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Test Code HVPPS HIV-1 and HIV-2 Antibody Confirmation and Differentiation Prenatal, Serum


Ordering Guidance


This test is not suitable for follow-up testing of patients with reactive results from any rapid HIV tests, except for pregnant patients who were reactive by the Determine HIV-1/-2 Ag/Ab Combo rapid point-of-care test on serum or plasma (but not whole blood). Per the latest CDC recommended HIV testing algorithm patients with reactive results from any rapid HIV tests should be tested subsequently with laboratory-based HIV antigen and antibody combination immunoassays, such as HVPRS / HIV Antigen and Antibody Prenatal Routine Screen, Serum or HIVSP / HIV Antigen and Antibody Prenatal Routine Screen, Plasma.

 

If specimens are autopsy or cadaver blood sources, the proper US Food and Drug Administration-licensed assay is HV1CD / HIV-1 and HIV-2 Antibodies for Cadaveric or Hemolyzed Specimens, Serum.

 

New York State clients: This test should not be requested for maternal/newborn HIV screening on specimens originating in New York State, due to state regulatory requirements for expedited result reporting.



Necessary Information


Date of collection is required.



Specimen Required


Supplies: Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions:

1. Centrifuge blood collection tube per collection tube manufacturer's instructions (eg, centrifuge and aliquot within 2 hours of collection for BD Vacutainer tubes).

2. Aliquot plasma into plastic vial.


Forms

If not ordering electronically, complete, print, and send an Infectious Disease Serology Test Request (T916) with the specimen.

Useful For

Confirmation and differentiation of HIV-1 and HIV-2 antibodies in serum specimens from prenatal patients who show reactive results with 3rd- (HIV-1/-2 antibody only) and 4th-generation (HIV antigen and antibody) HIV serologic assays

 

This test is not useful as a screening test for HIV infection in symptomatic or asymptomatic individuals.

 

This test should not be used as a screening or confirmatory test for blood donor specimens.

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
HPS12 HIV-1/HIV-2 RNA Detect Prenatal, S Yes No

Testing Algorithm

This test is for confirmation and differentiation of HIV-1/2 antibodies (Ab). If the following result types are obtained, HIV-1/HIV-1 RNA detection will be performed at an additional charge:

-Negative for both HIV-1 Ab and HIV-2 Ab

-Indeterminate for HIV-1 Ab but negative for HIV-2 Ab

-Negative for HIV-1 Ab but indeterminate for HIV-2 Ab

-Indeterminate for both HIV-1 Ab and HIV-2 Ab

-Positive for both HIV-1 Ab and HIV-2 Ab

 

For more information see HIV Prenatal Testing Algorithm, Including Follow-up of Reactive Rapid Serologic Test Results

Method Name

Rapid Immunochromatographic Assay

Reporting Name

HIV Ab Differentiation Prenatal, S

Specimen Type

Serum

Specimen Minimum Volume

0.8 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 30 days
  Refrigerated  6 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Clinical Information

AIDS is caused by 2 known types of HIV. HIV type 1 (HIV-1) is found in patients with AIDS or AIDS-related complex and in asymptomatic infected individuals at high risk for AIDS. The virus is transmitted by sexual contact, by exposure to infected blood or blood products, or from an infected mother to her fetus or infant. HIV type 2 (HIV-2) infection is endemic only in West Africa, and it has been identified in individuals who had sexual relations with individuals from that geographic region. HIV-2 is similar to HIV-1 in viral morphology, overall genomic structure, and its ability to cause AIDS.

 

Antibodies against HIV-1 and HIV-2 are usually not detectable until 6 to 12 weeks following exposure and are almost always detectable by 12 months. They may fall to undetectable levels (ie, seroreversion) in the terminal stage of AIDS when the patient's immune system is severely depressed.

 

Routine serologic screening of patients at risk for HIV-1 or HIV-2 infection usually begins with an HIV-1/-2 antigen and/or antibody screening test, which may be performed by various US Food and Drug Administration-approved assay methods, including rapid HIV antibody tests, enzyme immunoassays, and chemiluminescent immunoassays. In testing algorithms that begin with these methods, supplemental or confirmatory testing should be requested only for specimens that are repeatedly reactive by these methods according to assay manufacturers' instructions for use.

Reference Values

Negative

Interpretation

Negative results for both HIV-1 and HIV-2 antibodies usually indicate the absence of HIV-1 and HIV-2 infection. However, negative results do not rule-out acute or early HIV infection in patients with reactive initial combined HIV-1/-2 antigen and antibody test results. HPS12 / HIV-1/HIV-2 RNA Detection Prenatal, Serum reflex test will be performed automatically per testing algorithm.

 

Positive HIV-1 antibody but negative HIV-2 antibody results indicate the presence of HIV-1 infection. Together with reactive initial combined HIV-1/-2 antigen and antibody test results, individuals with such results are presumed to have HIV-1 infection. Verification of a first-time positive test result is recommended for the diagnosis of HIV-1 infection. Additional testing with a newly submitted plasma specimen for HIQNP / HIV-1 RNA Detection and Quantification, Prenatal, Plasma is recommended to determine the baseline HIV-1 viral load prior to initiating antiretroviral treatment.

 

Positive HIV-1 antibody but indeterminate HIV-2 antibody results indicate the presence of HIV-1 infection, with probable cross-reactivity of HIV-1 antibodies with HIV-2 antigens on the assay strip. Verification of a first-time positive test result is recommended for the diagnosis of HIV-1 infection by submitting a new plasma specimen for HIV-1 RNA quantification (HIQNP).

 

Indeterminate HIV-1 antibody but negative HIV-2 antibody results suggest either very early HIV-1 infection (in individuals with risk factors) or the presence of nonspecific cross-reactivity between the patients' serum specimens and HIV-1 antigens on the assay strip. HPS12 will be performed automatically per testing algorithm.

 

Negative HIV-1 antibody, but indeterminate HIV-2 antibody results, may be due to acute HIV-1 infection, very early HIV-2 infection (in individuals with risk factors), or presence of nonspecific cross-reactivity between the patients' serum specimens and HIV-2 antigens on the assay strip. HPS12 will be performed automatically per testing algorithm.

 

Positive results for both HIV-1 and HIV-2 antibodies suggest probable presence of HIV-1 and HIV-2 coinfection. However, such results may be rarely due to HIV-1 infection with HIV-2 antibody cross-reactivity, or HIV-2 infection with HIV-1 antibody cross-reactivity (eg, absence of HIV-1 p24 and p31 bands). Verification of a first-time positive test result is recommended for the diagnosis of HIV infection. HPS12 will be performed automatically per testing algorithm.

 

Indeterminate results for both HIV-1 and HIV-2 antibodies indicate either very early HIV infection (in individuals with risk factors) or the presence of nonspecific cross-reactivity between the patients' specimens and HIV antigens on the assay strip. Nonspecific cross-reactivity may be due to recent non-HIV infections, hypergammaglobulinemic states, connective tissue disorders, or pregnancy (alloantibodies). HPS12 will be performed automatically per testing algorithm.

 

Negative HIV-1 antibody but positive HIV-2 antibody results indicate the presence of HIV-2 infection. Together with a reactive initial HIV-1/-2 antigen and antibody screening test results, individuals with such results are presumed to have HIV-2 infection. Verification of a first-time positive test result is recommended for the diagnosis of HIV-2 infection, by submitting a new whole blood specimen for FHV2Q / HIV-2 DNA/RNA Qualitative Real-Time PCR.

 

Reactive HIV-1 antibody but positive HIV-2 antibody results usually indicate the presence of HIV-2 infection with HIV-1 antibody cross-reactivity (eg, presence of only HIV-1 gp41 and/or gp160 band). However, such results may be rarely due to HIV-1 and HIV-2 coinfection. Verification of a first-time positive test result is recommended for the diagnosis of HIV-2 infection, by submitting a new whole blood specimen for FHV2Q

 

Indeterminate HIV-1 antibody but positive HIV-2 antibody results indicate the presence of HIV-2 infection, with probable cross-reactivity of HIV-2 antibodies with HIV-1 antigens on the assay strip. Verification of a first-time positive test result is recommended for the diagnosis of HIV-2 infection, by submitting a new whole blood specimen for FHV2Q.

 

For more information see HIV Prenatal Testing Algorithm, Including Follow-up of Reactive Rapid Serologic Test Results

Cautions

A negative result for both HIV-1 and HIV-2 antibodies does not rule-out acute HIV infection.

 

All initially positive supplemental or confirmatory HIV test results should be verified by submitting a second specimen for repeat testing. Such positive HIV test results are required under laws in many states in the United States to be reported to the departments of health of the respective states where the patients reside.

 

Participation in the recipients of HIV-1 vaccine (eg, participants in HIV-1 vaccine study trials) may develop vaccine-specific antibodies that may cross-react with this test and yield to the vaccine giving a positive, indeterminate, or unreadable HIV-1 antibody result, while they may or may not be infected with HIV-1.

 

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

-Heat-inactivated specimens

-Cadaveric specimens

-Presence of particulate matter

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

86701

86702

87535 (if appropriate)

87538 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HVPPS HIV Ab Differentiation Prenatal, S 89365-1

 

Result ID Test Result Name Result LOINC Value
618221 HIV-1 Ab Differentiation Prenatal, S 68961-2
618222 HIV-2 Ab Differentiation Prenatal, S 81641-3