Laboratory Test DirectoryShare
Hepatitis C Virus Genotype
|Methodology:||Polymerase Chain Reaction|
Collect: Lavender (EDTA) OR Serum Separator Tube (SST) - 0.5 ml plasma or serum.
Specimen Preparation: Separate serum or plasma from cells within 6 hours. Transfer 2 mL serum or plasma to a Standard Transport Tube.
Storage/Transport Temperature: Frozen.
Unacceptable Conditions: Heparinized specimens.
Stability: On cells: Ambient: 6 hours. After separation from cells: Refrigerated: 72 hours; Frozen: 1 month.
NOTE: * This test is not available for New York patients, please refer to test code A776 for specimen requirements.*
Accu Reference Medical Laboratory
|Test Panel Components||Genotype 1a, Genotype 1b, Genotype 2a/c, Genotype 2b, Genotype 3, Genotype 4, Genotype 5, Genotype 6, Dual infections 1-4|
The hepatitis C virus (HCV) is a RNA virus that undergoes constant mutation, making it an infection that is a major, widespread public health problem.1 Globally, more than one million new cases are reported annually and currently, HCV is responsible for an estimated 8,000-to-10,000 deaths in the United States each year.2,3 HCV infection is also one of the main causes of cirrhosis to the liver, and hepatocellular carcinoma and HCV-related end stage liver disease is the leading reason for liver transplantation in the United States, as well.1,4
Upon infection, individuals may note fatigue, loss of appetite, muscle aches, or even fever.5 Among most individuals, the immune system is unable to clear the infection successfully, leading to chronic HCV infection that progresses over decades.5 Individuals who develop cirrhosis of the liver may continue to advanced cirrhosis, which can lead to death.5 As a result, HCV infections are the leading indication for liver transplants and account for up to 50% of hepatocellular carcinoma cases.5
Six total HCV genotypes with several distinct subtypes have been identified, it cover the vast majority of disease presence seen in the US and the world. Each genotype has distinct consequences and differs in their responsiveness to combination therapy.1 Typically, patients are only infected with one genotype, but since each genotype is actually a combination of quasi-species, these quasi-species mutate quickly. This results in patients becoming immune to treatments and makes it difficult to treat HCV. Genotype 1 is the most common HCV genotype in the United States, and is the most difficult genotype to treat.1,4
Indications For Use
Determining the HCV genotype is a useful clinical tool for making therapeutic recommendations.1,6 Individuals with HCV genotypes 2 and 3 are about 3x more likely than individuals with genotype 1 to respond to therapy (both mono- and combination therapy). When using combination therapy, recommended treatment duration also depends on the genotype, adding to the clinical value of HCV genotype testing.1
Patients with chronic HCV should be examined every 1-to-4 weeks while on therapy. Evaluation should continue for at least 6 months after stopping therapy to assess whether the response to therapy has been sustained.1
HCV Test components
The GenMark Dx eSensor HCV genotyping test is designed to genotype for the most common HCV types and subtypes, listed below:
Dual infections 1-4
Multiplex Reverse-Transcription Polymerase Chain Reaction (RT-PCR) using the GenMark Dx eSensor Technology to amplify specific regions of the HCV genome
o Analysis distinguishes among the major genotypes and the most common HCV subtypes within the serum- or plasma-extracted nucleic acids, inclusive of the 5’ UTR and core regions
- An HCV positive control is included in each assay
- The test also covers co-infection capabilities for 1a+1b, 1+2, 1+3, and 1+4 HCV types and subtypes
- Testing results are automatically generated on a single page for ease of understanding, and do not require any data interpretation
Individuals Suitable For Testing
- Patients suitable for testing are those with detectable hepatitis C viral RNA (estimated at >300 IU/mL) and those which are being evaluated for treatment1,3
- This RT-PCR test may not be successful if the HCV RNA viral load is less than 50 IU/mL, and results should be correlated with additional methods (eg, routine serologic and molecular-based testing) in addition to clinical presentation1
- Cross-reactivity between assay probes and various HCV genotypes may limit the ability of this assay to identify multiple HCV genotypes present in a given specimen5
- WHO. Hepatitis C. http://www.who.int/csr/disease/hepatitis/whocdscsrlyo2003/en/index2.html Accessed: July 12, 2015. Updated: 2015.
- National Institutes of Health Consensus Development Conference Panel. National Institutes of Health Consensus Development Conference Panel statement: Management of Hepatitis C. Hepatology. 1997;26(suppl1):2S-10S.
- Zein NN. Clinical Significance of Hepatitis C Virus Genotypes. Clin Microbiol Rev. 2000;13: 223–235.
- Ghany MG, Strader DB, Thomas DL, et al; American Association for the Study of Liver Diseases. Diagnosis, management, and treatment of hepatitis C: an update. Hepatology. 2009;49:1335-1374.
- O’Brien S. The clinical importance of hepatitis C genotyping in the United States. Medical Laboratory Observer. 2013. http://www.mlo-online.com/articles/201311/the-clinical-importance-of-hepatitis-c-genotyping-in-the-united-states.php Accessed: August 26, 2015. Updated: 2015.
- Germer JJ, Mandrekar JN, Bendel JL, et al: Hepatitis C virus genotypes in clinical specimens tested at a national reference testing laboratory in the United States. J Clin Microbiol. 2011;49:3040-3043.