33415/33416 - RealTime HCV Genotype | Clinical

Clinical Utility

Hepatitis C Genotyping can be used to help predict the outcome of therapy and to influence the choice of therapeutic drugs. Clinical outcome depends on the genotype of the infection, pretreatment viral load, and whether or not liver cirrhosis is present. Genotypes 1a and 1b have the poorest clinical outcomes with sustained viral response of only 46% with combination antiviral therapy.

About HCV Genotyping

Hepatitis C virus (HCV) is a member of the Flaviviridae family. It is a single-stranded, positive-sense RNA virus, which is spherical and lipid-enveloped. HCV was discovered in the late 1980s and is considered to be one of the leading causes of liver disease in the United States. Hepatitis C Genotyping can be used to help evaluate the outcome of HCV therapy and to influence the choice of therapeutic drugs. The ability to achieve a sustained virological response is influenced by the genotype of the infection, pretreatment HCV-RNA levels (viral load), early response to therapy and whether or not liver cirrhosis is present.^1-3 Six major genotypes (1 through 6) have been identified to date with more than 50 subtypes; however, most patients with HCV typically have only one principal genotype, rather than multiple genotypes.^5-7 Approximately 75% of Americans with HCV have genotype 1 of the virus (subtypes 1a or 1b), and 20-25% have genotypes 2 or 3, with small fraction of patients infected with genotypes 4, 5, or 6.⁸

Procedure

The Abbott RealTime HCV Genotype II is an in vitro reverse transcription-polymerase chain reaction (RT-PCR) assay for the identification of the genotype(s) of hepatitis C virus (HCV) in plasma or serum from individuals chronically infected with HCV. The Abbott RealTime HCV Genotype II assay detects genotypes 1, 1a, 1b and 2 – 5 through the use of genotype-specific fluorescent-labeled oligonucleotide probes.

Specificity

The Reproducibility / Precision of Abbott RealTime HCV Genotype II was evaluated by testing a 36-member panel (2 vials of 18 unique members) representing HCV genotypes 1a, 1b, 2, 3, 4, and 5, each at 3 concentration levels (500 to 1000, 5000 to 10000, > 50000 IU/mL). All panel members were composed of HCV positive donor units diluted in defibrinated human plasma.

A total of 3 Abbott RealTime HCV Genotype II Amplification reagent lots were used. Each of the 3 clinical sites tested 2 of the 3 Amplification reagent lots for 5 nonconsecutive days each, resulting in a total of 10 runs at each site. The percent correctly identified rate for the Abbott RealTime HCV Genotype II assay was 99.8% (1070/1072) overall for genotypes 1 – 5. The overall No Result (“HCV detected, No Genotype Result” or “HCV not detected”) rate was 0.2% (2/1072) for genotypes 1 – 5.

Within-run, between-run, between-lot, between-site, and total standard deviations and %CV for cycle number (CN) were determined. The total SD ranged from 0.25 to 1.55, the within-run component SD ranged from 0.15 to 1.37, the between-run component SD ranged from 0.00 to 0.14, the between-lot component SD ranged from 0.00 to 0.73, and the between-site component SD ranged from 0.00 to 0.71.
The results, representative of the reproducibility / precision of the Abbott RealTime HCV Genotype II assay, are summarized in Tables 1 and 2.

Turnaround Time

Up to 8 days from receipt of specimen. Setup on Wednesdays.

Specimen Information

Specimen Type	Test Code	CPT Code	NY Approved	Volume	Assay Range	Special Instructions
plasma	33415	87902	Yes	2 mL (min. 500 IU/mL)		Freshly drawn specimens (whole blood) may be held at 2 to 30°C for up to 6 hours prior to centrifugation. After centrifugation, remove serum or plasma from cells. Serum or plasma specimens may be stored: At 15 to 30°C for up to 24 hours At 2 to 8°C for up to 3 days At –25 to –15°C for up to 60 days At –70°C for up to 60 days Multiple freeze/thaw cycles should be avoided. If frozen, thaw specimens at 15 to 30°C or at 2 to 8°C. Once thawed, if specimens are not being processed immediately, they can be stored at 2 to 8°C for up to 6 hours. Specimens showing particulate matter or turbidity should be clarified by centrifugation at 2000 g for 5 minutes prior to testing.
serum	33416	87902	Yes	2 mL (min. 500 IU/mL)		Freshly drawn specimens (whole blood) may be held at 2 to 30°C for up to 6 hours prior to centrifugation. After centrifugation, remove serum or plasma from cells. Serum or plasma specimens may be stored: At 15 to 30°C for up to 24 hours At 2 to 8°C for up to 3 days At –25 to –15°C for up to 60 days At –70°C for up to 60 days Multiple freeze/thaw cycles should be avoided. If frozen, thaw specimens at 15 to 30°C or at 2 to 8°C. Once thawed, if specimens are not being processed immediately, they can be stored at 2 to 8°C for up to 6 hours. Specimens showing particulate matter or turbidity should be clarified by centrifugation at 2000 g for 5 minutes prior to testing.

Shipping

Ship specimens frozen on dry ice. Specimens should be packaged and labeled in compliance with applicable state and federal regulations covering the transport of clinical specimens and etiologic agents/ infectious substances.

Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name and collection date. A Eurofins Viracor test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St. Ste, #10, Lenexa, KS 66219

Causes for Rejection

Specimens beyond their acceptable length of time from collection as listed in the specimen handling, HCV RNA concentrations too low to allow for genotype testing, or specimen types other than those listed.

Disclaimer

Specimens are approved for testing in New York only when indicated in the Specimen Information field above.

The CPT codes provided are based on Eurofins Viracor's interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Eurofins Viracor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.

References

1. Fried MW, Shiffman ML, Reddy KR, Smith C, Marinos G, Goncales FL Jr, et al. Peginterferon alfa-2b plus ribavirin for chronic hepatitis C virus infection. New Eng J Med. 2002 Sep 28:347(13):975-82.
2. Ferenci P, Fried MW, Shiffman ML, Smith CI, Marinos G, Goncales FL Jr, et al. Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40KD ribavirin. J Heptol. 2005 Sep;43(3):425-33.
3. David GL, Wong JB, McHutchison JG, Manns MP, Harvey J, Albrecht J. Early virologic response to treatment with peginterferon alfa-2b plus ribavirin in patients with chronic hepatitis C. Hepatology. 2003 Sep;38(3):645-52.
4. Incivek™ package insert. Cambridge, MA: Vertex Pharmaceuticals Incorporated; 2011.
5. Manns MP, McHutchison JG, Gordon SC, et al. Peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of chronic hepatitis C: a randomized trial. Lancet. 2001; 358:958-65.
6. Fried MW, Shiffman ML, Reddy R, Smith C, Marinos G, Goncales FL Jr, et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection. N Engl J Med. 2002 Sep 26:347(13):975-82.
7. Hadziyannis SJ, Sette H Jr, Morgan TR, Balan V. Marcellin P, Ramadori G, et al. Peginterferon alpha-2a and ribavirin combination therapy in chronic hepatitis C: a randomized study of treatment duration and ribavirin dose. Ann Intern Med. 2004 Mar 2;140(5):348-55.
8. McHutchison JG, Gordon SC, Schiff ER, Shiffman ML, Lee WM, Rustgi VK, et al. Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C. N Engl J Med. 1998 Nov 19:339(21):1485-92.

RealTime Hepatitis C Virus (HCV) Genotyping

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