Hepatitis C Virus Genotypic Antiviral Drug Resistance [Test in Focus]

Interferon-free, direct-acting antiviral (DAA) drug combination therapy is now a standard of care for patients with chronic HCV infection. However, poor compliance with therapy and the existence of pretreatment antiviral drug resistance may compromise efficacy of such drug therapy. Naturally occurring (preexisting) or treatment-induced mutations in the viral genomic sequences that are targets of such antiviral agents can lead to antiviral resistance and therapeutic failure.

FDA Recommended Pretreatment Testing

Certain FDA-approved DAA drugs for treating chronic HCV due to genotypes 1a, 1b, and 3 (regardless of subtypes) require pretreatment testing for resistance-associated substitutions in the relevant HCV genomic sequences to best guide selection of optimal DAA combination therapy.

Joseph Yao, M.D., gives an overview of this new test available through Mayo Clinic Laboratories. He discusses when this testing should be ordered, how this testing improves upon other testing approaches, and what clinical action can be taken due to the results of this testing.


When to Order

  • This assay uses next-generation sequencing to detect and identify HCV antiviral drug resistance in patients with chronic hepatitis C and those being considered for direct-acting antiviral (DAA) drug combination therapy.
  • This test can be used to predict the likelihood of a curative response to current FDA-approved DAA drug combinations used for treatment of chronic hepatitis C.

Specimen Information

Supplies: Aliquot tube, 5 mL (T465)

Collection Container/Tube: Serum gel

Submission Container/Tube: Polypropylene vial (T465)

Specimen Volume: 2.5 mL

Collection Instructions:

1. Centrifuge blood collection tube per collection tube manufacturer's instructions.

2. Pour off serum into aliquot tube.


Day(s) and Time(s) Performed

Monday through Friday, 7 a.m.11 p.m.

Analytic Time

4 days

Additional Resources

Alyssa Frank

Alyssa Frank is a Marketing Segment Manager at Mayo Clinic Laboratories. She leads marketing strategies for product management and specialty testing. Alyssa has worked at Mayo Clinic since 2015.