ARUP's Laboratory Test Directory

Hepatitis C Virus Genotyping : 0055593

Mnemonic: HEPCGENO

Ordering Recommendation: Do not order prior to molecular confirmation of positive hepatitis C virus (HCV) screen. Order before initiating HCV therapy to aid in determining therapy of choice, likelihood of response, and probable therapeutic duration.
Methodology: Polymerase Chain Reaction/Sequencing
Performed: Sun-Sat
Reported: 3-7 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), plasma preparation tube or serum separator tube.

Specimen Preparation: Separate serum or plasma from cells within 6 hours. Transfer 2 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Frozen.

Remarks: Please submit most recent viral load and test date, if available.

Unacceptable Conditions: Heparinized specimens.

Stability (collection to initiation of testing): On cells: Ambient: 6 hours. After separation from cells: Refrigerated: 72 hours; Frozen: 4 months.
Reference Interval:
By report
Interpretive Data: Hepatitis C viral RNA is tested using reverse transcription polymerase chain reaction (RT-PCR) to amplify a specific portion of the 5' untranslated region (5' UTR) of the viral genome. The amplified nucleic acid is sequenced bi-directionally using dye-terminator chemistry (ABI). Sequencing data is compared to a database of characterized sequences.

Isolates of hepatitis C virus are grouped into six major genotypes (1-6). These genotypes are subtyped according to sequence characteristics. Due to high conservation of the 5' un-translated region of the HCV genome, this test has limitations in differentiating subtype 1a from 1b. Therefore, these subtypes will be reported as 1a or 1b. In rare instances, Type 6 virus may be misclassified as Type 1.

See Compliance Statement B: www.aruplab.com/CS
Note: This test may be unsuccessful if the HCV RNA viral load is less than log 2.8 or 600 IU/mL.
CPT Code(s): 87902
Cross References: HCV, Subtype (Hepatitis C Virus Genotyping)