The comparative superiority of IgM-IgG antibody test to real-time reverse transcriptase PCR detection for SARS-CoV-2 infection diagnosis

AbstractBackgroundAs the increasing number of Corona Virus Disease 2019 (COVID-19) patients caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2), which caused an outbreak initiated from Wuhan, China in December, 2019, the clinical features and treatment of COVID-19 patients have been understood. However, it is urgent to need the rapid and accurate detection for SARS-CoV-2 infection diagnosis. We aimed to evaluate the antibodies-based and nucleic acid-based tests (NAT) for SARS-CoV-2-infected patients.MethodWe retrospectively and observationally studied 133 patients diagnosed with SARS-CoV-2 and admitted in Renmin Hospital of Wuhan University, China, from Feb 17 to Mar 1, 2020. Demographic data, symptoms, clinical examination, laboratory tests, and clinical outcomes were collected. Data were compared between IgM-IgG antibody test and real-time RT-PCR detection for COVID-19 patients.ResultsOf 133 patients with SARS-CoV-2 infection, there were 44 moderate cases, 52 severe cases, and 37 critical cases with no significant difference of gender and age among three subgroups. Overall, the positive ratio in IgM antibody test was higher than in RT-PCR detection. In RT-PCR detection, the positive ratio was 65.91%, 71.15%, and 67.57% in moderate, severe, and critical cases, respectively. Whereas, the positive ratio of IgM/IgG antibody detection in patients was 79.55%/93.18%, 82.69%/100%, and 72.97%/97.30% in moderate, severe, and critical cases, respectively. Moreover, the concentrations of antibodies were also measured in three subgroups.ConclusionThe IgM-IgG antibodies-based test exhibited a comparative superiority to the NAT for COVID-19 diagnosis, which provides an effective complement to the false negative results from NAT for SARS-CoV-2 infection diagnosis.

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EVALUATION OF PERFORMANCE OF NINE SEROLOGICALASSAYS FOR THE DETECTION OF SARS-COV-2 ANTIBODIES.

10.36106/ijsr/1335520 ◽

2021 ◽

pp. 60-62

Author(s):

Tagajdid Mohamed Rida ◽

Konzi Clémence ◽

El Kochri Safae ◽

Elannaz Hicham ◽

Abi Rachid ◽

...

Keyword(s):

Clinical Performance ◽

Current Knowledge ◽

False Negative ◽

Antibody Test ◽

Antibody Detection ◽

Rt Pcr ◽

Igg Antibody ◽

Serological Tests ◽

Blood Samples ◽

Test Kit

Introduction: Currently, polymerase chain reaction (PCR) based viral RNAdetection is the standard for COVID-19 diagnosis [2]. Though, RNA testing based on throat or nasopharyngeal swabs has shown a number of false-negative results. Antibody detection tests have been developed to detect specic antibodies, IgM and IgG, to SRAS-CoV-2 virus. The clinical relevance of these tests is still under evaluation and is highly related to their clinical performance. Our objective is to assess analytical performances of nine SARS-CoV-2 antibodies immunoassays. Materiel and Method: We collected 80 blood samples from PCR-conrmed COVID-19 patients diagnosed in our Virology department (20 samples collected at day 10 after the onset of symptoms, 60 collected after day 14 following the onset of symptoms) and 20 blood samples from patients SARS-CoV-2 RT-PCR negative. All sera were tested with nine SARS-CoV-2 antibodies immunoassays ARCHITECT SARS-CoV-2 IgG® (Abbott), COVID-19 VIRCLIA® IgG MONOTEST (Vircell), COVID-19 VIRCLIA® IgM+IgA MONOTEST (Vircell), COVID-19 ELISA IgG® (Vircell), COVID-19 ELISA IgM+IgA® (Vircell), Elecsys® Anti-SARS-CoV-2 (Roche), FREND® COVID-19 IgG/IgM Duo (NanoEntek), COVID-PRESTO® (AAZ) and COVID-19 (SARS-CoV-2) IgM/IgG Antibody Test Kit® (Labnovation Technologies). Results: Sensitivity of tests increases once the seroconversion to anti-SARS-CoV-2 IgG positive in most individuals occurs toward the end of week 2 post-infection. COVID-19 PRESTO had the best accuracy in our study showing 100% sensitivity after day 14 following the onset of symptoms. All of the tests had a specicity of 100%. Conclusion: Serological tests are sensitive for the latest stages of COVID-19 infection. Recommendations on using SRAS-COV-2 antibody detection tests are continuously improving based on current knowledge of host antibody responses during infection. They are of great value in cases presenting COVID-19 symptoms with negative RT-PCR.

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Real-time RT-PCR detection of Citrus bark cracking viroid (CBCVd) in hops including an mRNA-based internal positive control

Journal of Plant Diseases and Protection ◽

10.1007/s41348-020-00317-x ◽

2020 ◽

Vol 127 (6) ◽

pp. 763-767

Author(s):

Luitgardis Seigner ◽

Marion Liebrecht ◽

Linda Keckel ◽

Katharina Einberger ◽

Carolin Absmeier

Keyword(s):

Real Time ◽

Detection Method ◽

Plant Protection ◽

False Negative ◽

Positive Control ◽

Pcr Detection ◽

Economic Losses ◽

Rt Pcr ◽

Validation Data ◽

Internal Positive Control

Abstract Citrus bark cracking viroid (CBCVd), formerly known as pathogen in the genus Citrus and first detected in Slovenian hops in 2014, threatens hop production as it leads to important economic losses. Reduction in yield and quality and even death of the infected plants within a few years are typical observations due to CBCVd infections of hops. The viroid is easily transmitted and spreads rapidly. As it cannot be controlled by plant protection measures, avoiding its introduction into hop gardens and eradicating first centres of infection are of utmost importance. An indispensable prerequisite is a reliable detection method suitable for large-scale routine testing. In this study, the development of primers and probe for real-time RT-PCR for sensitive CBCVd detection is described. To exclude “false negative” results, a nad5 mRNA-based internal positive control was included. To our knowledge, this is the first time such a duplex real-time RT-PCR detection method for CBCVd at least in hops is described. In addition, first method validation data are presented.

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Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients

10.1101/2020.03.13.20035428 ◽

2020 ◽

Cited By ~ 7

Author(s):

Yunbao Pan ◽

Xinran Li ◽

Gui Yang ◽

Junli Fan ◽

Yueting Tang ◽

...

Keyword(s):

Real Time ◽

Early Stage ◽

False Negative ◽

False Negative Rate ◽

Intermediate Stage ◽

Rt Pcr ◽

Igg Antibody ◽

Blood Samples ◽

Icg Strip ◽

Stage 1

AbstractAn outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nuclear acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nuclear acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1-7 days after onset), intermediate stage (8-14 days after onset), and late stage (more than 15 days), respectively. The ICG detection capacity in nuclear acid-negative suspected cases was 43.6%. In addition, the consistencies of whole blood samples with plasma were 100% and 97.1% in IgM and IgG strips, respectively. In conclusion, serological ICG strip assay in detecting SARS-CoV-2 infection is both sensitive and consistent, which is considered as an excellent supplementary approach in clinical application.

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Evaluating ELISA, Immunofluorescence, and Lateral Flow Assay for SARS-CoV-2 Serologic Assays

Frontiers in Microbiology ◽

10.3389/fmicb.2020.597529 ◽

2020 ◽

Vol 11 ◽

Author(s):

Moïse Michel ◽

Amar Bouam ◽

Sophie Edouard ◽

Florence Fenollar ◽

Fabrizio Di Pinto ◽

...

Keyword(s):

Rapid Test ◽

Antibody Test ◽

Immunofluorescence Assay ◽

Lateral Flow ◽

Antibody Detection ◽

Rt Pcr ◽

Igg Antibody ◽

Reliable Determination ◽

Test Kit ◽

Serological Status

BackgroundThe SARS-CoV-2 outbreak has emerged at the end of 2019. Aside from the detection of viral genome with specific RT-PCR, there is a growing need for reliable determination of the serological status. We aimed at evaluating five SARS-CoV-2 serology assays.MethodsAn in-house immunofluorescence assay (IFA), two ELISA kits (EUROIMMUN® ELISA SARS-CoV-2 IgG and NovaLisa® SARS-CoV-2 IgG and IgM) and two lateral flow assays (T-Tek® SARS-CoV-2 IgG/IgM Antibody Test Kit and Sure Bio-tech® SARS-CoV-2 IgM/IgG Antibody Rapid Test) were compared on 40 serums from RT-PCR-confirmed SARS-CoV-2 infected patients and 10 SARS-CoV-2 RT-PCR negative subjects as controls.ResultsControl subjects tested negative for SARS-CoV-2 antibodies with all five systems. Estimated sensitivities varied from 35.5 to 71.0% for IgG detection and from 19.4 to 64.5% for IgM detection. For IgG, in-house IFA, EuroImmun, T-Tek and NovaLisa displayed 50–72.5% agreement with other systems except IFA vs EuroImmun and T-Tek vs NovaLisa. Intermethod agreement for IgM determination was between 30 and 72.5%.DiscussionThe overall intermethod agreement was moderate. This inconsistency could be explained by the diversity of assay methods, antigens used and immunoglobulin isotype tested. Estimated sensitivities were low, highlighting the limited value of antibody detection in CoVID-19.ConclusionComparison of five systems for SARS-CoV-2 IgG and IgM antibodies showed limited sensitivity and overall concordance. The place and indications of serological status assessment with currently available tools in the CoVID-19 pandemic need further evaluations.

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Comparison of real-time reverse transcriptase polymerase chain reaction (RT-PCR) and IgM and IgG antibody test for the diagnosis of SARS-CoV-2 infection

Jurnal Teknologi Laboratorium ◽

10.29238/teknolabjournal.v9i1.232 ◽

2020 ◽

Vol 9 (1) ◽

pp. 78-86

Author(s):

Ömer ACER ◽

Osman ÖZÜDOĞRU

Keyword(s):

Computed Tomography ◽

Polymerase Chain Reaction ◽

Antibody Test ◽

Rt Pcr ◽

Chain Reaction ◽

Igg Antibody ◽

Positive Ratio ◽

Severe Group ◽

Polymerase Chain ◽

Pcr Test

In the present study, we compared the real-time reverse-transcription polymerase chain reaction (RT-PCR) and total IgM-IgG antibody tests for diagnosis SARS-CoV-2 patients. SARS-CoV-2 patients were divided into four additional subgroups according to clinical examination, and Computed Tomography (CT) for SARS-CoV-2. Groups were included 60 mild cases, 111 moderate cases, 53 severe cases, and 105 normal cases. In a mild group, 52.5% of 60 cases were found to be male, 45.9% female, and the average age was found as 38.4 ±2.011. The positive ratio was found as 80.3% in the RT-PCR test, while 39.3% in total IgM/IgG. In a moderate group, 49.1% of 111 cases were found to be male, 50% female, and the average age was 45.05 ±1.519. The positive ratio was found as 85.7% in the RT-PCR test while 54.5% in total IgM/IgG. In a severe group, 53.7%of 53 cases were found to be male, 44.4% female, and the average age was 55.5±2.122. The positive ratio was found as 75.9% both in RT-PCR and total IgM/IgG tests. In a normal group with no involvement according to Computed Tomography (CT), 49.1%of 105 cases were found to be male, 50% female, and the average age was found as 34.8±1.391. The positive ratio was found as 95.3% in the RT-PCR test while 5.7% in total IgM/IgG. Chronic diseases were detected more in severe cases, suggesting that persons who have chronic diseases or decreased immunity, such as diabetes mellitus, cardiovascular diseases, hypertension, and lung disease, are at a higher risk for developing severe COVID-19 if they are infected with SARS-CoV-2. According to our results, we can suggest a higher detection sensibility in RT-PCR than in total IgM/IgG antibody test for mild, moderate and normal group, while the detection sensibility of IgM/IgG antibody increases in a severe group with bilateral diffuse involvement according to CT.

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Viral Dynamics and Real-Time RT-PCR Ct Values Correlation with Disease Severity in COVID-19

Diagnostics ◽

10.3390/diagnostics11061091 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1091

Author(s):

Ali A. Rabaan ◽

Raghavendra Tirupathi ◽

Anupam A Sule ◽

Jehad Aldali ◽

Abbas Al Mutair ◽

...

Keyword(s):

Viral Load ◽

Real Time ◽

Disease Severity ◽

False Negative ◽

Influential Factors ◽

Confirmatory Test ◽

Acid Extraction ◽

Rt Pcr ◽

Viral Kinetics ◽

Ct Value

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.

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Incorporating false negative tests in epidemiological models for SARS-CoV-2 transmission and reconciling with seroprevalence estimates

Scientific Reports ◽

10.1038/s41598-021-89127-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rupam Bhattacharyya ◽

Ritoban Kundu ◽

Ritwik Bhaduri ◽

Debashree Ray ◽

Lauren J. Beesley ◽

...

Keyword(s):

False Negative ◽

Population Based ◽

Training Data ◽

Epidemiological Models ◽

Rt Pcr ◽

Antibody Prevalence ◽

Igg Antibody ◽

False Negatives ◽

Seir Model ◽

Study Population

AbstractSusceptible-Exposed-Infected-Removed (SEIR)-type epidemiologic models, modeling unascertained infections latently, can predict unreported cases and deaths assuming perfect testing. We apply a method we developed to account for the high false negative rates of diagnostic RT-PCR tests for detecting an active SARS-CoV-2 infection in a classic SEIR model. The number of unascertained cases and false negatives being unobservable in a real study, population-based serosurveys can help validate model projections. Applying our method to training data from Delhi, India, during March 15–June 30, 2020, we estimate the underreporting factor for cases at 34–53 (deaths: 8–13) on July 10, 2020, largely consistent with the findings of the first round of serosurveys for Delhi (done during June 27–July 10, 2020) with an estimated 22.86% IgG antibody prevalence, yielding estimated underreporting factors of 30–42 for cases. Together, these imply approximately 96–98% cases in Delhi remained unreported (July 10, 2020). Updated calculations using training data during March 15-December 31, 2020 yield estimated underreporting factor for cases at 13–22 (deaths: 3–7) on January 23, 2021, which are again consistent with the latest (fifth) round of serosurveys for Delhi (done during January 15–23, 2021) with an estimated 56.13% IgG antibody prevalence, yielding an estimated range for the underreporting factor for cases at 17–21. Together, these updated estimates imply approximately 92–96% cases in Delhi remained unreported (January 23, 2021). Such model-based estimates, updated with latest data, provide a viable alternative to repeated resource-intensive serosurveys for tracking unreported cases and deaths and gauging the true extent of the pandemic.

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Pooling of Upper Respiratory Specimens Using a SARS-CoV-2 Real-time RT-PCR Assay Authorized for Emergency Use in Low-Prevalence Populations for High-Throughput Testing

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa466 ◽

2020 ◽

Vol 7 (11) ◽

Author(s):

Gwynngelle A Borillo ◽

Ron M Kagan ◽

Russell E Baumann ◽

Boris M Fainstein ◽

Lamela Umaru ◽

...

Keyword(s):

Real Time ◽

False Negative ◽

False Negative Rate ◽

Nucleic Acid Amplification ◽

Rt Pcr ◽

Pooled Testing ◽

Negative Results ◽

Single Positive ◽

Upper Respiratory ◽

Respiratory Specimens

Abstract Background Nucleic acid amplification testing is a critical tool for addressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Specimen pooling can increase throughput and conserve testing resources but requires validation to ensure that reduced sensitivity does not increase the false-negative rate. We evaluated the performance of a real-time reverse transcription polymerase chain reaction (RT-PCR) test authorized by the US Food and Drug Administration (FDA) for emergency use for pooled testing of upper respiratory specimens. Methods Positive specimens were selected from 3 prevalence groups, 1%–3%, >3%–6%, and >6%–10%. Positive percent agreement (PPA) was assessed by pooling single-positive specimens with 3 negative specimens; performance was assessed using Passing-Bablok regression. Additionally, we assessed the distributions of RT-PCR cycle threshold (Ct) values for 3091 positive specimens. Results PPA was 100% for the 101 pooled specimens. There was a linear relationship between Ct values for pooled and single-tested specimens (r = 0.96–0.99; slope ≈ 1). The mean pooled Ct shifts at 40 cycles were 2.38 and 1.90, respectively, for the N1 and N3 targets. The median Cts for 3091 positive specimens were 25.9 (N1) and 24.7 (N3). The percentage of positive specimens with Cts between 40 and the shifted Ct was 1.42% (N1) and 0.0% (N3). Conclusions Pooled and individual testing of specimens positive for SARS-CoV-2 demonstrated 100% agreement, which demonstrates the viability of pooled specimens for SARS-COV-2 testing using a dual-target RT-PCR system. Pooled specimen testing can help increase testing capacity for SARS-CoV-2 with a low risk of false-negative results.

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Performance verification of anti-SARS-CoV-2-specific antibody detection by using four chemiluminescence immunoassay systems

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563220963847 ◽

2020 ◽

Vol 57 (6) ◽

pp. 429-434

Author(s):

Yafang Wan ◽

Zhijie Li ◽

Kun Wang ◽

Tian Li ◽

Pu Liao

Keyword(s):

False Positive ◽

Detection System ◽

False Positive Rate ◽

Antibody Test ◽

The Other ◽

Antibody Detection ◽

Igg Antibody ◽

Chi Square ◽

Chemiluminescence Immunoassay ◽

Chi Square Test

Objectives The purpose of the current study was to evaluate the analytical performance of seven kits for detecting IgM/IgG antibodies against coronavirus (SARS-CoV-2) by using four chemiluminescence immunoassay systems. Methods Fifty patients diagnosed with SARS-CoV-2 infection and 130 controls without coronavirus infection from the General Hospital of Chongqing were enrolled in the current retrospective study. Four chemiluminescence immunoassay systems, including seven IgM/IgG antibody detection kits for SARS-CoV-2 (A_IgM, A_IgG, B_IgM, B_IgG, C_IgM, C_IgG and D_Ab), were employed to detect antibody concentrations. The chi-square test, the receiver operating characteristic (ROC) curve and Youden’s index were determined to verify the cut-off value of each detection system. Results The repeatability verification results of the A, B, C and D systems are all qualified. D_Ab performed best (92% sensitivity and 99.23% specificity), and B_IgM performed worse than the other systems. Except for the A_IgM and C_IgG systems, the optimal diagnostic thresholds and cut-off values of the other kits and their recommendations are inconsistent with each other. B_IgM had the worst AUC, and C_IgG had the best diagnostic accuracy. More importantly, the B_IgG system had the highest false-positive rate for testing patients with AIDS, tumours and pregnancies. The A_IgM system test showed the highest false-positive rates among elderly individuals over 90 years old. COVID-2019 IgM/IgG antibody test systems exhibit performance differences. Conclusions The Innodx Biotech Total Antibody serum diagnosis kit is the most reliable detection system for anti-SARS-CoV-2 antibodies, which can be used together with nucleic acid tests as an alternative method for SARS-CoV-2 detecting.

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Possible Early Vertical Transmission of COVID-19 from an Infected Pregnant Female to Her Neonate: A Case Report

Journal of Tropical Pediatrics ◽

10.1093/tropej/fmaa094 ◽

2020 ◽

Author(s):

Tapas Bandyopadhyay ◽

Abhinav Sharma ◽

Pratima Kumari ◽

Arti Maria ◽

Rahul Choudhary

Keyword(s):

Public Health ◽

Vertical Transmission ◽

Antibody Test ◽

Public Health Emergency ◽

Pregnant Female ◽

Rare Entity ◽

Rt Pcr ◽

Igg Antibody ◽

Mode Of Transmission ◽

Reported Data

Abstract Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-19) has emerged as a public health emergency in recent times. The reported data on the mode of transmission of coronavirus disease 2019 (COVID-19) are largely through contact, droplet, airborne and fomite transmission methods with vertical transmission being a rare entity. We hereby report a case of a probable vertical transmission of SARS-CoV-19 from an infected pregnant female to her neonate. The transmission has been confirmed by a positive RT-PCR at 16 h of life along with a positive IgG antibody test for SARS-CoV-19 in the baby and after excluding the possible environmental contamination of the sample. The baby was asymptomatic during the course of hospital stay and was discharged from the facility on Day 9 of life.

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