Test ID: HIVQU
HIV-1 RNA Quantification, Plasma
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Quantifying plasma HIV-1 RNA levels (viral load) in HIV-1-infected patients:
-Before initiating anti-HIV-1 drug therapy (baseline viral load)
-Who may have developed HIV-1 drug resistance while on anti-HIV therapy
-Who may be noncompliant with anti-HIV-1 drug therapy
Monitoring HIV-1 disease progression while on or off anti-HIV-1 drug therapy
Evaluating infants <18 months of age born to HIV-infected mothers
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
The following algorithms are available in Special Instructions:
-HIV Testing Algorithm (excludes HIV rapid testing)
-HIV Treatment Monitoring Algorithm
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Reverse Transcription-Polymerase Chain Reaction (RT-PCR)
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
AIDS (Acquired Immune Deficiency Syndrome)
HIV (Human Immunodeficiency Virus)
HIV-1 (Human Immunodeficiency Virus-1) RNA, Viral Load
HIV-1 PCR
HIV-1 Quantitation, PCR
Human Immunodeficiency Virus (HIV)
Human Immunodeficiency Virus, PCR
PCR, HIV-1 Quantitation
Viral Load
Viral Load, HIV-1 RNA
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 2.5 mL
Collection Instructions:
1. Spin down and remove plasma from cells within 6 hours of draw.
2. Freeze plasma specimen immediately, and ship specimen frozen on dry ice.
3. If shipment will be delayed for >24 hours, freeze plasma specimen at -70 degrees C (up to 35 days) until shipment on dry ice.
Additional Information: This test can be used for detection and diagnosis of HIV-1 infections, including in children <18 months of age when serologic tests are not useful (due to presence of maternal HIV antibodies).
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross OK |
| Lipemia | Mild OK; Gross OK |
| Icterus | NA |
| Other | Green top (heparin) tube |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen (preferred) | |
| Refrigerated | 5 days | |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Currently, there are 2 types of HIV, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). HIV-1 has been isolated from patients with AIDS, AIDS-related complex, and asymptomatic infected individuals at high-risk for AIDS. Accounting for >99% of HIV infection in the world, HIV-1 is transmitted by sexual contact, by exposure to infected blood or blood products, from an infected pregnant woman to fetus in utero or during birth, or from an infected mother to infant via breast-feeding. HIV-2 has been isolated from infected patients in West Africa and it appears to be endemic only in that region. However, HIV-2 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 ability to cause AIDS.
Multiple clinical studies of plasma HIV-1 viral load (expressed as HIV-1 RNA copies/mL of plasma) have shown a clear relationship of HIV-1 RNA copy number to stage of HIV-1 disease and efficacy of anti-HIV-1 therapy. Quantitative HIV-1 RNA level in plasma (ie, HIV-1 viral load) is an important surrogate marker in assessing the risk of disease progression and monitoring response to anti-HIV-1 drug therapy in the routine medical care of HIV-1-infected patients.
HIV serologic tests may be unreliable for infants born to HIV-infected mothers. In infants up to 18 months of age, positive serologic test results can be due to the presence of maternal HIV antibodies. Therefore, the United States Working Group on Antiretroviral Therapy and Medical Management of HIV-Infected Children recommends use of proviral DNA or RNA tests for the detection of HIV infection in infants born to HIV-infected mothers.(3)
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.
Undetected
Interpretation Provides information to assist in interpretation of the test results
This assay has a plasma HIV-1 RNA quantification result range from 20 to 10,000,000 copies/mL (1.30-7.00 log copies/mL).
An "undetected" result indicates that the assay was unable to detect HIV-1 RNA within the plasma specimen.
A "detected" result with the comment, "HIV-1 RNA level is <20 copies/mL (<1.30 log copies/mL). This assay cannot accurately quantify HIV-1 RNA below this level." indicates that HIV-1 RNA is detected, but the level present is less than the lower quantification limit of this assay.
A "detected" result with the comment, "HIV-1 RNA level is >10,000,000 copies/mL (>7.00 log copies/mL). This assay cannot accurately quantify HIV-1 RNA above this level." indicates that HIV-1 RNA is detected, but the level present is above the upper quantification limit of this assay. Due to the increased sensitivity of this assay, patients with previously low or undetectable HIV-1 viral load may show increased or detectable viral load with this assay. However, the clinical implications of a viral load below 50 copies/mL remain unclear. Possible causes of such a result include very low plasma HIV-1 viral load present (eg, in the range of 1-19 copies/mL), very early HIV-1 infection (ie, less than 3 weeks from time of infection), or absence of HIV-1 infection (ie, false positive).
For the purpose of patient monitoring, the United States Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents defines virologic failure as a confirmed viral load of >200 copies/mL, which eliminates most cases of viremia resulting from isolated blips or assay variability. Confirmed viral load rebound (ie, >200 copies/mL) on 2 separate tests obtained at least 2 to 4 weeks apart should prompt a careful evaluation of patient's tolerance of current drug therapy, drug-drug interactions, and patient adherence.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not licensed by the FDA as a screening test for HIV-1 infections in a post-exposure setting. Although this quantitative HIV-1 RNA test is not FDA-approved for diagnostic purposes, the United States Working Group on Antiretroviral Therapy and Medical Management of HIV-Infected Children recommends the use of molecular-based assays to detect HIV-1 RNA or proviral DNA for the diagnosis of HIV infection in infants of <18 months of age and born to HIV-infected mothers.
A single HIV-1 viral load test result should not be used as the sole criterion in guiding therapeutic decisions and intervention in the clinical care of HIV-1-infected patients. Viral load results should be correlated with patient symptoms, clinical presentation, and CD4 cell count. Due to the inherent variability in the assay, physiologic variation and concurrent illnesses in the infected patients, <100-fold (<2 log) changes in plasma HIV-1 viral load should not be considered to be significant changes.
Viral load results of <20 copies/mL do not necessarily indicate absence of HIV-1 viral replication. Inhibitory substances may be present in the plasma specimen, leading to negative or falsely low HIV-1 RNA results. Improper specimen collection or storage may lead to negative or falsely lower plasma viral load results.
Although this commercial HIV-1 viral load assay is optimized for quantification of plasma viral load in HIV-1 infection due to HIV-1 groups M (subtypes A to H) and O strains, results generated from HIV-1 group O strains may be discordant (> or =0.5 log copies/mL) with those obtained from other commercially available HIV-1 viral load assays. The assay is not reliable for quantifying plasma viral loads in infection caused by HIV-1 group N and HIV-2 strains.
ACD-plasma specimens are not optimal for HIV-1 viral load testing because such plasma specimens show quantitative HIV-1 RNA levels that are approximately 15% lower than those collected in tubes containing EDTA.
Supportive Data
This assay was confirmed to have a lower limit of quantification of 20 copies/mL based on probit analysis (95% hit rate), with good correlation with expected viral load results and good linearity over the quantification range of the assay. Accuracy of results among HIV-1 groups M and O strains was confirmed.
The mean difference in HIV-1 viral load results between version 1.0 and version 2.0 of this commercial assay was -0.05 log copies/mL, with 96.6% (56 of 58 specimens with quantifiable results by both assays) of the differences falling within 0.51 log copies/mL of the mean difference and individual differences ranging from 0.57 to -0.69 log copies/mL. No bias was observed over the range of HIV-1 RNA levels tested.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Relucio K, Holodniy M: HIV-1 RNA and viral load. Clin Lab Med 2002;22:593-610
2. Thompson MA, Aberg JA, Cahn P, et al. Antiretroviral treatment of adult HIV infection: 2010 recommendations of the International AIDS Society-USA panel. JAMA 2010;304:321-333
3. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. January 10, 2011;1–166. Available at: http://www.aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf
Method Description Describes how the test is performed and provides a method-specific reference
COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, version 2.0, is an in vitro nucleic acid amplification test for the quantification of HIV-1 RNA in human plasma, using the COBAS AmpliPrep instrument for automated viral nucleic acid extraction (generic silica-based capture technique) and the COBAS TaqMan analyzer for automated amplification and detection of the viral nucleic acid target. To accommodate the polymorphism within the HIV-1 genomic target sequence, this assay employs multiple PCR primers for 2 target sequences (HIV-1 gag and LTR regions). The HIV-1 Quantitation Standards is used to detect and compensate for possible PCR inhibition and as a control for target amplification and detection processes. Dual-labeled fluorescent oligonucleotide probes are utilized to detect amplified material. Quantification of target sequences is monitored using the emission intensity of fluorescent reporter dyes released during the amplification process.(Package insert: COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, version 2.0, Roche Molecular Systems Inc., Branchburg, NJ, 6/2010)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; 7 a.m.-4 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
87536
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 81958 | HIV-1 RNA Quantification, P | 20447-9 |
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