Eurofins Biomnis code

HIVQ

Synonyms

• VIREMIE HIV
• HIV-RNA viral load
• HIV - viral load

Clinic significance

HIV is a lentivirus (Retroviridae) which cause AIDS. Infection results in major immunodeficiency due to the progressive killing of CD4+ T-lymphocytes. Immunodeficiency predisposes HIV-infected subjects to opportunistic infections and certain tumors. Two antigenically distinct serotypes are recognized, HIV1 and HIV2. The former is more common with most strains belonging to the M group which includes at least 10 different sub-types or recombinant forms (from A through J). HIV2 and sub-type A of HIV1 are mainly found in Africa. A few strains (Group O) are distinct from both HIV1 and HIV2 and can be difficult to diagnose using the conventional immunological and nucleic acid-based tests. Quantitative determination of the viral load in the blood gives a measure of the rate of viral replication and thus the activity of the infection. This test is often performed at the same time as a CD4+ lymphocyte count. It can only be performed for HIV1. It completely relies on the methods of molecular biology. The normal sensitivity threshold of the PCR assay is 200 copies of HIV1 RNA per milliliter but this threshold can be brought down to just 20 copies per milliliter if necessary (if no viral RNA is detected at the normal sensitivity). Viral load is considered high if the number of copies is over 100,000. Alternatively, the b-DNA technique can be used (threshold = 500 copies or, if necessary, 50 copies).A significant reduction in viral load after the instigation of a new drug or treatment regimen is indicative of its efficacy. On the other hand, if the viral load is clearly shown to have increased (in two successive tests), it may be a sign that the virus has developed resistance (which can be defined by sequencing) and that perhaps the drugs should be changed.

Prenalytics

• 2.5 mL
• EDTA Plasma (do not use tube with separator)
• FROZEN

Further information

• 1 individual aliquot for this analysis.
• Use standard EDTA tubes with centrifugation then transfer the plasma into a new tube

Methodology

Real Time TMA

Turnaround time

4 days