Hepatitis C Virus (HCV) Genotype with Reflex to HCV NS5A Drug Resistance by Sequencing

Casandra

Casandra Test Code AR52272Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2014598CPT Code 87902

Hepatitis C Virus (HCV) Genotype with Reflex to HCV NS5A Drug Resistance by Sequencing

Also known as: HCV RFX 5A

Clinical Use

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Use

This test is used to determine the genotype of Hepatitis C Virus (HCV) types 1-6 following a molecular confirmation of a positive HCV screening. It is particularly useful in guiding treatment decisions, especially before initiating therapy with NS5A inhibitors. If the genotype determined is '1a or 1b,' the test automatically reflexes to assess NS5A drug resistance through sequencing, which helps identify drug-resistance mutations that could impact treatment efficacy.

Special Instructions

Order this test prior to starting treatment with NS5A inhibitors. It assesses the HCV genotype and any drug resistance related to the NS5A inhibitors. This test includes a reflex component, meaning additional analysis is automatically conducted if certain results (type '1a or 1b') are obtained, which may result in extra charges.

Limitations

The test has limitations in differentiating between subtype 1a and 1b due to the high conservation in the 5' untranslated region of the HCV genome. Additionally, in rare cases, Type 6 virus may be misclassified as Type 1. Furthermore, the test may be unsuccessful if the HCV RNA viral load is below 4000 IU/mL or log 3.6. These limitations are important for interpreting the results accurately.

Test Details

New York Approved