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Hepatitis C Polymorphism Testing: A Review of the Clinical Evidence

Published on: February 24, 2014
Project Number: RC0526-000
Product Line: Rapid Response
Research Type: Drug
Report Type: Summary with Critical Appraisal
Result type: Report

Report in Brief

Context
Hepatitis C is a considerable public health problem. In Canada, hepatitis C is most commonly transmitted through injection drug use, and 75% to 80% of infected people develop chronic hepatitis C (CHC). In 2007, it was estimated that 242,000 Canadians had CHC.

CHC can progress to liver cirrhosis, liver cancer, and premature death, and is the most common reason for liver transplantation.

There are six major genotypes of the hepatitis C virus. In North America, genotype 1 is the most common and the most difficult to treat. New direct-acting antiviral drugs are now being used to treat CHC genotype 1. One of these drugs, simeprevir, may be less effective in patients with a specific type of the hepatitis C virus: genotype 1a, with Q80K polymorphism.

Technology
Genetic polymorphism means that there can be different forms, or mutations, of a certain gene. In the case of the hepatitis C virus, there is now a commercially available test (HCV GenoSure) that screens for mutations, particularly the Q80K polymorphism. A blood sample is taken from the patient and put through a nucleic acid sequencing assay.

This laboratory test analyzes the genetic sequence of the virus and reports on mutations.

Issue
The best outcome from CHC treatment is a sustained virologic response (SVR). This means that no virus is detectable, and this is considered to be a “cure.”

In clinical trials, patients with the Q80K polymorphism were less likely to achieve SVR if they were treated with simeprevir (58%, versus 84% for those without Q80K polymorphism). The simeprevir manufacturer recommends that, when accessible, testing for Q80K polymorphism be considered in patients with CHC genotype 1a. Information on the diagnostic accuracy of such tests would help inform decision-making on the use of simeprevir.

Methods
A limited literature search was conducted of key resources, and titles and abstracts of the retrieved publications were reviewed. Full-text publications were evaluated for final article selection according to predetermined selection criteria (population, intervention, comparator, outcomes, and study designs).

Results
The literature search identified 39 citations, 4 of which were potentially relevant, with 26 additional articles identified from other sources. Of these 30 articles, 30 were excluded after full-text screening, resulting in no articles meeting the criteria for inclusion in this review.

Key Messages

  • No evidence was found on the accuracy of laboratory tests for hepatitis C Q80K polymorphism.

Question

  1. What is the accuracy of laboratory tests for the identification of Q80K polymorphism in patients with hepatitis C virus genotype 1?

Key Message

No evidence regarding the diagnostic accuracy of laboratory tests for hepatitis C Q80K mutation was identified.

Tags

hepatitis c, hepatitis, polymorphism, genetic, laboratory tests, Polymorphism, Genetic