CMV Letermovir Resistance, UL56

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General Information

Lab Name
CMV Letermovir Resistance, UL56
Lab Code
CMVDRL
Epic Ordering
CMV Letermovir Resistance, UL56
Description

CMV Drug Resistance (UL56 gene), Letermovir

Mutations spanning about 700bp towards the 5’ end of the UL56 gene of the CMV genome have shown in phenotype testing to correspond to drug resistance to Letermovir. The UL56 region is part of the viral terminase complex that also includes components encoded by the UL89 and UL51genes. The viral terminase complex cleaves concatemeric DNA formed during viral replication into unit-length genomes and packages them into pre-formed viral capsids.

Genotypic analysis is performed by Sanger sequencing about 700bp towards the 5’ end of the UL56 gene.

The minimum virus level that yields a sequenceable PCR amplicon in 95% of replicates is 240 IU/mL (2.4 log IU/mL).

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.

For UL97 and UL54 CMV gene sequencing, see CMV UL97 and UL54 Drug Resistance Seq [CMVDRS].

For UL97, UL54 and UL56 CMV gene sequencing, see CMV Drug Resistance, Rapid UL97, UL54 and UL56 [CMVULR].

Synonyms
Acid CMV Drug Resistance, CMV Sequencing, Letermovir Resistance Test, UL56 Sequencing
Components

Interpretation

Method

Sequencing/Real-time Polymerase Chain Reaction.

Reference Range
See individual components

Ordering & Collection

Specimen Type
Blood, CSF, or Clear non-cellular fluid
Collection

Blood: 3 mL blood in EDTA (LAVENDER TOP), RED, SST, or PPT tube.

CSF or Clear non-cellular fluid: 1 mL of CSF in sterile container.

Unacceptable samples: Plasma collected in sodium or lithium Heparin. NO URINE SAMPLES. Extracted nucleic acid from an outside laboratory

Minimum sample requirement: 0.5 mL

Handling Instructions
Quantity
requested: 1 mL
minimum: 0.5 mL

Processing

Processing

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.

CSF or Clear non-cellular fluid: If CSF has cellular material, centrifuge & aliquot clear CSF. 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 Laboratory: 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. Shipment time must not exceed 48 hours from collection if stored at 2-8°C. Samples stored at 2-8°C greater than 48 hours old may be rejected. Do not freeze/thaw.

Performance

LIS Dept Code
Virology, Eastlake (EVIR)
Performing Location(s)
Other Virology, Molecular
206-685-6656

Virology Laboratory, Ste 320
1616 Eastlake Ave E.
Seattle, WA 98102
Frequency
Once a week.
Available STAT?
No

Billing & Coding

CPT codes
87910
LOINC
40444-2
Interfaced Order Code
UOW3617