitating Art ) incorporates separate HIV antigens on nitrocellulose strips, so each reaction can be visualized separately. The antigens used for this process are synthetic and recombinant, decreasing the background from non-specific host proteins, thereby decreasing the number of indeterminate results in non-infected patients and facilitating an easier interpretation. It offers better quality control and better reproducibility than WB. LIAs are also a popular confirmatory test. Technically simple, a rapid HIV test can be performed manually by a person with minimal experience and visually read in 20 minutes. It allows testing in pregnant women that are unaware of their status before delivery, reducing the risk of vertical transmission by providing the appropriate interventions. Similarly, after needle-stick accidental exposure, rapid testing provides useful information for clinicians to select prophylactic treatment prophylactic treatment n. The institution of measures to protect a person from a disease to which he or she has been, or may be, exposed. Also called preventive treatment. and potential early discontinuation dis·con·tin·u·a·tion n. A cessation; a discontinuance. Noun 1. discontinuation - the act of discontinuing or breaking off; an interruption (temporary or permanent) discontinuance . Rapid HIV diagnosis at point-of-care tests identifies high-risk infected patients, allowing the immediate establishment of support networks and medical care, reducing loss of follow up, time to establish care, and partner notification partner notification Public health Any formal and systematic means of informing the sexual partner(s) of a person with an STD, that the person being tested is infected with an organism–eg, HIV, N gonorrhoeae, T pallidum with great potential public-health implications. Currently, most protocols still recommend confirming any positive rapid test result with either WB or EIA. Follow-up with WB or EIA four weeks after is also recommended for those with negative or indeterminate confirmatory tests. (6) Oral fluid tests provide an alternative for people that do not want blood draws and avoid risk of needle-stick exposure for healthcare providers. IgG antibodies present in oral fluids can be detected by the technologies mentioned previously. Unfortunately, the use of oral fluids has been problematic due to specimen instability and assay insensitivity. Recently, the Food and Drug Administration (FDA FDA abbr. Food and Drug Administration FDA, n.pr See Food and Drug Administration. FDA, n.pr the abbreviation for the Food and Drug Administration. ) has cleared the OraQuick Advance HIV 1/2 Antibody Test for use with oral fluid and plasma (previously approved only for whole-blood specimens). With 99.3% sensitivity and greater than 99.6 % specificity, this is the only rapid HIV test to be cleared in the United States by the FDA for use with oral fluid. (7) Newer strip technologies (Saliva-Strip HIV-1/2, Saliva Diagnostics Systems.) are being developed and seem to be highly concordant with blood-testing methods in developing countries. Although the FDA has not cleared the other tests, results from developing countries suggest that these technologies will provide a rapid, simple, non-invasive point-of-care test. Similar to oral fluids, urine contains IgG antibodies. Several tests are now available, and they seem to have performances similar to serum samples. (8) The detection of p24 is a simple and cost-effective technique to demonstrate viral components in blood. Initially implemented in 1995 in the United States to supplement antibody screening of donated blood components, this test detects viral capsid (core) p24 protein in blood usually earlier than antibody after initial infection, and offers the same performance advantages as the EIA for antibody detection. The presence of antigen is highly specific for infection, but a significant limitation of these assays is their analytic sensitivity, because low concentrations of antigen are difficult to detect and antigenemia occurs only transiently during different stages of infection (e.g., most tests will only detect 25% of infected-seronegative patients). Although new molecular technologies have replaced the use of EIA detection of p24 for the diagnosis of acute HIV infection, (9) the addition of p24 antigen to the latest generation of EIAs has markedly improved their performance. Implementation of HIV molecular tests has changed the way that HIV medicine is practiced. This technology targets the detection of the virus itself, increasing the sensitivity for the diagnosis of early infection and allowing quantification of the viral load viral load n. The concentration of a virus, such as HIV, in the blood. viral load, n a measure of the number of virus particles present in the bloodstream, expressed as copies per milliliter. and genotyping to determine mutations associated with antiretroviral resistance. Currently, reverse-transcription polymerase chain reaction polymerase chain reaction (pŏl`ĭmərās') (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is (RT-PCR RT-PCR reverse transcriptase-polymerase chain reaction. See PCR1. ), nucleic-acid sequence-based amplification, or NASBA NASBA National Association of State Boards of Accountancy NASBA Nucleic Acid Sequence-Based Amplification (assay used to detect HIV viral load in blood plasma) , and branched DNA, or bDNA, are the nucleic-acid amplification technologies available. The use of viral load determination is now widely used to predict clinical outcome, progression of disease, and determination of need for therapy. Traditionally, the algorithm for HIV testing is comprised of two steps. Specimens are first screened for HIV specific antibodies using EIA. Specimens testing negative by EIA require no further work-up. For specimens testing positive, a confirmatory test (traditionally a Western Blot) is performed. During chronic HIV infection, the diagnosis is relatively straightforward since current technologies have very high sensitivity and specificity at this stage. A positive screen followed by a positive confirmatory test is diagnostic of HIV infection and a negative screening test rules out infection. During the acute HIV infection and the earlier stages of infection, however, most of the initial screening technologies can be falsely negative. Although the new EIAs are significantly decreasing this diagnostic window, to overcome this problem the use of molecular techniques is becoming progressively more common. As mentioned above, nucleic-acid amplification can detect HIV infection at its earliest stage, but it is an expensive and labor-intensive test. Since the cost of this technique can be prohibitive from a public-health perspective, the use of pooled samples has been a common practice. In this approach, the samples testing negative by EIAs are pooled in groups and tested using molecular techniques. If one of those groups test positive, the samples are tested individually looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. the infected one. (10) The setting in which the HIV testing will be applied should also affect the selection of the ideal testing algorithm. Targeted testing is offered to patients that are felt to be at risk or that have any symptoms suggestive of suggestive of Decision making adjective Referring to a pattern by LM or imaging, that the interpreter associates with a particular–usually malignant lesion. See Aunt Millie approach, Defensive medicine. HIV infection (see Table 2). In certain situations, however, in which missing a case can have serious clinical and public-health consequences (like in blood banks or very high-risk populations), all the members of a defined population are screened with a highly sensitive test. The positive results are then confirmed. Most importantly, the negative ones are further tested for acute infection by using nucleic-acid amplification technologies. This approach might not be the most cost-effective in populations with low HIV prevalence. Furthermore, with the development of new testing technologies, the selection of the initial screening test and the confirmatory one will also be influenced by particular characteristics of the test and the population. Rapid HIV testing is now being used to diagnose patients at physician offices, emergency rooms, and clinics, facilitating the early identification and treatment of new cases. Common indications for HIV testing are listed in Table 2. HIV testing has dramatically improved during the last two decades. Different HIV-testing technologies will perform differently in different settings. Selection of the most appropriate test should incorporate considerations regarding accuracy of the test, patient preferences, ease of sample collection, availability of trained personnel, availability of laboratory facilities, and prevalence of disease in the population that is being tested, among many other factors. In most cases, however, an EIA can be used as a screening test, followed by one of the many confirmatory tests. Nucleic-acid amplification should be used when the detection of acute HIV infection is necessary. Nicola Zetola, MD, works in the Division of Infectious Diseases, Department of Medicine at the University of California The University of California has a combined student body of more than 191,000 students, over 1,340,000 living alumni, and a combined systemwide and campus endowment of just over $7.3 billion (8th largest in the United States). in San Francisco, and is supported, in part, by the Universitywide AIDS Research Program. Jeffrey D. Klausner, MD, MPH, is deputy health officer and director of STD (Subscriber Trunk Dialing) Long distance dialing outside of the U.S. that does not require operator intervention. STD prefix codes are required and billing is based on call units, which are a fixed amount of money in the currency of that country. Prevention and Control Services at the San Francisco Department of Public Health, and associate clinical professor of medicine in the Divisions of AIDS and Infectious Diseases, Department of Medicine at the University of California in San Francisco. References 1. Lange JM, et al. Diagnostic value of specific IgM antibodies in primary HIV infection. AIDS. 1988 February;2(1):31-35. 2. Gaines et al. Antibody response in primary human immunodeficiency virus human immunodeficiency virus n. HIV. Human immunodeficiency virus (HIV) A transmissible retrovirus that causes AIDS in humans. infection. Lancet. 1987 May 30;1 (8544):1249-1253. 3. Schacker T, et al. Clinical and epidemiologic features of primary HIV infection. Ann Intern Med. 1996 August 15;125(4):257-264. 4. Saville RD, et al. Fourth-generation enzyme-linked immunosorbent assay enzyme-linked immunosorbent assay n. ELISA. Enzyme-linked immunosorbent assay (ELISA) A diagnostic blood test used to screen patients for AIDS or other viruses. for the simultaneous detection of human immunodeficiency virus antigen and antibody. J Clin Microbiol. 2001 July;39(7):2518-2524. 5. O'Gorman MR, et al. Interpretive criteria of the Western blot assay for serodiagnosis serodiagnosis /se·ro·di·ag·no·sis/ (-di?ag-no´sis) diagnosis of disease based on serologic tests.serodiagnos´tic se·ro·di·ag·no·sis n. pl. of human immunodeficiency virus type 1 infection. Arch Pathol Lab Med. 1991 January;115(1):26-30. 6. Protocols for confirmation of reactive rapid HIV tests. MMWR MMWR Morbidity & Mortality Weekly Report Epidemiology A news bulletin published by the CDC, which provides epidemiologic data–eg, statistics on the incidence of AIDS, rabies, rubella, STDs and other communicable diseases, causes of mortality–eg, Recomm Rep. 2004; 53(10):221-222. 7. Delaney KP, et al. Performance of an oral fluid rapid HIV-1/2 test: experience from four CDC See Control Data, century date change and Back Orifice. CDC - Control Data Corporation studies. AIDS. 2006 Aug 1;20(12):1655-1660. 8. Berrios DC, et al. Screening for human immunodeficiency virus antibody in urine. Arch Pathol Lab Med. 1995 Feb;119(2):139-141. 9. Stramer SL, et al. Detection of HIV-1 and HCV HCV abbr. hepatitis C virus HCV 1 Hepatitis C virus, see there 2. Human coronavirus. See Coronavirus. infections among antibody-negative blood donors by nucleic acid-amplification testing. N Engl J Med. 2004 Aug 19;351(8):760-768. 10. Pilcher CD, et al. Detection of acute infections during HIV testing in North Carolina North Carolina, state in the SE United States. It is bordered by the Atlantic Ocean (E), South Carolina and Georgia (S), Tennessee (W), and Virginia (N). Facts and Figures Area, 52,586 sq mi (136,198 sq km). Pop. . N Engl J Med. 2005 May 5;352(18):1873-1883. By Nicola Zetola, MD, and Jeffrey D. Klausner, MD, MPH
Table 1: Select HIV tests and characteristics
Target Molecule /
Name Format Sample Comments
HIV antigen assay for serum and plasma
Abbott HIVAG-1 EIA Serum/Plasma
monoclonal
Coulter HIV-1 EIA Serum/Plasma HIV-1 p24 antigen
p24 Ag assay
HIV Antibody Detection in Serum or Plasma
a. First- and second-generation EIAs
HIVAB HIV-1/HIV-2 EIA Scrum/Plasma Recombinant HIV-1 env
(rDNA) and gag and HIV-2 env
proteins
Vironostika HIV-1 EIA Serum/Plasma Purified, inactivated
Microelisa System Blood spot HIV-1 virus propagated
in T-lymphocyte culture
b. Third-generation (Detect HIV-1 group M and group O) EIA
Vironostika HIV-1 EIA Serum/Plasma Purified, inactivated
Plus O Microelisa HIV-1 viral lysate
System proteins, envelope
proteins, and a HIV-1
group O (ANT 70)
transmembrane protein
Genetic Systems EIA Serum/Plasma Purified gp 160 and p24
HIV-1/HIV-2 PLUS Cadaveric recombinant proteins
O EIA Serum from HIV-1, HIV-2
transmembrane
glycoprotein gp36, and
a synthetic epitope of
HIV-1 group O
c. Fourth-generation EIA
VIDAS HIV DUO Enzime Serum/Plasma HIV-1 gp160, p24
Ultra linked antigen, and peptides
fluorescence representing regions of
/ p24 gp41 from HIV-1 group O
and gp36 from HIV-2
Murex HIV Ag/Ab EIA/p24 - HIV-1 antigens p31 and
combination gp41, HIV-2 p36
recombinant protein,
HIV-1 group O gp 41, and
anti-p24 monoclonal
antibodies
d. HIV Antibody Detection in serum or plasma: Western Blot
Genetic Systems WB Serum/Plasma Purifie and inactivated
HIV-1 Western HIV-1 strain LAV grown
Blot Kit in CEM cell line
Immunoblot WB Serum/Plasma Purified and inactivated
Cambridge Biotech HIV-1 propagated in an
HIV-1 Western H9/HTLV-IIIB T-
Blot lymphocyte cell line
e. Detection in oral specimen
OraSure HIV-1 Collection - Device that enhances the
Specimen Device flow of mucosal
Collection Device transudate into a cotton
pad that has antibodies
preservatives against
dehydration and
proteases
OraSure HIV-1 WB Oral fluid Uses whole-cell purified
Western Blot and inactivated viral
lysate propagated in a
T-lymphocyte cell line
Oral Fluid EIA Oral fluid Purified and inactivated
Vironostika HIV-1 HIV-1 antigen coated
Microelisa System onto microelisa wells
f. Detection in urine
Calypte HIV-1 EIA Urine Recombinant HIV envelope
Urine EIA proteins (gp160) to
detect the presence of
specific antibodies
Cambridge Biotech WB Urine Partially purified and
HIV-1 Urine inactivated HIV-1
Western Blot propagated in an H9/
HTLV-IIIB T-lymphocyte
cell line
Home blood-collection for laboratory assays
Home Access HIV-1 Collection Collection device for
test System Device direct dried blood spot
Rapid tests/Rapid immunoassay
Reveal HIV-1 Rapid Serum/Plasma Single-use test
immunoassay cartridge. Uses
synthetic HIV structural
proteins
Uni-Gold Rapid Serum/Plasma Uses recombinant
Recombigen HIV immunoassay proteins representing
Test regions of the HIV-1
envelope proteins
OraQuick Rapid Rapid Serum/Plasma Lateral flow procedure
HIV-1 Antibody immunoassay
Test
HIV Viral Load Assays
Amplicor HIV-1 PCR Plasma Reverse transcriptase-
Monitor Test polymerase chain
reaction
NucliSens HIV-1 NASBA RNA Plasma Nucleic acid sequence-
QT Test amplification based amplification
Quantiplex HIV-1 bDNA signal Plasma Signal amplification
RNA amplification branched-chain DNA
Name Manufacturer FDA-cleared
HIV antigen assay for serum and plasma
Abbott HIVAG-1 Abbott Laboratories Yes
monoclonal
Coulter HIV-1 Beckman Coulter Yes
p24 Ag assay
HIV Antibody Detection in Serum or Plasma
a. First- and second-generation EIAs
HIVAB HIV-l/HIV-2 Abbott Laboratories Yes
(rDNA)
Vironostika HIV-1 bioMerieux Inc. Yes
Microelisa System
b. Third-generation (Detect HIV-1 group M and group O) EIA
Vironostika HIV-1 bioMerieux Inc. Yes
Plus O Microelisa
System
Genetic Systems Bio-Rad Laboratories. Yes
HIV-l/HIV-2 PLUS
O EIA
c. Fourth-generation EIA
VIDAS HIV DUO bioMerieux No
Ultra
Murex HIV Ag/Ab Abbott Laboratories No
combination
d. HIV Antibody Detection in serum or plasma: Western Blot
Genetic Systems Bio-Rad Laboratories Yes
HIV-1 Western
Blot Kit
Immunoblot Calypte Biomedical Corp. Yes
Cambridg Biotech
HIV-1 Western
Blot
e. Detection in oral specimen
OraSure HIV-1 Epitope Inc. Yes
Specimen
Collection Device
OraSure HIV-1 OraSure Technologies Inc. Yes
Western Blot
Oral Fluid bioMerieux Inc. Yes
Vironostika HIV-1
Microelisa System
f. Detection in urine
Calypte HIV-1 Calypte Biomedical Corp. No
Urine EIA
Cambridge Biotech Calypte Biomedical Corp. Yes
HIV-1 Urine
Western Blot
Home blood-collection for laboratory assays
Home Access HIV-1 Home Access Health Corp. Yes
test System
Rapid tests/Rapid immunoassay
Reveal HIV-1 MedMira Laboratories Inc. Yes
Uni-Gold Trinity Biotech Yes
Recombigen HIV
Test
OraQuick Rapid OraSure Iechnologies Inc. Yes
HIV-1 Antibody
Test
HIV Viral Load Assays
Amplicor HIV-1 Roche Diagnostic System Yes
Monitor Test
NucliSens HIV-1 Organon Teknika. Yes
QT Test Emeryville, CA
Quantiplex HIV-1 Bayer Diagnostics, No
RNA Emeryville, CA
Table 2: Common indications for HIV testing
Clinical signs or symptoms suggesting HIV infection
- Fever of unknown origin
- Oral candidiasis
- Chronic and/or recurrent skin problems (prurigo nodularis,
psoriasis, etc.)
- Unexplained lymphoadenopathy with or without fatigue or weight loss
Diagnoses suggesting increased risk for HIV infection
- Diagnosis of sexually transmitted diseases
- Diagnosis of hepatitis B or C
- Recurrent pneumonia
- Tuberculosis
- Opportunistic infections
- Cervical or anal cancer
- Lymphoma, Kaposi's sarcoma
Self-reported risk behaviors
- Injection drug users
- Men who have sex with men
- Unprotected vaginal or anal sex with a partner that might be
infected with HIV
- Unprotected vaginal or anal sex with more than one partner
Pregnant women
Occupational exposure
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