Architect Instrument Research Articles

Pre-analytical considerations in the development of a prototype SARS-CoV-2 antigen ARCHITECT automated immunoassay.

To evaluate pre-analytical challenges related to high-volume central laboratory SARS-CoV-2 antigen testing with a prototype qualitative SARS-CoV-2 antigen immunoassay run on the automated Abbott ARCHITECT instrument. Contrived positive and negative specimens and de-identified nasal and nasopharyngeal specimens in transport media were used to evaluate specimen and reagent on-board stability, assay analytical performance and interference, and clinical performance. TCID50/mL values were similar for specimens in various transport media. Inactivated positive clinical specimens and viral lysate (USA-WA1/2020) were positive on the prototype immunoassay. Within-laboratory imprecision was≤0.10 SD (<1.00S/C) with a≤10% CV (≥1.00S/C). Assay reagents were stable on board the instrument for 14days. No high-dose hook effect was observed with a SARS-CoV-2 stock of Ct 13.0 (RLU>1.0×106). No interference was observed from mucin, whole blood, 12 drugs, and more than 20 cross-reactants. While specimen stability was limited at room temperature for specimens with or without viral inactivation, a single freeze/thaw cycle or long-term storage (>30days) at-20°C did not adversely impact specimen stability or assay performance. Specificity of the prototype SARS-CoV-2 antigen immunoassay was≥98.5% and sensitivity was≥89.5% across two ARCHITECT instruments. Assay sensitivity was inversely correlated with Ct and was similar to that reported for the Roche Elecsys® SARS-CoV-2 Ag immunoassay. The prototype SARS-CoV-2 antigen ARCHITECT immunoassay is sensitive and specific for detection of SARS-CoV-2 in nasal and nasopharyngeal specimens. Endogenous proteases in mucus may degrade the target antigen, which limits specimen storage and transport times and complicates assay workflow.

Development of a new automated IL-6 immunoassay

ObjectivesQuantitative detection of interleukin-6 (IL-6) in serum and plasma can help monitor immune responses and the development of acute inflammation to guide patient management. We developed an IL-6 immunoassay for use with the automated ARCHITECT system for detecting an increase in the inflammatory response. MethodsImmunized mouse sera were tested and selected B-cells were harvested for fusion with myeloma cells. A panel of monoclonal antibodies were produced, from which capture and detection monoclonal antibodies for the prototype IL-6 immunoassay were selected and screened on the ARCHITECT instrument. The antibody pair that most effectively captured and detected IL-6 was selected to develop a prototype IL-6 immunoassay. Calibrator and panel preparations using an internal recombinant IL-6 standard were compared to serum panels prepared with the IL-6 International Standard 89/548. Assay specificity and spike recovery were determined, and assay sensitivity was compared with the Roche EUA Elecsys IL-6 assay run on the cobas analyzer. ResultsTwenty-one antibodies in 441 antibody pairs were screened. The prototype IL-6 assay showed high sensitivity with an estimated limit of detection of 0.317 pg/mL and limit of quantitation of <1.27. Spike recovery was 90%–110% in serum and plasma. The internal recombinant human IL-6 calibrator showed excellent stability for 63 days at 2–8 °C. The prototype IL-6 immunoassay was specific for IL-6, exhibited no cross reactivity to related cytokines and interleukins, and was 10-fold more sensitive than the Elecsys IL-6 assay. ConclusionsThe prototype ARCHITECT IL-6 automated immunoassay is a reliable and robust method for the quantitative determination of IL-6 in human serum and plasma.

W70. SMALL RNA EXPRESSION PROFILE FROM EXOSOMES OF FIRST EPISODE PSYCHOSIS PATIENTS

Validation of a non-targeted method for urine drug screening (UDS) by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF), and comparison to an established GC–MS method in a hospital setting.217 UDS specimens sent to a quaternary hospital pathology department, were analysed by a CEDIA® immunoassay screen (six drug panels; amphetamines, barbiturates, benzodiazepines, cocaine metabolites, cannabinoids and opiates) on an Abbott Architect instrument. Specimens were subsequently analysed by an established non-targeted qualitative GC–MS method and results compared with a general unknown screening method by LC-QTOF that was under evaluation as a replacement method.42 selected drugs were evaluated; limits of identification ranged from 2 to 100 µg/L and most drugs (n = 39) were stabile for 24 h after preparation. Matrix effects greater than 25% were observed in seven of the selected drugs. 87% of the specimens tested positive to 1 or more drug panels in a CEDIA® screen. A total of 537 positive drug findings were identified by GC–MS compared to 1,267 positive findings by LC-QTOF. On average, each GC–MS screen identified 2.5 ± 1.8 drugs and the LC-QTOF screen identified 5.8 ± 3.2 drugs. No drugs were identified in 11.3% of the GC–MS screens, whereas drugs were detected in 99% of these by the LC-QTOF. In almost all instances, the LC-QTOF screen could provide mass spectrometric confirmatory results of positive immunoassay screens and was able to identify a wider range of additional drugs and drug metabolites.The described general unknown screening (non-targeted, qualitative) LC-QTOF method can detect a larger range of drugs encountered in a hospital setting. The method has been shown to be suitable for comprehensive toxicology screening in a clinical toxicology laboratory.

Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors’ serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18–49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Urine toxicology screening by liquid chromatography time-of-flight mass spectrometry in a quaternary hospital setting

ObjectiveValidation of a non-targeted method for urine drug screening (UDS) by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF), and comparison to an established GC–MS method in a hospital setting. Methods217 UDS specimens sent to a quaternary hospital pathology department, were analysed by a CEDIA® immunoassay screen (six drug panels; amphetamines, barbiturates, benzodiazepines, cocaine metabolites, cannabinoids and opiates) on an Abbott Architect instrument. Specimens were subsequently analysed by an established non-targeted qualitative GC–MS method and results compared with a general unknown screening method by LC-QTOF that was under evaluation as a replacement method. Results42 selected drugs were evaluated; limits of identification ranged from 2 to 100 µg/L and most drugs (n = 39) were stabile for 24 h after preparation. Matrix effects greater than 25% were observed in seven of the selected drugs. 87% of the specimens tested positive to 1 or more drug panels in a CEDIA® screen. A total of 537 positive drug findings were identified by GC–MS compared to 1,267 positive findings by LC-QTOF. On average, each GC–MS screen identified 2.5 ± 1.8 drugs and the LC-QTOF screen identified 5.8 ± 3.2 drugs. No drugs were identified in 11.3% of the GC–MS screens, whereas drugs were detected in 99% of these by the LC-QTOF. In almost all instances, the LC-QTOF screen could provide mass spectrometric confirmatory results of positive immunoassay screens and was able to identify a wider range of additional drugs and drug metabolites. ConclusionsThe described general unknown screening (non-targeted, qualitative) LC-QTOF method can detect a larger range of drugs encountered in a hospital setting. The method has been shown to be suitable for comprehensive toxicology screening in a clinical toxicology laboratory.

Pre-treatment Serum HE4 Level as a Novel Independent Prognostic Biomarker for Uterine Cervical Carcinoma Patients.

In spite of the effective implementation of screening programs, uterine cervical carcinoma (UCC) remains one of the major causes of cancer death among women around the world. The aim of this study was to investigate the prognostic value of serum human epididymis protein 4 (HE4) in UCC. Pre-treatment serum samples from 109 UCC patients and 99 healthy women were analyzed for HE4 levels by a quantitative chemiluminescent microparticle immunoassay on the automated ARCHITECT instrument. HE4 serum (sHE4) levels were significantly higher in UCC patients, regardless of tumor stage, compared with healthy controls. Elevated sHE4 levels were significantly associated with advanced FIGO stage and absence of disease-free interval after treatment. In univariable analysis, higher sHE4 levels were significantly correlated with shorter overall survival and progression-free survival. In multivariable analysis, sHE4 retained its significance as independent adverse prognostic factor for both survival endpoints. This study indicates that sHE4 is associated with a more aggressive tumor phenotype and a worse patient's prognosis. These results suggest the potential role of sHE4 as a novel prognostic marker and as an indicator of high-risk UCC patients for a tailored surgical and adjuvant therapy.

Hepatitis C virus surveillance and identification of human pegivirus 2 in a large Cameroonian cohort

SummaryThe prevalence of chronic hepatitis C virus (HCV) and the presence of human pegivirus 2 (HPgV‐2) have not been examined in Cameroon, although HCV has been associated with HPgV‐2 infections previously. Herein we aimed to characterize the burden and genetic diversity of HCV and the presence of HPgV‐2 in Cameroon. Retrospective plasma specimens collected from N = 12 369 consenting subjects in South Cameroon from 2013 to 2016 were included in the study. The majority (97.1%) of participants were patients seeking health care. All specimens were screened for HCV using the Abbott RealTime HCV viral load assay and positive specimens with remaining volume were also screened for HPgV‐2 antibodies on the Abbott ARCHITECT instrument, followed by molecular characterization. Overall, HCV RNA was detected in 305 (2.47%; 95% CI: 2.21%‐2.75%) specimens. Notably, the prevalence of HCV RNA was 9.09% amongst participants over age 40 and 3.81% amongst males. Phylogenetic classification of N = 103 HCV sequences identified genotypes 1 (19.4%), 2 (15.5%) and 4 (65.1%) within the study cohort. Amongst HCV RNA‐positive specimens, N = 28 (10.6%; 95% CI: 7.44%‐14.90%) specimens also had detectable HPgV‐2 antibodies. Of these, N = 2 viremic HPgV‐2 infections were confirmed by sequencing and shared 93‐94 median % identity with strains found on other continents. This is the first study to determine the prevalence of chronic HCV in Cameroon, and the discovery of HPgV‐2 in this study cohort expands the geography of HPgV‐2 to the African continent, indicating a widespread distribution exists.

High prevalence of hepatitis delta virus in Cameroon

Hepatitis delta virus (HDV), a satellite virus of hepatitis B virus (HBV), infects an estimated 15–20 million people worldwide and confers a greater risk for accelerated progression to liver disease. However, limited HDV surveillance data are available in sub-Saharan Africa where HDV diversity is high. To determine the prevalence and diversity of HDV in Cameroon, serological and molecular characterization was performed on 1928 HBsAg positive specimens selected from retrospective viral surveillance studies conducted in Cameroon from 2010–2016. Samples were screened for HDV antibodies on the Abbott ARCHITECT instrument and for HDV RNA on the Abbott m2000 instrument by research assays. HDV positive specimens with sufficient viral load were selected for genomic sequencing. The seroprevalence of HDV in HBsAg positive samples from Cameroon was 46.73% [95% CI; 44.51–48.96%], with prevalence of active HDV infection being 34.2% [95% CI; 32.09–36.41%]. HDV genotypes 1, 6, 7 and 8 were identified amongst N = 211 sequences, including N = 145 genomes. HDV prevalence is high within the study cohort, indicating that a large portion of HBV infected individuals in Cameroon are at elevated risk for severe hepatitis and death. Collectively, these results emphasize the need for HBV vaccination and HDV testing in HBsAg positive patients in Cameroon.

The risk of HCV RNA contamination in serology screening instruments with a fixed needle for sample transfer

BackgroundHepatitis C diagnostics involve antibody screening and confirmation of current infection by detection of HCV RNA positivity. In screening instruments with fixed pipetting needle, there is a risk of sample carry-over contamination. ObjectivesThe aim of this study was to evaluate the risk of such contamination in a proposed clinical setting. Study designIn the present study, known HCV RNA positive (n=149) and negative (n=149) samples were analysed by anti-HCV Abbott in an Architect instrument in an alternating fashion in order to test for contamination. ResultsIn subsequent retesting of the previously HCV RNA-negative samples, six samples (4%) were positive by the Cobas Taqman assay with a maximum level of 33IU/mL. The results show that there is a risk for transfer of HCV in the Architect instrument but they also show that the levels of HCV RNA observed are low. ConclusionsWe conclude that complementary HCV RNA testing on samples identified as anti-HCV positive by screening can be recommended because the complementary results are reliable in the majority of cases when either HCV RNA is negative or HCV RNA is positive with a level >1000IU/mL. In a minority of cases, with low HCV RNA after anti-HCV antibody screening, cross-contamination should be suspected and a new sample requested for HCV RNA testing. This strategy would reduce the need for obtaining a new sample from the vast majority of patients with a newly discovered HCV antibody positivity.

Serum HE4 as a prognostic marker in endometrial cancer — A population based study

ObjectiveHE4 has emerged as a promising biomarker in gynaecological oncology. The purpose of this study was to evaluate serum HE4 as a biomarker for high-risk phenotypes in a population-based endometrial cancer cohort. MethodsPeri-operative serum HE4 and CA125 were measured in 373 patients identified from the prospective Australian National Endometrial Cancer Study (ANECS). HE4 and CA125 were quantified on the ARCHITECT instrument in a clinically accredited laboratory. Receiver operator curves (ROC), Spearman rank correlation coefficient, and chi-squared and Mann–Whitney tests were used for statistical analysis. Survival analysis was performed using Kaplan–Meier and Cox multivariate regression analyses. ResultsMedian CA125 and HE4 levels were higher in stage III and IV tumours (p<0.001) and in tumours with outer-half myometrial invasion (p<0.001). ROC analysis demonstrated that HE4 (area under the curve (AUC)=0.76) was a better predictor of outer-half myometrial invasion than CA125 (AUC=0.65), particularly in patients with low-grade endometrioid tumours (AUC 0.77 vs 0.64 for CA125). Cox multivariate analysis demonstrated that elevated HE4 was an independent predictor of recurrence-free survival (HR=2.40, 95% CI 1.19–4.83, p=0.014) after adjusting for stage and grade of disease, particularly in the endometrioid subtype (HR=2.86, 95% CI 1.25–6.51, p=0.012). ConclusionThese findings demonstrate the utility of serum HE4 as a prognostic biomarker in endometrial cancer in a large, population-based study. In particular they highlight the utility of HE4 for pre-operative risk stratification to identify high-risk patients within low-grade endometrioid endometrial cancer patients who might benefit from lymphadenectomy.

Human epididymis protein 4 as a serum marker for diagnosis of endometrial carcinoma and prediction of clinical outcome

The purpose of this study was to assess the diagnostic and prognostic impact of preoperative serum determination of human epididymis protein 4 (sHE4), and to investigate its potential correlation with clinicopathological features and survival endpoints in endometrial cancer patients. Preoperative serum samples from 193 endometrial cancer patients and 125 women with normal endometrium were measured for sHE4 and serum CA125 (sCA125) concentrations by quantitative chemiluminescent microparticle immunoassays on the automated Architect instrument. sHE4 concentrations were significantly higher in endometrial cancer patients regardless of tumour stage and grade compared with normal controls. Setting the specificity at 95 % , the sensitivities in detecting endometrial cancer patients were 66 % for HE4, 33 % for CA125 and 64 % for the combination of the two markers. High concentrations of both HE4 and CA125 significantly correlated with all clinicopathological features characterising a more aggressive tumour phenotype.In multivariate analysis, only high preoperative sHE4 concentrations, but not sCA125, were independent prognostic factors for shorter Overall Survival, Disease-Free Survival and Progression-Free Survival. HE4 is more sensitive and specifi c than CA125in distinguishing endometrial cancer patients from women with normal endometrium, regardless of tumour stage and grade. sHE4 appears to be associated with a more aggressive tumour variant and it could be clinically useful, in identifying high-risk endometrial cancer patients, for a tailored surgical and postoperative therapy. HE4 significant correlation with decreased Overall Survival, Disease Free Survival and Progression Free Survival suggests its potential role as a novel prognostic marker for endometrial cancer.

Determination of myeloperoxidase in EDTA plasma: Comparison of an enzyme-linked immunosorbent assay with a chemiluminescent automated immunoassay

Background The increased demand in clinical chemistry laboratories for determination of myeloperoxidase (MPO) as a potential marker for cardiovascular diseases has led to the development of several analytical methods, especially enzyme-linked immunosorbent assay (ELISA, e. g. from Immundiagnostik AG), and recently a new chemiluminescent automated immunoassay (CMIA, Architect MPO assay, Abbott Diagnostics). Methods We compared data from 115 patients obtained from an ELISA reference method (Immundiagnostik AG) with data obtained from the automated Architect MPO assay. Results The new MPO assay from Abbott Diagnostics correlates well with the ELISA ( y = 0.767 x + 7.035; R 2 = 0.9204). The difference plot according to Bland–Altman analysis shows a mean bias of − 1.048 μg/l, with a probability of 95%. Conclusions The Architect MPO assay can easily be adapted to the Architect instrument system and it is advantageous as far as technology and analysis time are concerned. This new automated MPO assay shows excellent analytical performance and provides a precise and convenient automated method for the measurement of MPO.

Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays

A panel of new cytomegalovirus (CMV) assays for use on the Architect instrument has been developed, including a CMV avidity assay based on a new technology. The purpose of this study was to compare the performance characteristics of the fully automated CMV immunoglobulin M (IgM), IgG, and IgG avidity tests on the Architect instrument with those of other available assays. A total of 503 consecutive fresh patient serum specimens (routine serum specimens) and 96 serum specimens from 33 pregnant women with a recent CMV primary infection (seroconversion serum specimens) were tested for CMV IgM and IgG by the Architect (Abbott), Vidas (BioMérieux), and Enzygnost (Siemens) assays. The seroconversion sera and 100 preselected serum specimens IgM negative and IgG positive by the AxSYM assay were also tested by the IgG avidity tests on the Architect and Vidas instruments. The relative agreements for CMV IgM determination with routine sera between the Architect assay and the Vidas, Enzygnost, and AxSYM assays were 97%, 94%, and 93%, respectively, for the CMV IgM tests and 99%, 98%, and 98%, respectively, for the CMV IgG tests. The specificities of the CMV IgG avidity test were 98% for the Architect assay and 76% for the Vidas assay. No high CMV IgG avidity test results were found within the first 3 months after seroconversion by either of those assays. The correlation between the results of the newly developed CMV IgM and IgG tests on the Architect instrument with the Vidas and Enzygnost assays was excellent (> or = 94%). The CMV IgG avidity test reliably excluded patients with recent infections and showed an excellent specificity (98%).

Evaluation of the new ARCHITECT Rubella IgM assay

Background Rubella infections are usually characterized by mild self-limiting courses in immunocompetent individuals. However, infections in pregnant women during the first trimester of pregnancy pose a high risk of congenital rubella syndrome possibly resulting in severe defects in the unborn child. Rubella serology of a primary rubella infection is mainly determined by diagnostic confirmation of levels of specific IgM. Study design Here, we report on the performance of the Rubella IgM assay in development on the ARCHITECT instrument, a fully automated high throughput chemiluminescent microparticle immunoassay platform. Sensitivity was examined using commercially available seroconversion panels from vaccinated individuals; specificity was addressed by testing populations of pregnant women, blood donors and hospitalized patients. In addition, the potential for assay interference was evaluated by testing samples of several disease states. As methods of comparison AxSYM, BioMérieux VIDAS and Behring Rubella IgM assays were used. Results The study demonstrates that the ARCHITECT Rubella IgM assay shows improved specificity compared to AxSYM and Behring. Seroconversion sensitivity is equivalent on all assays evaluated. Conclusion Together with high throughput, optimized specificity and suppression of rheumatoid factor (RF) interference the ARCHITECT assay provides a useful improvement for the diagnosis of rubella serology.