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Test Catalog

Test ID: HV1CM    
HIV-1 and HIV-2 Antibody Screen for Hemolyzed Specimens, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Screening cadaveric or hemolyzed serum specimens for HIV-1 and/or HIV-2 infection in non- symptomatic patients with or without risk factors for HIV infection

 

This test is not offered as a screening or confirmatory test for blood donor specimens.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This test begins with HIV-1/-2 antibody enzyme immunoassay (EIA). If HIV-1/-2 antibody EIA is reactive, then HIV antibody confirmation/differentiation by immunochromatographic method is performed at an additional charge.

 

See HIV Testing Algorithm (Fourth-Generation Screening Assay), Including Follow-up of Reactive Rapid Serologic Test Results in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Epidemiological data indicate that AIDS is caused by at least 2 types of HIV. The first virus, HIV-1, has been isolated from patients with AIDS, AIDS-related complex, and asymptomatic infected individuals at high risk for AIDS. HIV-1 is transmitted by sexual contact, exposure to infected blood or blood products, or from an infected mother to her fetus or infant. A second HIV virus, HIV-2, was isolated from patients in West Africa in 1986. HIV-2 appears to be endemic only in West Africa, but it also has been identified in individuals who have lived in West Africa or had sexual relations with individuals from that geographic region. HIV-2 is similar to HIV-1 in its morphology, overall genomic structure, and its ability to cause AIDS.

 

Antibodies against HIV-1 and HIV-2 are usually not detected until 6 to 12 weeks following exposure and are almost always detected by 12 months. They may fall into undetectable levels in the terminal stage of AIDS.

 

See HIV Testing Algorithm (Fourth-Generation Screening Assay), Including Follow-up of Reactive Rapid Serologic Test Results in Special Instructions.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Interpretation Provides information to assist in interpretation of the test results

A reactive HIV-1/-2 antibody screen result obtained by enzyme immunoassay (EIA) suggests the presence of HIV-1 and/or HIV-2 infection. However, it does not differentiate between HIV-1 and HIV-2 antibody reactivity. Diagnosis of HIV infection must be based on results of supplemental tests, such as HIV antibody confirmation/differentiation test (automatically reflexed on all samples with reactive screen test results at an additional charge).

 

All presumptive antibody-positive test results should be verified by submitting a second serum specimen for retesting.

 

A negative HIV-1/-2 antibody EIA screen result usually indicates the absence of HIV-1 or HIV-2 infection. However, for specimens that are reactive by the rapid HIV antibody tests, confirmatory testing is recommended even if the EIA results are negative.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The predictive value of a reactive (or positive) test is highly dependent on the prevalence of HIV infection in the population tested; the lower the prevalence of HIV infection, the lower the positive predictive value of the test.

 

A person who has participated in an HIV vaccine study may develop antibodies to the vaccine and may or may not be infected with HIV. Clinical correlation is indicated with appropriate counseling, medical evaluation, and possibly additional testing to decide whether a diagnosis of HIV infection is accurate.

 

Negative results should be evaluated cautiously if the patient has clinical symptoms and/or a history of high-risk behavior for HIV infection. The Centers for Disease Control and Prevention recommends confirmatory testing on serum specimens that are reactive by the rapid HIV antibody tests, even if the initial EIA results are negative.

 

Screening and confirmatory tests for HIV-1/-2 antibodies cannot distinguish between active neonatal HIV infection and passive transfer of maternal HIV antibodies in infants during the postnatal period (up to 2 years of age). Reactive and confirmed positive antibody test results in infants during this period may indicate passive transfer of maternal HIV antibodies. Diagnosis of HIV infection in newborns and infants up to 2 years should be made by virologic tests, such as detection of HIV-1 DNA or RNA (HIVP / HIV-1 DNA and RNA Qualitative Detection by PCR, Plasma) or HIV-1 RNA (HIVQN / HIV-1 RNA Detection and Quantification, Plasma).

 

A reactive screen and confirmed HIV antibody test result should be reported by the health care provider to the State Department of Health in accordance with the legislation in some states.

 

Assay performance characteristics have not been established for the following specimen characteristics:

-Lipemic

-Icteric

-Containing particulate matter

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Constantine N: HIV antibody assays In: HIV InSite Knowledge Base (online textbook). Regents of the University of California; May 2006. Available at http://hivinsite.ucsf.edu/InSite?page=kb-00&doc=kb-02-02-01

2. Centers for Disease Control and Prevention (CDC), Association of Public Health Laboratories: Laboratory testing for the diagnosis of HIV infection. CDC; Updated June 27, 2014. Available at: stacks.cdc.gov/view/cdc/23447

3. Centers for Disease Control and Prevention (CDC), Association of Public Health Laboratories: 2018 Quick reference guide: Recommended laboratory HIV testing algorithm for serum or plasma specimens. CDC; January 2018. Available at https://stacks.cdc.gov/view/cdc/50872

4. Hariri S, McKenna MT: Epidemiology of human immunodeficiency virus in the United States. Clin Microbiol Rev. 2007;20:478-4884

5. Owen SM, Yang C, Spira T, et al: Alternative algorithms for human immunodeficiency virus infection diagnosis using tests that are licensed in the United States. J Clin Microbiol. 2008;46:1588-1595

Special Instructions Library of PDFs including pertinent information and forms related to the test