HBV Drug Resistance and Genotyping

General Information

Lab Name

Lab Code

HBVGTD

Epic Ordering

HBV Drug Resistance and Genotyping

Description

HBV Drug Genotyping is determined by Sanger sequencing. An 850bp region of the HBV DNA polymerase gene, amino acids 25 to 344, is sequenced and compared to an HBV genotyping and resistance database provided by Genofar, a German, non-profit, scientific society. Minor subpopulations of mutant viruses below 20-25% of the total HBV population may not be detected. Drug resistance analysis includes Lamivudine, Adefovir, Entecavir, Tenofovir and Telbivudine. This test may be added-on to a positive HBV DNA quantitative PCR assay (HBVQNT), call the Virology Laboratory, (206) 685-6656, to confirm sample availability.

Synonyms

HBV Drug Resistance, HBV Genotype, HBV POL Gene Sequencing

Components

Code	Name
HBVSD	HBV Specimen Description
HBVGER	HBV Genotype Result
HBVGIN	HBV Genotype Interpretation
HBVDRM	HBV Drug Resistance Mutation
HBVLAM	HBV Lamivudine Resistance
HBVADE	HBV Adefovir Resistance
HBVENT	HBV Entecavir Resistance
HBVTEN	HBV Tenofovir Resistance
HBVTEL	HBV Telbivudine Resistance
HBVINT	HBV Generic Interpretation

Interpretation

Method: Real-Time Polymerase Chain Reaction/Sanger sequencing
Reference Range: See individual components

Ordering & Collection

Specimen Type: Blood
Collection: Blood: 3 mL blood in LAVENDAR, RED, GOLD SST, or PPT (pearl top). Plasma (ACD, EDTA, CPD, and plasma preparation tubes) or serum (including serum collected in serum separator tubes).

Unacceptable specimen: Plasma collected in sodium or lithium heparin (green top).

Note: Separate specimens MUST be submitted when both Viral Culture/Serology and PCR testing are ordered.
Handling Instructions
Quantity: requested: 1.0 mL
minimum: 0.7 mL

Processing

Processing: Blood: Separate plasma from whole blood within 24 hours of collection. Freeze plasma at -10°C or colder and ship on dry ice. Plasma may be stored at 2-8°C (ice pack) for up to 48 hours from collection. Do not freeze/thaw.

Outside Laboratory: Ship samples on dry ice. If freezer and/or dry ice not available, ship immediately at 2-8°C (ice pack). Shipment time must not exceed 48 hours from collection. Samples stored at 2-8°C greater than 48 hours old may be rejected. Do not freeze/thaw.

Performance

LIS Dept Code

Virology - OLD (VIRO)

Performing Location(s)

Other	Virology, Molecular 206-685-6656 Virology Laboratory, Ste 320 1616 Eastlake Ave E. Seattle, WA 98102

Frequency

Tuesday set-up, results by Friday

Available STAT?

Billing & Coding

CPT codes
LOINC: 49883-2
Interfaced Order Code: UOW3674