Roche TaqMan Research Articles

Efficacy of 8 weeks elbasvir/grazoprevir regimen for naïve-genotype 1b, HCV infected patients with or without glucose abnormalities: Results of the EGG18 study.

Direct Acting Antivirals(DAAs) achieve the highest rate of sustained viral response(SVR) in patients with genotype-1b(G1b) Hepatitis C virus(HCV) infection. Reducing treatment duration can simplify the management and improve adherence of therapy. The study evaluates the efficacy of 8 weeks of elbasvir/grazoprevir regimen in 75 treatment-naïve(TN), G1b patients with mild-moderate fibrosis(Liver Stiffness by Fibroscan® <9.0kPa). Viral load(VL) has been evaluated by Roche TaqMan RT-PCR(LLOQ<15 IU/ml). Mean age was 61.0±14.2 years, 44% were male, mean LS by Fibroscan® was 6.1±1.8kPa. Twenty-eight patients(37.3%) had an HOMA>2.5. Two patients were excluded from analysis(one dropped out and the other one had diagnosed genotype 2c at genotyping by sequencing performed after relapse). At 8 weeks(EOT), 71 out of 73 patients(97.3%) had undetectable HCV-RNA, while in two cases HCV-RNA was detectable but with VL<15 IU/ml. Both of them achieved SVR. Two G1b patients relapsed at 12 weeks of follow-up, both with baseline VL>800,000 IU/ml and HOMA score 1.3 and 3.8 respectively. Both had undetectable HCV VL at 4th week and at the EOT. Modified intention-to-treat SVR12 for G1b patients was 71/73(97.3%). In naïve, genotype-1b HCV-infected patients with mild/moderate liver fibrosis, short course of 8 weeks of EBR/GZR appears to achieve high efficacy regardless of features of insulin resistance.

Performance evaluation of Xpert HBV viral load (VL) assay: Point-of-care molecular test to strengthen and decentralize management of chronic hepatitis B (CHB) infection

IntroductionEstimation of hepatitis B (HBV) viral load (VL) is critical in hepatitis-B cascade-of-care and at present there is no point of care (POC) molecular assay available for the same. This study evaluated the performance of a new near point of care molecular assay Xpert HBV- VL assay against the approved assays. Materials & methodsIn this study 172 archived previously tested samples, were simultaneously re-tested for HBV DNA on 3 real-time PCR assays: Abbott Real-Time HBV, Roche TaqMan® HBV and Xpert HBV assay. ResultsOut of 172 samples, 119 were previously positive for HBV DNA with a median VL 4.46 (IQR: 1–8.76)log10IU/mL and 53 were HBV DNA negative. Genotyping could be done in 95 (79.8 %) samples and genotype D (83; 87.3 %) was the commonest type. The Xpert assay demonstrated a good correlation with Abbott (R2 = 0.94) and Roche (R2 = 0.96). On comparison, the mean difference with 95 % Confidence Interval of Xpert assay was −0.018 and −0.043 log10 IU/mL with Abbott and Roche assay, respectively. The overall sensitivity, specificity, negative predictive value, and positive predictive value of the Xpert assay was found 97.5 %, 100 %, 94.65 & 100 % respectively. ConclusionXpert HBV-VL assay which has a potential for near point of care molecular testing has shown excellent performance and found to be a reliable method for HBV DNA quantification.

Performance Comparison of Xpert HIV-1 Viral Load Assay and Roche Taqman and Abbott M2000 RT in Bamako, Mali.

Routine monitoring of HIV-1 Viral Load (VL) is important in patients on Antiretroviral Therapy (ART) management. Access to HIV VL remains a challenge in resource-limited settings, especially in rural areas. Universal access to VL requires more simplified and less restrictive alternatives to current conventional VL methods. The objective of this study was to evaluate the performance of the new rapid (2-hour turnaround time) Xpert HIV-1VL technique compared to Roche TaqMan and Abbott RT m2000 for HIV-1 RNA quantification in HIV- infected patients. We conducted a cross-sectional study in patients seen for routine VL monitoring between August and November 2018 in a HIV care site in Bamako. The performance of the Xpert HIV-1 VL assay was evaluated against the Roche TaqMan assay and Abbott m2000 RT assay. Performance, utility and reliability/reproducibility were verified using accuracy, sensitivity, specificity, positive and negative predictive values, Diagnostic Odds Ratio (DOR), Kappa coefficient, Pearson correlation coefficient, and Bland-Altman analysis. The Xpert assay compared well with the two current referral assays (Roche TaqMan and Abbott m2000 RT assays). Compared to Roche TaqMan assay the sensitivity was 93.10%, specificity (97.01%) and accuracy (95.20%), the correlation coefficient of Pearson (r) was 0.98 (p <0.01). Bland-Altman analysis showed a mean difference of 0.18 log10 cp/mL; (Standard Deviation) SD=0.33. Compared to the Abbott m2000 RT, the sensitivity, the specificity and the accuracy were respectively 93.44%; 92% and 92.65%. The Xpert HIV-1 VL assay showed a good correlation with a correlation coefficient of Pearson, r=0.99 (p <0.001). The overall mean difference in the HIV-1 VL values obtained by Xpert HIV-1 VL and Abbott m2000 RT assays was 0.08 log10 cp/mL; SD=0.30. Xpert HIV-1 VL showed a good performance compared to Roche TaqMan and Abbott m2000 RT. With the rapid test results (less than 2 h) and ease of testing individual specimens, the Xpert HIV-1 VL assay could be an effective alternative for HIV VL monitoring in resource-limited settings.

Point-of-care HCV RNA testing in the setting of DAA therapy: HCV-FiS (HEpatitis C Virus Fingerstick Study).

HCV-RNA assessment during therapy with Direct-Acting Antiviral (DAA) regimens still relies on assays requiring blood collection and transport to a specialised laboratory, which may compromise linkage to care. GeneXpert-HCV Viral Load (GXHVL) (Cepheid) is a plasma-based assay used at point of care (POC) with a sensitivity of ≤10IU/mL, and, results available within 2hours. Fifty-nine consecutive HCV-patients ready for DAAs treatment were enrolled. HCV-RNA was simultaneously tested using Roche TaqMan RT-PCR (venous blood sample) and GXHVL (capillary blood collected by fingerstick), at baseline (BL), week 4 (W4) of therapy, end of therapy (EOT) and week 12 of follow-up (W12FU). Both assays demonstrated undetectable HCV-RNA in all patients at EOT and identified the single case of HCV-relapse at W12FU. GXHVL used as a point-of-care assay in the outpatient setting provides results fully comparable to the laboratory-based test. Its excellent performance and ease of use suggest its adoption in non-specialist settings where simplicity of care is paramount to implement HCV eradication campaigns.

First-line antiretroviral treatment and virological response among HIV adult patients at an accredited HIV care center, Cameroon

BackgroundViral load (VL) monitoring in the clinical follow-up of HIV patients to detect treatment failure is not routinely offered in Cameroon. The study was designed to characterize virological response on antiretroviral treatment (ART) among adults living with HIV and to identify predictors of virological failure (VF).MethodsBetween November 2014 and January 2016, a prospective, population-based cohort study was conducted among HIV-positive adults under first-line treatment and monitored at the Accredited HIV Care Center (AHCC) of Laquintinie Hospital of Douala. Clinical and biological data at the initiation of ART were collected from patients’ medical records. HIV VL at 12 and 24 months after the patient started treatment on ART were performed using quantitative real-time PCR protocol with the generic HIV Roche TaqMan assay. Descriptive and logistic regression analysis were performed in Stata SE11 version in data analysis.ResultsOverall 150 (45.5%) of 330 adults living with HIV were tested with at least one VL, and of these patients, 51 (34.0%) were tested with two VL during the followed-up. The VF was observed in 13 of 51 (25.5%) patients and among them, 8 (61.5%) switched to second-line ART regimens. Thirty-five (68.6%) of the 51 patients had an undetectable VL at the first VL measurement, and seven (13.7%) patients subsequently developed viral load rebound (VLR) on tritherapy. Using a multivariate analysis, the risk of VF was seven times higher in HIV adults who did not respect the medication hours (OR = 7.38, 95%CI = 1.56–34.90, p = 0.012) and eleven times higher in patients with none or primary school education (OR = 11.38, 95% CI = 2.41–53.76, p = 0.002).ConclusionLow education level and poor adherence are the main risk factors for VF. Strengthening therapeutic failure prevention strategies and routine VL surveillance would allow early detection of VF and contribute in achieving the third goal of UNAIDS which recommends “90–90-90” targets for People Living with HIV in resource-limited settings.

The stability of HIV-1 nucleic acid in whole blood and improved detection of HIV-1 in alternative specimen types when compared to Dried Blood Spot (DBS) specimens

BackgroundCommercially-available kits for HIV-1 detection include instructions for detecting HIV-1 in plasma and DBS, but don’t support other specimen types. ObjectivesShow quantitative stability of HIV-1 total nucleic acid (TNA) in blood and improved HIV-1 detection in alternative specimen types. Study designWhole blood and DBS specimens, tested as part of an external quality assurance program for qualitative HIV-1 detection, were used to evaluated error rates (false negative [FN], false positive [FP] and indeterminant [IND] results) across assays (internally developed [IH], Roche Amplicor [RA], and Roche TaqMan Qual [TQ]) and specimen types (frozen whole blood [BLD], DBS and cell pellets [PEL]). A modified Roche TaqMan HIV-1 assay was used to quantify HIV-1 TNA. ResultsSignificantly higher error rates were noted in DBS across all of the assays (4% vs. 0% for DBS and PEL, IH, p = 0.005; 4% vs. 0.1% for DBS and PEL, RA, p < 0.001; 10% vs. 1% for DBS and PEL or BLD, TQ, p < 0.001). HIV TNA concentration is stable in BLD (day 1 vs. day 10, p = 0.39) and higher than DBS (p < 0.001). ConclusionsTransporting refrigerated whole blood for centralized processing into alternative specimen types will improve the sensitivitiy of HIV-1 detection in samples with low virus loads.

Sensitivity and specificity of two dried blood spot methods for HIV-1 viral load monitoring among patients in Hanoi, Vietnam.

The use of dried blood spot (DBS) specimens for HIV viral load (VL) monitoring is recommended to support the roll-out of routine VL monitoring in low and middle income countries (LMICs). To better understand the use of DBS for VL monitoring, we evaluated two DBS testing methods, Roche TaqMan® Free Virus Evolution protocol (DBS-FVE) and Roche TaqMan® SPEX protocol (DBS-SPEX)) in patients receiving ART at an HIV clinic in Hanoi, Vietnam. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each DBS testing method at the thresholds of 1000 and 5000 copies/ml compared to plasma VL. At a threshold of 1000 copies/ml, sensitivity, specificity, PPV and NPV of the DBS-SPEX method were 98.8% (95% CI: 93.3%-100%), 74.3% (95% CI: 70.8%-77.5%), 31.5% (95% CI: 25.8%-37.6%), and 99.8% (95% CI: 98.9%-100%), respectively. Increasing the VL threshold value to 5000 copies/ml improved specificity (97.9% CI: 96.6%-98.9%) and PPV (83.9% CI: 74.5%-90.9%). Using the DBS-FVE method, at the threshold of 1000 copies/ml and with a correction factor of +0.3 log copies/ml, sensitivity was 95.1% (87.8%-98.6%) and specificity was 98.8% (97.7%-99.5%). Sensitivity decreased at the threshold of 5000 copies/ml (65.8%, 95% CI: 54.3%-76.1%). With a correction factor of +0.7 log copies/ml, the sensitivity was 96.3% (89.6%-99.2%) and specificity was 98.2% (96.9%-99.1%) at the threshold of 1000 copies/ml. We found that the Roche DBS-FVE method, with a +0.7 log copies/ml correction factor, performed well with sensitivity and specificity greater than 96% at a VL threshold of 1000 copies/m. These findings add to the growing body of evidence supporting the use of DBS VL testing for ART monitoring. Future research should evaluate the association between VL results by DBS and clinical outcome measures such as HIV drug resistance, morbidity, and mortality.

Viral Blips Were Infrequent in HIV-1-Infected Virologically-Suppressed Adults Treated with Tenofovir Alafenamide or Tenofovir DF Rilpivirine-Containing Regimens

BackgroundDifferences between regimens in the frequency of transient episodes of viremia (viral blips) as well as the impact of these viral blips on the risk of virologic failure and resistance development is not fully understood. Here we investigate the frequency of viral blips in virologically-suppressed subjects switching to rilpivirine/emtricitabine/tenofovir alafenamide (R/F/TAF) vs. maintaining R/F/tenofovir disoproxil fumarate (TDF) and the association of viral blips with clinical outcome through Week 48 of study GS-US-366-1216.MethodsGS-US-366-1216 is a randomized, double-blind, phase 3b study evaluating the safety and efficacy of switching to R/F/TAF from R/F/TDF in HIV-1-infected virologically-suppressed subjects. For the viral blip analysis, treated subjects with ≥1 post-baseline HIV-1 RNA value were included. All on-drug HIV-1 RNA data points and FDA snapshot outcome data through Week 48 were utilized. Plasma HIV-1 RNA was measured using the Roche Taqman 2.0 assay. A viral blip was defined as any post-baseline HIV-1 RNA value ≥50 c/mL preceded and followed by HIV-1 RNA <50 c/mL.ResultsOf the 627 subjects included in the analysis, 23 (3.7%) experienced ≥1 blip through Week 48 and were distributed similarly between treatment groups (10/315, 3.2% R/F/TAF; 13/312, 4.2% R/F/TDF; P = 0.53; median 6 viral load measurements per subject). Twenty subjects had single blips (8 R/F/TAF, 12 R/F/TDF) and 3 subjects experienced 2 blips each (2 R/F/TAF, 1 R/F/TDF). Of 26 total blip events, 19 (73%) were low-level at 50–199 c/mL. Among subjects with blips, 22/23 (96%) were virologic successes at Week 48 (9/10, 90% R/F/TAF; 13/13, 100% R/F/TDF), similar to those subjects without blips (568/604, 94% overall; 287/305, 94% R/F/TAF; 281/299, 94% R/F/TDF). One subject in the R/F/TAF group had 2 blips prior to experiencing virologic rebound with mutations also detected at baseline (determined by retrospective proviral DNA sequencing).ConclusionViral blips were infrequent among subjects switching to R/F/TAF or maintaining R/F/TDF through Week 48 of study GS-US-366-1216. No differences in blip frequency or virologic failure post-blip were observed between treatment groups. Most blips were low-level (<200 c/mL) and most subjects with blips remained suppressed through Week 48.Disclosures D. A. Wohl, Gilead Sciences Inc.: Consultant and Investigator, Consulting fee and Research grant; ViiV: Consultant and Investigator, Consulting fee and Research grant; Janssen: Consultant, Consulting fee; Bristol Myers Squibb: Consultant, Consulting fee; R. Kulkarni, Gilead Sciences, Inc.: Employee and Shareholder, Salary; W. Garner, Gilead Sciences, Inc.: Employee and Shareholder, Salary; K. White, Gilead Sciences, Inc.: Employee and Shareholder, Salary; D. Porter, Gilead Sciences, Inc.: Employee and Shareholder, Salary

Comparison of Roche TaqMan v.2.0, Abbott RealTime and Modified Abbott Residual Viremia Assays in Testing of Routine Samples for Viremia Monitoring in HIV Care

BackgroundRoutine HIV RNA clinical monitoring frequently reports virermia (VL) as detectable, quantifiable <50 or blips >50 c/mL. To assess whether the results represent true increases or just assay variability, we designed comparisons of the Roche COBAS AmpliPrep / COBAS TaqMan HIV-1 Test version 2.0 (TM) and the Abbott RealTime HIV-1 assay (RT) to a residual viremia (RV) assay with a limit of detection of 3 c/mL, the Modified Abbott Residual Viremia assay (MARV).MethodsHIV suppressed patients on stable therapy presenting for routine visits at the HIV clinic in Henry Ford Hospital (HFH) were prospectively enrolled. Blood samples and questionnaires were obtained at each visit. Paired plasma samples were processed and analyzed per manufacturer instructions; HFH clinical laboratory processed the samples using the TM assay and the McKinnon Research Laboratory performed the FDA approved RT assay and RV testing using the MARV assay. Parametric and non-parametric analyses were conducted as indicated.Results124 HIV patients are reported with a mean age of 51, mostly male (84%) and African American (64%). Mean CD4 cell counts were 661 cells/mm3. TM assay results for 196 plasma samples were not detectable (ND) 119 (61%), detectable (DT) 61 (31%) and quantifiable viremia (QV) >20 c/mL 16 (8%). 5 patients had QV over 50 c/mL. 60 tested patients (49.5%) had at least one sample either DT or QV. TM results were not correlated to CD4 cell counts, antiretrovirals, medical conditions or reported adherence (avg. 97%). 174 RT and 187 MARV paired tests were ND on 142 (81%) / 121 (65%), DT on 34 (17%) RT, and quantifiable in 0% / 34 (33%) of the samples respectively. Higher VL detection by the TM was shown compared with the RT (P = 0.005) and MARV (P < 0.001) assays. Mean QV by the MARV was 5.0 vs.. 55 c/mL on the TM assay (P < 0.001). VL for all assays trends correlated when compared for ND, DT and >20 copies/mL (P < 0.001). Bland-Altman plots show higher VL detected by TM as compared with MARV (P < 0.001) and good correlation between RT and MARV assays (P = 0.6).ConclusionHIV viremia is more frequently reported by TM assay as compared with the RT assay and was significantly higher than VL detected by the MARV assay. Over detection of VL by the TM assay may impact clinical decision making and increase cost of care.Disclosures J. Mckinnon, Abbott Molecular: Speaker’s Bureau, Grant recipient, Research grant and Speaker honorarium D. Lucic, Abbott Molecular: Employee, Salary

Brief Report: High Sensitivity and Specificity of the Cepheid Xpert HIV-1 Qualitative Point-of-Care Test Among Newborns in Botswana.

HIV point-of-care (POC) testing allows for early infant HIV diagnosis and treatment, but POC accuracy at birth and in the setting of antiretroviral prophylaxis for the prevention of mother-to-child HIV transmission is unknown. We evaluated the Cepheid Xpert HIV-1 Qual POC test against the Roche Taqman HIV-1 DNA polymerase chain reaction (PCR) platform using dried blood spots from 15 HIV-infected and 75 HIV-exposed uninfected newborns. These infants were screened for HIV at <96 hours of life at 5 hospital maternity wards in Botswana; all infants received postexposure antiretroviral prophylaxis with single-dose nevirapine and zidovudine, and most mothers received 3-drug antiretroviral therapy in pregnancy and at delivery. Fourteen of the 15 PCR positive samples tested positive by Cepheid POC, yielding a sensitivity of 93.3% (95% confidence interval: 68.1 to 99.8). Baseline viral load among positive infants ranged from <40 to >10,000,000 copies/mL, with a median of 2403 copies/mL. The HIV RNA for the infant with false-negative POC testing was 1661 copies/mL. Of note, 2 infants with low HIV RNA (<40 and 272 copies/mL) were correctly identified as HIV positive by Cepheid POC. All the 75 PCR-negative samples tested negative by Cepheid POC, yielding a specificity of 100% (95% confidence interval: 96.1 to 100). Our study demonstrates high sensitivity and specificity for the Cepheid POC assay in the first week of life despite early infection and antiretroviral prophylaxis. This platform may be a useful approach for adding early infant HIV diagnosis to current testing programs.

A Single Quantifiable Viral Load Is Predictive of Virological Failure in Human Immunodeficiency Virus (HIV)-Infected Patients on Combination Antiretroviral Therapy: The Austrian HIV Cohort Study.

Background. Viral loads (VLs) detectable at low levels are not uncommon in patients on combination antiretroviral therapy (cART). We investigated whether a single quantifiable VL predicted virological failure (VF).Methods. We analyzed patients receiving standard regimens with at least 1 VL measurement below the limit of quantification (BLQ) in their treatment history. The first VL measurement after 6 months of unmodified cART served as baseline VL for the subsequent analyses of the time to reach single VL levels of ≥200, ≥400, and ≥1000 copies/mL. Roche TaqMan 2.0 was used to quantify human immunodeficiency virus-1 ribonucleic acid. Factors associated with VF were determined by Cox proportional hazards models.Results. Of 1614 patients included in the study, 68, 44, and 34 experienced VF ≥200, ≥400, and ≥1000 copies/mL, respectively. In multivariable analyses, compared with patients who were BLQ, a detectable VL ≤ 50 and VL 51–199 copies/mL predicted VF ≥ 200 copies/mL (hazards ratio [HR] = 2.19, 95% confidence interval [CI] = 1.06–4.55 and HR = 4.21, 95% CI = 2.15–8.22, respectively). In those with VL 51–199 copies/mL, a trend for an increased risk of VF ≥400 and VF ≥1000 copies/mL could be found (HR = 2.13, 95% CI = 0.84–5.39 and HR = 2.52, 95% CI = 0.96–6.60, respectively).Conclusions. These findings support closer monitoring and adherence counseling for patients with a single measurement of quantifiable VL <200 copies/mL.

Use of parenteral caffeinum natrio-benzoicum: an underestimated risk factor for HCV transmission in China.

BackgroundFuyu city in China has a high prevalence of hepatitis C virus (HCV) infection resulting in a high morbidity and mortality from chronic liver disease and hepatocellular carcinoma. This study was conducted to identify the risk factors for HCV infection in Fuyu city.MethodsRecruitment of study subjects involved a cross-sectional survey using non-random, convenience sampling. Information on demographic variables, risk factors for HCV infection, clinical manifestations, behavioral practices and family history was collected by administering a questionnaire. Anti-HCV antibody was detected using Abbott ARCHITECT i2000SR. HCV infection was confirmed by HCV-RNA testing by the Roche Taqman HCV test. Univariate and multivariate analyses were performed to identify the factors associated with HCV infection.ResultsOut of 3,228 persons that participated in the survey, 3,219 were enrolled in the study. The prevalence of HCV infection was 42.1 % (1355/3219). Among 734 patients with chronic HCV infection whose HCV-RNA genotyping was performed, genotype 1b was the most common (58.0 %), followed by genotype 2a (40.2 %), while co-infection with genotypes 1b and 2a was detected in 1.8 % of the subjects. On univariate analysis, male gender, older age, parenteral caffeinum natrio-benzoicum and share syringes (PCNBSS), and nine other factors were significantly associated with HCV infection. After adjusting for potential confounders, male gender, old age, cigarette smoking, lower education level, history of blood transfusion, blood donation, prior dental surgery, and PCNBSS were found to be independently associated with HCV infection.ConclusionsThe prevalence of HCV infection is likely to be high among residents in Fuyu and we observed that genotypes 1b and 2a dominated in the city. Our findings support the hypothesis that PCNBSS which became endemic in Fuyu city during 1970s-1980s is strongly associated with HCV positivity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2299-8) contains supplementary material, which is available to authorized users.

TG1050, a novel immunotherapeutic for the treatment of chronic hepatitis B, can control HBsAg and provoke HBsAg seroconversion in HBV-persistent mouse models

s / Journal of Clinical Virology 69 (2015) 223–246 227 evaluated with serial dilutions (106–100 IU/mL; Roche). The quantitative correlation and lower limit of detection were evaluated by use of clinical samples. Findings: Picodroplet digital PCR showed a high degree of linearity (R2 =0.9891) and accuracy (SD≤0.31 log copies/mL; CV≤15%) across their detectable ranges. The quantitative correlation between the picodroplet digital PCR and the Roche TaqMan HCV test was high (R2 =0.9439) across their detectable ranges (106–15 IU/mL). We also found discordance in detection of low HCVRNA samples between the twomethods. In 18 clinical samples (HCV RNA 15 copies/mL, 44.4% with an HCV RNA levels < 15 copies/mL, and in 33.3% of samples the target was not detected. The discordance in low RNA samples needs to be verified using a large sample size. Interpretation: Picodroplet digital PCR could provide a useful method for HCV quantification, especially for low HCV RNA levels, but the approach needs to be further optimised. http://dx.doi.org/10.1016/j.jcv.2015.06.018

Short duration response-guided treatment is effective for most individuals with recent hepatitis C infection: the ATAHC II and DARE-C I studies.

Background Individuals with recent HCV infection may benefit from shortened duration therapy. These studies evaluated the efficacy and safety of response-guided regimens with pegylated interferon-α2a and ribavirin for people with recent HCV infection. Methods Participants with recent hepatitis C (duration of infection ≤18 months) enrolled in the ATAHC II (pegylated interferon-α2a ± ribavirin) and DARE-C I (pegylated interferon-α2a, ribavirin and telaprevir) studies were included for analysis. Treatment duration was response-guided (ATAHC II: 8, 16, 24 or 48 weeks; DARE-C I: 8, 12 or 24 weeks) and dependent on time to first undetectable HCV RNA using Roche Taqman HCV RNA testing. The primary efficacy end point was sustained virological response at 12 weeks (SVR12) by intention-to-treat. Logistic regression analyses were used to identify predictors of SVR. Results A total of 82 participants (62% HIV-positive) were enrolled in ATAHC II (treated, n=52) and 14 (79% HIV-positive) in DARE-C I. The predominant modes of HCV acquisition were injecting drug use (ATAHC II 55%, DARE-C I 36%) and sexual intercourse with a partner of the same sex (ATAHC II 39%, DARE-C I 64%). SVR12 was 71% in both ATAHC II (37/52) and DARE-C I (10/14) with 56% in ATAHC II receiving shortened therapy (8 or 16 weeks). SVR was associated with a rapid virological response (odds ratio 10.80; P=0.001). Conclusions The majority of participants were able to receive short duration response-guided therapy with pegylated interferon-α2a and ribavirin. Response-guided therapy for recent hepatitis C infection could be considered in the absence of available interferon-free therapies. ClinicalTrials.gov registry (ATAHC II: NCT01336010; DARE-C I: NCT01743521).

Quantitation of substitutions at amino acid 70 in hepatitis C virus genotype 1b.

BackgroundSubstitutions of amino acid (aa) 70 in the core region of hepatitis C virus genotype 1b (HCV 1b) are a predictor of the non-virological response to pegylated interferon plus ribavirin (PEG-IFN/RBV) therapy. The aim of our study was to develop quantitative real-time reverse transcription polymerase chain reaction (qPCR) assays to quantify wild-type (70 W) and mutant (70 M) strains of HCV 1b.MethodsWe used the TaqMan system to quantify strains 70 W and 70 M. Codon 70 in the HCV 1b core region can be either CGN or CAN, therefore degenerate TaqMan minor groove binder (MGB) probes with inosine were used. We determined detection limits, sensitivity and specificity of the methods developed. Direct sequencing and cloning of the HCV core region were used to confirm the reliability of our new system. Serum samples from 138 Chinese patients infected with HCV 1b were examined with the system we developed and compared with results obtained from the Roche TaqMan RT-PCR HCV RNA quantitation system.ResultsDegenerate MGB probes were able to clearly distinguish 70 W from 70 M. The detection limit was 103 copies/mL. Cross-reactivity tests confirmed the specificity of our method. Our system can effectively quantify 70 W and 70 M for 99.6% of patients with HCV 1b. Further tests involving cloning and sequencing confirmed the reliability of our system.ConclusionsWe developed an assay system using degenerate TaqMan MGB probes with inosine to quantify wild-type and mutant viral RNAs of the HCV 1b core region at aa 70. Our developed assay system had high levels of sensitivity and accuracy, and could prove useful in investigating dynamic changes during PEG-IFN/RBV therapy to assess virological responses.

What is the meaning of a nonresolved viral nucleic acid test-reactive minipool?

This study aimed at analyzing the prevalence of hepatitis B virus (HBV) DNA among hepatitis B surface antigen (HBsAg)-negative donations by cobas TaqScreen MPX test (Roche Molecular Systems) and discussing the meaning of a reactive minipool (MP) that does not resolve to an individual donation (ID)-reactive result. Nucleic acid amplification testing (NAT) was performed in 12 Chinese blood centers on 826,044 serologic negative donations in MPs of six. MP-reactive pools that were resolved to ID-reactive donations were confirmed by Roche TaqMan viral load assays. Antibody to hepatitis B surface antigen and antibody to hepatitis B core antigen (anti-HBc) results were also analyzed. Cycle threshold (Ct) values of reactive MPs were analyzed in relation to the probability of pool resolution. A total of 1267 of 137,674 pools were reactive, of which 839 donations were reactive by ID-NAT. The MP6 HBV NAT-yield rate lay between 1 in 1600 and 1 in 1000. At MP Ct values equal or below 37, the probability of pool resolution was approximately 80%. The prevalence of anti-HBc in ID-reactive donations was 81%. The proportion of reactive pools that could not be resolved was 36%. The prevalence of anti-HBc in donations implicated in nonresolved MPs was significantly higher than those in nonreactive MPs (48% vs. 37%, p = 0.016). The anti-HBc data suggest that approximately 10% of nonresolved MPs contain HBV DNA from a low-viral-load occult carrier. We consider ID-NAT resolution testing in duplicate to minimize HBV transmission risk associated with transfusing nonreactive donations implicated in reactive MPs.

Characterization of hepatitis B virus genotypes and quantitative hepatitis B surface antigen titres in North American tertiary referral liver centres

Hepatitis B virus (HBV) genotype and quantitative hepatitis B surface antigen (qHBsAg) have been related to clinical outcome. In this nationwide cross-sectional study, we aimed to investigate the epidemiology and clinical significance of HBV genotype and qHBsAg in patients with chronic hepatitis B (CHB). Six hundred and thirty patients with CHB were seen in four urban tertiary referral centres in Canada. HBV genotype was determined by line probe assay (INNO-LIPA) and HBV DNA quantified by commercial PCR (Roche TaqMan, sensitivity <55IU/ml or AMPLICOR, sensitivity <60IU/ml). Titres of qHBsAg were determined by an in-house assay based on the WHO standard (calibration range 0.24-62.5IU/ml). In 630 patients (57% male, 69% Asian, median age 42years), 21% were hepatitis B e antigen positive and the median alanine aminotransferase was 29U/L. The HBV genotype distribution was A (16%), B (29%), C (31%), D (16%), E (6%). HBV genotype was strongly associated with ethnicity, but neither genotype nor qHBsAg correlated with the degree of fibrosis. In the treatment-naïve patients, the baseline qHBsAg levels correlated with HBV DNA (r=0.2517, P<0.0008). The median qHBsAg levels were lowest in patients with genotype B (P<0.0001), but no significant correlation was noted with all other HBV genotypes. In this large North American HBV epidemiological study, genotypes B and C were the most common; however, all genotypes (A-E) were observed with varied distribution nationwide. Baseline qHBsAg significantly correlated with HBV DNA and with HBV genotype B, but not with liver fibrosis.

Evaluation of Cepheid SmartCycler and EuroClone Duplicareal time Dual Easy CT assay for confirmation of Chlamydia trachomatis

assay for the confirmation of Roche COBAS TaqMan positive tests by comparing results obtained by each method. Consecutive clinical C. trachomatis positive (n = 67) and random negative (n = 17) urogenital samples received at a general district hospital in the North East of England over a 6-month period were examined. Of the total 67 TaqMan-positive samples, 62 (92.5%) of them were also positive by the SmartCycler/EuroClone. There were 5 discrepancies in total (7.5%) and 17 samples were negative on both Roche TaqMan and SmartCycler/EuroClone. The sensitivity and specificity of the method were 92.5 and 100%, respectively. To further assess its specificity, the SmartCycler/EuroClone method was challenged with additional organisms and proved to possess the ability of avoiding false-positive results by correctly identifying these as C. trachomatis DNA negative. Finally, it was found that confirmation of positive C. trachomatis by the SmartCycler/EuroClone method increases the turn around time of chlamydia investigation by 2-folds. In conclusion, the SmartCycler/EuroClone method gave good concordance with the established Roche TaqMan method and proved to be highly suitable for confirmation testing of C. trachomatis positive samples. The remarkable specificity and acceptable sensitivity also confirms its suitability and reliability for this purpose.

Faldaprevir combined with pegylated interferon alfa-2a and ribavirin in treatment-naïve patients with chronic genotype1 HCV: SILEN-C1 trial

Faldaprevir (BI 201335) is a potent, hepatitis C virus (HCV) NS3/4A protease inhibitor with pharmacokinetic properties supportive of once-daily (QD) dosing. Four hundred and twenty-nine HCV genotype (GT)-1 treatment-naïve patients without cirrhosis were randomized 1:1:2:2 to receive 24 weeks of pegylated interferon alfa-2a and ribavirin (PegIFN/RBV) in combination with placebo, faldaprevir 120 mg QD with 3 days of PegIFN/RBV lead-in (LI), 240 mg QD with LI, or 240 mg QD without LI, followed by an additional 24 weeks of PegIFN/RBV. Patients in the 240 mg QD groups achieving maintained rapid virologic response (mRVR; viral load [VL] <25 IU/mL at week 4 and undetectable at weeks 8-20) were rerandomized to cease all treatment at week 24 or continue receiving PegIFN/RBV up to week 48. VL was measured by Roche TaqMan. Sustained virologic response (SVR) rates were 56%, 72%, 72%, and 84% in the placebo, faldaprevir 120 mg QD/LI, 240 mg QD/LI, and 240 mg QD groups. Ninety-two percent of mRVR patients treated with faldaprevir 240 mg QD achieved SVR, irrespective of PegIFN/RBV treatment duration. Eighty-two percent of GT-1a patients who received faldaprevir 240 mg QD achieved SVR versus 47% with placebo. Mild gastrointestinal disorders, jaundice resulting from isolated unconjugated hyperbilirubinemia, and rash or photosensitivity were more common in the active groups than with placebo. Discontinuations resulting from adverse events occurred in 4%, 11%, and 5% of patients treated with 120 mg QD/LI, 240 mg QD/LI, and 240 mg QD of faldaprevir versus 1% with placebo. Faldaprevir QD with PegIFN/RBV achieved consistently high SVR rates with acceptable tolerability and safety at all dose levels. The 120 and 240 mg QD doses are currently undergoing phase 3 evaluation. (HEPATOLOGY 2013;57:2143-2154).

Faldaprevir combined with peginterferon alfa-2a and ribavirin in chronic hepatitis C virus genotype-1 patients with prior nonresponse: SILEN-C2 trial

Faldaprevir (BI 201335) is a potent, hepatitis C virus (HCV) NS3/4A protease inhibitor. In all, 290 noncirrhotic HCV genotype (GT)-1 patients with prior null (<1 log10 viral load [VL] drop at any time on treatment) or partial response (≥1 log10 VL drop but never undetectable on treatment) were randomized 2:1:1 to receive 48 weeks of peginterferon alfa-2a and ribavirin (PegIFN/RBV) in combination with faldaprevir 240 mg once daily (QD) with 3 days PegIFN/RBV lead-in (LI), 240 mg QD without LI, or 240 mg twice daily (BID) with LI. Patients in the 240 mg QD/LI group achieving maintained rapid virologic response (mRVR; VL <25 IU/mL [Roche TaqMan] at week 4 and undetectable at weeks 8 to 20) were rerandomized to cease all treatment at week 24 or continue PegIFN/RBV up to week 48. Sustained virologic response (SVR) rates were 32%, 50%, and 42% in prior partial responders, and 21%, 35%, and 29% in prior null responders in the faldaprevir 240 mg QD/LI, 240 mg QD, and 240 mg BID/LI groups, respectively. In the 240 mg QD/LI group, a significantly higher proportion of mRVR patients rerandomized to 48 weeks' treatment achieved SVR compared with those assigned to 24 weeks treatment (72% versus 43%; P = 0.035). Rates of gastrointestinal disorders, jaundice, dry skin, and photosensitivity were increased at 240 mg BID compared with the 240 mg QD dose. Faldaprevir discontinuations owing to adverse events occurred in 6%, 4%, and 23% of patients in the 240 mg QD/LI, 240 mg QD, and 240 mg BID/LI groups, respectively. Faldaprevir 240 mg QD with PegIFN/RBV was safe and tolerable and produced substantial SVR rates in prior null and partial responders. The 240 mg QD dose is currently undergoing phase 3 evaluation.