Wednesday, April 26, 2017

HCV Viral Load test can detect active infection from a finger-stick sample

Point-of-care hep C test developed
By LabOnline Staff
Monday, 24 April, 2017
A research team led by UNSW’s Kirby Institute has evaluated a new test that enables diagnosis of hepatitis C infection in a single visit, with promising results. Their study has been published in The Lancet Gastroenterology & Hepatology.

The researchers conducted the first evaluation of the Xpert HCV Viral Load test, manufactured by molecular diagnostics company Cepheid — a point-of-care hepatitis C virus test that can detect active infection from a finger-stick sample of blood. They established that the test demonstrated good sensitivity and specificity in blood tests collected by finger-stick in participants attending drug health and homelessness services in Australia.

“This test represents a major advance over point-of-care antibody-based tests, which only indicate previous exposure to the virus but cannot detect whether you are actively infected,” said Associate Professor Jason Grebely from The Kirby Institute. “We really need to scale up testing for active hepatitis C infection in order to enhance diagnosis, get people linked to appropriate care and provide highly curative treatment with direct-acting antivirals to prevent advanced liver disease and onward transmission of the virus.”

Importantly, new point-of-care platforms enable detection of hepatitis C virus and diagnosis of active infection in a single visit, rather than having to come back for a second visit to obtain test results. As noted by Associate Professor Grebely, “Requiring people to come back for a second appointment to receive their results can present significant barriers, especially for people living in remote areas and for vulnerable and marginalised populations… who are the people we need to reach the most in order to eliminate hepatitis C.”

The finger-stick test is not yet registered in Australia, but international clinical trials are underway to evaluate this point-of-care assay as a diagnostic test for the detection of active HCV infection.

Read more: Point-of-care hep C test developed

Abstract
Evaluation of the Xpert HCV Viral Load point-of-care assay from venepuncture-collected and finger-stick capillary whole-blood samples: a cohort
study
Dr Jason Grebely, PhD Francois M J Lamoury, EiCNAM, Behzad Hajarizadeh, PhD, Yasmin Mowat, BSc, Alison D Marshall, MA, Sahar Bajis, MIPH, Philippa Marks, MPH, Janaki Amin, PhD, Julie Smith, RN, Michael Edwards, MBBS, Carla Gorton, MPH, Nadine Ezard, PhD, David Persing, PhD, Marika Kleman, PhD, Philip Cunningham, PhD, Beth Catlett, BSc, Prof Gregory J Dore, PhD, Tanya L Applegate, PhD on behalf of the LiveRLife Study Group

Published: 21 April 2017
DOI: http://dx.doi.org/10.1016/S2468-1253(17)30075-4

Summary
Background
Point-of-care hepatitis C virus (HCV) RNA testing offers an advantage over antibody testing (which only indicates previous exposure), enabling diagnosis of active infection in a single visit. In this study, we evaluated the performance of the Xpert HCV Viral Load assay with venepuncture and finger-stick capillary whole-blood samples.

Methods
Plasma and finger-stick capillary whole-blood samples were collected from participants in an observational cohort enrolled at five sites in Australia (three drug and alcohol clinics, one homelessness service, and one needle and syringe programme). We compared the sensitivity and specificity of the Xpert HCV Viral Load test for HCV RNA detection by venepuncture and finger-stick collection with the Abbott RealTime HCV Viral Load assay (gold standard).

Findings
Of 210 participants enrolled between Feb 8, 2016, and July 27, 2016, 150 participants had viral load testing results for the three assays tested. HCV RNA was detected in 45 (30% [95% CI 23–38]) of 150 participants based on Abbott RealTime. Sensitivity of the Xpert HCV Viral Load assay for HCV RNA detection in plasma collected by venepuncture was 100·0% (95% CI 92·0–100·0) and specificity was 99·1% (95% CI 94·9–100·0). Sensitivity of the Xpert HCV Viral Load assay for HCV RNA detection in samples collected by finger-stick was 95·5% (95% CI 84·5–99·4) and specificity was 98·1% (95% CI 93·4–99·8). No adverse events caused by the index test or the reference standard were observed

Implications
The Xpert HCV Viral Load test can detect active infection from a finger-stick sample, which represents an advance over antibody-based tests that only indicate past or previous exposure.

Funding
National Health and Medical Research Council (Australia), Cepheid, South Eastern Sydney Local Health District (Australia), and Merck Sharp & Dohme (Australia).
Lancet

Xpert HCV Viral Load Test Can Detect Active Hepatitis C Infection From Fingerstick
Posted on April 25, 2017
Jason Grebely PhD
Associate Professor
Senior Research Fellow (UNSW)
Viral Hepatitis Clinical Research Program

MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Globally, testing and diagnosis of hepatitis C virus infection remain low. Although point of care tests for HCV infection exist, but many of these tests only measure HCV antibodies (previous exposure), not HCV RNA (active infection). Given that 25% of individuals spontaneously clear HCV infection, efforts to enhance diagnosis of chronic HCV infection and improve the HCV care cascade requires enhanced uptake of HCV RNA testing.
We conducted the first evaluation of the Xpert HCV Viral Load test (manufactured by Cepheid) – a point-of-care hepatitis C virus test that can detect active infection – from a finger-stick sample of blood. We established that there is good sensitivity and specificity of the Xpert HCV Viral Load point-of-care test using blood samples collected by finger-stick in participants attending drug health and homelessness services in Australia.

MedicalResearch.com: What should readers take away from your report?
Response: This test represents a major advance over point of care antibody-based tests, which only indicate previous exposure to the virus but cannot detect whether you are actively infected. This new point of care platform enables detection of hepatitis C virus and diagnosis of active infection in a single visit, rather than having to come back for a second visit to obtain test results. Data have shown that on-site HCV testing with integrated care improves linkage to HCV care.
We really need to scale up testing for active hepatitis C infection in order to enhance diagnosis, get people linked to appropriate care, and provided highly curative treatment with direct-acting antivirals to prevent advanced liver disease and onward transmission of the virus.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: Further validation studies are needed to further evaluate the performance of this assay in different settings and populations (eg, patients given DAA therapy, those with a sustained virological response, or those with HIV/HCV co-infection). Also, future research should evaluate the effectiveness of integrating point of care testing into interventions to enhance linkage to HCV care and treatment.

Disclosures: JG is a consultant and adviser and has received research grants from AbbVie, Bristol-Myers Squibb, Cepheid, Gilead Sciences, and Merck/MSD.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
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