Sign in →

Test Code PSHIV HIV-1 RNA Patient Source, Plasma


Shipping Instructions


Ship specimen frozen on dry ice. If shipment will be delayed for more than 24 hours, freeze plasma specimen at -20 to -80° C until shipment on dry ice.



Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions:

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

2. Freeze aliquoted plasma for shipment.


Secondary ID

65819

Useful For

Detection and diagnosis of HIV-1 infection in an acutely or early infected individual (including infants of <2 years of age) who is the source of blood or body fluid in an occupational exposure event

Method Name

Real-Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR)

Reporting Name

HIV-1 RNA Pt Source, P

Specimen Type

Plasma EDTA

Specimen Minimum Volume

0.8 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma EDTA Frozen (preferred) 84 days
  Refrigerated  6 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Clinical Information

Currently, 2 types of HIV, HIV type 1 (HIV-1) and HIV type 2 (HIV-2), are known to infect humans. HIV-1 has been isolated from patients with AIDS or AIDS-related complex, and from asymptomatic infected individuals at high-risk for AIDS. Accounting for more than 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 individuals living with HIV-1.

 

HIV serologic tests may be unreliable for infants born to HIV-infected mothers. In infants up to 2 years of age, positive serologic test results can be due to the presence of maternal HIV antibodies. Therefore, the US Department of Health and Human Services Panel on Antiretroviral Therapy and Medical Management of HIV-Infected Children recommends the use of HIV RNA or proviral DNA tests for the detection of HIV infection in infants born to HIV-infected mothers.

Reference Values

Undetected

Interpretation

This assay has a plasma HIV-1 RNA quantification result range of 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 in the plasma specimen tested.

 

A result of "less than 20 copies/mL" indicates that HIV-1 RNA is detected, but the level present is less than the lower 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 20 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, <3 weeks from time of infection), or absence of HIV-1 infection (ie, false-positive).

 

A result of "greater than 10,000,000 copies/mL" with the result comment of "HIV-1 RNA level is greater than 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.

 

For the purpose of monitoring patient's response to antiretroviral therapy, the US Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents defines virologic failure as a confirmed viral load above 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.

Method Description

The cobas HIV-1 assay is a US Food and Drug Administration-approved, in vitro nucleic acid amplification test for the quantification of HIV-1 RNA in human plasma using the cobas 6800 System or cobas 8800 System for fully automated viral nucleic acid extraction (generic silica-based capture technique) and automated amplification and detection of the viral nucleic acid sequence. This polymerase chain reaction (PCR) assay amplifies sequences within the gag gene and long terminal repeat (LTR) region of the HIV-1 genome and generates amplification products that are detected and quantified in real-time with 2 sequence-specific TaqMan probes. A non-HIV armored RNA quantitation standard (RNA-QS) is introduced into each specimen during sample preparation to serve as internal control for nucleic acid extraction and PCR amplification and detection processes. Fluorescent reporter dye-labeled TaqMan probes hybridized to the complementary HIV-1 target sequences and RNA-QS sequence undergo hydrolysis during PCR amplification step to generate fluorescent signal detected in 2 different dye channels. Concentration of the HIV-1 RNA in a patient's plasma sample is determined by a ratio of the intensity of the fluorescent dye from the cleaved HIV-1 target sequence probes and that from the RNA-QS target probe detected throughout the PCR process.(Package insert: cobas HIV-1-Quantitative nucleic acid test for use on the cobas 6800/8800 Systems; Roche Molecular Systems, Inc; Doc rev. 2.0, 12/2020)

Day(s) Performed

Monday through Saturday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

87536

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PSHIV HIV-1 RNA Pt Source, P 70241-5

 

Result ID Test Result Name Result LOINC Value
65819 HIV-1 RNA Pt Source, P 70241-5