EBM Consult

Lab Test: HIV RNA Viral Load (Serum) Level

    Lab Test
    • HIV RNA Viral Load (Serum)
    • Used to determine the amount of human immunodeficiency virus (HIV) viral load in the blood of an infected patient.
    Reference Range
    • Normal findings:  undetected
    Indications & Uses
    • Accurate marker for prognosis, disease progression, response to antiviral treatment, and indication for antiretroviral prophylactic treatment. 
    • Differentiating newborn HIV infection from passive transmission of HIV antibodies from a HIV infective mother
    • To determine patient survival - in patients with a HIV RNA viral load >30,000 copies/mL, 69.5% will die from AIDS; between 10.,001-30,000 copies/mL, 34.9% will die; between 3001-10,000 copies/mL, 18.1%; between 501-3,000 copies/mL, 6.3% and <500 copies/mL, 0.9%.
    Clinical Application
    • Quantitation of HIV RNA in the blood of patients infected with HIV can be used as a confirmatory or supplementary test after serologic tests are positive.  Quantification is also helpful when confirmatory tests are indeterminate or cannot be accurately interpreted.
      • HIV viral load is determined by quantifying the amount of genetic material of the virus in the blood. 
      • There are several different laboratory methods of measuring HIV viral load and it is important that the same method be used in monitoring the course of the disease.  It is important to know which method is used when considering whether to initiate treatment.
    • In general, it is recommended to determine the baseline viral load by obtaining two measurements 2 to 4 weeks apart after HIV infection.  The viral load test can be repeated every 4 to 6 weeks after starting or changing antiviral therapy.  Usually antiviral treatment is continued until the HIV viral load is < 50 copies/mL. 
    • Increased levels HIV infection.  Generally, the level of HIV viral load parallels the course of HIV disease.  Reduction in viral loads can be expected with successful therapy.
    Related Tests
    • HIV serology - this test is used to diagnose HIV infection
    • Lymphocyte immunophenotyping - this test is used to measure CD4 lymphocyte counts.  This is another marker for disease prognosis, response to treatment, and also an indicator for starting prophylactic antiretroviral treatment. 
    • HIV drug resistance testing - HIV drug sensitivity testing estimates the ability of a cloned copy of the patient's virus to replicate in a cell culture in the presence of a particular antiviral drug.  It can help determine the amount of the drug needed to inhibit viral replication.
    Drug-Lab Interactions
    • Incorrect handling and processing of the specimen can cause inconsistent results.
    • Recent flu shots may temporarily increase viral levels.
    • Concurrent infections can cause inconsistent results.
    • Variable compliance to therapy may alter test results.
    Test Tube Needed
    • Lavender top (EDTA) tube
    • Maintain a nonjudgmental attitude toward the patient's sexual practices.  Allow the patient ample time to express his or her concerns regarding the results. 
    • Observe universal body and blood precautions.  Wear gloves when handling blood products from all patients.
    • Collect a blood sample.  If the test is sent out, the plasma is separated out and at least 2.5 mL is frozen and sent.
    • Never recap needles.  Dispose of needles and syringes required for obtaining the blood specimen in a puncture-proof container designed for this purpose. 
    • Apply pressure to the venipuncture site. 
    • Do not give the results over the telephone.  Increasing viral load may have devastating consequences.
    Storage and Handling
    • Immediately transport the specimen to the laboratory.
    • Specimens are often sent to a central laboratory.
    What To Tell Patient Before & After
    • Explain the procedure to the patient.
    • Tell the patient that no fasting or preparation is required. 
    • Instruct the patient to observe the venipuncture site for infection.  Patients with AIDs are immunocompromised and susceptible to infection.
    • Encourage the patient to discuss his or her concerns regarding the prognostic information that may be obtained by these results.

MESH Terms & Keywords

  • HIV, RNA, Viral, Load