Diagnosis and Monitoring of Hepatitis B Virus Infection Using the Cobas® HBV Test for Use on the Cobas® 4800 System.

(1) Background: Sensitive and accurate nucleic acid amplification technologies are now recommended for hepatitis B virus (HBV) DNA detection and quantification in clinical practice to diagnose and monitor hepatitis B infection. The aim of this study was to assess the analytical and clinical performance of the cobas® HBV Test on the cobas® 4800 System. (2) Methods: Standard panel and clinical specimens were tested in parallel with three different real-time commercial PCR assays including the cobas ® HBV Test, the Cobas® AmpliPrep/Cobas® TaqMan HBV Test v2.0 and Alinity™ m HBV assay. (3) Results: The specificity of the cobas® HBV Test was 97.9%. The limit of detection was estimated to be 2.1 IU/mL. Intra-assay and interassay coefficients of variation varied from 0.14% to 1.92% and 2.16% to 12.02%, respectively. HBV DNA levels in patients infected with different HBV genotypes strongly correlated with those measured by the two other commercial comparators assays. (4) Conclusions: The cobas® HBV Test can be confidently used to detect and accurately quantify HBV DNA in clinical practice as well as in clinical trials with the new anti-HBV drugs currently in development.

Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test.

Accurate measurement of the hepatitis B virus (HBV) DNA is important for the management of patients with chronic HBV infection. Here, the performance of the Xpert® HBV Viral Load test (Xpert HBV Viral Load) versus the Roche COBAS® Ampliprep/COBAS® TaqMan® system (CAP/CTM HBV) HBV test v2.0 was evaluated. From September 2017 to December 2017, a total of 876 prospectively collected or archived serum or EDTA plasma specimens from subjects chronically infected with HBV were tested using the Xpert HBV Viral Load and the CAP/CTM HBV v2.0 assays. Of the 876 specimens tested, 560 were within the quantitative range of both assays. The agreement between the two methods was 90.0%. No difference in plasma or serum samples was observed. Deming regression analysis showed a good correlation of the Xpert HBV Viral Load assay with the CAP/CTM HBV v2.0 assay. The Bland-Altman analysis showed a good agreement between the results of the Xpert HBV Viral Load assay and the CAP/CTM HBV assay, with a mean difference (±1.96 standard deviation) of 0.0091 ± 0.3852 Log IU/mL. Comparing the two assays, only nineteen specimens (2.1%) had a difference greater than 1.96 times the standard deviation. The Xpert® HBV Viral Load test is suitable for monitoring patients with HBV infection and is useful in diagnostic settings.

Assessing Molecular Point-of-Care Testing and Dried Blood Spot for Hepatitis C Virus Screening in People Who Inject Drugs.

BACKGROUND: Injecting drug use is a major driver of hepatitis C virus (HCV) spread worldwide, and the World Health Organization (WHO) has identified people who inject drugs (PWID) as a key population to target for HCV screening and care. Point-of-care (POC) hepatitis C tests and dried blood spot (DBS) sampling offer benefits for the management of patients with HCV infection by increasing HCV testing and linkage to care in different nonclinical settings. The aims of this prospective study were to evaluate the feasibility and the acceptability of use HCV ribonucleic acid (RNA) POC and fingerstick DBS testing in social-medical risk-reduction centers and to describe the cascade of care among PWID in France. METHODS: Between June 2018 and February 2019, 89 consecutive HCV-seropositive PWID attending 2 drug treatment services and 1 supervised consumption room in inner Paris were invited to participate in further evaluation, undergoing a clinical review with a liver assessment and blood tests including fingerstick capillary whole blood POC HCV RNA testing and fingerstick DBS sampling. RESULTS: Of the 89 participants enrolled, HCV RNA was detected in 34 (38.6%) participants. Fingerstick whole blood POC RNA testing and HCV RNA detection from DBS sample were feasible and acceptable among PWID with no major difference in terms of HCV RNA detection rate. Overall, 16 participants received pan-genotypic antiviral treatment. The proportion of PWID with sustained virologic response at 12 weeks was 81.2%, with data for 3 patients still pending. CONCLUSIONS: One-step screening strategy based on the detection of HCV RNA would engage people in care for treatment scale-up and HCV elimination.

Evaluation of the Xpert HBV Viral Load for hepatitis B virus molecular testing.

BACKGROUND: Accurate molecular methods to detect and quantify hepatitis B virus (HBV) DNA are essential to diagnose chronic infections, guide treatment decisions, assess response to treatment, and determine risk of HBV-related complications. New HBV DNA generations of real-time assay platforms are now available with the availability of results in less than 2-3 h and a continuous loading of specimens with true random access. OBJECTIVES: The aim of this prospective study was to evaluate the performance of the new Xpert HBV Viral Load assay to accurately quantify HBV DNA in plasma and in whole blood collected on dried blood spot (DBS). METHODS: Plasma and whole blood from 143 patients chronically infected with HBV were tested in parallel using two commercially real-time PCR assay (Cobas AmpliPrep/Cobas Taqman HBV test, version 2.0, and Xpert HBV Viral Load assay). RESULTS: HBV DNA levels in whole blood strongly correlated with those measured in plasma. A positive significant correlation between the HBV DNA levels in plasma measured with the new Xpert HBV Viral Load and CAP/CTM HBV v2.0 assays was found. CONCLUSIONS: The newly developed real-time PCR-based assay Xpert HBV Viral Load accurately quantifies HBV DNA in whole blood specimens as well as in plasma samples from patients with chronic HBV infection. Whole blood specimens collected on DBS can be confidently used for replicative HBV infection detection in patients with HBV DNA level above 3 Log using standardized, commercially available methods.

The new Xpert HCV viral load real-time PCR assay accurately quantifies hepatitis C virus RNA in serum and whole-blood specimens.

BACKGROUND: Sensitive and accurate hepatitis C virus (HCV) RNA detection and quantification are essential to diagnose and monitor the virological response to antiviral treatment and the emergence of resistance. OBJECTIVE AND STUDY DESIGN: The aim of this study was to assess the ability of the new Xpert HCV Viral Load assay to accurately detect and quantify HCV RNA in serum and in whole blood collected on dried blood spot (DBS). Serum and whole blood from a large series of patients chronically infected with different HCV genotypes were tested in parallel for HCV RNA detection and quantification. RESULTS: A significant relationship between HCV RNA levels measured with the Xpert HCV Viral Load assay and the two commercial real-time PCR comparators (Abbott RealTime HCV test and Cobas AmpliPrep/Cobas Taqman HCV 2.0 test) was found in serum as well as in whole blood specimens. CONCLUSIONS: The Xpert HCV Viral Load assay accurately quantifies HCV RNA regardless of the HCV genotype and can thus confidently be used to detect active HCV infection in serum and in whole blood specimens.

Performance assessment of a fully automated deep sequencing platform for HCV resistance testing.

BACKGROUND: International liver society guidelines recommended to perform HCV resistance testing at baseline of first-line therapy with certain combination regimens or prior to retreatment in patients previously exposed to a direct-acting antiviral (DAA) containing regimen. Currently, no standardized assays have been developed as purchasable kits for HCV resistance testing. The aim of this study was to evaluate the performance of the Sentosa SQ HCV Genotyping Assay, a novel deep sequencing-based assay, to identify resistance-associated substitutions (RASs) in the NS3 protease, NS5A protein domain I and NS5B polymerase regions for patients infected with HCV genotypes-1a and 1b. METHODS: Serum samples collected from patients with chronic hepatitis C infection who failed to achieve a sustained virological response after receiving a DAA-containing treatment regimen were extracted and sequenced by two methods including population sequencing of the NS3, NS5A and NS5B coding region reference method and the deep sequencing-based Sentosa SQ HCV Genotyping Assay. RESULTS: A high concordance rate with Sanger sequencing, the reference method, was found for the NS3, NS5A and NS5 coding regions, regardless of the genotype-1 subtypes. The deep sequencing-based assay was more sensitive than population sequencing to detect minority variants, representing less than 10% of the viral populations, but also some variants representing up to 30% of the viral quasispecies, as expected. CONCLUSIONS: The Sentosa SQ HCV Genotyping Assay can be confidently used in clinical practice in the indications of HCV resistance testing for these subtypes. Technical improvements are now required to allow for pangenotypic coverage.

Performance of a new rapid diagnostic test for the detection of antibodies to hepatitis C virus.

Rapid diagnostic tests (RDTs) represent an attractive alternative to conventional diagnostic methods for hepatitis C virus (HCV) infection. The aim of the present study was to assess the clinical performance of the new CE-marked Advanced Quality™ Rapid Anti-HCV Test for the detection of HCV antibodies in various patient populations. A total of 396 individuals, including 178 patients with chronic HCV infection, 26 patients with resolved HCV infection, and 192 subjects not infected with HCV, were studied. The clinical sensitivity and specificity in serum samples of the Advanced Quality™ Rapid Anti-HCV Test were both 99%. The new CE-marked RDT Advanced Quality™ Rapid Anti-HCV Test fulfills the World Health Organization recommendations acceptance criteria for serological assays in terms of sensitivity and specificity and can thus be confidently used for the screening of HCV antibodies.