Update Type: Replacement Test
Test Updated: 06/02/2021
Test Overview
Test Methodology

Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination Analysis

Test Usage

Predicting responsiveness of genotype 1 hepatitis C viral infections to combined pegylated-interferon and ribavirin-based therapies. Samples may contain donor DNA if obtained from patients who received heterologous blood transfusions or allogeneic blood or marrow transplantation. Results from samples obtained under these circumstances may not accurately reflect the recipient's genotype. For individuals who have received blood transfusions, the genotype usually reverts to that of the recipient within 6 weeks. For individuals who have received allogeneic blood or marrow transplantation, a pretransplant DNA specimen is recommended for testing. For liver transplant patients, the IL28B genotype of the recipient and the donor are independent predictors of sustained virologic response with combined pegylated-interferon and ribavirin therapy.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

This test does not detect polymorphism or mutations other than the single-nucleotide polymorphism (SNP) of rs12979860 C/T. Rare polymorphisms exist and could lead to false-negative or false-positive results.

Test Details
Days Set Up
Monday - Friday
Analytic Time

3 - 8 days

Soft Order Code
MiChart Code
Interleukin 28B Polymorphism Genotype
  • IL28B
  • IL28B Polymorphism Genotype
  • IL28B Polymorphism (rs12979860)
Reference Laboratory
Mayo IL28Q
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a lavender top tube. Send intact blood at room temperature. Note that this test should be performed only once per patient lifetime on patients who are proven to be HCV positive. Saliva kit and extracted DNA are also acceptable

Alternate Specimen
Saliva and extracted DNA
Normal Volume
3 mL EDTA whole blood; 1 swab in Saliva Swab Collection Kit, 100 mcL of DNA at concentration 250 ng/mcL
Minimum Volume
0.4 mL EDTA whole blood
Storage Temperature
Ambient preferred for all. Blood may also be refrigerated for up to 30 days
Additional Information

Test sent to Mayo Medical Laboratories.

CPT Code
Fee Code