HIV Genotypic Resistance Assay

HIV genotypic testing for resistance assesses the genotype of a patient’s HIV status and indicates which drugs the patient’s HIV is likely to be resistant to. This provides a helpful guide for the clinician to provide appropriate anti-retroviral therapy for the patient. Viral RNA is amplified into DNA, cleaned, and then sequenced using fluorescein-labelled dyes. Raw sequenced data is further analyzed to construct the genotype of the patient’s HIV1. The Pol gene encodes enzymes including the Protease, Reverse transcriptase and Integrase. This genotype is then compared to a wild-type HIV sequence, and the mutations noted. All mutations are listed in a report. The report also includes an interpretation of the mutation pattern in order to give a resistance profile of the patient’s HIV.

Specimens with RNA loads<40 copies/ml will be rejected prior to performing RNA extraction. Approximately 1000 copies/mL are required to yield a sequenceable PCR amplicon.

This test was developed and its performance characteristics determined by the University of Washington Department of Laboratory Medicine and Pathology. It has not been cleared or approved by the US Food and Drug Administration.

Blood: 6 mL blood in EDTA (LAVENDER TOP), SST, RED, or PEARL TOP (PPT).

Note: HIVGRA and HVINTA all test can be done on same 2 mL aliquot.

Unacceptable: GREEN TOP, Extracted nucleic acid from an outside laboratory.

Minimum sample requirement: 2 mL

Blood: Separate plasma/serum from whole blood within 24 hours of collection. Freeze at -10°C or colder and ship on dry ice. If freezer and/or dry ice is not available, ship immediately at 2-8°C (ice pack). Sample may be stored at 2-8°C (ice pack) for up to 48 hours of collection. Samples stored at 2-8°C greater than 48 hours old may be rejected. Do not freeze/thaw.

Outside Laboratories: Centrifuge sample and remove plasma/serum. Send Frozen plasma/serum at -10°C or colder and ship on dry ice.