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HIV Genotyping

Item Value
Approval req'd? No
Available Stat? No
Test code MOLT (Order in Apex as 'Miscellaneous Outside Lab Test' using the complete test name above)
Test group HIV
Performed by Monogram Bioscience
Sendout? Yes
Method PCR/ABI
Collection Instructions Note: If both genotyping and phenotyping are requested for B&T patients, TWO separate tubes should be drawn.
Container type Lavender top
Amount to Collect 6 mL blood
Sample type EDTA Plasma
Preferred volume 3 mL plasma
Min. Volume 3 mL plasma
Processing notes Centrifuge sample @ 100-1200g x 10-15 min. and separate plasma within 6 hours of sample collection. Transfer plasma to capped plastic tube and freeze at -20C. Do not thaw sample after freezing. Ship frozen with dry ice.

Note: If both genotyping and phenotyping are requested for B&T patients, aliquot the two tubes separately and freeze at -20C.
Normal range
Synonyms PCR
Additional information Note: Patients must have a viral load of at least 500 copies/mL for genotyping to be performed.

Testing recommnedations:

Drug-Resistance Testing (Last updated February 12, 2013; last reviewed February 12, 2013: http://aidsinfo.nih.gov/guidelines)

Panel's Recommendations:
· HIV drug-resistance testing is recommended in persons with HIV infection at entry into care regardless of whether antiretroviral therapy (ART) will be initiated immediately or deferred (AII). If therapy is deferred, repeat testing should be considered at the time of ART initiation (CIII).
· Genotypic testing is recommended as the preferred resistance testing to guide therapy in antiretroviral (ARV)-na•ve patients (AIII).
· Standard genotypic drug-resistance testing in ARV-naive persons involves testing for mutations in the reverse transcriptase (RT) and protease (PR) genes. If transmitted integrase strand transfer inhibitor (INSTI) resistance is a concern, providers may wish to supplement standard genotypic resistance testing with an INSTI genotype test (CIII).
· HIV drug-resistance testing should be performed to assist in the selection of active drugs when changing ARV regimens in persons with virologic failure and HIV RNA levels >1,000 copies/mL (AI). In persons with HIV RNA levels >500 but <1,000 copies/mL, testing may be unsuccessful but should still be considered (BII).
· Drug-resistance testing should also be performed when managing suboptimal viral load reduction (AII).
· In persons failing INSTI-based regimens, genotypic testing for INSTI resistance should be performed to determine whether to include a drug from this class in subsequent regimens (AII).
· Drug-resistance testing in the setting of virologic failure should be performed while the person is taking prescribed ARV drugs or, if not possible, within 4 weeks after discontinuing therapy (AII).
· Genotypic testing is recommended as the preferred resistance testing to guide therapy in patients with suboptimal virologic responses or virologic failure while on first or second regimens (AII).
· The addition of phenotypic to genotypic testing is generally preferred for persons with known or suspected complex drugresistance mutation patterns, particularly to protease inhibitors (PIs) (BIII).
· Genotypic resistance testing is recommended for all pregnant women before initiation of ART (AIII) and for those entering pregnancy with detectable HIV RNA levels while on therapy (AI)

Rating of Recommendations A = Strong B = Moderate C = Optional
Rating of Evidence I = Data from randomized controlled trials II = Data from well-designed nonrandomized trials or observational
cohort studies with long-term clinical outcomes III = Expert opinion

Last Updated 2/20/2014 3:08:05 PM
Entry Number 513
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