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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 6131-6134, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019370

RESUMO

Point-of-care diagnostic devices aid in the early and rapid detection of immunological markers leading to better medical outcomes. Lateral flow immunoassays (LFIA) are fast assays that provide both qualitative and semi-quantitative results on site. Sample preparation for LFIA tests is usually done manually with multiple mixing steps and is prone to errors. The iQuant Auto is an entirely automated system that can handle sample preparation, effective transfer to lateral flow test membrane, and subsequent result estimation. The system uses a pneumatic system for fluid handling and sample preparation, and an image-based fluorescence reader for reaction visualization. The device works with test specific milli-fluidic lateral flow kit called iQPrep Kit, which has integrated reagent storage areas and valves for fluid control. The test kit can be manufactured using standard manufacturing techniques and can be produced at scale cheaply. The iQPrep Kit can be modified to test for various markers like HbA1c, Vitamin D, and TSH, while the hardware for sample preparation and the fluorescence reader remains the same. The device has a minimalist and intelligible graphical interface aiding smooth operation by less skilled people at resource-limited settings. Standard reference cartridges of different volume ratios were used to validate the functionality of the instrument. The intra- instrument coefficient of variation (CoV) of the mobile kit reader was found to be less than 0.62%. The positional accuracy of the system to ensure precise kit engagement with the other auxiliary systems was checked, and the CoV was 0.16%. The fluid handling capabilities were tested, and it was found that an average fluid loss of 10 µl results due to the liquid adherence to fluid channel walls and valve interfaces. The iQuant Auto is an easily operable, total analysis system for immunodiagnostics.


Assuntos
Imunoensaio , Testes Imunológicos , Sistemas Automatizados de Assistência Junto ao Leito , Biomarcadores , Humanos , Tempo de Protrombina , Kit de Reagentes para Diagnóstico
2.
Mem Inst Oswaldo Cruz ; 115: e200201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32965330

RESUMO

Angiostrongylus costaricensis is the causative agent of abdominal angiostrongyliasis, a zoonotic infection that may produce severe eosinophilic enterocolitis or hepatitis in humans. Parasites are usually not released in stools and serology has an important role in diagnosis. Since cross-reactivity is demonstrated between A. costaricensis and another metastrongylid worm, A. cantonensis, we tested heterologous recombinant galectin as a probe in an immunochromatographic rapid diagnostic test (ICT-RDT) for detection of anti-A. costaricensis antibodies. Almost all (11/12) positive control sera from A. costaricensis infected patients were positive at ICT RDT. These are preliminary indications that r-galectin ICT-RDT is useful for diagnosing A. costaricensis infection.


Assuntos
Angiostrongylus cantonensis , Angiostrongylus , Infecções por Strongylida/diagnóstico , Animais , Humanos , Imunoensaio , Testes Imunológicos
3.
PLoS Pathog ; 16(9): e1008817, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970782

RESUMO

There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.


Assuntos
Anticorpos Antivirais/análise , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Testes Sorológicos/métodos , Adulto , Idoso , Betacoronavirus , Técnicas de Laboratório Clínico , Serviços de Saúde Comunitária , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitais , Humanos , Imunoensaio , Medições Luminescentes , Masculino , Pessoa de Meia-Idade , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
4.
Medicine (Baltimore) ; 99(38): e22363, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32957411

RESUMO

BACKGROUND: Neurofilament light (NfL) level was obviously increased in traumatic brain injury (TBI) individuals. But, no comprehensive meta-analysis has ever been conducted to assess the diagnostic performance of NfL. This study aims to evaluate the relationship between NfL level and TBI through a meta-analysis. METHODS: Studies were selected from Pubmed, Web of science, Embase, Google Scholar, PMC and Chinese National Knowledge Infrastructure (CNKI), and the Chinese Biomedical Literature Database (CBM) through inclusion and exclusion criteria. The standard mean difference (SMD) and 95% confidence interval (CI) were calculated using the random-effect model or fixed-effect model to assess the association between NfL level and TBI. Subgroup analysis according to sample collection time, sample type and detection method was performed. The influence analysis and publication bias was also conducted. All analyses were performed using the RevMan 5.3 and Stata 12 software. RESULTS: A total of 9 studies were included. Results indicated that TBI individuals had a higher NfL expression level compared with the non-TBI individuals (SMD = 2.48, 95% CI = 1.52-3.43, I = 96%, P < .01). Similar NfL increasing was also observed in Caucasian population, 0-48 hour and 6-10 days sample collection time, as well as cerebrospinal fluid (CSF), serum, plasma sample subgroup analysis. Moreover, the NfL increasing still existed no matter the NfL expression level was detected by ELISA or Simoa assay. CONCLUSION: NfL expression level was increased in TBI individuals, which indicated that NfL could be a potential biomarker in the diagnosis of TBI and other neurodegenerative diseases.


Assuntos
Lesões Encefálicas Traumáticas/metabolismo , Proteínas de Neurofilamentos/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Análise Química do Sangue , Lesões Encefálicas Traumáticas/diagnóstico , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
J Clin Virol ; 131: 104609, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32866811

RESUMO

INTRODUCTION: IgG immunoassays have been developed and used widely for clinical samples and serosurveys for SARS-CoV2, with most detecting antibodies against the spike/receptor-binding-domain or nucleocapsid. Limited information is available on comparative evaluation of IgG immunoassays against a clinical reference standard, i.e., RT-PCR positivity with >20 days of illness. This study addresses the need for comparing clinical performance of IgG immunoassays with respect to this alternate reference standard. METHODS: We compared the performance of three immunoassays, an in-house RBD assay, and two commercial assays, the Diasorin LIAISON SARS-CoV-2 S1/S1 IgG CLIA which detects antibodies against S1/S2 domains of the Spike protein and the Zydus Kavach assay based on inactivated virus using a well-characterized panel of sera. 379 sera and plasma samples from RTPCR positive individuals >20 days of illness in symptomatic or RT-PCR positivity in asymptomatic individuals and 184 samples collected prior to 2019 were used for assay evaluation. RESULTS: The sensitivity of the assays were 84.7 (95 %CI 80.6-88.1), 82.6 (95 %CI 78.3-86.2) and 75.7 (95 %CI 71.0-79.9) respectively for RBD, LIAISON and Kavach. Kavach and the in-house RBD ELISA showed a specificity of 99.5 % and 100 %, respectively. The RBD and LIAISON (S1/S2) assays showed high agreement (94.7 %; 95 %CI: 92.0, 96.6) and were able to correctly identify more positive sera/plasma than Kavach. CONCLUSION: Independent comparisons support the evaluation of performance characteristics of immunoassays. All three assays are suitable for serosurveillance studies, but in low prevalence sites, estimation of exposure may require adjustment based on our findings.


Assuntos
Anticorpos Antivirais/sangue , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/imunologia , Imunoensaio/métodos , Imunoglobulina G/sangue , Pneumonia Viral/imunologia , Automação Laboratorial , Betacoronavirus , Infecções por Coronavirus/diagnóstico , Humanos , Índia , Estudos Longitudinais , Medições Luminescentes , Pandemias , Estudos Prospectivos , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
6.
BMC Infect Dis ; 20(1): 650, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887568

RESUMO

BACKGROUND: Cryptococcus is a conditional pathogenic fungus causing cryptococcosis, which is one of the most serious fungal diseases faced by humans. Lateral flow immunochromatographic assay (LFA) is successfully applied to the rapid detection of cryptococcal antigens. METHODS: Studies were retrieved systematically from the Embase, PubMed, Web of Science, and Cochrane Library before July 2019. The quality of the studies was assessed by Review Manager 5.0 based on the Quality Assessment of Diagnostic Accuracy Study guidelines. The extracted data from the included studies were analyzed by Meta-DiSc 1.4. Stata 12.0 software was used to detect the publication bias. RESULTS: A total of 15 articles with 31 fourfold tables were adopted by inclusion and exclusion criteria. The merged sensitivity and specificity in serum were 0.98 and 0.98, respectively, and those in the cerebrospinal fluid were 0.99 and 0.99, respectively. CONCLUSIONS: Compared to the urine and other samples, LFA in serum and cerebrospinal fluid is favorable evidence for the diagnosis of cryptococcosis with high specificity and sensitivity.


Assuntos
Criptococose/diagnóstico , Imunoensaio/métodos , Antígenos de Fungos/sangue , Antígenos de Fungos/líquido cefalorraquidiano , Antígenos de Fungos/urina , Líquido Cefalorraquidiano/microbiologia , Testes Diagnósticos de Rotina/métodos , Humanos , Sensibilidade e Especificidade
7.
Emerg Microbes Infect ; 9(1): 2157-2168, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32940547

RESUMO

This multicenter, retrospective study included 346 serum samples from 74 patients with coronavirus disease 2019 (COVID-19) and 194 serum samples from non-COVID-19 patients to evaluate the performance of five anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests, i.e. two chemiluminescence immunoassays (CLIAs): Roche Elecsys® Anti-SARS-CoV-2 Test (Roche Test) and Abbott SARS-CoV-2 IgG (Abbott Test), and three lateral flow immunoassays (LFIAs): Wondfo SARS-CoV-2 Antibody Test (Wondfo Test), ASK COVID-19 IgG/IgM Rapid Test (ASK Test), and Dynamiker 2019-nCoV IgG/IgM Rapid Test (Dynamiker Test). We found high diagnostic sensitivities (%, 95% confidence interval [CI]) for the Roche Test (97.4%, 93.4-99.0%), Abbott Test (94.0%, 89.1-96.8%), Wondfo Test (91.4%, 85.8-94.9%), ASK Test (97.4%, 93.4-99.0%), and Dynamiker Test (90.1%, 84.3-94.0%) after >21 days of symptom onset. Meanwhile, the diagnostic specificity was 99.0% (95% CI, 96.3-99.7%) for the Roche Test, 97.9% (95% CI, 94.8-99.2%) for the Abbott Test, and 100.0% (95% CI, 98.1-100.0%) for the three LFIAs. Cross-reactivity was observed in sera containing anti-cytomegalovirus (CMV) IgG/IgM antibodies and autoantibodies. No difference was observed in the time to seroconversion detection of the five serological tests. Specimens from patients with COVID-19 pneumonia demonstrated a shorter seroconversion time and higher chemiluminescent signal than those without pneumonia. Our data suggested that understanding the dynamic antibody response after COVID-19 infection and performance characteristics of different serological test are crucial for the appropriate interpretation of serological test result for the diagnosis and risk assessment of patient with COVID-19 infection.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Imunoensaio/métodos , Medições Luminescentes/métodos , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Reações Cruzadas/imunologia , Feminino , Humanos , Imunoensaio/normas , Medições Luminescentes/normas , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Reprodutibilidade dos Testes , Soroconversão , Testes Sorológicos , Índice de Gravidade de Doença , Taiwan/epidemiologia
8.
J Nanobiotechnology ; 18(1): 130, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32912236

RESUMO

Fast point-of-care (POC) diagnostics represent an unmet medical need and include applications such as lateral flow assays (LFAs) for the diagnosis of sepsis and consequences of cytokine storms and for the treatment of COVID-19 and other systemic, inflammatory events not caused by infection. Because of the complex pathophysiology of sepsis, multiple biomarkers must be analyzed to compensate for the low sensitivity and specificity of single biomarker targets. Conventional LFAs, such as gold nanoparticle dyed assays, are limited to approximately five targets-the maximum number of test lines on an assay. To increase the information obtainable from each test line, we combined green and red emitting quantum dots (QDs) as labels for C-reactive protein (CRP) and interleukin-6 (IL-6) antibodies in an optical duplex immunoassay. CdSe-QDs with sharp and tunable emission bands were used to simultaneously quantify CRP and IL-6 in a single test line, by using a single UV-light source and two suitable emission filters for readout through a widely available BioImager device. For image and data processing, a customized software tool, the MultiFlow-Shiny app was used to accelerate and simplify the readout process. The app software provides advanced tools for image processing, including assisted extraction of line intensities, advanced background correction and an easy workflow for creation and handling of experimental data in quantitative LFAs. The results generated with our MultiFlow-Shiny app were superior to those generated with the popular software ImageJ and resulted in lower detection limits. Our assay is applicable for detecting clinically relevant ranges of both target proteins and therefore may serve as a powerful tool for POC diagnosis of inflammation and infectious events.


Assuntos
Biomarcadores/análise , Proteína C-Reativa/análise , Imunoensaio/métodos , Interleucina-6/análise , Pontos Quânticos/química , Sepse/diagnóstico , Anticorpos/imunologia , Betacoronavirus/isolamento & purificação , Proteína C-Reativa/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Humanos , Interleucina-6/imunologia , Limite de Detecção , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Sepse/metabolismo , Software , Raios Ultravioleta
9.
Talanta ; 220: 121392, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32928412

RESUMO

COVID-19 pandemic is a serious global health issue today due to the rapid human to human transmission of SARS-CoV-2, a new type of coronavirus that causes fatal pneumonia. SARS -CoV-2 has a faster rate of transmission than other coronaviruses such as SARS and MERS and until now there are no approved specific drugs or vaccines for treatment. Thus, early diagnosis is crucial to prevent the extensive spread of the disease. The reverse transcription-polymerase chain reaction (RT-PCR) is the most routinely used method until now to detect SARS-CoV-2 infections. However, several other faster and accurate assays are being developed for the diagnosis of COVID-19 aiming to control the spread of infection through the identification of patients and immediate isolation. In this review, we will discuss the various detection methods of the SARS-CoV-2 virus including the recent developments in immunological assays, amplification techniques as well as biosensors.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Técnicas Biossensoriais , Diagnóstico Precoce , Humanos , Imunoensaio , Pandemias , Reação em Cadeia da Polimerase
10.
PLoS One ; 15(9): e0237694, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941461

RESUMO

BACKGROUND: The SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2) is responsible for the infectious respiratory disease called COVID-19 (COronaVIrus Disease 2019). In response to the growing COVID-19 pandemic, point-of-care (POC) tests have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. We conducted a prospective observational study to evaluate the performance of two POC tests, COVID-PRESTO® and COVID-DUO®, compared to the gold standard, RT-PCR (real-time reverse transcriptase polymerase chain reaction). METHODS: RT-PCR testing of SARS-Cov-2 was performed from nasopharyngeal swab specimens collected in adult patients visiting the infectious disease department at the hospital (Orléans, France). Capillary whole blood (CWB) samples from the fingertip taken at different time points after onset of the disease were tested with POC tests. The specificity and sensitivity of the rapid test kits compared to test of reference (RT-PCR) were calculated. RESULTS: Among 381 patients with symptoms of COVID-19 who went to the hospital for a diagnostic, 143 patients were RT-PCR negative. Results of test with POC tests were all negative for these patients, indicating a specificity of 100% for both POC tests. In the RT-PCR positive subgroup (n = 238), 133 patients were tested with COVID-PRESTO® and 129 patients were tested with COVID-DUO® (24 patients tested with both). The further the onset of symptoms was from the date of collection, the greater the sensitivity. The sensitivity of COVID-PRESTO® test ranged from 10.00% for patients having experienced their 1st symptoms from 0 to 5 days ago to 100% in patients where symptoms had occurred more than 15 days before the date of tests. For COVID-DUO® test, the sensitivity ranged from 35.71% [0-5 days] to 100% (> 15 days). CONCLUSION: COVID-PRESTO® and DUO® POC tests turned out to be very specific (none false positive) and to be sensitive enough after 15 days from onset of symptom. These easy to use IgG/IgM combined test kits are the first ones allowing a screening with CWB sample, by typing from a finger prick. These rapid tests are particularly interesting for screening in low resource settings.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pneumonia Viral/diagnóstico , Kit de Reagentes para Diagnóstico , Adulto , Idoso , Especificidade de Anticorpos , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Capilares , Infecções por Coronavirus/sangue , Dedos/irrigação sanguínea , Humanos , Pessoa de Meia-Idade , Nasofaringe/virologia , Pandemias , Pneumonia Viral/sangue , Testes Imediatos , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Adulto Jovem
11.
Emerg Microbes Infect ; 9(1): 2200-2211, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32962560

RESUMO

Serology detection is recognized for its sensitivity in convalescent patients with COVID-19, in comparison with nucleic acid amplification tests (NAATs). This article aimed to evaluate the diagnostic accuracy of serologic methods for COVID-19 based on assay design and post-symptom-onset intervals. Two authors independently searched PubMed, Cochrane library, Ovid, EBSCO for case-control, longitudinal and cohort studies that determined the diagnostic accuracy of serology tests in comparison with NAATs in COVID-19 cases and used QUADAS-2 for quality assessment. Pooled accuracy was analysed using INLA method. A total of 27 studies were included in this meta-analysis, with 4 cohort, 16 case-control and 7 longitudinal studies and 4565 participants. Serology tests had the lowest sensitivity at 0-7 days after symptom onset and the highest at >14 days. TAB had a better sensitivity than IgG or IgM only. Using combined nucleocapsid (N) and spike(S) protein had a better sensitivity compared to N or S protein only. Lateral flow immunoassay (LFIA) had a lower sensitivity than enzyme-linked immunoassay (ELISA) and chemiluminescent immunoassay (CLIA). Serology tests will play an important role in the clinical diagnosis for later stage COVID-19 patients. ELISA tests, detecting TAB or targeting combined N and S proteins had a higher diagnostic sensitivity compared to other methods.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Testes Sorológicos/métodos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/imunologia , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Pandemias , Pneumonia Viral/imunologia , Viés de Publicação , Sensibilidade e Especificidade , Testes Sorológicos/normas , Avaliação de Sintomas
12.
Biosens Bioelectron ; 169: 112604, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32980805

RESUMO

Virus severely endangers human life and health, and the detection of viruses is essential for the prevention and treatment of associated diseases. Metal-organic framework (MOF), a novel hybrid porous material which is bridged by the metal clusters and organic linkers, has become a promising biosensor platform for virus detection due to its outstanding properties including high surface area, adjustable pore size, easy modification, etc. However, the MOF-based sensing platforms for virus detection are rarely summarized. This review systematically divided the detection platforms into nucleic acid and immunological (antigen and antibody) detection, and the underlying sensing mechanisms were interpreted. The nucleic acid sensing was discussed based on the properties of MOF (such as metal ion, functional group, geometry structure, size, porosity, stability, etc.), revealing the relationship between the sensing performance and properties of MOF. Moreover, antibodies sensing based on the fluorescence detection and antigens sensing based on molecular imprinting or electrochemical immunoassay were highlighted. Furthermore, the remaining challenges and future development of MOF for virus detection were further discussed and proposed. This review will provide valuable references for the construction of sophisticated sensing platform for the detection of viruses, especially the 2019 coronavirus.


Assuntos
Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Viroses/virologia , Vírus/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Modelos Moleculares , Impressão Molecular/instrumentação , Impressão Molecular/métodos , Ácidos Nucleicos/análise , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Viroses/diagnóstico
13.
BMC Res Notes ; 13(1): 372, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32762746

RESUMO

OBJECTIVE: COVID19 has caused a global and ongoing pandemic. The need for population seroconversion data is apparent to monitor and respond to the pandemic. Using a lateral flow assay (LFA) testing platform, the seropositivity in 63 New York Blood Center (NYBC) Convelescent Plasma (CP) donor samples were evaluated for the presence of COVID19 specific IgG and IgM. RESULTS: CP donors showed diverse antibody result. Convalescent donor plasma contains SARS-CoV-2 specific antibodies. Weak antibody bands may identify low titer CP donors. LFA tests can identify antibody positive individuals that have recovered from COVID19. Confirming suspected cases using antibody detection could help inform the patient and the community as to the relative risk to future exposure and a better understanding of disease exposure.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Betacoronavirus/imunologia , Doadores de Sangue , Técnicas de Laboratório Clínico/métodos , Convalescença , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Pneumonia Viral/diagnóstico , Testes Imediatos , Glicoproteína da Espícula de Coronavírus/imunologia , Especificidade de Anticorpos , Infecções por Coronavirus/terapia , Coloide de Ouro , Humanos , Imunização Passiva , Plasma , Domínios Proteicos , Proteínas Recombinantes/imunologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soroconversão
14.
Sensors (Basel) ; 20(15)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32752043

RESUMO

Coronaviruses have received global concern since 2003, when an outbreak caused by SARS-CoV emerged in China. Later on, in 2012, the Middle-East respiratory syndrome spread in Saudi Arabia, caused by MERS-CoV. Currently, the global crisis is caused by the pandemic SARS-CoV-2, which belongs to the same lineage of SARS-CoV. In response to the urgent need of diagnostic tools, several lab-based and biosensing techniques have been proposed so far. Five main areas have been individuated and discussed in terms of their strengths and weaknesses. The cell-culture detection and the microneutralization tests are still considered highly reliable methods. The genetic screening, featuring the well-established Real-time polymerase chain reaction (RT-PCR), represents the gold standard for virus detection in nasopharyngeal swabs. On the other side, immunoassays were developed, either by screening/antigen recognition of IgM/IgG or by detecting the whole virus, in blood and sera. Next, proteomic mass-spectrometry (MS)-based methodologies have also been proposed for the analysis of swab samples. Finally, virus-biosensing devices were efficiently designed. Both electrochemical immunosensors and eye-based technologies have been described, showing detection times lower than 10 min after swab introduction. Alternative to swab-based techniques, lateral flow point-of-care immunoassays are already commercially available for the analysis of blood samples. Such biosensing devices hold the advantage of being portable for on-site testing in hospitals, airports, and hotspots, virtually without any sample treatment or complicated lab precautions.


Assuntos
Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Betacoronavirus/metabolismo , Técnicas Biossensoriais/métodos , Infecções por Coronavirus/virologia , Humanos , Imunoensaio/métodos , Pandemias , Pneumonia Viral/virologia , Proteômica/métodos , RNA Viral/análise , RNA Viral/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos
15.
J Clin Virol ; 131: 104592, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32827898

RESUMO

OBJECTIVES: We evaluated a rapid chromatographic immunoassay (IgG/IgM antibodies) and an ELISA assay to diagnose COVID-19 in patient sat two Brazilian hospitals. METHODS: A total of 122 subjects with COVID-19 were included: 106 SARS-COV-2 RT-PCR-positive patients and 16 RT-PCR-negative patients with symptoms and chest computed tomography (CT) consistent with COVID-19. Ninety-six historical blood donation samples were used as controls. Demographic and clinical characteristics were retrieved from electronic records. Sensitivity and specificity were calculated, as were their 95% binomial confidence intervals using the Clopper-Pearson method. All analyses were performed in R version 3.6.3. RESULTS: The sensitivity of the chromatographic immunoassay in all RT-PCR-positive patients, irrespective of the timing of symptom onset, was 85.8% (95% binomial CI 77.7% to 91.9%). This increased with time after symptom onset, and at >14 days was 94.9% (85.9% to 98.9%). The specificity was 100% (96.4% to 100%). 15/16 (94%) RT- PCR-negative cases tested positive. The most frequent comorbidities were hypertension and diabetes mellitus and the most frequent symptoms were fever, cough, and dyspnea. All RT-PCR-negative patients had pneumonia. The most frequent thoracic CT findings were ground glass changes (n = 11, 68%), which were bilateral in 9 (56%) patients, and diffuse reticulonodular infiltrates (n = 5, 31%). CONCLUSIONS: The COVID-19 rapid chromatographic immunoassay evaluated in this study had a high sensitivity and specificity using plasma, particularly after 14 days from symptom onset. ELISA and qualitative rapid chromatographic immunoassays can be used for the diagnosis of RT-PCR-negative patients.


Assuntos
Anticorpos Antivirais/sangue , Cromatografia , Infecções por Coronavirus/diagnóstico , Imunoensaio , Pneumonia Viral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus , Brasil , Técnicas de Laboratório Clínico , Infecções por Coronavirus/imunologia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
16.
J Clin Microbiol ; 58(10)2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32747400

RESUMO

The Elecsys Anti-SARS-CoV-2 immunoassay (Roche Diagnostics) was developed to provide accurate, reliable detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated sensitivity, specificity, cross-reactivity, and agreement with a vesicular stomatitis virus-based pseudoneutralization assay for the Elecsys Anti-SARS-CoV-2 immunoassay. Sensitivity and agreement between Elecsys Anti-SARS-CoV-2 immunoassay and pseudoneutralization assay measurements were evaluated using samples from patients with PCR-confirmed SARS-CoV-2 infection, a majority of whom were hospitalized. Specificity was evaluated using samples from routine diagnostic testing/blood donors collected before December 2019 and thus deemed negative for SARS-CoV-2-specific antibodies. Cross-reactivity was evaluated using samples containing a wide range of potentially cross-reacting analytes, purchased from commercial vendors. For sensitivity and specificity, point estimates and 95% confidence intervals (CIs) were calculated. Agreement between the Elecsys Anti-SARS-CoV-2 immunoassay and the pseudoneutralization assay was calculated. The sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay in patients with prior PCR-confirmed SARS-CoV-2 infection was 99.5% (95% CI, 97.0 to 100.0%) at ≥14 days post-PCR confirmation. Overall specificity (n = 10,453) was 99.80% (95% CI, 99.69 to 99.88%). Only 4/792 samples containing potential cross-reacting analytes were reactive with the Elecsys Anti-SARS-CoV-2 immunoassay, resulting in an overall specificity in this cohort of 99.5% (95% CI, 98.6 to 99.9%). Positive, negative, and overall agreement (n = 46) between the Elecsys Anti-SARS-CoV-2 immunoassay and the pseudoneutralization assay were 86.4% (95% CI, 73.3 to 93.6%), 100% (95% CI, 34.2 to 100%), and 87.0% (95% CI, 74.3 to 93.9%), respectively. The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated high sensitivity (99.5% at ≥14 days post-PCR confirmation) and specificity (99.80%), supporting its use as a tool for identification of past SARS-CoV-2 infection, including use in populations with low disease prevalence.


Assuntos
Betacoronavirus/isolamento & purificação , Imunoensaio , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Reações Cruzadas , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Clin Virol ; 130: 104576, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32763810

RESUMO

BACKGROUND: The unsatisfactory accuracy and capacity of real time RT-PCR depends on several unavoidable reasons, which cannot meet the demands for COVID-19 diagnosis. METHODS: 206 serum samples were collected from patients who were treated in the General Hospital of the Central Theater Command of the PLA between January 18 and April 4, 2020. 270 serum samples from healthy blood donors were used as control. IgM and total antibodies (Ab) against SARS-CoV-2 were detected by Chemiluminescence Microparticle Immunoassay (CMIA). RESULTS: Among the 206 patients, the positive rate of IgM and Ab were 149/206 (72.3 %) and 187/206 (90.8 %), respectively. And the specificity of IgM and Ab detection were 99.3 % and 98.9 %, respectively. The sensitivity of CMIA for Ab detection was significantly higher than that of IgM. An increase of the positive rate and S/CO value for detecting IgM and Ab accompanied with the increasing of days post-disease onset (d.p.o.) were observed. The positive rate of Ab detected by CMIA increased rapidly after 7 d.p.o., while that of IgM was obviously increased after 14 d.p.o.. In addition, the age and gender of these patients did not affect the seroconversion and titer of antibodies during the whole course. The disease-severity of patients had no effect on the seroconversion of antibodies. However, the critical patients possessed a much higher antibody titers than the no-critical cases after 14 d.p.o.. CONCLUSIONS: The CMIA can provide important complementation to nucleic acid assay and help to enhance the accuracy and capacity of diagnosis of SARS-CoV-2 infection.


Assuntos
Anticorpos Antivirais/sangue , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Pneumonia Viral/diagnóstico , Adulto , Idoso , Betacoronavirus , Infecções por Coronavirus/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Medições Luminescentes , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade , Soroconversão
18.
J Clin Virol ; 130: 104572, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32769024

RESUMO

BACKGROUND: The emergence of SARS-CoV-2 has led to the development of serological assays that could aid in an understanding of the burden of COVID-19 disease. Many available tests lack rigorous evaluation and therefore results may be misleading. OBJECTIVES: The aim of this study was to assess the performance of a novel multiplexed immunoassay for the simultaneous detection of antibodies against SARS-CoV-2 trimeric spike (S), spike receptor binding domain (RBD), spike N terminal domain and nucleocapsid antigen and a novel pseudo-neutralisation assay. METHODS: A multiplexed solid-phase chemiluminescence assay (Meso Scale Discovery) was evaluated for the simultaneous detection of IgG binding to four SARS-CoV-2 antigens and the quantification of antibody-induced ACE-2 binding inhibition (pseudo-neutralisation assay). Sensitivity was evaluated with a total of 196 COVID-19 serum samples (169 confirmed PCR positive and 27 anti-nucleocapsid IgG positive) from individuals with mild symptomatic or asymptomatic disease. Specificity was evaluated with 194 control serum samples collected from adults prior to December 2019. RESULTS: The specificity and sensitivity of the binding IgG assay was highest for S protein with a specificity of 97.4 % and sensitivity of 96.2 % for samples taken 14 days and 97.9 % for samples taken 21 days following the onset of symptoms. IgG concentration to S and RBD correlated strongly with percentage inhibition measured by the pseudo-neutralisation assay. CONCLUSION: Excellent sensitivity for IgG detection was obtained over 14 days since onset of symptoms for three SARS-CoV-2 antigens (S, RBD and N) in this multiplexed assay which can also measure antibody functionality.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Pneumonia Viral/diagnóstico , Adulto , Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus/imunologia , Feminino , Humanos , Medições Luminescentes/métodos , Masculino , Pessoa de Meia-Idade , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia
20.
Hell J Nucl Med ; 23 Suppl: 8-14, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32860390

RESUMO

On December 2019, a new coronavirus disease (COVID-19) emerged in China and spread worldwide, causing acute severe respiratory syndrome. Due to the increased transmission rate of the virus, it became of great importance the early diagnosis of the disease. The coronavirus pandemic led to the development of numerous tests in order to mass screening population for active viral load and for the identification of antibodies for epidemiological purposes. This review summarizes the different diagnostic tests available to the clinicians for the diagnosis and follow up of the SARS COV-2 infections.


Assuntos
Infecções por Coronavirus/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Pneumonia Viral/diagnóstico , Radiografia Torácica/métodos , Técnicas de Cultura de Células/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico por imagem , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Técnicas de Diagnóstico Molecular/normas , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico por imagem , Radiografia Torácica/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Sensibilidade e Especificidade , Testes Sorológicos/métodos , Testes Sorológicos/normas
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