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1.
Am J Case Rep ; 21: e927812, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33009361

RESUMO

BACKGROUND This is a case report of an immunocompromised patient with a history of non-Hodgkin lymphoma and persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who was seronegative and successfully treated with convalescent plasma. CASE REPORT A 63-year-old woman with a past medical history of non-Hodgkin lymphoma in remission while on maintenance therapy with the anti-CD20 monoclonal antibody, obinutuzumab, tested positive for SARS-CoV-2 via nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) testing over 12 weeks and persistently tested seronegative for immunoglobulin G (IgG) antibodies using SARS-CoV-2 IgG chemiluminescent microparticle immunoassay technology. During this time, the patient experienced waxing and waning of symptoms, which included fever, myalgia, and non-productive cough, but never acquired severe respiratory distress. She was admitted to our hospital on illness day 88, and her symptoms resolved after the administration of convalescent plasma. CONCLUSIONS As the understanding of the pathogenesis of SARS-CoV-2 continues to evolve, we can currently only speculate about the occurrence of chronic infection vs. reinfection. The protective role of antibodies and their longevity against SARS-CoV-2 remain unclear. Since humoral immunity has an integral role in SARS-CoV-2 infection, various phase 3 vaccine trials are underway. In the context of this pandemic, the present case demonstrates the challenges in our understanding of testing and treating immunocompromised patients.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Hospedeiro Imunocomprometido , Linfoma não Hodgkin/imunologia , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Antineoplásicos Imunológicos/administração & dosagem , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/terapia , Feminino , Seguimentos , Humanos , Imunização Passiva/métodos , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/tratamento farmacológico , Pessoa de Meia-Idade , Pandemias , Reação em Cadeia da Polimerase em Tempo Real/métodos , Testes Sorológicos/métodos , Índice de Gravidade de Doença , Resultado do Tratamento
2.
Nat Commun ; 11(1): 4698, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943630

RESUMO

Given the limited availability of serological testing to date, the seroprevalence of SARS-CoV-2-specific antibodies in different populations has remained unclear. Here, we report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seroreactivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors in early April 2020. We additionally describe the longitudinal dynamics of immunoglobulin-G (IgG), immunoglobulin-M (IgM), and in vitro neutralizing antibody titers in COVID-19 patients. The median time to seroconversion ranged from 10.3-11.0 days for these 3 assays. Neutralizing antibodies rose in tandem with immunoglobulin titers following symptom onset, and positive percent agreement between detection of IgG and neutralizing titers was >93%. These findings emphasize the importance of using highly accurate tests for surveillance studies in low-prevalence populations, and provide evidence that seroreactivity using SARS-CoV-2 anti-nucleocapsid protein IgG and anti-spike IgM assays are generally predictive of in vitro neutralizing capacity.


Assuntos
Anticorpos Neutralizantes/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Anticorpos Antivirais/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , São Francisco/epidemiologia , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Testes Sorológicos/métodos
4.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916926

RESUMO

Currently available COVID-19 antibody tests using enzyme immunoassay (EIA) or immunochromatographic assay have variable sensitivity and specificity. Here, we developed and evaluated a novel microsphere-based antibody assay (MBA) for detecting immunoglobulin G (IgG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein (NP) and spike protein receptor binding domain (RBD). The seropositive cutoff value was set using a cohort of 294 anonymous serum specimens collected in 2018. The specificity was assessed using serum specimens collected from organ donors or influenza patients before 2020. Seropositive rate was determined among COVID-19 patients. Time-to-seropositivity and signal-to-cutoff (S/CO) ratio were compared between MBA and EIA. MBA had a specificity of 100% (93/93; 95% confidence interval (CI), 96-100%) for anti-NP IgG, 98.9% (92/93; 95% CI 94.2-100%) for anti-RBD IgG. The MBA seropositive rate for convalescent COVID-19 patients was 89.8% (35/39) for anti-NP IgG and 79.5% (31/39) for anti-RBD IgG. The time-to-seropositivity was shorter with MBA than EIA. MBA could better differentiate between COVID-19 patients and negative controls with higher S/CO ratio for COVID-19 patients, lower S/CO ratio with negative controls and fewer specimens in the equivocal range. MBA is robust, simple and is suitable for clinical microbiology laboratory for the accurate determination of anti-SARS-CoV-2 antibodies for diagnosis, serosurveillance, and vaccine trials.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/sangue , Proteínas do Nucleocapsídeo/imunologia , Pneumonia Viral/sangue , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Infecções por Coronavirus/diagnóstico , Feminino , Humanos , Lactente , Masculino , Microesferas , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Sensibilidade e Especificidade , Testes Sorológicos/normas
5.
mSphere ; 5(5)2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938700

RESUMO

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Here, we present an efficient, competitive serological assay that can simultaneously determine an individual's seroreactivity against the SARS-CoV-2 Spike protein and determine the proportion of anti-Spike antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. In this approach based on the use of enzyme-linked immunosorbent assays (ELISA), we present natively folded viral Spike protein receptor-binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then competed with soluble ACE2-Fc, or with a higher-affinity variant thereof, to determine the proportion of ACE2 blocking anti-RBD antibodies. Assessment of sera from 144 SARS-CoV-2 patients ultimately revealed that a remarkably consistent and high proportion of antibodies in the anti-RBD pool targeted the epitope responsible for ACE2 engagement (83% ± 11%; 50% to 107% signal inhibition in our largest cohort), further underscoring the importance of tailoring vaccines to promote the development of such antibodies.IMPORTANCE With the emergence and continued spread of the SARS-CoV-2 virus, and of the associated disease, coronavirus disease 2019 (COVID-19), there is an urgent need for improved understanding of how the body mounts an immune response to the virus. Here, we developed a competitive SARS-CoV-2 serological assay that can simultaneously determine whether an individual has developed antibodies against the SARS-CoV-2 Spike protein receptor-binding domain (RBD) and measure the proportion of these antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. Using this assay and 144 SARS-CoV-2 patient serum samples, we found that a majority of anti-RBD antibodies compete for ACE2 binding. These results not only highlight the need to design vaccines to generate such blocking antibodies but also demonstrate the utility of this assay to rapidly screen patient sera for potentially neutralizing antibodies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Peptidil Dipeptidase A/imunologia , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Antígenos Virais/imunologia , Sítios de Ligação/imunologia , Infecções por Coronavirus/prevenção & controle , Ensaios de Triagem em Larga Escala/métodos , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Ligação Proteica , Domínios Proteicos/imunologia
6.
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
7.
Emerg Microbes Infect ; 9(1): 2212-2221, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32969769

RESUMO

Background: Several serological tests for SARS-CoV-2 have been developed or use, but most have only been validated on few samples, and none provide medical practitioners with an easy-to-use, self-contained, bedside test with high accuracy. Material and methods: Two-hundred fifty-six sera from 101 patients hospitalized with SARS-CoV-2 infection (positive RT-PCR) and 50 control sera were tested for IgM/IgG using the NG-Test IgM-IgG COVID all-in-one assay. The seroconversion dynamic was assessed by symptom onset and day of RT-PCR diagnosis. Results: Among the SARS-CoV-2 infected patients, positive IgG and/or IgM result was observed for 67.3% of patients (68/101), including 17 (16.8%) already positive at the day of RT-PCR, and 51 (50.5%) with observable seroconversion, and 32.7% (33/101) remained negative as subsequent sampling was not possible (patient discharge or death). The sensitivity increased with the delay between onset of symptoms and sampling, going from 29.1%, 78.2% and 86.5% for the time periods of 0-9-, 10-14- and >14-days after the onset of symptoms, respectively. Cumulative sensitivity, specificity, Positive Predictive Value and Negative Predictive Value were 97.0%, 100%, 100% and 96.2%, respectively 15-days after the onset of symptoms. No difference in seroconversion delay was observed regardless of whether patients received ventilation. Conclusions: The NG-test is a bedside serological assay that could serve as a complementary source of diagnostic information to RT-PCR and chest imaging. It may also be useful to monitor immunological status of medical and non-medical workers during the ongoing pandemic, and the general population after social distancing measures have eased.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Testes Imediatos , Testes Sorológicos/métodos , Adulto , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Estudos de Casos e Controles , Infecções por Coronavirus/virologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase , Fitas Reagentes , Sensibilidade e Especificidade , Soroconversão , Testes Sorológicos/normas
8.
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
9.
Nat Commun ; 11(1): 4378, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873791

RESUMO

Children are strikingly underrepresented in COVID-19 case counts. In the United States, children represent 22% of the population but only 1.7% of confirmed SARS-CoV-2 cases as of April 2, 2020. One possibility is that symptom-based viral testing is less likely to identify infected children, since they often experience milder disease than adults. Here, to better assess the frequency of pediatric SARS-CoV-2 infection, we serologically screen 1,775 residual samples from Seattle Children's Hospital collected from 1,076 children seeking medical care during March and April of 2020. Only one child was seropositive in March, but seven were seropositive in April for a period seroprevalence of ≈1%. Most seropositive children (6/8) were not suspected of having had COVID-19. The sera of seropositive children have neutralizing activity, including one that neutralized at a dilution > 1:18,000. Therefore, an increasing number of children seeking medical care were infected by SARS-CoV-2 during the early Seattle outbreak despite few positive viral tests.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Visitas a Pacientes , Adolescente , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Feminino , Hospitais , Humanos , Lactente , Recém-Nascido , Masculino , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Estudos Prospectivos , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Estados Unidos/epidemiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-32906596

RESUMO

A critical point in the management of the SARS-CoV-2 pandemic is the need to promptly identify the greatest number of infected people and to implement strict public health measures. In this study, the performance of a rapid serological test in a clinical setting was evaluated. Samples from 819 consecutive patients (with or without respiratory symptoms) admitted to a large Emergency Department were tested between 23 March and 21 April 2020. Patient samples were tested in a real-time PCR assay and a serological assay. In total, 148/819 patients (18.1%) tested positive for SARS-CoV-2 by real-time PCR. The serological test revealed that 70/819 patients (8.5%) had anti-SARS-CoV-2 IgM and/or IgG. The prevalence of anti-SARS-CoV-2 antibodies was significantly higher in patients with respiratory symptoms lasting for >7 days than in those with respiratory symptoms lasting for 0-7 days (p < 0.001). The serological assay had an overall sensitivity of 35.1% and an overall specificity of 97.3%. A high negative predictive value (96.7%) was reported for patients without respiratory symptoms. The results confirm that rapid serological assays alone are not sufficient for diagnosis of SARS-CoV-2 infection but can be incorporated into large-scale screening programs during periods in which the virus circulation is low.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Serviço Hospitalar de Emergência/estatística & dados numéricos , Pandemias , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Infecções por Coronavirus/epidemiologia , Humanos , Imunoglobulina G/sangue , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
11.
Rev Peru Med Exp Salud Publica ; 37(2): 203-209, 2020.
Artigo em Espanhol, Inglês | MEDLINE | ID: mdl-32876207

RESUMO

OBJECTIVE: To determine the additional diagnostic performance of a rapid serological test for detection of IgM and IgG antibodies compared to the real-time polymerase chain reaction (RT-PCR) test; for detection of SARS-CoV-2. MATERIALS AND METHODS: A cross-sectional study was carried out including patients hospitalized for COVID-19 in 3 hospitals, health workers exposed to the infection and outpatients who met suspicious case criteria, all of which underwent the molecular test (RT-PCR) and the rapid serological test. The additional diagnostic performance of rapid serological test was evaluated in comparison to molecular tests. Likewise, an approximation was made to the sensitivity and specificity of the rapid serological test. RESULTS: 144 people were included. With the rapid test, 19.4% of positive results were obtained compared to 11.1% in the molecular test (p = 0.03). The rapid serological test detected 21 cases that had been negative by the initial (RT-PCR), providing an additional diagnostic performance of 56.8% compared to the RT-PCR. The additional diagnostic performance was 50.0% during the first week, 70.0% during the second week and 50.0% during the third week of symptom onset. The sensitivity of the rapid serological test was 43.8% and the specificity of 98.9%. CONCLUSIONS: The rapid serological test was able to detect a greater number of cases than those detected by the molecular test especially after the second week of onset of symptoms. It also showed high specificity. It is therefore useful as a complementary test to RT-PCR, especially during the second and third week of illness.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pneumonia Viral/diagnóstico , Adulto , Infecções por Coronavirus/imunologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Testes Sorológicos/métodos
12.
Arch Iran Med ; 23(9): 629-632, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979911

RESUMO

BACKGROUND: The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic broke out in December 2019 and is now characterized as a pandemic. Effective control of this infectious disease requires access to diagnostic techniques, for both case finding and epidemic size estimation. The molecular technique is routinely used worldwide. Although it is the "standard" case detection and management method, it has its own shortcomings. Thus, some easy-to-use rapid serological tests have been developed. METHODS: One hundred and fourteen positive RT-PCR-diagnosed patients were tested by VivaDiag Kit, a brand of rapid serological kits available in hospitals affiliated to Tehran University of Medical Sciences (TUMS), Tehran, Iran. Frozen serum specimens taken from healthy people in summer and fall 2019 were also tested as negative controls. RESULTS: Test sensitivity was 47.9% (95% confidence interval [CI]: 38.8-56.9) for IgM and 47.0% (95% CI: 38.0-56.0) for IgG. There was no difference between IgG and IgM seropositivity except in one case. Specificity was calculated as 99.0% (95% CI: 96.4-99.9) for IgM and of 100.0% (95% CI: 0.98.2-100.0) for IgG. Sensitivity was higher in men and older participants. CONCLUSION: This test can be used for epidemiological investigations, especially for the estimation of the level of infection in the community, after it is properly corrected for sensitivity and specificity. The low sensitivity could be attributed to the technical limitations of the kit or low levels of antibodies after infection. The different sensitivity in age and sex groups supports the hypothesis that different people show different immune responses to this virus.


Assuntos
Anticorpos Antivirais/análise , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Adulto , Infecções por Coronavirus/epidemiologia , Feminino , Humanos , Incidência , Irã (Geográfico)/epidemiologia , Masculino , Pandemias , Pneumonia Viral/epidemiologia
13.
S Afr Med J ; 110(9): 842-845, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32880264

RESUMO

Antibody tests for the novel coronavirus, SARS-CoV2, have been developed both as rapid diagnostic assays and for high-throughput formal serology platforms. Although these tests may be a useful adjunct to a diagnostic strategy, they have a number of limitations. Because of the antibody and viral dynamics of the coronavirus, their sensitivity can be variable, especially at early time points after symptom onset. Additional data are required on the performance of the tests in the South African population, especially with regard to development and persistence of antibody responses and whether antibodies are protective against reinfection. These tests may, however, be useful in guiding the public health response, providing data for research (including seroprevalence surveys and vaccine initiatives) and development of therapeutic strategies.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus , Testes Imunológicos/métodos , Pandemias , Pneumonia Viral , Testes Sorológicos/métodos , Betacoronavirus/genética , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Humanos , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , África do Sul/epidemiologia
14.
Rev. esp. quimioter ; 33(4): 258-266, ago. 2020. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-192948

RESUMO

INTRODUCTION: The diagnosis of SARS-CoV-2 infection is crucial for medical and public health reasons, to allow the best treatment of cases and the best control of the pandemic. Serology testing allows for the detection of asymptomatic infections and 19-COVID cases once the virus has been cleared. We analyzed the usefulness of the SARS-CoV-2 rapid test of Autobio and tried to correlate its pattern with the severity of COVID19 infection. MATERIAL AND METHOD: We analyzed the accuracy and clinical usefulness of a point-of-care IgM and/or IgG test for SARS-CoV-2 in 35 COVID-19 patients [12 (34.3%) mild-moderate and 23 (65.7%) severe-critical] admitted to a field hospital in Madrid, as well as in 5 controls. RESULTS: The mean time from the first day of symptoms to the antibody test was 28 days (SD: 8.7), similar according to the severity of the disease. All patients with SARS-CoV-2 PCR+ showed the corresponding IgG positivity, while these results were negative in all control individuals. A total of 26 (74%) cases also presented with positive IgM, 19 (83%) were severe-critical cases and 7 (58%) were mild-moderate cases. The IgM response lasted longer in the severe critical cases (mean: 29.7 days; SD: 8.4) compared to the moderate cases (mean: 21.2 days; SD: 2.0). CONCLUSIONS: Rapid serology tests are useful for the diagnosis of patients with COVID-19 (mainly IgG detection) and may also be correlated with the severity of the infection (based on IgM detection)


INTRODUCCIÓN: El diagnóstico de la infección por SARSCoV-2 es crucial por razones médicas y de salud pública, para permitir el mejor tratamiento de los casos y el mejor control de la pandemia. Las pruebas de serología permiten la detección de infecciones asintomáticas y de casos de COVID-19 una vez que se ha logrado la eliminación del virus. El objetivo fue analizar la utilidad del test rápido SARS-CoV-2 de Autobio e intentar correlacionar su patrón con la gravedad de la infección por COVID19. MATERIAL Y MÉTODOS: Hemos analizado la precisión y la utilidad clínica de un test de IgM y/o IgG en el punto de atención para el SARS-CoV-2 en 35 pacientes COVID-19 [12 (34,3%) leves-moderados y 23 (65,7%) severos-críticos] ingresados en un hospital de campaña en Madrid, así como en 5 controles. RESULTADOS: El tiempo medio desde el primer día de síntomas hasta la prueba de anticuerpos fue de 28 días (DE: 8,7), similar según la gravedad de la enfermedad. Todos los pacientes con SARS-CoV-2 PCR+ mostraron la correspondiente positividad de IgG, mientras que estos resultados fueron negativos en todos los individuos de control. Un total de 26 (74%) casos también se presentaron con IgM positiva, 19 (83%) fueron casos severos-críticos y 7 (58%) fueron casos leves-moderados. La respuesta a la IgM duró más tiempo en los casos críticos severos (media: 29,7 días; DE: 8,4) en comparación con los casos moderados (media: 21,2 días; DE: 2,0). CONCLUSIONES: Las pruebas de serología rápida son de utilidad para el diagnóstico de los pacientes con COVID-19 (principalmente la detección de IgG) y también pueden estar correlacionadas con la gravedad de la infección (basada en la detección de IgM)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Infecções por Coronavirus/diagnóstico , Vírus da SARS/isolamento & purificação , Infecções Assintomáticas/epidemiologia , Testes Sorológicos/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Índice de Gravidade de Doença , Estudos Transversais , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
15.
ACS Sens ; 5(9): 2663-2678, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32786383

RESUMO

The global sanitary crisis caused by the emergence of the respiratory virus SARS-CoV-2 and the COVID-19 outbreak has revealed the urgent need for rapid, accurate, and affordable diagnostic tests to broadly and massively monitor the population in order to properly manage and control the spread of the pandemic. Current diagnostic techniques essentially rely on polymerase chain reaction (PCR) tests, which provide the required sensitivity and specificity. However, its relatively long time-to-result, including sample transport to a specialized laboratory, delays massive detection. Rapid lateral flow tests (both antigen and serological tests) are a remarkable alternative for rapid point-of-care diagnostics, but they exhibit critical limitations as they do not always achieve the required sensitivity for reliable diagnostics and surveillance. Next-generation diagnostic tools capable of overcoming all the above limitations are in demand, and optical biosensors are an excellent option to surpass such critical issues. Label-free nanophotonic biosensors offer high sensitivity and operational robustness with an enormous potential for integration in compact autonomous devices to be delivered out-of-the-lab at the point-of-care (POC). Taking the current COVID-19 pandemic as a critical case scenario, we provide an overview of the diagnostic techniques for respiratory viruses and analyze how nanophotonic biosensors can contribute to improving such diagnostics. We review the ongoing published work using this biosensor technology for intact virus detection, nucleic acid detection or serological tests, and the key factors for bringing nanophotonic POC biosensors to accurate and effective COVID-19 diagnosis on the short term.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico , Nanoestruturas/química , Pneumonia Viral/diagnóstico , Ressonância de Plasmônio de Superfície/métodos , Antígenos Virais/análise , Betacoronavirus/química , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico , Genoma Viral , Humanos , Imunoensaio/métodos , Nanoestruturas/efeitos da radiação , Pandemias , Testes Sorológicos/métodos
16.
BMJ Case Rep ; 13(8)2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32784236

RESUMO

Since the beginning of the COVID-19 pandemic, healthcare providers worldwide have faced many obstacles in the diagnostic evaluation of patients for severe acute respiratory syndrome coronavirus 2, the causative virus. Even with the application of statistical inference by Bayes' theorem to estimate the probability of a diagnosis, with and without testing capabilities, some cases may still carry a degree of uncertainty. This has important implications for limiting the spread of disease. The basis for isolation and quarantine is a known diagnosis. This case is an example of a diagnostic conundrum that required more thorough use of testing methods, particularly serological testing, to guide the isolation recommendations for a patient with COVID-19. This will be helpful to other diagnosticians by providing an example of how serological findings may be effectively applied in the course of individual COVID-19 management.


Assuntos
Betacoronavirus , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Teorema de Bayes , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Pandemias , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
17.
PLoS One ; 15(8): e0237833, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797108

RESUMO

OBJECTIVE: Serological testing is needed to investigate the extent of transmission of SARS-CoV-2 from front-line essential workers to their household members. However, the requirement for serum/plasma limits serological testing to clinical settings where it is feasible to collect and process venous blood. To address this problem we developed a serological test for SARS-CoV-2 IgG antibodies that requires only a single drop of finger stick capillary whole blood, collected in the home and dried on filter paper (dried blood spot, DBS). We describe assay performance and demonstrate its utility for remote sampling with results from a community-based study. METHODS: An ELISA to the receptor binding domain of the SARS-CoV-2 spike protein was optimized to quantify IgG antibodies in DBS. Samples were self-collected from a community sample of 232 participants enriched with health care workers, including 30 known COVID-19 cases and their household members. RESULTS: Among 30 individuals sharing a household with a virus-confirmed case of COVID-19, 80% were seropositive. Of 202 community individuals without prior confirmed acute COVID-19 diagnoses, 36% were seropositive. Of documented convalescent COVID-19 cases from the community, 29 of 30 (97%) were seropositive for IgG antibodies to the receptor binding domain. CONCLUSION: DBS ELISA provides a minimally-invasive alternative to venous blood collection. Early analysis suggests a high rate of transmission among household members. High rates of seroconversion were also noted following recovery from infection. Serological testing for SARS-CoV-2 IgG antibodies in DBS samples can facilitate seroprevalence assessment in community settings to address epidemiological questions, monitor duration of antibody responses, and assess if antibodies against the spike protein correlate with protection from reinfection.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Teste em Amostras de Sangue Seco , Características da Família , Pessoal de Saúde , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Testes Sorológicos/métodos , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
18.
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
20.
J Clin Virol ; 130: 104549, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32763809

RESUMO

BACKGROUND: The global market for SARS-CoV-2-immunoassays is becoming ever more crowded with antibody-tests of various formats, targets and technologies, careful evaluation is crucial for understanding the implications of individual test results. Here, we evaluate the clinical performance of five automated immunoassays on a set of clinical samples. METHODS: Serum/plasma samples of 75 confirmed COVID-19 patients and 320 pre-pandemic serum samples of healthy blood donors were subjected to two IgG and three total antibody SARS-CoV-2-immunoassays. All test setups were automated workflows. RESULTS: Positivity of assays (onset of symptoms > 10 days) ranged between 68.4 % and 81.6 % (Diasorin 68.4 %, Euroimmun 70.3 %, Siemens 73.7 %, Roche 79.0 % and Wantai 81.6 %). All examined assays demonstrated high specificity of >99 % (Euroimmun, Diasorin: 99.1 %, Wantai: 99.4 %) but only two reached levels above 99.5 % (Roche: 99.7 %, Siemens 100 %). Interestingly, there was no overlap in false positive results between the assays. The strongest correlation of quantitative results was observed between the Diasorin and Euroimmun IgG tests (r2 = 0.76). Overall, we observed no difference in the distribution of test results between female and male patients (p-values: 0.18-0.87). A significant difference between severely versus critically ill patients was demonstrated for the Euroimmun, Diasorin, Wantai and Siemens assays (p-values:0.041). CONCLUSION: All assays showed good clinical performance. Our data confirm that orthogonal test strategies as recommended by the CDC can enhance clinical specificity. However, the suboptimal rates of test positivity found at time of hospitalization in this cohort underline the importance of molecular diagnostics to rule out/confirm active infection with SARS-CoV-2.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação Laboratorial , Betacoronavirus , Técnicas de Laboratório Clínico , Estudos de Coortes , Infecções por Coronavirus/imunologia , Reações Falso-Positivas , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade , Adulto Jovem
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