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Test Code HVDSP HIV-1 and HIV-2 Antibody Confirmation and Differentiation, Prenatal, Plasma


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 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: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 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.


Secondary ID

601759

Useful For

Confirmation and differentiation of HIV-1 and HIV-2 antibodies in plasma 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.

Disease States

  • HIV-2 infection
  • HIV infection

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-2 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

 

If the following result types are obtained, HIV-1 RNA detection and quantification will be performed at an additional charge:

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

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

 

The following algorithms are available:

-HIV Prenatal Testing Algorithm, Including Follow-up of Reactive Rapid Serologic Test Results

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

Method Name

Rapid Immunochromatographic Assay

Reporting Name

HIV Ab Differentiation Prenatal, P

Specimen Type

Plasma

Specimen Minimum Volume

0.8 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma 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, in patients with reactive initial combined HIV-1/-2 antigen and antibody test results, such negative results do not rule-out acute or early HIV infection. HPP12 / HIV-1/HIV-2 RNA Detection, Prenatal, Plasma 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. HIQNP / HIV-1 RNA Detection and Quantification, Prenatal, Plasma will be performed automatically per testing algorithm.

 

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. HIQNP will be performed automatically per testing algorithm.

 

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' specimens and HIV-1 antigens on the assay strip. HPP12 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 the presence of nonspecific cross-reactivity between the patients' specimens and HIV-2 antigens on the assay strip. HPP12 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 either an HIV-1 infection with HIV-2 antibody cross-reactivity or an 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. HPP12 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). HPP12 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. Additional testing with a newly submitted whole blood specimen for FHV2Q / HIV-2 DNA/RNA Qualitative Real-Time PCR is recommended to verify and confirm the diagnosis of HIV-2 infection prior to initiating antiretroviral treatment.

 

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 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 whole blood specimen for FHV2Q.

 

The following algorithms are available:

-HIV Prenatal Testing Algorithm, Including Follow-up of Reactive Rapid Serologic Test Results

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

Method Description

The Geenius HIV 1/2 Supplemental Assay cassette contains antibody-binding protein A, which is conjugated to colloidal gold dye particles, and HIV-1 and HIV-2 antigens, which are bound to the membrane solid phase. The sample is applied to the sample and buffer well. After the sample and buffer have migrated onto the test strip, additional buffer is added to the buffer well. The buffer causes the specimens and reagents to flow laterally and facilitates the binding of antibodies to the antigens. In a reactive sample, the antibodies are captured by the antigens immobilized in the test area.

 

The protein A-colloidal gold binds to the captured antibodies, causing development of pink or purple lines. When there are no HIV antibodies, there are no pink or purple lines in the test area. The sample continues to migrate through the membrane and a pink or purple line develops in the control area, which contains protein A. This built-in procedural control provides evidence that the test was performed properly and that the sample and reagents have migrated through the cassette.(Package insert: Geenius HIV 1/2 Supplemental Assay. Bio-Rad Laboratories; 07/2019)

Day(s) Performed

Monday through Friday

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)

87536 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HVDSP HIV Ab Differentiation Prenatal, P 89365-1

 

Result ID Test Result Name Result LOINC Value
91952 HIV-1 Ab Differentiation Prenatal, P 68961-2
91953 HIV-2 Ab Differentiation Prenatal, P 81641-3

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
HPP12 HIV-1/HIV-2 RNA Detect Prenatal, P Yes No
HIQNP HIV-1 RNA Detect/Quant Prenatal, P Yes No