scholarly journals Serological detection of 2019-nCoV respond to the epidemic: A useful complement to nucleic acid testing

2020 ◽  
Author(s):  
Jin Zhang ◽  
Jianhua Liu ◽  
Na Li ◽  
Yong Liu ◽  
Rui Ye ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Virus Disease ◽  
Roc Curves ◽  
Laboratory Diagnosis ◽  
Healthy People ◽  
Antibody Detection ◽  
Nucleic Acid Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Epidemic Area

AbstractBackgroundPneumonia caused by 2019 novel coronavirus (2019-nCoV) was first reported in Wuhan, Hubei Province, China in December 2019. Then it has been reported in more than 20 countries and regions overseas rapidly. More than eighty thousand cases have been infected, resulting in more than three thousand deaths. Due to the limitation of nucleic acid detection, many clinical suspected cases cannot be diagnosed in time.MethodsWe used automated chemiluminescent immunoassay to detect serum IgM and IgG antibodies to 2019-nCoV of 736 subjects including confirmed Corona Virus Disease 2019 (COVID-19) patients, non-COVID-19 fever patients, other disease patients and medical staff as well as healthy people. The dynamic process of antibody production in COVID-19 disease progression were analyzed, and the value of antibody detection in the laboratory diagnosis of COVID-19 were evaluated.ResultsCOVID-19 patients were becoming reactive(positive) for specific anti-2019-nCoV IgM antibodies from 7-12 days after the onset of morbidity, followed closely by the IgG. The levels of specific IgM and IgG antibodies increased with the progression of the disease. The trend of IgM and IgG changes in different cases is not exactly the same. The levels of IgM and IgG and their distributions in different groups were different with that of healthy people. The areas under the ROC curves for IgM and IgG to diagnose COVID-19 were 0.988 and 1.000, respectively.ConclusionsSpecific IgM or IgG antibody detection had good sensitivity and specificity for the diagnosis of suspected fever cases. Detection of specific antibodies in patients with fever can be a good distinction between COVID-19 and other diseases in low epidemic area.

scholarly journals Optimize Clinical Laboratory Diagnosis of COVID-19 from Suspect Cases by Likelihood Ratio of SARS-CoV-2 IgM and IgG antibody

2020 ◽  
Author(s):  
Feng Yangchun
Keyword(s):  
Nucleic Acid ◽  
Likelihood Ratio ◽  
Posterior Probability ◽  
Clinical Laboratory ◽  
Laboratory Diagnosis ◽  
Antibody Detection ◽  
Nucleic Acid Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Antibody Tests

ObjectiveTo optimize clinical laboratory diagnosis of COVID-19 from suspect cases by Likelihood Ratio of SARS-CoV-2 IgM and IgG antibody.MethodsBy reinterpreting the data in the article “Diagnostic Value of Combined Detection of Serum 2019 novel coronavirus IgM and IgG Antibodies in novel coronavirusin Infection”, the positive likelihood ratio of IgM and IgG antibody in diagnosis of COVID-19 (nucleic acid positive patients) was calculated, and the posterior probability of IgM and IgG antibodies and their tandem detection to diagnose was finally calculated.ResultsThe positive likelihood ratios of single IgM and IgG antibody were 18.50 and 12.65 respectively, and the posterior probabilities were 90.18% and 86.26% respectively. However, the posterior probability of the two antibodies tandem detection is 99.15%, which can give clinicians quantitative confidence in the diagnosis of COVID-19 from suspected cases. According to the results of this study, combining the advantages and disadvantages of nucleic acid detection and antibody detection, the clinical pathway for clinicians to diagnose COVID-19 is found.ConclusionFor suspected cases, IgM and IgG antibody tests should be firstly done at the same time. If the antibody tests are all positive, COVID-19 can be confirmed. If not, nucleic acid detection (one or more times) is performed, and in extreme cases, high-throughput viral genome sequencing is performed.

scholarly journals Highlighted Prospects of an IgM/IgG Antibodies Test in Identifying Individuals With Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection

2020 ◽  
Vol 145 (1) ◽  
pp. 39-45
Author(s):  
Yaqing Li ◽  
Qiang He ◽  
Rizhen Yu ◽  
Hui Jiang ◽  
Weizhong Wang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Severe Acute Respiratory Syndrome ◽  
Ct Scanning ◽  
Immunoglobulin M ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Imaging Results ◽  
Close Contacts ◽  
Nucleic Acid Tests

Context.— Covert severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections could be seeding new outbreaks. How to identify asymptomatic SARS-CoV-2 infections early has become a global focus. Objective.— To explore the roles of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies detection, nucleic acid tests, and computed tomography (CT) scanning to identify asymptomatic SARS-CoV-2 infection. Design.— The clinical data of 389 individuals with close contacts, including in general characteristics, SARS-CoV-2 etiology, serum-specific IgM and IgG antibody detection and CT imaging results, were systematically analyzed. Results.— The present study showed that only 89 of 389 individuals with close contacts were positive after the first nucleic acid test, while 300 individuals were still negative after 2 nucleic acid tests. Among the 300 individuals, 75 did not have pneumonia, and the other 225 individuals had pulmonary imaging changes. A total of 143 individuals were eventually diagnosed as having asymptomatic infection through IgM antibody and IgG antibody detection. The sensitivity, specificity, and false-negative rate of IgM and IgG antibody detection were approximately 97.1% (347 of 357), 95.3% (204 of 214), and 4.67% (10 of 214), respectively. It also indicated that during approximately 2 weeks, most individuals were both IgM positive and IgG positive, accounting for 68.57% (72 of 105). During approximately 3 weeks, the proportion of IgM-positive and IgG-positive individuals decreased to 8.57% (9 of 105), and the proportion of IgM-negative and IgG-positive individuals increased to 76.19% (80 of 105). Conclusions.— There are highlighted prospects of IgM/IgG antibody detection as a preferred method in identifying the individuals with asymptomatic SARS-CoV-2 infection, especially combined with nucleic acid tests and pulmonary CT scanning.

scholarly journals A Case of Malaria Patient with SARS-CoV-2 Antibody False-Positive

2021 ◽  
Author(s):  
hong zhou
Keyword(s):  
Nucleic Acid ◽  
False Positive ◽  
Malaria Patient ◽  
Antibody Detection ◽  
Nucleic Acid Detection ◽  
Malaria Rapid Diagnostic Test ◽  
Igg Antibody ◽  
Case Presentation ◽  
Igm Antibody ◽  
Positive Results

Abstract Background: The SARS-CoV-2 antibody detection are used to diagnose or exclude suspected COVID-19 patients as a supplement to nucleic acid detection. False-positive results of SARS-CoV-2 antibody have been reported but rarely associated with malaria. A case of malaria patient with SARS-CoV-2 antibody false-positive is described.Case presentation: A 24 year-old male returned from Côte d’Ivoire was diagnosed Plasmodium falciparum by Malaria rapid diagnostic test. The patient had suspicious exposure to COVID-19. His SARS-CoV-2 IgM antibody was positive one day before admission and turned negative on the 18th day of admission, while the IgG antibody and nasopharyngeal swabs SARS-Cov-2 nucleic acid had been negative. Conclusion: Malaria might cause false positive for SARS-CoV-2 IgM antibody. A careful interpretation of the SARS-CoV-2 antibody result is useful to avoid wasting medical resources especially malaria-endemic areas.

scholarly journals The positive rate of IgM and IgG antibodies against SARS-CoV-2 is similar in severe and non-severe COVID-19 patients

2021 ◽  
Vol 29 (1) ◽  
pp. 85-91
Author(s):  
Nan Jiang ◽  
Yaoyao Sun ◽  
Hongyan Sun ◽  
Bo Yang ◽  
Juan Tan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Method ◽  
Effective Means ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Nucleic Acid Test ◽  
Positive Rate ◽  
Antibody Levels ◽  
Acid Test

Abstract Background: Coronavirus disease 2019 (COVID-19) has spread rapidly in China and globally. In order to control the spread of the epidemic, it is important to find an efficient diagnostic method. Objectives: The aim of this study was to assess the responses of antibodies during SARS-CoV-2 infection in relation to disease severity and to evaluate the association between the positive rate of antibody detection and nucleic acid test. Methods: Ninety patients with SARS-CoV-2 infection were recruited in this retrospective observational study. Demographic, clinical data, and SARS-CoV-2 IgM and IgG antibodies in serum specimens were detected at 4 and 6 weeks after diagnosis. Results: IgM and IgG antibody levels showed a decreased tendency, the titers at week 4 were higher than the titers at week 6: The positive rates of IgM at week 4 and 6 were 92.9% and 67.9%, respectively. The positive rates of IgG at week 4 and week 6 were 100%. No association was found between the positive rate of antibody detection at week 4 or 6 and that of nucleic acid test (P>0.05). No difference between the positive rate of antibodies against SARS-CoV-2 in severe and non-severe COVID-19 patients was observed. Conclusions: Antibody detection is an effective means in the diagnosis of COVID-19. The titer and positive rate of IgM are lower than those of IgG in the first six weeks after infection. Positive rate of antibodies was not different between severe and non-severe patients.

scholarly journals Rapid Detection of SARS-CoV-2 Using Reverse transcription RT-LAMP method

2020 ◽  
Author(s):  
Weihua Yang ◽  
Xiaofei Dang ◽  
Qingxi Wang ◽  
Mingjie Xu ◽  
Qianqian Zhao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcription ◽  
Virus Disease ◽  
Lamp Assay ◽  
Nucleic Acid Amplification ◽  
N Gene ◽  
Nucleic Acid Detection ◽  
Lamp Method ◽  
Rt Pcr ◽  
Rapid Amplification

AbstractCorona Virus Disease 2019 (COVID-19) is a recently emerged life-threatening disease caused by SARS-CoV-2. Real-time fluorescent PCR (RT-PCR) is the clinical standard for SARS-CoV-2 nucleic acid detection. To detect SARS-CoV-2 early and control the disease spreading on time, a faster and more convenient method for SARS-CoV-2 nucleic acid detecting, RT-LAMP method (reverse transcription loop-mediated isothermal amplification) was developed. RNA reverse transcription and nucleic acid amplification were performed in one step at 63 °C isothermal conditions, and the results can be obtained within 30 minutes. ORF1ab gene, E gene and N gene were detected at the same time. ORF1ab gene was very specific and N gene was very sensitivity, so they can guarantee both sensitivity and specificity for SARS-CoV-2. The sensitivity of RT-LAMP assay is similar to RT-PCR, and specificity was 99% as detecting 208 clinical specimens. The RT-LAMP assay reported here has the advantages of rapid amplification, simple operation, and easy detection, which is useful for the rapid and reliable clinical diagnosis of SARS-CoV-2.

The application of viral nucleic acid detection and lung CT in COVID-19 diagnosis

2020 ◽  
Author(s):  
Rui Hu
Keyword(s):  
Nucleic Acid ◽  
Clinical Symptoms ◽  
Virus Disease ◽  
False Negative ◽  
False Negative Rate ◽  
Diagnostic Methods ◽  
Nucleic Acid Detection ◽  
Viral Nucleic Acid ◽  
Early Medical Intervention ◽  
Lung Ct

The Corona Virus Disease 2019 (COVID-19) has the characteristics of fast propagation speed and strong pathogenicity and has attracted wide attention of people, medical workers, and researchers around the world. Accurate, rapid, and timely screening and diagnosis of COVID-19 is of great significance to control the development of the epidemic situation and save the lives of patients. Currently, the detection of viral nucleic acid and lung CT is the main screening and diagnostic methods of COVID-19. Nucleic acid detection has the advantages of fast, strong specificity and high sensitivity, but there is a certain false-negative rate. CT result of lung examination is visual, but it is not typical due to the uncertain time of clinical symptoms and the early medical intervention. Therefore, the diagnosis of COVID-19 should include a combination of epidemiological history, clinical symptoms, imaging, and laboratory tests.

Development of Dual Fluorescent Microsphere Immunological Assay for Detection of Pseudorabies Virus gE and gB IgG Antibodies

2020 ◽  
Author(s):  
chihai ji ◽  
Jingyu Wang ◽  
Yuchen Zeng ◽  
Haoming Pan ◽  
Yingfang Wei ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
High Specificity ◽  
Antibody Detection ◽  
Economic Losses ◽  
Igg Antibodies ◽  
Wild Type ◽  
Swine Industry ◽  
Igg Antibody ◽  
Fluorescent Microsphere ◽  
Specificity And Sensitivity

Abstract Background Pseudorabies, also known as Aujezsky’s disease, is an acute viral infection caused by pseudorabies virus (PRV). Swine are one of the natural hosts of pseudorabies, therefore, the disease brings huge economic losses to the swine industry. Establishment of a differential diagnosis technique that can distinguish between wild-type infected and vaccinated pigs, and monitor vaccine-induced IgG is crucial for eventual eradication of pseudorabies.Results The aim of this study was to develop a rapid dual detection method for PRV gE and gB protein IgG antibodies with high specificity and sensitivity. PRV gE codons at amino acid residues (aa) 52–238 and gB codons at aa 539–741 were expressed to obtain recombinant PRV gE and gB proteins by pMAL-c5x vector. After purification with Qiagen Ni–NTA agarose affinity, the two proteins were analyzed by SDS-PAGE and immunoblotting assay. Two single fluorescent-microsphere immunoassays (FMIA) were established by coupling two recombinant proteins (gE and gB) with two magnetic microbeads and an effective dual FMIA was developed by integrating the two single assays. Optimal serum dilution for each assay, correlation with other common swine virus-positive sera and comparison with ELISA for two PRV antigens were tested for validation. Compared with ELISA, the specificity and sensitivity were 99.26% and 92.3% for gE IgG antibody detection and 95.74% and 96.3% for gB IgG antibody detection by dual-FMIA.Conclusion We provide a new method for monitoring PRV protective antibody in vaccinated pigs and differentiating wild-type-PRV-infected from vaccinated pigs

scholarly journals Diagnostic value of serum Aspergillus IgG antibody for invasive pulmonary aspergillosis and chronic pulmonary aspergillosis in non-agranulocytic patients

2020 ◽  
Author(s):  
Qihong Yu ◽  
Jingdong He ◽  
Bin Xing ◽  
Xin Li ◽  
Hongyu Qian ◽  
...  
Keyword(s):  
Bacterial Pneumonia ◽  
Invasive Pulmonary Aspergillosis ◽  
Roc Curves ◽  
Antibody Detection ◽  
Healthy Controls ◽  
Igg Antibody ◽  
Pulmonary Aspergillosis ◽  
Igm Antibody ◽  
Positive Rate ◽  
Chronic Pulmonary Aspergillosis

Abstract Background: At present, serum Aspergillus IgG and IgM antibody detection is mainly used in the diagnosis of chronic pulmonary aspergillosis (CPA), but its value in the diagnosis of invasive pulmonary aspergillosis (IPA) in non-agranulocytic patients is still unclear. IgG is a marker of long-term infection and is used to assist in the diagnosis of pre-existing or chronic infection-related diseases. The aim of this study was to investigate and compare the value of serum Aspergillus IgG and IgM antibody detection in the diagnosis of IPA and CPA in non-agranulocytic patients. Methods: Fifty-eight cases of pulmonary aspergillosis (37 IPA and 21 CPA cases), 15 cases of community-acquired bacterial pneumonia and 50 cases in the healthy control group were collected. The serum (1,3)-β-D-glucan test (G test) was performed with a chromogenic method, and the galactomannan test (GM test) and Aspergillus IgG and IgM antibody detection were performed by commercial enzyme-linked immunosorbent assay (ELISA) in all patients. The sensitivity and specificity, cut-off value and area under the curve (AUC) of Aspergillus IgG and IgM antibodies were further obtained by receiver operating characteristic (ROC) curves. Results: The positive rate of the G test, Aspergillus IgG antibody detection and the GM test also showed notable differences among the IPA, CPA, community-acquired bacterial pneumonia and healthy groups ( P = 0.006, P < 0.001 and P = 0.217, respectively). Only the positive rate of the GM test showed a significant difference between the IPA and CPA groups ( P = 0.04). ROC curves indicated that Aspergillus IgG antibody detection had a higher specificity in the IPA group than in the CPA group (0.952). The detection of Aspergillus IgG antibody can preferably distinguish IPA from community-acquired bacterial pneumonia and healthy controls (sensitivity = 0.923, specificity = 0.459, cut-off value = 134.46, AUC = 0.727). It can also distinguish CPA from community-acquired bacterial pneumonia and healthy controls (sensitivity = 0.952, specificity = 0.692, cut-off value = 75.46, AUC = 0.873). Conclusions: Serum Aspergillus IgG antibody detection may have certain clinical value in the diagnosis of IPA and CPA in non-agranulocytic patients.

scholarly journals Diagnosis of dengue fever: roles of different laboratory test methods

2018 ◽  
Vol 5 (2) ◽  
pp. 395
Author(s):  
Abhra Banerjee ◽  
Uttam Kumar Paul ◽  
Arup Bandyopadhyay
Keyword(s):  
Laboratory Test ◽  
Dengue Fever ◽  
Tertiary Care ◽  
Rapid Test ◽  
Laboratory Diagnosis ◽  
Test Methods ◽  
Antibody Detection ◽  
Igg Antibody ◽  
Capture Elisa ◽  
Study Laboratory

Background: Dengue fever is currently the most important arthropod borne viral disease. Since occurrence of dengue infections has been an epidemic in many parts of India and complications like DHF and DSS are increasing, while at the same time the diagnosis is challenging, particularly the laboratory diagnosis is confusing, this study was conducted to evaluate the different laboratory test methods and to compare their respective efficacy, timing, advantages and disadvantages.Methods: This study was done in the Department of Microbiology in collaboration with the Department of Medicine and Pediatrics in two tertiary care medical colleges and hospitals in eastern India. Blood samples from 319 patients with clinical features suggestive of Dengue fever were included in this study. Laboratory investigations were done which included immunological assays that were performed using commercially available kits - SD dengue duo NS1Ag + Ab combo rapid test, NS1 Ag capture ELISA, IgM capture ELISA, IgG capture ELISA test for dengue and other routine tests -full blood cell count, coagulation tests, routine biochemical and lipid profile were also done. Ethical considerations were taken care of and statistical evaluations were done.Results: An increased detection of IgM antibody (46.15%) was seen in the early febrile period (1-5 days) as compared to the mid-febrile period (6-10 days), and late febrile period (6-10 days) when it is 6.89%. IgG antibody is much less in early febrile period (4.16%). Compared to mid-febrile period (24.13%), and late febrile period (62.5%). IgM antibodies were detected in 44.5% of the samples, IgG antibodies were detected in 43.5% of the samples, Rapid test was positive in 36.9% and NS1AG ELISA was detected in 43.5% of the samples in the study.Conclusions: It can be inferred from our study that for detection of dengue in the early febrile period (1-5 days), estimation of dengue-specific serum IgM is the most sensitive antibody detection method.

scholarly journals Development and multicenter performance evaluation of fully automated SARS-CoV-2 IgM and IgG immunoassays

2020 ◽  
Vol 58 (9) ◽  
pp. 1601-1607 ◽  
Author(s):  
Chungen Qian ◽  
Mi Zhou ◽  
Fangming Cheng ◽  
Xiaotao Lin ◽  
Yijun Gong ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Human Serum ◽  
Normal Population ◽  
Laboratory Diagnosis ◽  
Hospitalized Patients ◽  
Nucleic Acid Testing ◽  
Igg Antibodies ◽  
Clinical Sensitivity ◽  
Specificity And Sensitivity ◽  
Assay Precision

AbstractObjectivesThe outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally. The laboratory diagnosis of SARS-CoV-2 infection has relied on nucleic acid testing; however, it has some limitations, such as low throughput and high rates of false negatives. Tests of higher sensitivity are needed to effectively identify infected patients.MethodsThis study has developed fully automated chemiluminescent immunoassays to determine IgM and IgG antibodies to SARS-CoV-2 in human serum. The assay performance has been evaluated at 10 hospitals. Clinical specificity was evaluated by measuring 972 hospitalized patients and 586 donors of a normal population. Clinical sensitivity was assessed on 513 confirmed cases of SARS-CoV-2 by RT-PCR.ResultsThe assays demonstrated satisfied assay precision with coefficient of variation of less than 4.45%. Inactivation of specimen did not affect assay measurement. SARS-CoV-2 IgM showed clinical specificity of 97.33 and 99.49% for hospitalized patients and the normal population respectively, and SARS-CoV-2 IgG showed clinical specificity of 97.43 and 99.15% respectively. SARS-CoV-2 IgM showed clinical sensitivity of 82.54, 92.93, and 84.62% before 7 days, 7–14 days, and after 14 days respectively, since onset of symptoms, and SARS-CoV-2 IgG showed clinical sensitivity of 80.95, 97.98, and 99.15% respectively at the same time points above.ConclusionsWe have developed fully automated immunoassays for detecting SARS-CoV-2 IgM and IgG antibodies in human serum. The assays demonstrated high clinical specificity and sensitivity, and add great value to nucleic acid testing in fighting against the global pandemic of the SARS-CoV-2 infection.

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