Comparative evaluation of the Geenius HCV supplemental assay and Inno-LIA HCV score assay in detecting anti-HCV antibodies

ObjectiveThis study compared two assays aimed at confirming the presence of anti-HCV antibodies (Ab) after a positive screening: Geenius HCV supplemental assay (Bio-Rad, Marne la Coquette, France) and the Inno-LIA HCV score assay (Fujirebio, Les Ulis, France).Material and methodsA total of 180 archived samples were investigated including 119 samples collected at different stages of HCV infection in 25 hemodialyzed patients who underwent HCV seroconversion, 14 samples from 4 commercial seroconversion panels, 47 Ab positive/HCV-RNA positive blood donations of which 7 showing an single reactivity in confirmatory assays. Samples were investigated and results were interpreted with the two assays according to the manufacturers’ instructions.ResultsOverall, Geenius and Inno-LIA were concordant for 84% (151/180) samples: 38 negative, 17 indeterminate and 96 positive. Of the 29 discrepant results, 26 were overclassified with Inno-LIA. HCV seroconversion was detected with Inno-LIA 4 and 7 days prior to Geenius in two panels. The high positive rate observed with Inno-LIA (64%) compared to Geenius (54%) was mainly due to low reactivities considered positive according to interpretation criteria, which could affect specificity.ConclusionAlthough HCV supplemental assays are not recommended for the diagnostic of HCV infection, which is primarily based on HCV-RNA testing, both assays are suitable as second line anti-HCV tests when Ab screening is positive and RNA testing cannot be performed. Moreover, Geenius system provides an objective result in less than 30 minutes, which is compatible when a rapid diagnostic is required.     

Clinical performance of the novel DiaSorin LIAISON® XL murex: HBsAg Quant,HCV-Ab,HIV-Ab/Ag assays

BackgroundThe fully automated and closed LIAISON^®XL platform was developed for reliable detection of infection markers like hepatitis B virus (HBV) surface antigen (HBsAg), hepatitis C virus (HCV) antibodies (Ab) or human immunodeficiency virus (HIV)-Ag/Ab. To date, less is known about the diagnostic performance of this system in direct comparison to the common Abbott ARCHITECT^® platform.ObjectivesWe compared the diagnostic performance and usability of the DiaSorin LIAISON^®XL with the commonly used Abbott ARCHITECT^® system.Study designThe qualitative performance of the above mentioned assays was compared in about 500 sera. Quantitative tests were performed for HBsAg-positive samples from patients under therapy (n = 289) and in vitro expressed mutants (n = 37). For HCV-Ab, a total number of 155 selected samples from patients chronically infected with different HCV genotypes were tested.ResultsThe concordance between both systems was 99.4% for HBsAg, 98.81% for HCV-Ab, and 99.6% for HIV-Ab/Ag. The quantitative LIAISON^®XL murex HBsAg assay detected all mutants in comparable amounts to the HBsAg wild type and yielded highly reliable HBsAg kinetics in patients treated with antiviral drugs. Dilution experiments using the 2nd International Standard for HBsAg (WHO) showed a high accuracy of this test. HCV-Ab from patients infected with genotypes 1–3 were equally detected in both systems. Interestingly, S/CO levels of HCV-Ab from patients infected with genotype 3 seem to be relatively low using both systems.ConclusionsThe LIAISON^®XL platform proved to be an excellent system for diagnostics of HBV, HCV, and HIV with equal performance compared to the ARCHITECT^® system.     

Rate and predictors of serum HCV-RNA >6 million IU/mL in patients with chronic hepatitis C

BackgroundBaseline serum HCV-RNA predicts sustained virological response in chronic hepatitis C patients treated with antiviral therapy. A threshold at 6 million IU/mL has been proposed to best discriminate treatment outcomes on sofosbuvir-based regimens. In comparison with the general population, immunosuppressed individuals exhibit greater viral load values.ObjectivesTo estimate the rate and predictors of serum HCV-RNA above 6 million IU/mL in chronic hepatitis C patients on care outside clinical trials.Study designSerum HCV-RNA values recorded from all chronic hepatitis C patients consecutively attended at our clinic during the last decade were analyzed. Testing had been performed using the COBAS TaqMan HCV test v2.0.ResultsA total of 816 individuals with detectable serum HCV-RNA were identified. The main characteristics of this population were as follows: mean age 48.6 years-old; 73.4% males; mean ALT 82.6 IU/L; mean HCV-RNA 6.02 log IU/mL; 80.6% HCV genotypes 1 or 4; 34.9% advanced liver fibrosis; 35.4% IL28B-CC alleles. HIV coinfection in 78.7%, of whom 91% were on antiretroviral therapy.Overall, 127 (15.6%) had serum HCV-RNA values >6 million IU/mL. This high viremia was found in 18.2% of HIV-positive versus 5.7% of HIV-negative subjects (p < 0.001). In multivariate analysis, serum HCV-RNA >6 million IU/mL was only significantly associated with HIV coinfection (OR: 4.03; 95% CI: 1.98–8.19, p < 0.01) and HCV genotypes 1 or 4 (OR: 1.88; 95% CI: 1.05–3.37, p = 0.03).ConclusionsSerum HCV-RNA >6 million IU/mL is roughly seen in 6% of chronic hepatitis C monoinfected patients, and increases up to 18% in HIV coinfection.     

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

BackgroundThe diagnosis of HCV relies on the detection of viral RNA.ObjectiveTo evaluate the performance of the VERIS/MDx System HCV Assay, a new automated system for quantifying HCV RNA, and to compare with the COBAS^® Ampliprep/COBAS^® Taqman™ (CAPCTM) HCV Test version 2.0.Study designThe limit of detection was determined by Probit analysis with the 3rd International WHO HCV standard and precision by assaying in duplicate control samples with HCV RNA concentrations of 7.9; 5.0; 3.4; 1.6 and 0 log IU/ml over 20 days. Analytical specificity was assessed by assaying 180 samples from negative anti-HCV and HCV RNA blood donors and linearity with replicates of serial dilutions of a clinical plasma (6.4–0.6 log IU/ml). We compared the VERIS MDx HCV and CAPCTM HCV assays by testing 209 samples.ResultsThe limit of detection was 6.1 IU/ml [CI 95%: 5.0–8.3] and the precision, given by the standard deviation, was ≤0.11 log IU/ml. Specificity was 100%. The linearity ranged from 1.5 to 6.4 log IU/ml. Passing-Bablok regression analysis gave: VERIS log IU/ml = −0.33 + [1.04× CAPCTM] log IU/ml, with biases for the 25th, 50th, 75th percentiles of 0.18, −0.10 and −0.06 log IU/ml. The two assays were well correlated (ρ = 0.92, p < 0.001) and Bland-Altman analysis gave biases of 0.12, log IU/ml for genotype 1, −0.19 for genotype 2, −0.26 for genotype 3, and −0.77 for genotype 4.ConclusionThe VERIS MDx HCV assay performed well. But, we observed an under-quantification of the genotype 4 samples.     

The fourth generation AlereTM HIV Combo rapid test improves detection of acute infection in MTN-003 (VOICE) samples

BackgroundEarly and accurate detection of HIV is crucial when using pre-exposure prophylaxis (PrEP) for HIV prevention to avoid PrEP initiation in acutely infected individuals and to minimize the risk of drug resistance in individuals with breakthrough infection.ObjectiveTo determine if fourth-generation antigen/antibody (Ag/Ab) rapid diagnostic tests (RDT) would have detected HIV infection earlier than the third-generation RDT used in MTN-003 (VOICE).Study design5029 VOICE participants were evaluated with third-generation Alere Determine™ HIV-1/2, OraQuick ADVANCE^® Rapid HIV-1/2, Uni-Gold™ Recombigen^® HIV-1/2 and Bio-Rad GS HIV-1/2 + O EIA; and fourth-generation Alere Determine™ HIV-1/2 Ag/Ab Combo, Conformité Européene (CE)-Marked Alere™ HIV Combo and Bio-Rad HIV Combo Ag/Ab EIA. Multispot^®, GS HIV-1 Western Blot (WB) and Geenius™ (Bio-Rad) were also evaluated.ResultsOf 57 antibody-negative pre-seroconversion plasma samples with HIV RNA >20 copies/mL identified, 16 (28%) were reactive by CE-Marked Alere™ HIV Combo (1 Ab; 9 Ag; 6 Ag/Ab reactive) and 4 (7%) by Alere Determine™ HIV-1/2 Ag/Ab Combo (2 Ab; 2 Ag; 0 Ag/Ab reactive) (p = 0.0005). Multispot^® confirmed only 1 of 16 acute infections while WB and Geenius™ confirmed none. GS HIV Combo Ag/Ab EIA identified 27 of 57 (47%) pre-seroconversion RNA-positive samples.ConclusionIn VOICE, 28% of infections missed by current third-generation RDT would have been identified with the use of CE-Marked Alere™ HIV Combo. Geenius™, Multispot^® and WB were all insensitive ( < 10%) in confirming infections detected by fourth-generation assays. An improved diagnostic algorithm that includes a fourth-generation RDT with HIV RNA testing will be essential for efficiently identifying seroconverters on PrEP.     

Real-life validation of a sample pooling strategy for screening of hepatitis C

ObjectivesTo test a real-life sample pooling screening strategy which contributes to increasing the diagnostic capacity of clinical laboratories and expanding access to massive screening of hepatitis C.MethodsAfter evaluating the sensitivity of the pooling strategy for seven different commercial assays which are used to determine the concentration of hepatitis C virus (HCV)-RNA in the plasma or serum, consecutive samples submitted for HCV diagnosis during the first 3 weeks of November 2021 were tested for HCV antibodies and, in parallel and in a blinded way, were pooled into 100 samples and tested for HCV-RNA. When the result was positive, a strategy to un-mask the positive(s) pool(s), which needed up to 15 total HCV-RNA tests, was used.ResultsAll platforms were able to detect the presence of HCV-RNA in a single sample from a patient with viremic HCV present in pools of up to at least 10 000 HCV-RNA-free samples. A total of 1700 samples (17 pools) were analysed, with an overall prevalence of anti-HCV and HCV-RNA of 0.24%. After pooling, we could detect all samples previously detected using standard diagnosis tests (reflex testing) with a specificity and sensitivity of 100% (CI, 99.78–100%). Given the median current prices of anti-HCV and HCV-RNA on the market in Spain as well as personnel costs, testing using the pooling strategy would have resulted in a save of 3320€.ConclusionsHere, we demonstrated that by improving cost effectiveness, with no loss of sensitivity and specificity, the strategy of pooling samples may serve as an appropriate tool for use in large-scale screening of HCV.     

Comparison of three quantitative HCV RNA assays in samples from HCV genotype 1- or 4-infected patients treated with the NS3/4A protease inhibitor simeprevir

BackgroundMonitoring HCV RNA levels during treatment is an important tool for managing protease-inhibitor-based regimens, and different assays used in clinical practice can impact treatment decisions.ObjectivesThe concordance of three HCV RNA assays was determined, and their impact on treatment decisions assessed using samples from HCV genotype (GT) 1- and GT4-infected patients treated with the NS3/4A inhibitor simeprevir in combination with pegylated interferon-α/ribavirin.Study designPlasma samples collected during the simeprevir Phase III studies QUEST-1 and QUEST-2 (GT1), and RESTORE (GT4) were analyzed with the Roche High-Pure-System COBAS^® TaqMan^® HCV v2.0 (HPS), the Roche AmpliPrep COBAS^® TaqMan^® HCV v2.0 (CAP), and the Abbott RealTime HCV (ART) assay.ResultsIn GT1, of the 440 samples, 81% were undetectable (rapid virological response; RVR) by HPS at Week 4, 76% by CAP and 44% by ART. In GT4 (103 samples), RVR rates were 67% by HPS and 24% by ART. HCV RNA <25 IU/mL at Week 4 was observed for 95–96% and 92% GT1 samples and 86% and 74% GT4 samples by HPS/CAP and ART, respectively. At Week 12, assay concordance for undetectability was high in GT1 and GT4, (95–98% and 93%, respectively).ConclusionsWhile different HCV RNA assays can lead to substantially different RVR rates, a good concordance was observed with a cut-off of 25 IU/mL. Sustained virologic response rates among GT1 patients achieving RVR or <25 IU/mL at Week 4 were high and similar between assays used. At later time points, when viremia is low, assay concordance was high.     

Performance and clinical utility of a novel fully automated quantitative HCV-core antigen assay

BackgroundRecently, a novel quantitative HCVcoreAg immunoassay developed for commercialisation by Abbott has become available in Europe and Asia.ObjectivesWe evaluated the correlation of HCV-RNA and HCVcoreAg and investigated the stability of HCVcoreAg and HCV-RNA.Study designHCVcoreAg was quantified by a novel fully automated immunoassay (Architect HCVAg, Abbott, Germany). HCV-RNA quantification was performed either using the Cobas-TaqMan assay or Amplicor-HCV-Monitor (Roche-Diagnostics, Germany). Correlation of HCVcoreAg with HCV-RNA was studied cross-sectionally and longitudinally in untreated patients followed for up to 8 years. Stability of HCVcoreAg and HCV-RNA was evaluated in plasma and whole blood stored for up to 96 h at different conditions.ResultsHCVcoreAg showed good correlation with HCV-RNA in all 118 cross-sectional tested samples irrespective of the HCV genotype (r = 0.75). In the majority but not all of the 10 longitudinally studied patients HCVcoreAg also demonstrated a good correlation with HCV-RNA. HCVcoreAg was stable in plasma at 4, 20, and 37 °C for up to 96 h, whereas HCV-RNA significantly declined at 37 °C. In whole blood, HCVcoreAg and HCV-RNA levels declined at all conditions with exception of HCVcoreAg at 37 °C. HCVcoreAg was stable after 1–5 freezing/thawing cycles and not light-sensitive.ConclusionsHCVcoreAg represents a stable and reliable marker of viral replication showing a good correlation with HCV-RNA irrespective of the HCV genotype. HCVcoreAg determination can be used to confirm viral replication and monitor viral load or acquisition of HCV over time.     

Evaluation of the COBAS® AmpliPrep/COBAS® TaqMan® HCV Test,v2.0 and comparison to assays used in routine clinical practice in an international multicenter clinical trial: The ExPECT study

BackgroundThe COBAS^® AmpliPrep^®/COBAS^® TaqMan^® HCV Test, v2.0 (CAP/CTM2) is used for HCV RNA viral load monitoring.ObjectivesThe performance of the CAP/CTM2 was compared to other widely used tests, including a manual version of the assay (the COBAS^® TaqMan^® HCV Test, v2.0 for use with the High Pure System, HPS/CTM2) predominantly used during phase III clinical trials for the new direct acting antiviral therapies.Study designLow HCV RNA level comparisons were performed across tests (Abbott Realtime HCV Test, ART; COBAS^® AmpliPrep^®/COBAS^® TaqMan^® HCV Test, v1.0, CAP/CTM1; CAP/CTM2; and HPS/CTM2) using dilutions of the 2nd HCV WHO International Standard. Additionally, the clinical performance of the CAP/CTM2 was evaluated with 421 leftover HCV RNA-positive routine clinical samples.ResultsAll quantifiable WHO dilutions were within ±0.3 log₁₀ IU/mL of the expected results across tests and the analytical sensitivity resulted in a limit of detection of 12 IU/mL (95% confidence interval, 10, 15). When clinical samples were tested the results for 87% (367 of 421) of all sample comparisons were within ±0.5 log₁₀ IU/mL. When low viral load results (25–3500 IU/mL) were compared, values obtained by the ART assay were significantly lower (p < 0.0001) than those obtained with the CAP/CTM2.ConclusionsThe new CAP/CTM2 showed good accuracy with comparable sensitivity to comparator assays. The new kit is well-suited for use in the routine diagnostic laboratory, especially for accurate monitoring of patients receiving triple therapy or interferone-free regimens.     

HCV-specific lymphocyte responses in individuals with positive anti-HCV but negative HCV-RNA

BackgroundHepatitis C virus (HCV) status cannot be reliably predicted in anti-HCV positive/HCV-RNA negative individuals who may either have recovered spontaneously or have a false-positive test due to antibody cross-reaction. Investigating T lymphocyte responses in individuals with different HCV status may help understand the cellular immune mechanisms underlying spontaneous recovery, treatment response, and chronicity.ObjectiveWe aimed to determine whether anti-HCV positive, HCV-RNA negative individuals are truly spontaneous recoverers from acute HCV infection.Study designWe used enzyme-linked immunosorbent spot (ELISPOT) assay to compare HCV-specific lymphocyte response among anti-HCV positive/HCV-RNA negative individuals, patients with sustained virological response to interferon-γ/ribavirin treatment, and patients with chronic HCV infection.ResultsWe found that 83% of anti-HCV positive/HCV-RNA negative individuals without a past medical history of acute icteric hepatitis had an HCV-specific T lymphocyte response in peripheral blood. Lymphocyte responses in these individuals were similar in magnitude to treatment responders unlike patients with chronic HCV whose virus-directed immunity was significantly suppressed.ConclusionsDetection of HCV-specific T lymphocyte responses using ELISPOT is a feasible method to ascertain past asymptomatic acute HCV infection.     

Parallel declines in HIV and hepatitis C virus prevalence,but not in herpes simplex virus type 2 infection: A 10-year,serial cross-sectional study in an inner-city emergency department

BackgroundThe Johns Hopkins Hospital Emergency Department (JHHED) has served as an observational window on the HIV epidemic in a socioeconomically depressed, urban population. We previously reported that HIV incidence among JHHED patients is decreasing and that prevalence has declined from 11.4% in 2003–5.6% in 2013.ObjectivesThis study sought to observe temporal trends in hepatitis C virus (HCV) and herpes simplex virus type 2 (HSV-2) seroprevalence, which are surrogate markers for parenteral and sexual risk behavior, respectively.Study designIdentity unlinked-serosurveys were conducted over 6–8 weeks in the adult JHHED in 2003, 2007, and 2013. Excess sera from 10,274 patients, previously tested for HIV, were assayed for HSV-2 and HCV antibodies.ResultsOverall HCV seroprevalence declined steadily from 22.0% in 2003–13.8% in 2013 (P_trend < 0.01), and was significant by all gender and race strata. Overall HSV-2 prevalence declined from 55.3% in 2003–50.0% in 2013 (P_trend < 0.01), but was non-significant after adjustment for demographics. Among HIV+ individuals <45 years of age, there was a significant decrease in the proportion of individuals with HCV co-infection [without HSV-2] (P_trend = 0.02) from 2003 to 2013, however, there was an increase in individuals with HSV-2 co-infection [without HCV] (P_trend  <  0.01).DiscussionLittle change in age-specific HSV-2 prevalence suggests the decrease in HIV prevalence was likely not associated with changes in sexual risk behavior. In addition to clinical interventions, strategies to address sexual health disparities and continued parenteral harm-reduction efforts are needed to further drive the decline in HIV.     

Clinical performances of two real-time PCR assays and bDNA/TMA to early monitor treatment outcome in patients with chronic hepatitis C

BackgroundEarly viral monitoring is essential for the management of treatment outcome in patients with chronic hepatitis C. A variety of commercially available assays are now available to quantify HCV-RNA in routine clinical practice.ObjectivesCompare the clinical results of 3 commercially available assays to evaluate the positive predictive value (PPV) and the negative predictive value (NPV) of rapid virological response (RVR) at week 4 and early virological response (EVR) at week 12.Study design287 patients treated with standard care regimen combination therapy were studied. HCV-RNA values measured at baseline, week 4, week 12 with VERSANT^® HCV 3.0 Assay (bDNA), and VERSANT^® HCV-RNA Qualitative Assay (TMA) (bDNA/TMA); COBAS Ampliprep/COBAS/TaqMan (CAP/CTM) and Abbott m2000sp extraction/m2000rt amplification system (ART). RVR was defined as undetectable serum HCV-RNA and EVR as a ≥2 log decline in baseline viral load (BLV).ResultsMedian (range) BVLs were: 5.585(2.585–6.816), 5.189(2.792–7.747) and 4.804(2.380–6.580) log₁₀ IU/ml, with bDNA/TMA, CAP/CTM and ART, respectively (p < 0.01); RVR was observed in 22%, 30% and 27% of the patients and PPVs were 97%, 91% and 94% with bDNA/TMA, CAP/CTM and ART, respectively (p = 0.317). EVR was observed in 76%, 73% and 67% of the patients and NPVs were 93%, 83% and 79% with bDNA/TMA, CAP/CTM and ART, respectively (p = 0.09).ConclusionsTreatment monitoring should include both detection of serum HCV-RNA at week 4 to predict SVR and at week 12 to predict non-SVR. The value of all 3 assays was similar for evaluating RVR or EVR. Because of viral load discrepancies the same assay should be used throughout patient treatment follow-up.     

Coexistence of circulating HBsAg and anti-HBs antibodies in chronic hepatitis B carriers is not a simple analytical artifact and does not influence HBsAg quantification

BackgroundPresence at the same time of HBsAg and anti-HBs antibodies (HBsAg/Ab) is an entity sometimes encountered in chronic hepatitis B (CHB) carriers.ObjectivesThis study was designed to characterize such serological profiles and to assess the reliability of serological marker quantification by three commercially available assays in this setting.Study designAmong 2578 CHB identified patients, 129 (5%) had an HBsAg/Ab profile as determined by Abbott Architect. After exclusion of co-infections (HIV, HCV, HDV), HBV reactivation or HBIg treatment, 101 samples from 62 patients were tested for HBsAg and anti-HBs quantification using Architect, DiaSorin Liaison-XL and Roche Modular-Cobas. Influence of genotype and HBsAg variants was studied in 31 samples with HBV replication.ResultsHBsAg detection was confirmed with the 3 techniques for 98% (n = 99) of the samples while the HBsAg/Ab profile was concordant between all techniques for 65% of them. The overall correlation between the 3 HBsAg quantification techniques was good (R²: 0.94–0.97). The median HBsAg concentration was comparable for the 99 samples whatever the used technique but a bias of −0.11 and 0.02 log IU/mL were noticed for DiaSorin and Roche compared to Abbott, respectively. Anti-HBs quantifications were poorly correlated between techniques with major discrepancies observed. Genotype and substitutions within the “a” determinant showed an impact on HBsAg quantification.ConclusionsThe double HBsAg/Ab profile is not an analytical artifact and is confirmed on all commercially available techniques. While such profile does not influence HBsAg quantification, differences of HBsAg quantification were noticed according to HBV genotype or HBsAg variant.     

血清中丙型肝炎NS3抗原ELISA检测方法的建立和初步应用

目的 评价血清中丙型肝炎病毒(HCV)游离NS3抗原的酶联免疫吸附(ELISA)检测方法的特异性和灵敏度,初步探讨该方法在临床应用中的意义.方法 对77例正常人血清标本,173例抗-HCV阳性标本和3708例抗-HCV阴性的其他类型肝炎血清标本检测HCV游离NS3抗原;对部分HCV NS3抗原阳性标本进行验证,包括HCV RNA测定、中和试验和免疫斑点试验;对11例患者的25份系列血清标本进行了HCV游离NS3抗原、HCV RNA和HCV抗体的联合检测,并结合临床资料综合分析.结果 3708例抗-HCV阴性的其他类型肝炎血清标本中有48例为HCV NS3抗原阳性,其中3030例单纯乙型肝炎和445例其他类型肝炎血清标本中分别有44例和4例为HCV NS3抗原阳性;173例HCV抗体阳性标本中有42例为HCV NS3抗原阳性;77例正常人血清标本的HCV NS3抗原检测结果均为阴性;15例HCV NS3抗原阳性标本中有9例为HCV RNA阳性;23例HCV NS3抗原阳性标本的中和率和免疫斑点试验的阳性率分别为87.0%和69.6%;25份系列血清标本的检测结果显示其HCV NS3抗原的吸光度值与时间呈负相关,并有2例HCV NS3抗原阳性标本随着血清中HCV NS3抗原的吸光度值下降,其HCV抗体转阳.结论 血清中HCV游离NS3抗原的ELISA检测方法有较好的特异性和敏感度,在发展中国家应用此方法进行HCV感染的早期诊断有一定的临床意义和推广价值.     

Improvement in the aetiological diagnosis of acute hepatitis C: A diagnostic protocol based on the anti-HCV-IgM titre and IgG Avidity Index

BackgroundThe gold standard for the diagnosis of acute hepatitis C (AHC) is seroconversion to anti-HCV/HCV-RNA positivity, an occurrence frequently missed in clinical practice.ObjectivesThis study aims to diagnose AHC by the combined use of the HCV Avidity Index (HCV-AI) and HCV-IgM titre.Study designWe enrolled 45 patients with AHC diagnosed by seroconversion to anti-HCV/HCV-RNA positivity and 36 with exacerbation of chronic hepatitis C (e-CHC) diagnosed at least 1 year earlier. HCV-IgM titres were determined by a commercial enzyme-linked immunosorbent assay (ELISA) and HCV-AI by an ELISA for detection of HCV IgG with a partial modification. For each test, specific cut-off values at four selected checking points were established during the observation (<10 days, 11–15 days, 16–20 days and >20 days from the onset of symptoms): for the HCV-IgM assay, the highest value in e-CHC +5% and for HCV-AI assay, the lowest value in e-CHC ?5%.ResultsAround 90% of patients with AHC or e-CHC were correctly diagnosed at all checking points by combining the results of both tests. This practice afforded an improvement in sensitivity for the diagnosis of AHC, with the highest values at first and third checking points (92.3% and 92.6%, respectively) and an improvement in negative predictive value (NPV), with the highest value at first checking point (92.6%).ConclusionsThe diagnosis of AHC, made by seroconversion to anti-HCV/HCV-RNA positivity, was confirmed in more than 90% of patients by combining the results of IgG Avidity Index (IgG-AI) and HCV-IgM obtained in a single serum sample.     

Performance comparison of the 4th generation Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA on the EVOLIS™ automated system versus Abbott ARCHITECT HIV Ag/Ab Combo,Ortho Anti-HIV 1 + 2 EIA on Vitros ECi and Siemens HIV-1/O/2 enhanced on Advia Centaur

BackgroundA multisite study was conducted to evaluate the performance of the Bio-Rad 4th generation GS HIV Combo Ag/Ab EIA versus Abbott 4th generation ARCHITECT HIV Ag/Ab Combo. The performance of two 3rd generation EIAs, Ortho Diagnostics Anti-HIV 1 + 2 EIA and Siemens HIV 1/O/2 was also evaluated.ObjectiveStudy objective was comparison of analytical HIV-1 p24 antigen detection, sensitivity in HIV-1 seroconversion panels, specificity in blood donors and two HIV false reactive panels.Study designAnalytical sensitivity was evaluated with International HIV-1 p24 antigen standards, the AFFSAPS (pg/mL) and WHO 90/636 (IU/mL) standards; sensitivity in acute infection was compared on 55 seroconversion samples, and specificity was evaluated on 1000 negative blood donors and two false reactive panels.ResultsGS HIV Combo Ag/Ab demonstrated better analytical HIV antigen sensitivity compared to ARCHITECT HIV Ag/Ab Combo: 0.41 IU/mL versus 1.2 IU/mL (WHO) and 12.7 pg/mL versus 20.1 pg/mL (AFSSAPS); GS HIV Combo Ag/Ab EIA also demonstrated slightly better specificity compared to ARCHITECT HIV Ag/Ab Combo (100% versus 99.7%). The 4th generation HIV Combo tests detected seroconversion 7–11 days earlier than the 3rd generation HIV antibody only EIAs.ConclusionBoth 4th generation immunoassays demonstrated excellent performance in sensitivity, with the reduction of the serological window period (7–11 days earlier detection than the 3rd generation HIV tests). However, GS HIV Combo Ag/Ab demonstrated improved HIV antigen analytical sensitivity and slightly better specificity when compared to ARCHITECT HIV Ag/Ab Combo assay, with higher positive predictive values (PPV) for low prevalence populations.     

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

BackgroundBeckman Coulter has developed the VERIS HCV Assay for use on the new fully automated DxN VERIS Molecular Diagnostic System^¥ for HCV viral load monitoring.ObjectivesEvaluate the clinical performance of the new quantitative VERIS HCV Assay.Study designComparison 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.ResultsThe average bias between the VERIS HCV Assay and the COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test was 0.04 log₁₀ IU/mL, while between the VERIS HCV Assay and the RealTime HCV Assay average bias was 0.21 log₁₀ IU/mL. Bias, however, was not consistent across the measuring range. Analysis at the lower end of quantification levels 50, 100, and 1000 IU/mL showed a predicted bias for VERIS HCV Assay versus COBAS^® Ampliprep/COBAS^® Taqman^® HCV Test between −0.42 and −0.22 log₁₀ IU/mL and for VERIS HCV Assay versus RealTime HCV Assay between 0.00 and 0.13 log₁₀ IU/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).ConclusionsVERIS 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.     

High seroprevalence against hepatitis E virus in patients with chronic hepatitis C virus infection

BackgroundHepatitis E virus (HEV) genotype 3 is endemic in Europe. Superinfection with HEV in patients with underlying chronic liver disease can cause hepatic decompensation leading to increased morbidity and mortality.ObjectivesThe prevalence of anti-HEV antibodies was investigated in 204 patients with chronic hepatitis C virus (HCV) infection and different stages of fibrosis.Study designSera were analyzed for anti-HEV IgG, IgM and HEV RNA.ResultsThe median age of the patients was 55 years (IQR 40–62 years); 126 (62%) were men. Ninety-eight (48%) patients had a METAVIR fibrosis stage F2 or higher. The prevalence of anti-HEV IgG was 30% (62/204), which was significantly higher than among Swedish blood donors (17%, p < 0.01). The prevalence of anti-HEV antibodies was associated with higher age (OR 1.08 (1.05–1.11); p < 0.01). It was also higher for patients with a prior history of blood transfusion (48%) as compared to intravenous drug use (IDU; 26%) as the risk factor for acquisition of the HCV infection (OR 2.72 (1.2–6.19); p < 0.02). The prevalence of anti-HEV IgG was also significantly higher in patients with significant fibrosis, i.e. ≥F2 (38%; OR 2.04 (1.11–3.76); p = 0.02) and/or neoplasm (72%; OR 7.27 (2.46–21.44); p < 0.01).ConclusionsWhen adjusted for age, the prevalence of anti-HEV antibodies was significantly higher in patients with previous or current malignant liver disease compared to blood donors. The lack of significant correlation between HCV and HEV infections indicate low level of transmission of HEV by IDU. HEV infections warrant more attention, especially in patients with preexisting liver disease.     

Evaluation of the performance of a new automated HIV combination assay

BackgroundMore and more countries test for HIV infection using combination assays that simultaneously detect p24 antigen and HIV antibodies.ObjectiveTo assess the performance of a new HIV combo assay: LIAISON^® XL murex HIV Ab/Ag HT.Study designThe assays were examined with a total of 3090 samples that included 769 selected HIV antibody-negative samples, 1849 unselected HIV samples, 15 HIV-1 p24 Ag reference samples, 90 primary HIV-1 infection (PHI) samples, 167 HIV-1 antibody-positive samples (well characterized of groups M and O), 95 HIV-1 antibody-positive samples and 105 HIV-2 antibody-positive samples.ResultsThe specificity of the LIAISON^® XL murex HIV Ab/Ag HT was 99.7%. The analytical sensitivity of Ag p24 of the LIAISON^® XL murex HIV Ab/Ag HT was 0.58 IU/mL and 9.93 pg/mL when using WHO and French national standards, respectively. All screened HIV subtypes was identified by this assay. Also, 90 PHI specimens were detected by this screening assay.ConclusionThe sensitivity and specificity of the LIAISON^® XL murex HIV Ab/Ag HT assay are high. Hence the assay offers automated high-throughput screening with ability to detect primary infection.     

Peginterferon alfa-2a and peginterferon alfa-2b combined with ribavirin in patients with genotype 1 chronic hepatitis C: Results of a prospective single-centre study

PurposeThis prospective, randomized, single-centre study compared peginterferons alfa-2a and alfa-2b, combined with ribavirin, in treating patients infected with hepatitis C virus (HCV) genotype 1.Material/methodsHundred-and-one patients received 48 weeks of open-label treatment with peginterferon alfa-2a (180 μg/week) and 111 patients received peginterferon alfa-2b (1.5 μg/kg/week). All patients received the same dose of ribavirin 1000/1200 mg/day, depending on weight. The primary efficacy endpoint was sustained virologic response (SVR), defined as undetectable HCV RNA (<50 IU/mL) 24 weeks after the end of treatment.ResultsEarly virologic response (EVR), defined as at least 2 log₁₀ IU/mL reduction of viral load at 12 weeks, was more common in patients treated with peginterferon alfa-2a (88% vs. 74.8%; p = 0.04). However, the difference in SVR was not statistically significant (49.5% vs. 44.1%; p = 0.43).ConclusionsPeginterferon alfa-2a treated patients were also more likely to be HCV RNA negative at the end of treatment (67.3% vs. 57.7%), but this difference did not reach statistical significance. Multivariate logistic regression analysis found that SVR was associated with low fibrosis stage (F1–2 by Scheuer; p = 0.001) and low serum HCV RNA level (<400,000 IU/L; p = 0.023). While both forms of peginterferon showed similar efficacy as measured by SVR, use of peginterferon alfa-2b could lower the number of patients receiving unnecessary treatment beyond 12 weeks.