Human Immunodeficiency Virus Viral Load

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Human Immunodeficiency Virus Viral Load
Also known as : [HIV Viral Load]

Blood
Test performed by: LabPLUS VIM Molecular Diagnostics

Relevant clinical details MUST be written on the request form otherwise the test will be declined .

Specimens from the following clinical areas/situations will be accepted:

Infectious Diseases
Sexual Health
Confirmation of HIV infection in a patient with a reactive HIV screening test (HIV Ab/Ag+)
Viral load monitoring in a patient with known HIV
Child at risk of vertical HIV transmission from mother with known HIV
Clinical suspicion of acute HIV prior to seroconversion
Bone marrow transplant (BMT) donor screening
Other clinical details which justify HIV Viral Load testing

A dedicated specimen (i.e. no other tests to be performed) is required for this assay.

Do not use heparin tubes

Do not use serum.

Viral load results may be adversely affected by delay in transport.

Specimen Collection
5 mL PPT Plasma (Preferred)
The absolute minimum volume required for the test is 2.5 mL
Do not freeze unseparated PPT tubes . If the specimen requires freezing, the supernatant must be removed from the gel first.
Require dedicated PPT specimen (no other tests requested).
Transport at 2 - 8 degrees C if transport time from collection is less than 5 days.

Specimens need to be separated and frozen after 5 days. Unseparated specimens are unsuitable for analysis after this time.

4 mL EDTA Whole Blood
Require dedicated EDTA specimens (no other tests requested).

Centrifuge and separate EDTA plasma samples within 24 hours of collection into a sterile tube.
Transport at 2 - 8 degrees C if transport time from collection is less than 24 hours. Transport frozen if more than 24 hours.
Whole blood, the absolute minimum volume required is 2.5 mL

Paediatric Micro-EDTA Whole Blood
5 full microcollect EDTA tubes required.
Must be full containers or there will be insufficient sample to assay

Turnaround Time: Within 4 days
Assay Method

The COBAS HIV-1 test is a RT/PCR based assay that effectively detects all HIV-1 group M subtypes and HIV-1 group O and group N infected patients.

Either 650uL or 350uL of specimen can be used for testing. Limit of detection for this assay is 20 - 1.0E+07 (log 1.3-7.0) HIV DNA copies/mL (3 3 - 1.67E+07 IU/mL) when 650uL, and 50 -1.00 +E07 (log 1.7-7.0) HIV RNA IU/mL (8 3 to 1.67E+07 IU/mL) when 350uL of specimen are used .

The conversion factor for COBAS HIV-1 is 0.6 copies/IU as defined by the kit.

Diagnostic Use and Interpretation

HIV Drug Resistance Genotyping
HIV Proviral DNA

Contact Information
For further information contact the laboratory (contact via Lablink: 22000 or (09) 307-8995 or 0800 522 7587) ,or:
the Virology team virology@adhb.govt.nz

Specimen Transport Instructions for Referring Laboratories

        Whole blood in PPT can remain unspun in PPT tubes for no longer than 6hrs at ambient temperature
        Within 6 hrs of collection, the tube must be spun at 1100 x g for 20min
       On the arrival of PPT tube in virus laboratory, re-centrifuge the PPT tube at 600 x g for 5 minutes prior to aliquoting plasma to the storage tube for further storage in -70 ^o C.
        If testing is performed within 5 days, the sample should be stored at 4 ^o C.
        If the volume of plasma is less than required amount, transfer collected plasma to a conical microfuge tube prior to 600 x g centrifugation for 5 minutes. Recover remaining plasma without disturbing the pellet.

Last updated at 15:55:05 16/09/2021