HCV Assay Research Articles

Performance of HCV core antigen and PCR testing in a predominantly genotype 3 population.

Hepatitis C core antigen (HCVcAg) is becoming increasingly recognized as an alternative to molecular testing for the confirmation of chronic hepatitis C. However, there are limited data on the performance of this assay in a genotype 3 (GT3) predominant country like Pakistan. We conducted a study to evaluate the diagnostic performance of HCVcAg against the HCV polymerase chain reaction (PCR) molecular test. HCV antibody-positive patients requiring confirmatory testing were recruited from August to October 2018 at the Pakistan Kidney and Liver Institute and Research Center (PKLI&RC), Lahore, Pakistan. Patients with previously known diagnoses or treatment histories were excluded. The Abbott HCV Ag assay was used for HCVcAg testing. Results ≥3.00 fmol/L were considered positive for HCVcAg. The Abbott RealTime HCV assay was used for PCR testing with a lower detection limit of ≥12 IU/mL. We computed the sensitivity, specificity and correlation of HCVcAg against HCV PCR. A total of 394 patients were recruited. The median age of the patients was 42 years. Most participants were females (51.5%, n = 203), 30.7% (n = 121) had HTN, 10.4% DM (n = 41) and 5% had APRI ≥2. The overall sensitivity was 98.0% and the specificity was 98.6%. The lowest detection limit of cAg was an HCV RNA value of 4657 IU/mL. The levels of cAg were highly correlated with those of HCV RNA by Spearman's rank correlation test (r = 0.935, p < .001). HCVcAg represents a suitable alternative with high sensitivity and specificity compared with HCV PCR in the GT3-predominant population and can be incorporated into algorithms to improve linkage to care.

Evaluation of GeneXpert and advanced biological laboratories UltraGene HCV diagnostic detection and performance against Roche real time PCR in Myanmar

BackgroundDeveloping countries experience limited access to HCV laboratory tests for different reasons. Providing near to real–time HCV testing and results especially to at–risk populations including those in rural settings for timely initiation to treatment is key. Within a rural Myanmar setting, we compared HCV diagnostic detection and quantification of the GeneXpert, and Advanced Biological Laboratories UltraGene–HCV assays against the gold standard and reference method Roche real–time HCV in Myanmar. MethodsBlood samples from 158 high–risk individuals were assessed using three different methods at baseline. Results were checked for normality and log transformed. Log differences and bias between methods were calculated and correlated. Pearson's correlation coefficient was used to determine the association of HCV viral loads across all methods. The level of agreement with the standard method (Roche real time HCV) was assessed using Bland–Altman analyses. ResultsThere was a strong positive correlation coefficient between all three methods with GeneXpert and Roche having the strongest, r = 0.96, (p<0.001). Compared to Roche, ABL (mean difference, 95 % limits of agreement; -0.063 and -1.4 to 1.3 Log10IU/mL) and GeneXpert (mean difference, 95 % limits of agreement; -0.28 and -0.7 to 1.8 Log10IU/mL) showed a good level of agreement with the GeneXpert being slightly superior. ConclusionWe demonstrate the excellent performance and no-inferiority, in terms of levels of agreements of both GeneXpert and ABL compared to the Roche platform and supporting the use of the POC assays as alternative a cost-effective methods in HCV detection and diagnosis in developing and low resource settings countries.

Clinical performance evaluation of HCV and HIV-1 assays on the fully automated molecular system Alinity m

The demand for molecular virology testing continues to grow in clinical laboratories worldwide. The Alinity m system is a fully automated, continuous, random-access molecular diagnostic analyzer that was designed to streamline the laboratory workflow. In this study, we assessed the clinical performance characteristics of the Alinity m HCV and HIV-1 assays to detect and quantify these two bloodborne pathogens in 71 serum and plasma specimens. The overall qualitative agreement between the Alinity m and Abbott m2000 was 100 % for HCV and 94.4 % for HIV-1. Our data demonstrated a weak bias across the quantitative range of the Abbott m2000 and Alinity m HCV and HIV-1 assays, indicating a strong correlation on viral loads between them. Taken together, the Alinity m HCV and HIV-1 assays had comparable results to their current predecessors, the Abbott RealTime HCV and HIV-1 assays.

A-244 Performance Comparison of the Alinity i Hepatitis C Core Antigen Assay in Routine Laboratory Testing vs HCV RNA Testing

Abstract Background The elimination of Hepatitis C by 2030 is a goal established by the WHO and other country specific health organizations worldwide. This goal is enabled by the availability of effective treatment regimens. A recent surprise in the US has been the increase in HCV infections during the COVID 19 pandemic, which may be caused by increased needle sharing. HCV Antibody assays have been used to screen for HCV, but confirmation of acute infection is relegated in the current US guidelines to PCR which often takes multiple days and may result in a loss to follow up and treatment, especially in high prevalence populations. HCV Core Antigen is a new immunoassay on the Alinity i system. The aim of the study was to evaluate the precision, linearity, and sensitivity of this research use assay in a US-based population. Methods Alinity i assay HCV Ab is an automated chemiluminescent immunoassay built to measure total antibody to the virus. Similarly, the Alinity i HCV Core Ag is a research use only automated chemiluminescent immunoassay for detection of HCV Core antigen in human plasma and serum. Precision (repeatability, and reproducibility) was determined over 3 days (4–10 replicates/day) using control material consisting of a negative human plasma control, and positive controls made with recombinant core Ag in buffer. Linearity was evaluated by preparing 4 dilutions of a remnant specimen with detectable HCV RNA viral load. Clinical sensitivity was determined using 90 remnant specimens with positive HCV Ab results. Specimens were confirmed positive for Hepatitis C via HCV RNA quantitation using the Aptima HCV Quant Dx transcription-mediated amplification (TMA) assay on the Panther System. Correlation between the HCV Ag assay and TMA was evaluated using specimens submitted for either Hepatitis C infection screening and monitoring of known infection. Results The repeatability of the HCV Ag assay ranged between 3.7% and 11.1% CV depending on the sample S/CO level tested. Dilution recovery averaged 98.2% (range 90.2%–107.3%) and a plot of HCV Ag concentration vs dilution factor showed a correlation coefficient R = 0.998 The Hepatitis C core antigen assay had a correlation coefficient R = 0.92 with the TMA. The HCV assay demonstrated a clinical sensitivity of 96.7% vs TMA. Conclusion The performance characteristics of the Alinity i HCV Core Ag assay highlight an opportunity to speed time to treatment by reflexing on the same instrument from HCV Ab to Ag and confirming effectiveness of treatment.

Clinical performance evaluation of the Aptima viral assays for the quantitation of HIV-1, HCV, and HBV in plasma samples

The clinical performance of the Aptima® HIV-1 Quant Dx, Aptima HCV Quant Dx, and Aptima HBV Quant Dx were evaluated and compared to the Roche cobas HIV-1, HCV, and HBV assays performed on the Roche cobas 6800 system. The Aptima Quant assays exhibited an overall percent agreement of 99.4% for HBV, 98.3% for HCV, and 85.14% for HIV-1. The average log difference between the Aptima and Roche assays was below 0.2 IU (or copies)/mL and the quantitative correlation's (R-squared value (R2)) was between 0.95 and 0.97. The Aptima viral assays demonstrated a high level of quantitative correlation with the Roche cobas assays for HCV, HBV, and HIV-1.

Serological testing on the ADVIA Centaur system for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in specimens from deceased and living individuals demonstrates equivalent resultsƚ.

IntroductionTo determine the suitability of human tissues and cells for transplantation, guidelines mandate infectious disease testing of serum or plasma obtained from deceased donors, which are often collected after cessation of the heartbeat. Tests used for this purpose are required to show equivalent performance when compared to pre‐mortem specimens. This study evaluated whether serology assays for HIV Ag/Ab Combo, hepatitis B virus (HBc Total; HBsAgII), and HCV on the ADVIA Centaur system, were fit for testing post‐mortem sera. Performance evaluation studies included precision, specificity, and sensitivity.MethodsBlood specimens were collected within 24 h after death from 82 deceased and 83 healthy living individuals. Studies followed standard guidelines. The 20‐day precision study was performed on five levels of post‐mortem specimens (non‐spiked and spiked). The specificity study compared 81–83 pre‐mortem and 74–82 post‐mortem specimens. The sensitivity study compared 50 pre‐mortem and 50 post‐mortem specimens spiked with positive sera for each analyte at two levels to achieve a low (near cutoff) positive result and a second higher positive result.ResultsPrecision, specificity, and sensitivity study results met acceptance criteria for all assays and lots; post‐mortem and pre‐mortem results were equivalent.ConclusionBased on this study, the ADVIA Centaur CHIV, HBcT, HBsAgII, and HCV assays are acceptable for use in routine testing of deceased donor sera collected after cessation of the heartbeat.

Clinical performance evaluation of Elecsys HIV Duo, Anti-HCV II, HBsAg II, Anti-HBc II, and Syphilis assays for routine screening of first-time blood donor samples at a French blood donation center.

Implementing fully automated analyzers has become a crucial safety step in blood donation centers. The Elecsys® assays were evaluated on the cobas e 801 module (Roche Diagnostics) for routine first-time blood donor screening. Five Elecsys infectious disease assays were tested on the cobas e 801 module at Etablissement Français du Sang, Montpellier, France (March-April 2018). The performance of Elecsys HIV Duo, Anti-HCV II, HBsAg II, Anti-HBc II, and Syphilis assays was compared with PRISM HIV O Plus, HCV, HBsAg, HBcore, and newbio pk TPHA assays (specificity analyses)/ARCHITECT Syphilis TP (sensitivity analyses), respectively. Specificity was determined in residual fresh serum samples from unselected first-time blood donors (n≥5195 per parameter). Elecsys assay sensitivity was tested using 30 preselected, positively characterized samples per assay and compared with archived routine testing data for comparator assays. Across all parameters, specificities for repeatedly reactive samples ranged from 99.81-100.00% for Elecsys assays and 99.71-99.98% for comparator assays. Sensitivities of Elecsys and comparator assays were the same for hepatitis C (85.19%), hepatitis B surface antigen (70.00%), hepatitis B core antigen antibodies (100.00%), and syphilis (100.00%). The sensitivity of the Elecsys HIV Duo assay was higher than the comparator assay (83.33% vs. 76.67%), but the difference was not statistically significant. Elecsys infectious disease assays on the cobas e 801 module demonstrated high specificity and sensitivity for screening first-time blood donor samples, and were comparable with other commercially available assays. The Elecsys assays are reliable tests for screening blood donations.

Background rate of low-level HCV RNA in anti-HCV confirmed-positive and minipool nucleic acid test-nonreactive blood donations.

In 2019, the Food and Drug Administration revised the requirement for further testing of anti-HCV-reactive donations testing nucleic acid (NAT)-nonreactive via routine mini-pool (MP)-NAT. Individual donation (ID)-HCV NAT was required as a supplemental test prior to a second FDA-licensed anti-HCV assay; if ID-HCV-NAT is reactive, no further testing is required. This study investigated the rate of low-level RNA in anti-HCV-reactive donation samples prior to and following the implementation of supplemental ID-HCV NAT. A retrospective analysis was conducted on frozen plasma unit samples from 1161 anti-HCV confirmed-positive/HCV-NAT-nonreactive donations collected from December 2014 to January 2020. Samples were tested by multiple replicates on the Grifols Procleix Ultrio Elite (UE) assay and corresponding discriminatory HCV (dHCV) assay on the Procleix Panther System. Prospectively, the prevalence of low-level RNA in 2912 anti-HCV-reactive donations detected through routine screening from April 2020 through March 2021 was determined. In retrospective analyses, 10 (0.86%) of 1161 plasma samples were UE reactive, of which four (0.34%) were dHCV reactive (in all replicates of UE and dHCV). Of 2912 anti-HCV-reactive donation samples testing NAT-nonreactive via routine MP-NAT, three (0.1%; 95% CI: 0.04-0.30) were dHCV reactive; 37% of the remaining samples were reactive by a second anti-HCV assay and thus serologically confirmed. Retrospective and prospective analysis in comparison to earlier studies revealed that low-level HCV-RNA reactivity is decreasing over time. The very low HCV-RNA rates may be due to the widespread use of highly effective, direct-acting anti-viral treatments for those diagnosed with HCV infection.

Chromatographic Isolation and Characterization of Certain Bioactive Chemical Ingredients of Phyllanthus emblica Extracts and Assessment of Their Potentials as Antiviral and Anticancer Agents

Aim: our study has been aimed to evaluate the antioxidant, anticancer and antiviral activities of Phyllanthus emblica leaves, as well as characterization of bioactive chemical constituents. Methods: The total phenolic and flavonoid contents of plant extracts were determined using Folin-Ciocalteu’s and aluminium trichloride assays, respectively. The antioxidant activities were evaluated by different methods as well as the anticancer activity via MTT assay, while the antiviral activity was evaluated using cytopathic effect (CPE) inhibition and anti- HCV assays. Moreover, the extracts phytoconstituents were characterized using reversed phase high-performance liquid-chromatography method. Results: Our finding revealed that P. emblica is rich in glycosides, flavonoids, phenolics, terpenoids and tannins. The n-butanol fraction exhibited the highest total phenolic and flavonoid contents with values 654.78 mg GAE /g ext and 110.14 mg RE / g ext, respectively. Also, it possessed the most effective antioxidant activities (DPPH; SC50=19.59 µg/mL, RPAA; 0.948 mg AAE /g ext., and TAC; 543.62mg AAE /g ext.) and anticancer activity against HepG-2 and MCF-7 cell lines with an IC50 of 25.63 and 22.80μg/mL, respectively. Moreover, Phyllanthus emblica extracts exhibited anti-HCV activity. The HPLC finger print results of Phyllanthus emblica extracts showed 14 peaks superimposed to the standards. Structure elucidation of pure isolates was achieved via IR, UV, 1H & 13C-NMR

Performance evaluation of the fully automated molecular system Alinity m in a high-throughput central laboratory.

New partially or fully automated molecular diagnostic testing platforms are being developed to address the growing demand for fast, accurate, and cost-effective testing. To evaluate the analytical and clinical performance of the Alinity m system compared to the Abbott RealTime m2000 assay system in a large central molecular laboratory. Alinity m HIV-1, HCV, and HBV assay precision, reproducibility, and sensitivity were assessed using commercial customized dilution panels. Clinical performance of the Alinity m and m2000 assay systems was compared using standard lab protocols and residual, de-identified patient specimens. A workflow analysis of 1,068 samples compared turnaround times (TATs) on five m2000 systems and one Alinity m system running Alinity m HIV-1, HCV, HBV, HR HPV, and STI assays. The Alinity m assay system demonstrated high detectability and precision at clinical decision points and excellent correlation with Abbott RealTime assay results. Processing TAT for 100 % of results was 117 min on Alinity m. Sample onboard TAT, from sample loading to 95 % of results, was 5:15 h for Alinity m and 7:30 h for m2000. 100 % of STAT samples were processed within 4 h on Alinity m. Total TAT for 100 % of results from all five assays was 80 h for m2000 versus 9 h for Alinity m. The Alinity m system produces assay results comparable to those of the Abbott RealTime m2000 system, but with significantly faster turnaround times due to continuous loading and the ability to run multiple assays simultaneously on the same sample.

A study of performance evaluation of cobas e 801 infectious diseases panel

BackgroundInfectious diseases, such as HCV infection, HBV infection and syphilis, put a huge burden on public health. Accurate and fast testing is required for clinical usage. ObjectivesThis study aimed to evaluate the clinical performance of Elecsys® Anti−HCV II, Elecsys® HBsAg II and Elecsys® Syphilis using samples from routine diagnosis in China. MethodsSpecificity was tested in approximately 3000 unselected pseudonymized samples from routine clinical patients for each assay. Sensitivity of HCV and HBsAg assays was tested in 2 seroconversion panels, respectively. ResultsThe 3 investigational assays on cobas e 801 were showed to have excellent sensitivity and specificity which is comparable to existing assays. ConclusionThey are suitable for routine clinical diagnostic use, including pre-operative assessment in China.

Evaluation of the Point of Care Molecular Diagnostic Genedrive HCV ID Kit for the detection of HCV RNA in clinical samples.

2. Abstract BACKGROUND Despite the availability of an effective treatment for HCV infection, major bottle neck in the HCV care cascade is difficulty in getting the HCV RNA done on serologically positive (antibody to HCV) patients. This is due to the limited availability of HCV RNA test in the periphery. Nucleic acid amplification testing at point of care might revolutionise the HCV care continuum through its increased sensitivity, decreased turn around time and ease of performance in the field. Genedrive is one such assay which has recently got a CE- IVD certification. OBJECTIVES The diagnostic accuracy of Genedrive HCV ID kit for the qualitative detection of HCV RNA was evaluated by comparing with Abbott HCV RNA in an Indian demographic setting and across a range of different genotypes commonly found in India. STUDY DESIGN For the assay evaluation 150 HCV RNA positive and 170 HCV RNA negative samples as tested by Abbott HCV RNA assay (Abbott, Wiesbaden, Germany) on Automated m2000sp/m2000rt platform, as per the manufacturer’s instructions, that were retrieved from −80°C in the Virology repository were included in the study. All the samples were retrieved and re tested for HCV RNA on Genedrive HCV ID kit and compared with Abbott HCV RNA results. RESULTS Comparison of the Genedrive HCV ID kit with the Abbott Real Time HCV assay revealed a sensitivity of 100 % (95% CI 97.9 to 100) and a specificity of 100 % (95% CI 97.9 to 100) with a positive predictive value and negative predictive value of 100%. Overall diagnostic accuracy of Genedrive was found to be 100% (95% CI 98.9 to 100). CONCLUSION This study demonstrates that Genedrive HCV ID kit can be used for decentralised testing of HCV and ultimately finding the missing million. Highlights Decentralisation of HCV RNA assays is the need of hour for finding the missing millions. Genedrive HCV ID kit is one such assay which can qualitatively detect HCV RNA and can be used as a point of care molecular assay thereby reducing the dropouts and improving the HCV care cascade.

Multicenter clinical evaluation of alinity m HCV assay performance.

Nucleic acid testing is essential for the detection and quantification of HCV RNA in the diagnosis of HCV infection and treatment monitoring. The Alinity m HCV assay was recently developed by Abbott Molecular for rapid detection and quantification of HCV RNA on the fully automated, continuous, random-access Alinity m analyzer. Our study assessed the performance of the new Alinity m HCV assay for detection and quantification of HCV RNA in a large series of patient samples of various genotypes. This international, multicentric study evaluated the linearity, precision, and reproducibility of the Alinity m HCV assay and its performance in comparison to three other HCV assays currently used in clinical practice. The Alinity m HCV assay demonstrated high linearity (correlation coefficient r = 1.00), precision (coefficients of variation [CV] 6.6-13.5 %) and reproducibility (CV 1.7-4.3 % across three control lots). At a concentration near the lower limit of detection, the Alinity m HCV assay exhibited >98 % detectability. The Alinity m HCV assay showed excellent correlation with comparator HCV assays in serum (n = 406) and plasma (n = 1401) samples (correlation coefficients ≥0.96, bias 0.01 to 0.14 Log10 IU/mL). More than 95 % of the quantified results with the Alinity m HCV assay were less than mean bias ± 1.96 SD different from those of the comparator assays. The newly developed Alinity m HCV assay is sensitive, reproducible, and accurately quantifies HCV RNA levels in serum and plasma samples from patients with chronic HCV infection, with no impact of HCV genotype on assay performance.

Comparison of the Abbott Alinity m and m2000 assays for the quantification of HIV-1, HCV and HBV in clinical samples

BackgroundViral load (VL) determination is an essential parameter of the management of patients infected with HIV, HBV or HCV. Many available molecular systems run on a "batch" mode while "random access" systems provide more flexibility. ObjectivesWe compared the performance of HIV-1, HCV and HBV quantification assays on the recently developed Abbott Alinity m system to the m2000 RealTime assays. Study designPlasma specimens sent for viral load determination were prospectively tested on m2000 and Alinity m systems, according to manufacturers' instructions. Additional low and high tittered samples were used to assess reproducibility. ResultsAssays concordance was evaluated from 180 samples for HIV-1, 122 for HBV, and 92 for HCV. A good correlation and a linear relation over the quantification range was observed for the three markers (r > 0.974). The Alinity m assays yielded higher results with a mean quantification bias of 0.22 log cp/ml for 75 HIV-1, 0.3 log IU/ml for 79 HBV, and 0.2 log for 35 HCV samples, though results were equivalent within an allowable difference of 0.3–0.4 log. Qualitative discordance was observed for 43/180 HIV results, 10/122 HBV and 7/92 HCV and involved undetectable or low-level VL. ConclusionThe Alinity m assays have performance equivalent to m2000. Upon implementation, physicians should be aware of the relative overquantification compared to previous Abbott assays, particularly around clinical decision thresholds. With reduced turnarounds and hands-on times compared to the m2000 system, the Alinity m platform may improve significantly the laboratory workflow efficiency for the benefit of physicians and patients.

Clinical utility of hepatitis C virus core antigen assay in the monitoring of direct-acting antivirals for chronic hepatitis C.

BackgroundHepatitis C virus core antigen (HCV Ag) assay has been proposed as a more economical alternative to HCV RNA detection. This study aimed to investigate the clinical utility of HCV Ag assay in the monitoring of direct-acting antivirals (DAAs) for chronic hepatitis C patients.MethodsWe analyzed serum samples from 110 patients treated with paritaprevir/ritonavir, ombitasvir, and dasabuvir (PrOD) with or without ribavirin. The levels for both HCV Ag and HCV RNA assessed by COBAS TaqMan HCV (CTM) Test or Abbott RealTime HCV (ART) assay were evaluated at baseline, week 2, 4, and 12 during treatment and 12 weeks after completion.ResultsBaseline HCV Ag levels showed good correlations with HCV viral load (r = 0.879; p<0.001); whereas the correlation was slightly stronger with CTM test than with ART assay (p = 0.074). The concordance of HCV Ag and HCV RNA undetectability was significantly better in CTM test than in ART assay at week 2 (p = 0.003) and week 4 (p = 0.003). A sustained viral response 12 weeks off therapy (SVR12) was achieved in 108 patients (98%); the HCV Ag assay identified 99% of these patients. Both undetectability of serum HCV Ag and HCV RNA had high positive predictive value at week 2 (98% vs. 100%) and at week 4 (97% vs. 99%) in predicting SVR12.ConclusionsHCV Ag assay may be a feasible alternative to HCV RNA for the determination of SVR12 in patients treated with DAAs.

Verification of the Roche cobas® 6800 PCR 200 µl and 500 µl protocols for the quantification of HIV-1 RNA, HBV DNA and HCV RNA and evaluation with COBAS® Ampliprep/COBAS® TaqMan® assays.

The analytical performance of the cobas 6800 HIV-1, HBV and HCV assays was verified and evaluated to the COBAS Ampliprep/COBAS TaqMan assays. The precision, limit of detection (LoD), limit of quantification (LoQ) and linearity were verified using pooled residual clinical samples. The analytical specificity was verified with negative plasma. HIV-1 analytical reactivity was verified with WHO reference preparations. Accuracy was verified using EQA plasma panels. Evaluation of the equipment was performed using prospectively collected clinical whole blood samples. Excellent precision was demonstrated using both testing protocols (coefficient of variation ≤15 %). The LoDs using the 500 and 200 µl protocols were 20 and 50 cp ml-1 for HIV-1, 10 and 20 IU ml-1 for HBV and 15 and 40 IU ml-1 for HCV, respectively. The LoQs were 40 and 100 cp ml-1 for HIV-1, 20 and 25 IU ml-1 for HBV and 30 and 80 IU ml-1 for HCV, respectively. Assays demonstrated good linearity (R2 ≥0.96). The analytical specificity of the assays was 100 %. There was excellent agreement between the cobas 6800 and CAP/CTM assays (kappa>0.94). The sensitivity, specificity, positive predictive value and negative predictive value for each of the assays were ≥99 %. The cobas HIV-1 and HCV mean quantifications were 0.03 log10 cp ml-1 and 0.17 log10 IU ml-1 higher than the CAP/CTM. The cobas HBV mean quantification was 0.17 log10 IU ml-1 lower than the CAP/CTM. Subtype/genotype specific differences were not observed. Cobas 6800 equipment and assays demonstrated excellent performance and correlated well with CAP/CTM assay results.

Analytical and field evaluation of the Biocentric Generic HCV assay on open polyvalent PCR platforms in France and Cambodia

BackgroundImplementation of affordable methods for HCV viremia is a key priority for identifying individuals who need treatment among persons screened positive for HCV antibodies. Different HCV PCR assays for use on open polyvalent PCR platforms are currently commercially available but studies evaluating the performances of these nucleic acid tests are needed. ObjectivesIn the present study, we evaluated the analytical and clinical performances of a recently developed HCV RNA PCR assay for detection and quantification of HCV viremia. Study designIn this study the Biocentric Generic HCV PCR was compared to the Roche Cobas AmpliPrep/Cobas TaqMan HCV RNA assay. Analytical and clinical performances was evaluated on reference materials and HCV plasma samples collected in 141 patients attending at the Montpellier University Hospital in France. Field evaluation was performed on samples collected in 185 patients attending at Medical Laboratory, Institut Pasteur in Cambodia. ResultsThe lower limit of detection ranged from 50 HCV RNA IU/ml to 300 HCV RNA IU/ml using four different Diasorin and Qiagen automated or manual extraction methods. The specificity (CI) and sensitivity of the assay were 100% (92.5–100), and 98.7% (92.3–99.9), respectively, in France, and 100% (95.5–100), and 100% (94.4–100%), respectively, in Cambodia. Bland–Altman analysis shown good agreement between the two assays including for genotypes 6 HCV, which represent the majority of HCV isolates in Cambodia. ConclusionsThe Biocentric Generic HCV assay has shown overall satisfactory analytical performances and a close agreement to the Cobas HCV assay on clinical specimens collected in France and Cambodia. There is an urgent need to further evaluate commercial assays dedicated to HCV detection and quantification using open polyvalent PCR platforms in different settings.

Evaluating the aptima HIV-1 quant Dx, HCV quant Dx and HBV quant assays against the Abbott HIV-1, HCV and HBV RealTime assays

BackgroundViral load measurement is routine for the management of patients infected with HIV, HCV or HBV, using sensitive, quantitative, nucleic acid amplification tests (NAATs). However, platforms are not equivalent in terms of turnaround time, random access capability and operator hands-on time. Objectives and study designWe compared the performance of the Hologic Panther transcription-mediated amplification based Aptima assays for HIV, HBV and HCV viral load measurement with the corresponding Abbott m2000 RealTime assays. All Aptima assays were run according to the manufacturer’s instructions, on archived patient samples for HIV (n = 251 including subtypes 01_AE, A (A1), B, BG recombinant, C CRF02_AG and G), HBV (n = 117 including genotypes A, B, C and D) and HCV (n = 82 including genotypes 1, 2, 3 and 4). Additional testing was performed with WHO international standards and expanded HIV-1 subtype and HCV NIBSC genotype panels. ResultsThe Hologic Panther Aptima assays for HIV-1 RNA, HBV DNA and HCV RNA viral load measurements performed equivalently to the Abbott m2000 RealTime assays. The performance of the Aptima assays was also acceptable on the WHO and NIBSC standards and subtype/genotype panels. ConclusionsThe Aptima Panther platform offers equivalent clinical performance for the viral load measurement of these three viruses, with the added benefits of reduced turnaround time, random access capability and reduced ‘hands-on time’ for staff, resulting in a potentially superior workflow for diagnostic laboratories.

Significance of detectable HCV RNA below the limit of quantification in patients treated with DAAs using standard and ultrasensitive protocols

Predictive factors of HCV relapse after treatment with DAAs are poorly understood. In this study, we aimed to assess whether the residual viral load positivity observed during or at the end of treatment (EOT) has an impact on viral outcome. Blood samples were collected from 337 patients with genotypes (GT) 1a, 1b, 2, 3, and 4 HCV chronic infection, treated with DAAs to determine HCV RNA load by the Abbott RealTime HCV (ART) assay at treatment week (W) 4, at EOT, and 4, 12, 24 weeks after discontinuation. EOT and other samples with "detected <12/mL" (DNQ) were retested by an ultrasensitive protocol (USP) to confirm the result. Frequency of DNQ was analyzed in subgroups of patients and clinical conditions to assess potential correlations. At W4, 22% and 30.9% of the samples were undetectable and DNQ by ART assay, respectively, but no correlation for achieving SVR was found. In contrast, an HCV RNA cut-off of ≥50/mL at W4 was a significant predictor of therapy failure (P = 0.036, univariate analysis). At EOT, DNQ was associated to 12W treatment duration (P < 0.001) and GT1a infection (P = 0.036). Overall, 20/41 (48.8%) of DNQ samples at EOT or post-treatment W4, were confirmed by USP but only in a single case the patient experienced viral relapse. HCV RNA at W4 can predict SVR, irrespective to genotype or DAA regimen. HCV RNA DNQ at EOT is associated to shorter treatment duration and to GT1a, but is not a predictor of therapy failure.

Implications of HCV RNA level at week 4 of direct antiviral treatments for hepatitis C.

We aimed to determine whether the HCV viral load after four weeks of treatment (W4VL) with direct-acting antiviral agents (DAAs) predicts sustained virologic response (SVR) in a real-world clinical setting. We identified 21095 patients who initiated DAA-based antiviral treatment in the national Veterans Affairs (VA) healthcare system from 01/01/2014 to 06/30/2015. Week 4 viral load was categorized as undetectable, detectable below quantification (DBQ), detectable above quantification (DAQ) with viral load ≤42IU/mL and DAQ with viral load >42IU/mL. Week 4 viral load was undetectable in 36.1%, detectable below quantification in 45.6%, DAQ ≤42 in 9.3%, DAQ >42 in 9.1%. Detectable above quantification was much more common and undetectable week 4 viral load much less common when tested with the Abbott RealTime HCV assay vs the Roche COBAS AmpliPrep/COBAS TaqMan Version 2 assay. Compared to patients with undetectable week 4 viral load (SVR=93.5%), those with detectable below quantification (SVR=91.8%, adjusted odds ratio [AOR] 0.79, P-value=.001), DAQ ≤42 (SVR=90.0%, AOR 0.63, P-value<.001) and DAQ >42 (SVR=86.2%, AOR 0.52, P-value<.001) had progressively lower likelihood of achieving SVR after adjusting for baseline characteristics and treatment duration. Among genotype 1-infected patients who were potentially eligible for 8-week sofosbuvir/ledipasvir monotherapy, we did not find evidence that treatment for 12weeks instead of 8weeks was associated with higher SVR, even among those with detectable above quantification. In summary, DBQ and DAQ W4VL are very common in real-world practice, contrary to what was reported in clinical trials, and strongly predict reduced SVR across genotypes and clinically relevant patient subgroups. Whether and how week 4 viral load results should influence treatment decisions requires further study.