Performance of eight commercial immunoassays for the detection of cytomegalovirus-specific IgM antibodies in pregnancy - no test fits all needs.

Detection of cytomegalovirus (CMV)-specific immunoglobulin M (IgM) antibodies as first-line serologic diagnosis plays an important role in identifying CMV primary infection during pregnancy. The performance characteristics of eight commercially available CMV IgM assays were compared. Sensitivity and IgM antibody kinetics were assessed using 100 acute phase and follow-up sera from 39 pregnant women with a well-defined onset of CMV primary infection. Specificity was analyzed using 50 well-characterized serum samples from pregnant women not infected or latently infected with CMV and from patients with other acute infections. Until 12 weeks after the onset of primary infection, four assays showed sensitivities of 100%, whereas the others had individual gaps to detect all primary infections in this time period. All assays showed a time-dependent decrease of IgM levels. More than 12 weeks after the onset of infection, the IgM-positive rates varied considerably between tests. The specificity was between 92% and 98% in all but one assay. The observed differences in the performance characteristics must be taken into account in CMV screening and diagnosis of primary infection during pregnancy.

Toxoplasma gondii Infection in Pregnancy - Recommendations of the Working Group on Obstetrics and Prenatal Medicine (AGG - Section on Maternal Disorders).

Aim The AGG (Working Group for Obstetrics and Prenatal Diagnostics, Section Maternal Diseases) has issued these recommendations to improve the detection and management of Toxoplasma gondii infection in pregnancy. Methods Members of the Task Force developed the recommendations and statements presented here using recently published literature. The recommendations were adopted after a consensus process by members of the working group. Recommendations This article focuses on the epidemiology and pathophysiology of Toxoplasma gondii infection in pregnancy and includes recommendations for maternal and fetal diagnosis, transmission prophylaxis, therapy, prevention, screening, and peripartum management.

Polio type 2 and 3 eradication: Relevance to the immunity status of individuals living in Germany, 2005-2020.

Since October 2019, poliovirus type 3 (PV3) has been certified as globally eradicated, and further laboratory use of PV3 will be restricted according to the WHO Polio Eradication Initiative and containment measures. To examine a possible gap in PV3 immunity and a lack of immunity against poliovirus type 2 (PV2), which was already declared as eradicated in 2015, neutralising antibodies against polioviruses (PV) of individuals living in Germany (n = 91,530 samples; mainly outpatients (≈90%) who received immune status testing) were investigated from 2005 to 2020 (age distribution: <18 years 15.8%, 18-64 years 71.2% and ≥65 years 9.5% for 2005-2015; <18 years 19.6%, 18-64 years 67% and ≥65 years 11.5% for 2016-2020). The results showed that the proportion of sera exclusively lacking antibodies against PV3 was 10.6% in 2005-2015 and 9.6% in 2016-2020 and against PV2 2.8% in 2005-2015. As there is decreased protection against PV3 and to detect potential antigenically (immune escape) variant PVs not covered by used vaccines, we recommend continued testing of PV1 and PV3.

Accuracy and real life performance of a novel interferon-γ release assay for the detection of SARS-CoV2 specific T cell response.

BACKGROUND: The reliable detection of T cell response to COVID-19 or COVID-19 vaccination is important for individual patient care and for monitoring the immune response e.g. in COVID-19 vaccine trials in a standardized fashion. OBJECTIVES AND STUDY DESIGN: We used blood samples from health care workers (HCW) with or without history of COVID-19 to define test accuracy of a novel interferon-γ release assay (IGRA). For a real-life performance evaluation, we analysed interferon-γ response to complete COVID-19 vaccination in HCW receiving homologous or heterologous vaccination regimens and in patients receiving immunosuppressive or immune modulating therapies. RESULTS: The assay had a specificity of 100%. Sensitivity of the IGRA to detect past infection was 72.2% after infection more than 5 months ago and 93.8% after COVID-19 up to 5 months ago. Quantitative results showed significant differences between first and second vaccine dose, but no difference between homologous and heterologous vaccination regimen. Immunocompromised patients often had no immune response or isolated T cell or antibody response to complete vaccination. CONCLUSIONS: The novel IGRA proved to be a highly specific tool to detect SARS-CoV-2 specific T cell response to COVID-19 as well as COVID-19 vaccination, with sensitivity getting lower over time. In perspective, it may serve as a standardized tool in COVID-19 vaccine trials and in clinical care of immunosuppressed patients.

Serial Monitoring and Hyperimmunoglobulin versus Standard of Care to Prevent Congenital Cytomegalovirus Infection: A Phase III Randomized Trial.

INTRODUCTION: Nonrandomized studies support the potential of cytomegalovirus hyperimmunoglobulin (CMV-HyperIg) in preventing maternofetal CMV transmission, but prospective interventional studies show equivocal results. We pre-sent a prospective phase-III international randomized open-label trial on the potential effect of CMV-HyperIg following serial monitoring of CMV serostatus. METHODS: CMV-seronegative pregnant women (gestational age [GA] <14 weeks) were 1:1 randomized to monthly CMV-serostatus monitoring and CMV-HyperIg upon seroconversion (treatment), or routine prenatal care with CMV-serostatus testing at end of pregnancy (control). Ethical considerations required that control subjects with confirmed seroconversion be offered Cytotect®. The primary endpoint was the proportion of fetuses/newborns with congenital CMV infection. Secondary endpoints included neonatal CMV disease and safety during the 24-month follow-up. RESULTS: The treatment arm counted 4,800 randomized subjects: 52 seroconverted (median GA 24 [11-35] weeks), of which 45 completed follow-up. The control arm counted 4,735 randomized subjects: 42 seroconverted, of which 34 completed follow-up (evaluable data for 28 newborns) and 8 subjects chose off-label Cytotect®. Congenital CMV rates were 13/28 newborns (46.4% [CI 27.51; 66.13]) vs. 16/45 newborns (35.6% [CI 21.87; 51.22]) in control and treated arms, respectively (p = 0.46). Newborn CMV disease was mostly mild and spontaneously resolving. There were no major safety concerns. The target sample was not reached within an acceptable time frame. CONCLUSIONS: Serial monitoring of CMV serostatus with CMV-HyperIg treatment was associated with a mild nonsignificant reduction in the vertical CMV transmission rate. Studies on the optimal preventive strategy are hampered by epidemiological and ethical challenges and should focus on GA-dependent transmission rates and accurate dating of infection.

The Hierarchy-of-Hypotheses Approach: A Synthesis Method for Enhancing Theory Development in Ecology and Evolution.

In the current era of Big Data, existing synthesis tools such as formal meta-analyses are critical means to handle the deluge of information. However, there is a need for complementary tools that help to (a) organize evidence, (b) organize theory, and (c) closely connect evidence to theory. We present the hierarchy-of-hypotheses (HoH) approach to address these issues. In an HoH, hypotheses are conceptually and visually structured in a hierarchically nested way where the lower branches can be directly connected to empirical results. Used for organizing evidence, this tool allows researchers to conceptually connect empirical results derived through diverse approaches and to reveal under which circumstances hypotheses are applicable. Used for organizing theory, it allows researchers to uncover mechanistic components of hypotheses and previously neglected conceptual connections. In the present article, we offer guidance on how to build an HoH, provide examples from population and evolutionary biology and propose terminological clarifications.

High reproducibility of the interferon-gamma release assay T-SPOT.TB in serial testing.

Longitudinal studies regarding the reproducibility of Interferon-gamma release assay (IGRA) T-SPOT.TB for the diagnosis of Mycobacterium tuberculosis (M. tb) infection in serial testing are limited. We retrospectively analysed results of serially tested subjects in a medical laboratory in Germany over a time period of 14 years. From October 2004 to December 2018, a total of 5440 subjects were identified with a second T-SPOT.TB test after a median time interval of 258 days (interquartile range [IQR] 62-665). Consistently negative (n = 4520) or positive results (n = 682) were observed in 5202 (95.6%) subjects, indicating a high degree of concordance in serial testing (κ = 0.83). Test conversions occurred in 101 of 4621 (2.2%) subjects with initially negative tests. Of 819 subjects with initially positive test results, 137 (16.7%) had a test reversion which was associated with low spot numbers of the first test. Of 529 subjects retested within 1 year, only 60 (11.3%) displayed a test reversion. In subjects retested after more than 1 year, 77 of 290 (26.6%) tests reverted. This significantly higher rate of test reversions after more than 1 year was age-dependent and only observed in subjects above the age of 40 years. In the medical laboratory, the T-SPOT.TB test demonstrates a high reproducibility in serial testing.

Characteristics and mechanisms to control a COVID-19 outbreak on a leukemia and stem cell transplantation unit.

Immunosuppressed patients like patients with leukemia or lymphoma, but also patients after autologous or allogeneic stem cell transplantation are at particular risk for an infection with COVID-19. We describe a COVID-19 outbreak on our leukemia and stem cell transplantation unit (LSCT-Unit) originating from a patient with newly diagnosed acute myeloid leukemia. The patient was treated with intensive induction chemotherapy and we characterize the subsequent outbreak of COVID-19 on a LSCT-Unit. We describe the characteristics of the 36 contacts among the medical team, the results of their PCR and antibody tests and clinical aspects and features of infected employees. Of these 36 close contacts, 9 employees of the LSCT-Unit were infected and were tested positive by PCR and/or antibody-testing. 8/9 of them were symptomatic, 3/9 with severe, 5/9 with mild symptoms, and one person without symptoms. Due to stringent hygiene measures, the outbreak did not lead to infections of other patients despite ongoing clinical work. Moreover, we demonstrate that incubation period and clinical course of a COVID-19 infection in an immunosuppressed patient could be unusual compared to that of immunocompetent patients. Consistent PCR and antibody testing are helpful to understand, control, and prevent outbreaks. For the safety of health-care workers and patients alike, all employees wore FFP2 masks and were trained to adhere to several further safety guidelines. The implementation of rigorous hygiene measures is the key to controlling an outbreak and preventing infections of other patients.

Sulfadiazine plasma concentrations in women with pregnancy-acquired compared to ocular toxoplasmosis under pyrimethamine and sulfadiazine therapy: a case-control study.

BACKGROUND: Dosing recommendations for the treatment of pregnancy-acquired toxoplasmosis are empirical and widely based on experimental data. There are no pharmacological data on pregnant women with acute Toxoplasma gondii infection under treatment with pyrimethamine (PY) and sulfadiazine (SA) and our study intends to tighten this gap. METHODS: In this retrospective case-control study, we included 89 pregnant women with primary Toxoplasma infection (PT) treated with PY (50 mg first dose, then 25 mg/day), SA (50 mg/kg of body weight/day), and folinic acid (10-15 mg per week). These were compared to a group of 17 women with acute ocular toxoplasmosis (OT) treated with an initial PY dose of 75 mg, thereafter 25 mg twice a day but on the same SA and folinic acid regimen. The exact interval between drug intake and blood sampling and co-medication had not been recorded. Plasma levels of PY and SA were determined 14 ± 4 days after treatment initiation using liquid chromatography-mass spectrometry and compared using the Mann-Whitney U test at a p < 0.05 level. RESULTS: In 23 PT patients (26%), SA levels were below 20 mg/l. Fifteen of these 23 patients (17% of all patients) in parallel presented with PY levels below 700 µg/l. Both drug concentrations differed remarkably between individuals and groups (PY: PT median 810 µg/l, 95% CI for the median [745; 917] vs. OT 1230 µg/l [780; 1890], p = 0.006; SA: PT 46.2 mg/l [39.9; 54.4] vs. OT 70.4 mg/l [52.4; 89], p = 0.015) despite an identical SA dosing scheme. CONCLUSIONS: SA plasma concentrations were found in the median 34% lower in pregnant women with PT compared to OT patients and fell below a lower reference value of 50 mg/l in a substantial portion of PT patients. The interindividual variability of plasma concentrations in combination with systematically lower drug levels and possibly a lower compliance in pregnant women may thus account for a still not yet supportable transmission risk. Systematic drug-level testing in PT under PY/SA treatment deserves to be considered.

Diagnosis of intrauterine parvovirus B19 infection at birth - Value of DNA detection in neonatal blood and dried blood spots.

BACKGROUND: Diagnosis of congenital viral infection at birth is generally attempted by direct detection of the virus by PCR in various neonatal materials. How to reliably diagnose intrauterine infection with parvovirus B19 (B19 V) at birth is unknown. OBJECTIVES: To evaluate the performance of B19 V DNA detection in cord blood (CB) or neonatal dried blood spots (DBS) in diagnosing fetal infection. STUDY DESIGN: Two cohorts of children diagnosed prenatally with an intrauterine B19 V infection were included in this study. CB samples of intrauterine B19 V infections that were sent to a reference laboratory for congenital infections in Stuttgart, Germany in the period 1995-2014 were tested in triplicate for B19 V DNA by quantitative PCR. DBS from children with intrauterine B19 V infection that underwent IUT at the LUMC, Leiden, the Netherlands in the period 2009-2014 were tested for B19 V DNA by quantitative B19 V PCR in triplicate. RESULTS: Fourteen of twenty (70 %) CB samples tested positive for B19 V DNA. The positivity rate was 40 % (4/10) in those with a prenatal diagnosis <20 weeks gestation. When intrauterine B19 V infection was diagnosed thereafter, 100 % (10/10) samples were B19 V DNA positive. Of the thirteen available DBS, twelve (92 %) tested positive. Viral load in CB and DBS corresponded inversely with time from fetal diagnosis to birth. CONCLUSION: B19 V DNA can be detected in neonatal blood samples of children following intrauterine B19 V infection, although the possibility of false-negatives, even in severe infections, should be considered. B19 V viral load at birth correlates with timing of infection.

Low-level positive results in the Liaison CMV IgG II assay may misclassify pregnant woman as immune.

The aim of this study is to report on the specificity in the low-positive range of the Liaison CMV IgG II assay for determination of cytomegalovirus immune status in pregnancy. Sera with test results between 12.0 and 40.0 U/mL were retested with the Enzygnost Anti-CMV/IgG assay. Enzygnost-negative samples were analyzed by the Serion ELISA classic Cytomegalovirus IgG assay and, if positive or equivocal, also with the Mikrogen recomLine CMV IgG assay. A total of 12,117 sera were tested with the Liaison assay. Sixty sera were equivocal (12.0-13.9 U/mL), and 400 of 4295 positive sera were low-positive (14.0-40.0 U/mL). Based on consensus, at least 14% of the low-positives and 1.3% of all Liaison-positives can be considered as misclassified. The proportion of misclassified sera increased with lower Liaison IgG results. We suggest that the range for equivocal results in the Liaison assay should be revised.

Timing of Vaccination after Training: Immune Response and Side Effects in Athletes.

OBJECTIVES: Influenza vaccination was used to assess whether induction of immunity or side effects are influenced by the timing of the last training session before vaccination. METHODS: Forty-five healthy athletes (36 male, 23 ± 8 yr, ≥5 training sessions per week, predominantly national competition level) were vaccinated with the tetravalent influenza vaccine; blood samples were collected immediately before and 1, 2, and 26 wk after vaccination. Athletes were randomly assigned to vaccination within 2 h after the last training session versus after 24-26 h. Influenza-specific T cells were quantified after stimulation with the vaccine based on intracellular cytokine staining. Antibodies (IgA, IgG, IgM) were quantified by enzyme-linked immunosorbent assay and neutralization assay. Participants documented resulting side effects and training restrictions using a standardized diary. RESULTS: Both groups showed an increase in influenza-reactive CD4 T-cell levels, which peaked 1 wk after vaccination (fold changes to baseline; median (interquartile range), 3.7 (3.0-5.4; P < 0.001) in the 2-h group; 4.6 (2.8-7.4; P < 0.001) in the 26-h group) with no difference between groups (P = 0.52). Influenza-specific antibodies showed a significant increase after vaccination in both groups (at least 1.4-fold, each P < 0.001, no group differences; P = 0.24-0.97 for different antibody types). Only antibodies toward the Brisbane strain showed a trend toward significant differences in neutralization titers between groups (4-fold (2-17.8) in the 2-h group, 16-fold (4-32.9) in the 26-h group; P = 0.06), whereas other specificities did not differ (P = 0.16-0.72). No intergroup differences were found for side effects; no athlete reported a loss of training time due to the vaccination or its side effects. CONCLUSION: Infection prophylaxis in elite athletes by influenza vaccination seems to be effective and safe. Timing of vaccination after prior training does not seem to require specific constraints.

A conceptual map of invasion biology: Integrating hypotheses into a consensus network.

BACKGROUND AND AIMS: Since its emergence in the mid-20th century, invasion biology has matured into a productive research field addressing questions of fundamental and applied importance. Not only has the number of empirical studies increased through time, but also has the number of competing, overlapping and, in some cases, contradictory hypotheses about biological invasions. To make these contradictions and redundancies explicit, and to gain insight into the field's current theoretical structure, we developed and applied a Delphi approach to create a consensus network of 39 existing invasion hypotheses. RESULTS: The resulting network was analysed with a link-clustering algorithm that revealed five concept clusters (resource availability, biotic interaction, propagule, trait and Darwin's clusters) representing complementary areas in the theory of invasion biology. The network also displays hypotheses that link two or more clusters, called connecting hypotheses, which are important in determining network structure. The network indicates hypotheses that are logically linked either positively (77 connections of support) or negatively (that is, they contradict each other; 6 connections). SIGNIFICANCE: The network visually synthesizes how invasion biology's predominant hypotheses are conceptually related to each other, and thus, reveals an emergent structure - a conceptual map - that can serve as a navigation tool for scholars, practitioners and students, both inside and outside of the field of invasion biology, and guide the development of a more coherent foundation of theory. Additionally, the outlined approach can be more widely applied to create a conceptual map for the larger fields of ecology and biogeography.

Elite athletes on regular training show more pronounced induction of vaccine-specific T-cells and antibodies after tetravalent influenza vaccination than controls.

Compliance of elite athletes with vaccination recommendations is low mainly based on concerns about side-effects and perceived poor vaccine efficacy due to continued physical training. We therefore employed seasonal influenza vaccination to investigate the effect of regular physical training on vaccine-induced cellular and humoral immunity in elite athletes and controls. Lymphocyte subpopulations and vaccine-specific T-cells were quantified and functionally characterized from 45 athletes and 25 controls before, and 1, 2 and 26 weeks after vaccination. Moreover, influenza-specific antibodies and their neutralizing function were quantified. Both groups showed a significant increase in vaccine-reactive CD4 T-cell levels which peaked one week after vaccination (p < 0.0001). The increase was significantly more pronounced in athletes (4.1-fold) compared to controls (2.3-fold; p = 0.0007). The cytokine profile changed from multifunctional T-cells co-producing IFNγ, IL-2 and TNFα to cells with restricted cytokine expression. This change in functionality was associated with a significant increase in CTLA-4 expression (p < 0.0001), which again was more pronounced in athletes. Likewise, the increase in neutralizing antibodies was stronger in athletes (p = 0.004 for H1N1; p = 0.032 for H3N2). In conclusion, both groups mounted a strong vaccine-specific cellular and humoral immunity after standard vaccination. The more pronounced increase in specific T-cells and neutralizing antibodies indicates that high frequency and intensity of training enhance vaccine-responses in elite athletes.

Primary cytomegalovirus (CMV) infection in pregnancy: Diagnostic value of CMV PCR in saliva compared to urine at birth.

BACKGROUND: Due to its ease of collection saliva was recently recommended as the preferred specimen, not only for screening, but also for diagnosis of congenital cytomegalovirus (CMV) infection. OBJECTIVE: To compare the diagnostic performance of saliva PCR to urine PCR in infants born to mothers with primary CMV infection during pregnancy. STUDY DESIGN: We retrospectively analyzed available data of infants tested for CMV DNA in urine and saliva at birth. PCR was performed with RealStar® CMV-PCR Kit 1.0 (altona Diagnostics). Infectious virus was detected in urine by rapid culture. RESULTS: A total of 133 newborns were eligible for final analysis. Saliva swabs and urine were collected at birth with a time interval of 0-8 days (median 0; IQR 0-1). In 55% of newborns, cord blood was also tested. The overall concordance of saliva and urine PCR was 91% (27 positive, 94 negative). In 12 cases with discordant findings the discrepancy was due to false-negative (n = 2) or false-positive (n = 10) PCR results in saliva. Compared to urine, PCR in saliva showed a positive predictive value of 73%. Viral load in saliva was significantly lower (p < 0.0001; Mann-Whitney test) in the 10 false-positive cases than in the 27 cases with concordantly positive results. CONCLUSIONS: Positive CMV PCR results in saliva, especially low positive, have to be confirmed by urine testing. In our opinion detection of CMV by PCR in neonatal urine remains the gold standard for diagnosing congenital CMV infection in infants of mothers with primary infection in pregnancy.

No evidence of obstetrical adverse events after hyperimmune globulin application for primary cytomegalovirus infection in pregnancy: experience from a single centre.

PURPOSE: To determine the frequency of obstetrical adverse events and clinical outcome in infants following antenatal hyperimmune globulin (HIG) treatment for primary cytomegalovirus (CMV) infection in pregnancy. METHODS: Data from 50 women including three twin pregnancies were retrospectively evaluated. Primary infection was defined by seroconversion or the presence of CMV-specific IgM and low IgG avidity. All women received two or more infusions of HIG (200 U/kg). Congenital CMV (cCMV) infection was diagnosed by detection of CMV in amniotic fluid and/or neonatal urine. We compared gestational age (GA) at birth, head circumference (HC) and birth weight (BW) of infants in our study cohort with those of live-born infants delivered in our clinic between 2015 and 2016. RESULTS: Median gestational age at time of maternal CMV diagnosis was 13 weeks. One-hundred-forty-one maternal HIG doses were given. No HIG-related severe adverse reactions occurred. Preterm birth rate was 4.2% (2/47) in singleton pregnancies. None of the neonates had birth weight or head circumference < 3rd percentile (< 3P) for gestational age. There was no statistically significant difference regarding GA, BW and HC between our study cohort and the total population of live-born infants. The frequency of CMV-related sequelae in infants with cCMV infection was 10.5% (2/19) (one with bilateral hearing loss and one with mild motoric delay), both cases following first trimester maternal infection. CONCLUSION: Antenatal HIG treatment was well tolerated and not associated with prematurity or decreased birth weight. HIG application might have a favorable effect on the clinical course of congenital CMV infection.

Accessing complex patient data from Arden Syntax Medical Logic Modules.

OBJECTIVE: Arden Syntax is a standard for representing and sharing medical knowledge in form of independent modules and looks back on a history of 25 years. Its traditional field of application is the monitoring of clinical events such as generating an alert in case of occurrence of a critical laboratory result. Arden Syntax Medical Logic Modules must be able to retrieve patient data from the electronic medical record in order to enable automated decision making. For patient data with a simple structure, for instance a list of laboratory results, or, in a broader view, any patient data with a list or table structure, this mapping process is straightforward. Nevertheless, if patient data are of a complex nested structure the mapping process may become tedious. Two clinical requirements - to process complex microbiology data and to decrease the time between a critical laboratory event and its alerting by monitoring Health Level 7 (HL7) communication - have triggered the investigation of approaches for providing complex patient data from electronic medical records inside Arden Syntax Medical Logic Modules. METHODS AND MATERIALS: The data mapping capabilities of current versions of the Arden Syntax standard as well as interfaces and data mapping capabilities of three different Arden Syntax environments have been analyzed. We found and implemented three different approaches to map a test sample of complex microbiology data for 22 patients and measured their execution times and memory usage. Based on one of these approaches, we mapped entire HL7 messages onto congruent Arden Syntax objects. RESULTS: While current versions of Arden Syntax support the mapping of list and table structures, complex data structures are so far unsupported. We identified three different approaches to map complex data from electronic patient records onto Arden Syntax variables; each of these approaches successfully mapped a test sample of complex microbiology data. The first approach was implemented in Arden Syntax itself, the second one inside the interface component of one of the investigated Arden Syntax environments. The third one was based on deserialization of Extended Markup Language (XML) data. Mean execution times of the approaches to map the test sample were 497ms, 382ms, and 84ms. Peak memory usage amounted to 3MB, 3MB, and 6MB. CONCLUSION: The most promising approach by far was to map arbitrary XML structures onto congruent complex data types of Arden Syntax through deserialization. This approach is generic insofar as a data mapper based on this approach can transform any patient data provided in appropriate XML format. Therefore it could help overcome a major obstacle for integrating clinical decision support functions into clinical information systems. Theoretically, the deserialization approach would even allow mapping entire patient records onto Arden Syntax objects in one single step. We recommend extending the Arden Syntax specification with an appropriate XML data format.

Evaluation of the Aptima HBV Quant assay vs. the COBAS TaqMan HBV test using the high pure system for the quantitation of HBV DNA in plasma and serum samples.

BACKGROUND: Proper management of patients with chronic hepatitis B virus (HBV) infection requires monitoring of plasma or serum HBV DNA levels using a highly sensitive nucleic acid amplification test. Because commercially available assays differ in performance, we compared herein the performance of the Hologic Aptima HBV Quant assay (Aptima) to that of the Roche Cobas TaqMan HBV test for use with the high pure system (HPS/CTM). METHODS: Assay performance was assessed using HBV reference panels as well as plasma and serum samples from chronically HBV-infected patients. Method correlation, analytical sensitivity, precision/reproducibility, linearity, bias and influence of genotype were evaluated. Data analysis was performed using linear regression, Deming correlation analysis and Bland-Altman analysis. RESULTS: Agreement between the assays for the two reference panels was good, with a difference in assay values vs. target <0.5 log. Qualitative assay results for 159 clinical samples showed good concordance (88.1%; κ=0.75; 95% confidence interval: 0.651-0.845). For the 106 samples quantitated by both assays, viral load results were highly correlated (R=0.92) and differed on average by 0.09 log, with 95.3% of the samples being within the 95% limit of agreement of the assays. Linearity for viral loads 1-7 log was excellent for both assays (R2>0.98). The two assays had similar bias and precision across the different genotypes tested at low viral loads (25-1000 IU/mL). CONCLUSIONS: Aptima has a performance comparable with that of HPS/CTM, making it suitable for use for HBV infection monitoring. Aptima runs on a fully automated platform (the Panther system) and therefore offers a significantly improved workflow compared with HPS/CTM.

Performance of the New Aptima HCV Quant Dx Assay in Comparison to the Cobas TaqMan HCV2 Test for Use with the High Pure System in Detection and Quantification of Hepatitis C Virus RNA in Plasma or Serum.

Quantitating the level of hepatitis C virus (HCV) RNA is the standard of care for monitoring HCV-infected patients during treatment. The performances of commercially available assays differ for precision, limit of detection, and limit of quantitation (LOQ). Here, we compare the performance of the Hologic Aptima HCV Quant Dx assay (Aptima) to that of the Roche Cobas TaqMan HCV test, version 2.0, using the High Pure system (HPS/CTM), considered a reference assay since it has been used in trials defining clinical decision points in patient care. The assays' performance characteristics were assessed using HCV RNA reference panels and plasma/serum from chronically HCV-infected patients. The agreement between the assays for the 3 reference panels was good, with a difference in quantitation values of <0.5 log. High concordance was demonstrated between the assays for 245 clinical samples (kappa = 0.80; 95% confidence interval [CI], 0.720 to 0.881); however, Aptima detected and/or quantitated 20 samples that HPS/CTM did not detect, while Aptima did not detect 1 sample that was quantitated by HPS/CTM. For the 165 samples quantitated by both assays, the values were highly correlated (R= 0.98;P< 0.0001). The linearity of quantitation from concentrations of 1.4 to 6 log was excellent for both assays for all HCV genotypes (GT) tested (GT 1a, 1b, 2b, and 3a) (R(2)> 0.99). The assays had similar levels of total and intra-assay variability across all genotypes at concentrations from 1,000 to 25 IU/ml. Aptima had a greater analytical sensitivity, quantitating more than 50% of replicates at 25-IU/ml target. Aptima showed performance characteristics comparable to those of HPS/CTM and increased sensitivity, making it suitable for use as a clinical diagnostic tool on the fully automated Panther platform.

Comparative evaluation of the Aptima HIV-1 Quant Dx assay and COBAS TaqMan HIV-1 v2.0 assay using the Roche High Pure System for the quantification of HIV-1 RNA in plasma.

BACKGROUND: Quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma has become the standard of care in the management of HIV-infected patients. There are several commercially available assays that have been implemented for the detection of HIV-1 RNA in plasma. Here, the new Hologic Aptima® HIV-1 Quant Dx assay (Aptima HIV) was compared to the Roche COBAS® TaqMan® HIV-1 Test v2.0 for use with the High Pure System (HPS/CTM). METHODS: The performance characteristics of the assays were assessed using commercially available HIV reference panels, dilution of the WHO 3rd International HIV-1 RNA International Standard (WHO-IS) and plasma from clinical specimens. Assay performance was determined by linear regression, Deming correlation analysis and Bland-Altman analysis. RESULTS: Testing of HIV-1 reference panels revealed excellent agreement. The 61 clinical specimens quantified in both assays were linearly associated and strongly correlated. CONCLUSIONS: The Aptima HIV assay offers performance comparable to that of the HPS/CTM assay and, as it is run on a fully automated platform, a significantly improved workflow.