Analytical performance of the VERIS MDx system HCV assay for detecting and quantifying HCV RNA

Performance evaluation of NeuMoDx 96 system for hepatitis B and C viral load

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) viral load (VL) estimation is essential for the management of both HBV and HCV infections. Due to a longer turnaround time for VL estimation, many patients drop out from the cascade of care. To achieve the global goals of reducing morbidity and mortality due to HBV/HCV and moving towards their elimination by 2030, molecular diagnostic platforms with faster and random (i.e. single sample) access are needed.

AIM

To evaluate the performance of the recently launched NeuMoDx 96 random access system with the conventional COBAS®AmpliPrep/COBAS TaqMan system for HBV and HCV VL estimation.

METHODS

Archived once-thawed plasma samples were retrieved and tested on both platforms. Correlation between the assays was determined by linear regression and Bland-Altman analysis. The study included samples from 186 patients, 99 for HBV of which 49 were true infected HBV cases (hepatitis B surface antigen, anti-hepatitis B core antibody, and HBV DNA-positive) and 87 for HCV assay in which 39 were true positives for HCV infection (anti-HCV and HCV RNA-positive).

RESULTS

The median VL detected by NeuMoDx for HBV was 2.9 (interquartile range [IQR]: 2.0-4.3) log10 IU/mL and by COBAS it was 3.70 (IQR: 2.28-4.56) log10 IU/mL, with excellent correlation (R2 = 0.98). In HCV, the median VL detected by NeuMoDx was 4.9 (IQR: 4.2-5.4) log10 IU/mL and by COBAS it was 5.10 (IQR: 4.07-5.80) log10 IU/mL with good correlation (R2 = 0.96).

CONCLUSION

The overall concordance between both the systems was 100% for both HBV and HCV VL estimation. Moreover, no genotype-specific bias for HBV/HCV VL quantification was seen in both the systems. Our findings reveal that NeuMoDx HBV and HCV quantitative assays have shown overall good clinical performance and provide faster results with 100% sensitivity and specificity compared to the COBAS AmpliPrep/COBAS TaqMan system.

Performances of NeuMoDx™, a random-access system for hepatitis B virus DNA and hepatitis C virus RNA quantification

OBJECTIVE

Monitoring of viral loads (VL) for hepatitis B and C viruses (HBV; HCV) is essential to evaluate disease progression and treatment response. Automated, random-access rapid systems are becoming standard to provide clinicians with reliable VL. The aim of this study was to evaluate the analytical performances of the recently launched NeuMoDx™ for HBV-DNA and HCV-RNA quantification.

METHODS

Clinical samples routinely quantified on the Beckman-Veris system were either retrospectively (frozen samples; HBV n = 178, HCV n = 249), or in parallel (fresh primary tubes; HBV n = 103, HCV n = 117) tested using NeuMoDx™. Linearity range was assessed on serial dilutions of high-titre plasmas containing different genotypes for HBV (A-E, n = 9) and HCV (1a,1b,2-5, n = 12).

RESULTS

Overall test failure, mostly internal control amplification failure, was 2.3% and was not influenced by matrix types (fresh or frozen). For HBV VL, κ agreement was 74%, with 27 (12.6%) discrepancies. Correlation between HBV assays on 72 quantified samples by both methods was excellent (r = 0.963) with a mean bias (NeuMoDx™-Veris) of 0.21 log IU/mL. For HCV VL, κ agreement reached 94%, with 9 (2.8%) discrepancies. The r correlation factor between assays on 104 samples was 0.960 with a mean bias of -0.14 log IU/mL (NeuMoDx™-Veris). Serial dilutions confirmed the claimed linear ranges for all analysed HBV and HCV genotypes. The mean turnaround time was 72 minutes (range 55-101 minutes) for HBV and 96 minutes (range 78-133 minutes) for HCV.

CONCLUSION

Results obtained on the NeuMoDx™ confirmed the overall good functionality of the system with a short turn-around-time, full traceability and easy handling. These results on HBV and HCV VL look promising and should be challenged with further comparisons.

Comparison of Performance Characteristics of DxN VERIS System versus Qiagen PCR for HBV Genotype D and HCV Genotype 1b Quantification

The Beckman Coulter DxN VERIS system is a fully automated, closed molecular diagnostic instrument for viral load quantification of hepatitis B virus and hepatitis C virus. In this study, the analytical performance of this new system was compared to routine diagnostic Qiagen PCR kit by using the same clinical samples. The DxN VERIS system demonstrated a high analytical performance. The DxN VERIS allows random access, which means that samples can be uploaded straight on to the system at any time; so, it provides an improvement of workflow, staff productivity and allows faster turn-around of viral load results.

Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples

BACKGROUND

Chronic hepatitis C virus (HCV) infection can be effectively treated with directly acting antiviral (DAA) therapy. Measurement of HCV RNA is used to evaluate patient compliance and virological response during and after treatment.

OBJECTIVES

To compare the analytical performance of the Aptima HCV Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HCV Test v2.0 (CAPCTMv2) for the quantification of HCV RNA in plasma samples, and compare the clinical utility of the two tests in patients undergoing treatment with DAA therapy.

STUDY DESIGN

Analytical performance was evaluated on two sets of plasma samples: 125 genotyped samples and 172 samples referred for quantification of HCV RNA. Furthermore, performance was evaluated using dilutions series of four samples containing HCV genotype 1a, 2b, 3a, and 4a, respectively. Clinical utility was evaluated on 118 plasma samples obtained from 13 patients undergoing treatment with DAAs.

RESULTS

Deming regression of results from 187 plasma samples with HCV RNA >2 Log IU/mL indicated that the Aptima assay quantified higher than the CAPCTMv2 test for HCV RNA >4.9 Log IU/mL. The linearity of the Aptima assay was excellent across dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs.

CONCLUSIONS

The analytical performance of the Aptima assay makes it well suited for monitoring patients with chronic HCV infection undergoing antiviral treatment.

Clinical performance of the VERIS HCV assay for hepatitis C virus RNA quantification

BACKGROUND

Diagnosis of hepatitis C virus (HCV) infection and treatment monitoring rely on detection/quantification of HCV RNA and real-time polymerase chain reaction (PCR) techniques are expected to equivalently quantify the different HCV genotypes.

OBJECTIVE

The clinical performance of the VERIS HCV assay for HCV RNA quantification was compared to that of the Abbott RealTime HCV assay.

STUDY DESIGN

Qualitative concordance and quantitative comparison were evaluated on a first panel of 286 clinical samples containing HCV genotypes 1-6. Forty additional genotype 4 samples were tested to explore genotype 4 HCV RNA underquantification.

RESULTS

Qualitative discrepancies were observed for low viral loads (<2 log₁₀ IU/mL) in patients under antiviral therapy and would not have had any impact on patients' management with the current guidelines for the monitoring of patients on direct-acting antivirals (DAAs). Quantification results were well correlated (R²=0.89) with an overall minimal quantification bias (mean VERIS - Abbott difference) of -0.09 log₁₀ IU/mL. Quantification agreement for genotypes 1, 2 and 3 samples was excellent, but reached -0.57 log₁₀ IU/mL for 46 genotype 4 samples. A lower quantification bias of -0.24 log₁₀ IU/mL was observed when testing 40 additional genotype 4 samples with a second reagent lot. Underquantification was not associated with 5' untranslated region (UTR) sequence polymorphisms but could be explained by 5' UTR RNA molecular modeling.

CONCLUSION

HCV RNA quantification by the VERIS HCV assay and the Abbott RealTime HCV assay was well correlated for all HCV genotypes, except genotype 4 where 5' UTR RNA folding may impact quantification. Nevertheless, this underestimation of HCV RNA levels had no impact on clinical use.

A European multicentre study on the comparison of HCV viral loads between VERIS HCV assay and COBAS® TaqMan® HCV Test and RealTime HCV Assay

BACKGROUND

Beckman Coulter has developed the VERIS HCV Assay for use on the new fully automated DxN VERIS Molecular Diagnostic System^¥ for HCV viral load monitoring.

OBJECTIVES

Evaluate the clinical performance of the new quantitative VERIS HCV Assay.

STUDY DESIGN

Comparison was performed on 279 plasma specimens from HCV infected patients tested with the VERIS HCV Assay and COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test and 369 specimens tested with the VERIS HCV Assay and RealTime HCV Assay. Patient monitoring sample results from four time points were also compared.

RESULTS

The average bias between the VERIS HCV Assay and the COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test was 0.04 log₁₀IU/mL, while between the VERIS HCV Assay and the RealTime HCV Assay average bias was 0.21 log₁₀IU/mL. Bias, however, was not consistent across the measuring range. Analysis at the lower end of quantification levels 50, 100, and 1000IU/mL showed a predicted bias for VERIS HCV Assay versus COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test between -0.42 and -0.22 log₁₀IU/mL and for VERIS HCV Assay versus RealTime HCV Assay between 0.00 and 0.13 log₁₀IU/mL. Patient monitoring of HCV viral load over time demonstrated similar levels between VERIS HCV Assay results and COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test (52 samples from 13 patients) and RealTime HCV Assay (112 samples from 28 patients).

CONCLUSIONS

VERIS HCV Assay for use on the DxN VERIS Molecular Diagnostic System represents a reliable new tool for easy sample to result HCV RNA viral load monitoring.

Profile of Roche's cobas® HCV tests

INTRODUCTION

Molecular assays for detection and accurate quantitation of hepatitis C virus (HCV) RNA have been important for identification and management of the hepatitis C. Furthermore, the HCV genotype should be assessed prior to treatment initiation. Recently, Roche developed the cobas® HCV tests for use on the cobas® 6800/8800 Systems and the cobas® 4800 System and the cobas® HCV genotyping (GT) test for use on the cobas® 4800 System. Areas covered: The analytic and clinical performance of the newly-developed tests is described according to the currently existing literature. Both tests for detection and quantitation of HCV RNA have been shown to be sensitive and linear, and correlate well with established Roche tests used in the routine diagnostic laboratory. The cobas® HCV GT test shows a good performance and is suitable for identification of HCV genotypes 1 to 6 and genotype 1 subtypes a and b in clinical specimens from individuals with chronic HCV infection. Expert commentary: The new tests are effective in screening for hepatitis C infection and in the management of patients with chronic HCV infection ensuring full HCV genotype coverage. They will replace the established Roche tests within the next few years.