Evaluation of the Xpert HCV Viral Load Finger-Stick Point-of-Care Assay

Abstract

Point-of-care hepatitis C virus (HCV) RNA testing is advantageous, enabling diagnosis of active infection in a single visit. This study evaluated the sensitivity and specificity of the Xpert HCV Viral Load Finger-Stick assay (Xpert HCV VL FS) for HCV RNA detection (finger-stick) and the Xpert HCV Viral Load assay (plasma) compared with the Abbott RealTime HCV Viral Load assay by venepuncture. Plasma and finger-stick capillary whole-blood samples were collected from participants in an observational cohort in Australia. Of 223 participants enrolled, HCV RNA was detected in 40% of participants (85 of 210) with available Xpert HCV Viral Load testing. Participants receiving HCV therapy were excluded from subsequent analyses (n = 16). Sensitivity of the Xpert HCV Viral Load assay for HCV RNA quantification in plasma collected by venepuncture was 100.0% (95% confidence interval [CI] 96.9%-100.0%) and specificity was 100.0% (95% CI, 94.4%-100.0%). Sensitivity of the Xpert HCV VL FS assay for HCV RNA quantification in samples collected by finger-stick was 100.0% (95% CI, 93.9%-100.0%) and specificity was 100.0% (95% CI, 96.6%-100.0%). The Xpert HCV VL FS test can accurately detect active infection from a finger-stick sample in 1 hour allowing single-visit HCV diagnosis.

Hepatitis C virus testing, liver disease assessment and treatment uptake among people who inject drugs pre‐ and post‐universal access to direct‐acting antiviral treatment in Australia: The LiveRLife study

“…Although the project incorporated point‐of‐care HCV RNA testing, due to a lack of regulatory approval these results were not made available to participants. The development of well‐tolerated, pangenotypic DAA regimens and the recent licensing of point‐of‐care HCV RNA testing technology provides the opportunity to enhance linkage to treatment. Studies will shortly commence to evaluate rapid HCV RNA screening and same‐day DAA initiation among PWID attending needle and syringe programs and among inmates of a remand prison setting.…”

“…The study endpoints included HCV infection (detectable HCV RNA), significant liver disease (stage > F2), linkage to care (defined as clinical follow‐up attendance) and HCV treatment uptake (treatment initiation). HCV infection was determined by HCV RNA quantification using the Xpert ® HCV Viral Load Fingerstick Assay, performed on fingerstick whole‐blood samples . Prior to the availability of the Xpert ® HCV Viral Load Fingerstick Assay on 14 Jan 2016, HCV RNA testing was completed using a validated in‐house qualitative polymerase chain reaction assay, performed on dried blood spots collected by fingerstick whole‐blood samples …”

Field evaluation of GeneXpert® (Cepheid) HCV performance for RNA quantification in a genotype 1 and 6 predominant patient population in Cambodia

“…The use of DBS eliminates the need for cold chain and the set‐up of the assay in a laboratory, helping to further improve access to the most underserved patient populations. A new Xpert platform, recently developed for use on finger‐stick capillary whole blood, demonstrated excellent performance, with a shorter processing time (one hour), compared to the standard Xpert HCV assay and avoids the special equipment and laboratory skills required for the centrifugation of plasma. However, the platform requires that testing immediately follows sample collection, nevertheless necessitating a similar laboratory set‐up to the conventional Xpert HCV assay.…”

In‐field evaluation of Xpert® HCV viral load Fingerstick assay in people who inject drugs in Tanzania

“…DBS have also been validated for HCV RNA quantification on the new Hologic Aptima assay as well as HCV core antigen quantification on the Abbott Architect platform, reporting sensitivities of 96.4% and 76.1% respectively . Furthermore, a Fingerstick assay using 100 µL has recently been validated for the Xpert ® system (Xpert ® HCV viral load [VL] Fingerstick assay), which has a lower limit of detection of 40 IU/mL and lower limit of quantification of 100 IU/mL . When compared with the Genedrive ® device, not only does the Xpert ® HCV VL Fingerstick assay have a superior threshold for HCV RNA detection and avoid the need for any sample prepreparation, it also has a faster turn‐around time (60 minutes vs 90 minutes) and is half the price.…”