Diagnosis and monitoring of HCV infection using the cobas® HCV test for use on the cobas® 6800/8800 systems

Nanoparticle-Based Visual Detection of Amplified DNA for Diagnosis of Hepatitis C Virus

Rapid, simple, and inexpensive diagnostic point-of-care tests (POCTs) are essential for controlling infectious diseases in resource-limited settings. In this study, we developed a new detection system based on nanoparticle–DNA aggregation (STat aggregation of tagged DNA, STAT-DNA) to yield a visual change that can be easily detected by the naked eye. This simplified optical detection system was applied to detect hepatitis C virus (HCV). Reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers labeled with biotin and digoxigenin. Streptavidin-coated magnetic particles (1 μm) and anti-digoxigenin antibody-coated polystyrene particles (250–350 nm) were added to form aggregates. The limit of detection (LoD) and analytical specificity were analyzed. The STAT-DNA results were compared with those of the standard real-time PCR assay using serum samples from 54 patients with hepatitis C. We achieved visualization of amplified DNA with the naked eye by adding nanoparticles to the PCR mixture without employing centrifugal force, probe addition, incubation, or dilution. The LoD of STAT-DNA was at least 10¹ IU/mL. STAT-DNA did not show cross-reactivity with eight viral pathogens. The detection using STAT-DNA was consistent with that using standard real-time PCR.

SHBG, Bone Mineral Density, and Physical Function Among Injection Drug Users With and Without HIV and HCV

CONTEXT

Sex hormone-binding globulin (SHBG) is a glycoprotein that regulates the bioavailability of sex hormones and is higher in people with HIV (PWH) and hepatitis C virus (HCV). SHBG is associated with aging-related diseases, including osteoporosis and frailty in the general population. However, the relationship between SHBG concentration and bone mineral density (BMD) and physical function among PWH and HCV is unclear.

OBJECTIVE

This study aimed to evaluate the association between chronic infection with HIV and HCV and SHBG, and to assess the relationship of circulating SHBG concentrations with low BMD, physical function impairment, and frailty.

METHODS

A cross-sectional study was conducted of 278 HCV-exposed (HCV antibody positive) adults enrolled with and without HIV and HCV from the AIDS Linked to the IntraVenous Experience cohort study into 4 groups: HCV-/HIV-, HCV-/HIV+, HCV+/HIV-, and HCV+/HIV+. We evaluated the association between SHBG concentrations and grip strength, gait speed, Short Physical Performance Battery score, frailty (Fried Frailty Phenotype), and BMD (lumbar spine, total hip, and femoral neck T-score) by using adjusted multivariable regression stratified by sex.

RESULTS

SHBG concentrations were higher in women, in those with HIV RNA greater than 400 copies/mL (P = .02) and HCV RNA greater than 15 IU/mL (P < .001). In adjusted models, higher SHBG concentrations among women were statistically significantly associated with lower grip strength (-0.43 [95% CI, -0.77 to -0.081] kg/10 nmol/L, P < .05), higher odds of frailty (odds ratio, 1.49 [95% CI, 1.07 to 2.08], P < .05), and lower T-scores at the lumbar spine (-0.070 [95% CI, -0.15 to -0.001] SD/10 nmol/L T-score BMD, P < .05). Similar associations were not observed among men.

CONCLUSION

Higher SHBG concentrations are associated with the presence of HIV and HCV viremia. Among women, but not men, higher SHBG concentrations were associated with lower grip strength, higher odds of frailty, and lower lumbar spine BMD. The underlying mechanisms of these associations require further investigation.

Performance Evaluation of In Vitro Screening and Diagnostic Kits for Hepatitis C Virus Infection

Aim

A reliable kit with high sensitivity and specificity is indispensable for diagnosing hepatitis C virus (HCV) infection. Detection kits for anti-HCV antibodies (anti-HCV) are used for screening, and quantification kits for HCV RNA and HCV antigen (Ag) are used for the definite diagnosis of HCV infection or the evaluation of the pathological condition of and therapeutic effects in patients with chronic hepatitis C. Several kits are currently available for these purposes and are provided for clinical use in Japan. In this study, we aimed to evaluate the performance of these kits.

Methods

We used International Standards for HCV RNA and HCV Ag and a regional reference panel to evaluate the performance of thirteen anti-HCV, five HCV RNA, and two HCV Ag kits.

Results

All specimens in the regional reference panel were diagnosed correctly by all anti-HCV kits, although the distributions of the quantified values varied, and the ratios of titer classification were not identical across kits. All HCV RNA kits quantified the International Standard with minimum deviation and diagnosed the specimens of the reference panel correctly. The quantified values of the International Standard by two HCV Ag kits were inconsistent. HCV Ag titers of some specimens were underestimated owing to the amino acid polymorphisms in comparison with HCV RNA titers.

Conclusions

The evaluation with International Standards and the regional reference panel was useful for assessing the quality of screening and diagnostic kits for HCV infection, and such quality control is essential for the clinical usage of these kits.

Qualitative and quantitative effects of thermal treatment of naso-oropharyngeal samples before cobas SARS-CoV-2 testing

To improve laboratory safety we thermally treated naso-oropharyngeal samples before testing with the cobas SARS-CoV-2 assay. This study aimed to determine if thermal treatment significantly affects the qualitative detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the quantitative measurement of cobas SARS-CoV-2 ORF1a and E-gene target copy number using an in-house quantitative method. A collection of positive (n = 238) and negative samples (n = 196) was tested in parallel comparing thermal treatment (75 °C for 15 minutes) to room-temperature. There were no significant differences in the final qualitative outcomes for thermal treatment versus room-temperature (99.8% agreement) despite a statistically significant reduction (P < 0.05) in target copy number following thermal treatment. The median ORF1a and E-gene reduction in target copy number was ­0.07 (1.6%) and ­0.22 (4.2%) log₁₀ copies/mL respectively. The standard curves for both ORF1a and E-gene targets were highly linear (r² = 0.99). Good correlation was observed for ORF1a (r² = 0.96) and E-gene (r² = 0.98) comparing thermal treatment to room-temperature control.

Non-pharmacologic direct cost of a simplified strategy with glecaprevir/pibrentasvir for 8 weeks in naïve non-cirrhotic patients with hepatitis C implemented in clinical practice. The Just SIMPLE Study

BACKGROUND AND OBJECTIVE

The emergence of highly tolerable, effective, and shorter duration direct-acting antivirals (DAAs) regimens offers the opportunity to simplify hepatitis C virus management but medical costs are unknown. Thus, we aimed to determine the direct medical costs associated with a combo-simplified strategy (one-step diagnosis and low monitoring) to manage HCV infection within an 8-week glecaprevir/pibrentasvir (GLE/PIB) regimen in clinical practice in Spain.

PATIENTS AND METHODS

Healthcare resources and clinical data were collected retrospectively from medical charts of 101 eligible patients at 11 hospitals. Participants were adult, treatment naïve subjects with HCV infection without cirrhosis in whom a combo-simplified strategy with GLE/PIB for 8 weeks were programmed between Apr-2018 and Nov-2018.

RESULTS

The GLE/PIB effectiveness was 100% (CI95%: 96.2-100%) in the mITT population and 94.1% (CI95%: 87.5-97.8%) in the ITT population. Three subjects discontinued the combo-simplified strategy prematurely, none of them due to safety reasons. Five subjects reported 8 adverse events, all of mild-moderate intensity. Combo-simplified strategy mean direct costs were 754.35±103.60€ compared to 1689.42€ and 2007.89€ of a theoretical 12-week treatment with 4 or 5 monitoring visits, respectively; and 1370.95€ and 1689.42€ of a theoretical 8-week with 3 or 4 monitoring visits, respectively. Only 4.9% of the subjects used unexpected health care resources.

CONCLUSIONS

8-week treatment with GLE/PIB combined with a combo simplified strategy in real-life offers substantial cost savings without affecting the effectiveness and safety compared to traditional approaches.

Evaluation of a quantitative RT-PCR assay for the detection of the emerging coronavirus SARS-CoV-2 using a high throughput system

Facing the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), high-volume respiratory testing is demanded in laboratories worldwide. We evaluated the performance of a molecular assay for the detection of SARS-CoV-2 on a high-throughput platform, the cobas 6800, using the 'open channel' for integration of a laboratory-developed assay. We observed good analytical performance in clinical specimens. The fully automated workflow enables high-throughput testing with minimal hands-on time, while offering fast and reliable results.

Utility of the new cobas HCV test for viral load monitoring during direct-acting antiviral therapy

Background

The COBAS AmpliPrep/COBAS TaqMan assay HCV (CAP/CTM) is widely used in clinical routine for HCV testing. Recently, the new cobas HCV test was established for high throughput testing with minimal operator intervention. As different assays may yield different quantitative/qualitative results that possibly impact treatment decisions, the aim of this study was to externally evaluate the cobas HCV test performance in comparison to CAP/CTM in a clinically relevant setting.

Methods

Serum samples were obtained from 270 patients who received direct acting antiviral therapy with different treatment regimens at two study sites (Hannover and Frankfurt) in 2016. Overall, 1545 samples (baseline, on-treatment and follow-up) were tested in parallel by both assays.

Results

The mean difference between cobas HCV and CAP/CTM for the quantification of HCV RNA was 0.008 log₁₀ IU/ml HCV RNA (95% limits of agreement: -0.02–0.036) showing excellent agreement of both assays. With respect to clinical cut offs (HCV RNA detectable vs. target not detected and HCV RNA above the lower limit of quantification (LLOQ) vs. <LLOQ), discordant results were obtained in 9.5% and 4.6%, respectively; the greatest differences were observed during early stages of antiviral therapy (week 1, week 2 and week 4), but none were statistically significant. Overall percent agreement for SVR between cobas HCV and CAP/CTM at the 15 IU/ml cutoff was 99.2% (95%CI 92.7%-100%).

Conclusion

The performance of the new cobas HCV test was comparable to CAP/CTM in a clinical setting representing a large patient population with HCV GT 1 and 3 treated with DAAs.

Clinical diagnostic performance of light-initiated chemiluminescent assay compared with the Architect chemiluminescence immunoassay for detection of HCV antibody

BACKGROUND

Hepatitis C virus antibody (anti-HCV) test had been approved as a preliminary screening test for HCV infection. Light-initiated chemiluminescent assay (LiCA) was a homogenous method. We aimed to assess the clinical diagnostic performance of LiCA and compare it with that of chemiluminescence immunoassay (CLIA) which was widely used in clinical laboratories.

METHODS

A total of 10 772 patients from the Peking University Third Hospital were enrolled. The serum samples were detected on the ChIVD LiCA500 and Abbott Architect i2000SR platforms. Recombinant immunoblot assay (RIBA) and HCV RNA assay were used for confirmation.

RESULTS

The negative agreement rate between ChIVD LiCA anti-HCV assay and Abbott Architect anti-HCV assay was 99.91%, the positive agreement rate was 37.31%, the total agreement rate was 98.74%, and the kappa coefficient (κ) was 0.519. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ChIVD LiCA anti-HCV assay were 96.39%, 99.95%, 89.58%, and 99.97%, respectively, which were superior to those of Abbott Architect anti-HCV assay (93.98%, 99.25%, 51.90%, and 99.95%, respectively).

CONCLUSION

ChIVD LiCA anti-HCV assay was a highly sensitive, specific homogenous method with good diagnostic performance, and was applicable for the routine screening of HCV infection in clinical laboratories.

Association of serum interferon-λ3 levels with hepatocarcinogenesis in chronic hepatitis C patients treated with direct-acting antiviral agents

AIM

Although the efficacy of hepatitis C virus (HCV) treatment is improved dramatically by direct-acting antiviral agents (DAAs), the assessment of hepatocellular carcinoma (HCC) remains important. Interferon lambda 3 (IFN-λ3) is associated with liver fibrosis and inflammation in chronic hepatitis C (CHC) patients, but its impact on carcinogenesis remains controversial and little is known about its effects after viral clearance. To determine the contribution of IFN-λ3 to hepatocarcinogenesis after HCV clearance, we analyzed IFNL3 genotypes and serial serum IFN-λ3 levels in CHC patients who achieved sustained virologic responses (SVR).

METHODS

This study comprised 201 CHC patients treated with DAAs. Serum samples were collected sequentially and IFN-λ3 levels were quantified by chemiluminescence enzyme immunoassay. The IFNL3 polymorphism (rs8099917) was genotyped in 195 patients.

RESULTS

One hundred and twenty-five patients were rs8099917 T/T and 70 were non-T/T. Serum IFN-λ3 levels did not differ significantly with IFNL3 genotype, dropped markedly by 1 week and remained low up to 24 weeks after the end of treatment. Interferon-λ3 levels were significantly higher after viral clearance in patients who developed HCC and were associated with a higher potential for hepatocarcinogenesis, such as a higher frequency of non-hypervascular hypointensive nodules (P = 0.046), higher stages of liver fibrosis (P < 0.001), and higher post-treatment levels of Wisteria floribunda agglutinin positive Mac-2 binding protein (P < 0.001) and alanine aminotransferase (P < 0.001).

CONCLUSIONS

Serum IFN-λ3 levels after HCV clearance are associated with the potential for HCC development. Interferon-λ3 could be helpful for elucidating the relationships among immunologic status, liver fibrosis, liver inflammation, and hepatocarcinogenesis, after achieving SVR.

Clinical evaluation of multiplex RT-PCR assays for the detection of influenza A/B and respiratory syncytial virus using a high throughput system

BACKGROUND

Lower respiratory tract infections are a major threat to public health systems worldwide, with RSV and influenza being the main agents causing hospitalization. In outbreak situations, high-volume respiratory testing is needed. In this study, we evaluated the analytical and clinical performance of a pre-designed primer/probe set for the simultaneous multiplex detection of both viruses on a high-throughput platform, the cobas^® 6800, using the "open channel" of the system for integration of lab-developed assays for the detection of influenza and RSV.

RESULTS

Using the influenza/RSV qPCR Assay with swabs, LoD (95%) in TCID50/mL for influenza-A was 0.009, influenza-B 0.003, RSV-A 0.202, and RSV-B 0.009. Inter-run variability (3xLoD) was low (<1 Ct for all targets). Of 371 clinical respiratory specimens analyzed, results were concordant for 358 samples. The calculated sensitivity and specificity of the assay were 98.3% and 98.4% for Flu-A, 100% and 98.5% for Flu-B, and 98.6% and 99.7% for RSV. All quality assessment panel specimens (N = 63, including avian influenza strains) were correctly identified. None of the tested microorganisms showed cross-reactivity.

CONCLUSION

Compared with CE-IVD assays, the assay evaluated here showed good analytical and clinical sensitivity and specificity with broad coverage of different virus strains. It offers high-throughput capacity with low hands-on time, facilitating the laboratory management of large respiratory outbreaks.

Development and validation of an RT-qPCR assay for rapid detection and quantification of hepatitis C virus RNA for routine testing in Moroccan clinical specimens

A one-step reverse transcription quantitative PCR (RT-qPCR) assay in combination with rapid RNA extraction was evaluated for routine testing of hepatitis C virus (HCV) RNA. Specific primers and probes were designed for the detection of a 150 bp sequence located in the 5'untranslated region (5'UTR) of HCV RNA. The target sequence was selected as the most conserved region between the six known HCV subtype sequences following an alignment. The assay was able to quantify a dynamic linear range of 10⁸ to 10¹ plasmid copies/reaction (r²  = 0.98) containing the target sequence. Two copies of this HCV plasmid corresponds to one international unit (IU) measured using a standard obtained by serial dilutions of the World Health Organization (WHO) standard. The detection limit of the assay was about 10 IU/mL of HCV RNA (20 copies/mL) in plasma samples. The assay was comparable to Cobas AmpliPrep/Cobas TaqMan® HCV Test, v2.0 Quantitative assay (Roche Molecular Systems, Inc., Branchburg, NJ) with correlation coefficient r²  = 0.98. The present assay could be completed within 3 hours from RNA extraction to data analysis of at least 30 plasma samples. Our test provides sufficient sensitivity, specificity, and reproducibility and proved to be fast, labor-saving, and cost-effective. Indeed, our system will definitely allow low-income countries to monitor accurately this viral infection and to efficiently treat their infected patients.