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1.
BMC Infect Dis ; 20(1): 835, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176708

RESUMO

BACKGROUND: The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity. METHODS: Eligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence. RESULTS: Only 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001). CONCLUSIONS: Overall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.


Assuntos
Vírus da Dengue/genética , Vírus da Dengue/imunologia , Dengue/diagnóstico , Dengue/epidemiologia , Febre/diagnóstico , Adolescente , Criança , Pré-Escolar , Dengue/virologia , Testes Diagnósticos de Rotina/efeitos adversos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Malária/diagnóstico , Malária/epidemiologia , Malária/parasitologia , Masculino , Plasmodium/imunologia , Plasmodium/isolamento & purificação , Prevalência , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Estudos Soroepidemiológicos , Uganda/epidemiologia
3.
PLoS One ; 15(10): e0240395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33091042

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging threat worldwide. This study aims to assess the serologic profiles and time kinetics of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with COVID-19 using two immunoassays. METHODS: A total of 97 samples serially collected from 17 patients with COVID-19 and 137 negative control samples were analyzed for IgM and IgG against SARS-CoV-2 using the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA). RESULTS: With both assays, IgM and IgG rapidly increased after 7 days post symptom onset (PSO). IgM antibody levels reached a peak at 15-35 d PSO and gradually decreased. IgG levels gradually increased and remained at similar levels after 22-35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO were 21.4%/35.7~57.1% and increased to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 negative controls, 12 samples (8.8%) showed positive or indeterminate results. CONCLUSIONS: The antibody kinetics against SARS-CoV-2 are similar to common findings of acute viral infectious diseases. Antibody testing is useful for ruling out SARS-CoV-2 infection after 14 d PSO, detecting past infection, and epidemiologic surveys.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Testes Sorológicos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Coronavirus/virologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Imunofluorescência/métodos , Seguimentos , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Cinética , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Sensibilidade e Especificidade , Adulto Jovem
4.
Sci Immunol ; 5(52)2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033172

RESUMO

We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset. In contrast, anti-RBD IgG responses decayed slowly through 90 days with only 3 seropositive individuals seroreverting within this time period. IgG antibodies to SARS-CoV-2 RBD were strongly correlated with anti-S neutralizing antibody titers, which demonstrated little to no decrease over 75 days since symptom onset. We observed no cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies with other widely circulating coronaviruses (HKU1, 229 E, OC43, NL63). These data suggest that RBD-targeted antibodies are excellent markers of previous and recent infection, that differential isotype measurements can help distinguish between recent and older infections, and that IgG responses persist over the first few months after infection and are highly correlated with neutralizing antibodies.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Domínios Proteicos/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Biomarcadores/sangue , Estudos de Coortes , Infecções por Coronavirus/virologia , Reações Cruzadas , Teste em Amostras de Sangue Seco , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Glicoproteína da Espícula de Coronavírus/química
5.
G Ital Nefrol ; 37(5)2020 Oct 05.
Artigo em Italiano | MEDLINE | ID: mdl-33026198

RESUMO

We report the brief experience of the Nephrology Center located in a "no-COVID" Hospital in Massa Marittima. We describe the actions taken to prevent the transmission of the virus SARS-CoV-2 among hemodialysis patients and healthcare workers and the methods for diagnosing COVID-19, with particular attention to serological tests and nasopharyngeal swabs in asymptomatic subjects. The detection of IgM and IgG antibodies through the serological test performed on 34 patients, all negative for nasopharyngeal swabs, showed positivity in 41,18% of cases. These have been classified as false positives following repeated negative nasopharyngeal swabs, the evaluation of clinical and epidemiological history and of clinical manifestations and, finally, a second serological test performed after 18 days, which resulted negative for all patients. Interpreting serological tests is not easy; the strategies for diagnosis should include clinical and epidemiological history and clinical manifestations, as well as the results of confirmation tests and the evaluation over a precise observation period. Otherwise, there is a risk of considering as protected by antibodies subjects that are in fact false positives.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Unidades Hospitalares de Hemodiálise/estatística & dados numéricos , Pandemias , Pneumonia Viral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas , Betacoronavirus/isolamento & purificação , Reações Falso-Positivas , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Itália , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Guias de Prática Clínica como Assunto , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Sci Immunol ; 5(52)2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033173

RESUMO

While the antibody response to SARS-CoV-2 has been extensively studied in blood, relatively little is known about the antibody response in saliva and its relationship to systemic antibody levels. Here, we profiled by enzyme-linked immunosorbent assays (ELISAs) IgG, IgA and IgM responses to the SARS-CoV-2 spike protein (full length trimer) and its receptor-binding domain (RBD) in serum and saliva of acute and convalescent patients with laboratory-diagnosed COVID-19 ranging from 3-115 days post-symptom onset (PSO), compared to negative controls. Anti-SARS-CoV-2 antibody responses were readily detected in serum and saliva, with peak IgG levels attained by 16-30 days PSO. Longitudinal analysis revealed that anti-SARS-CoV-2 IgA and IgM antibodies rapidly decayed, while IgG antibodies remained relatively stable up to 105 days PSO in both biofluids. Lastly, IgG, IgM and to a lesser extent IgA responses to spike and RBD in the serum positively correlated with matched saliva samples. This study confirms that serum and saliva IgG antibodies to SARS-CoV-2 are maintained in the majority of COVID-19 patients for at least 3 months PSO. IgG responses in saliva may serve as a surrogate measure of systemic immunity to SARS-CoV-2 based on their correlation with serum IgG responses.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Saliva/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Infecções por Coronavirus/virologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia
8.
Lab Chip ; 20(22): 4255-4261, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33064114

RESUMO

COVID-19 is a widespread and highly contagious disease in the human population. COVID-19 is caused by SARS-CoV-2 infection. There is still a great demand for point-of-care tests for detection, epidemic prevention and epidemiological investigation, both now and after the epidemic. We present a lateral flow immunoassay kit based on a selenium nanoparticle-modified SARS-CoV-2 nucleoprotein, which detects anti-SARS-CoV-2 IgM and anti-SARS-CoV-2 IgG in human serum, and the results can be read by the naked eye in 10 minutes. We expressed and purified the SARS-CoV-2 nucleoprotein in HEK293 cells, with a purity of 98.14% and a concentration of 5 mg mL-1. Selenium nanoparticles were synthesized by l-ascorbic acid reduction of seleninic acid at room temperature. After conjugation with the nucleoprotein, a lateral flow kit was successfully prepared. The IgM and IgG detection limits of the lateral flow kit reached 20 ng mL-1 and 5 ng mL-1, respectively, in human serum. A clinical study sample comprising 90 COVID-19-diagnosed patients and 263 non-infected controls was used to demonstrate a sensitivity and specificity of 93.33% and 97.34%, respectively, based on RT-PCR and clinical results. No cross-reactions with rheumatoid factor and positive serum for anti-nuclear antibodies, influenza A, and influenza B were observed. Moreover, the lateral flow kit remained stable after storage for 30 days at 37 °C. Our results demonstrate that the selenium nanoparticle lateral flow kit can conveniently, rapidly, and sensitively detect anti-SARS-CoV-2 IgM and IgG in human serum and blood; it can also be suitable for the epidemiological investigation of COVID-19.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pneumonia Viral/sangue , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Desenho de Equipamento , Células HEK293 , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Dispositivos Lab-On-A-Chip , Limite de Detecção , Nanopartículas/química , Pandemias , Pneumonia Viral/imunologia , Testes Imediatos , Fitas Reagentes/análise , Selênio/química
9.
J Med Internet Res ; 22(10): e19152, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33031048

RESUMO

BACKGROUND: Real-time polymerase chain reaction (RT-PCR) testing for the identification of viral nucleic acid is the current standard for the diagnosis of SARS-CoV-2 infection, but technical issues limit its utilization for large-scale screening. Serological immunoglobulin M (IgM)/IgG testing has been proposed as a useful tool for detecting SARS-CoV-2 exposure. OBJECTIVE: The objective of our study was to compare the results of the rapid serological VivaDiag test for SARS-CoV-2-related IgM/IgG detection with those of the standard RT-PCR laboratory test for identifying SARS-CoV-2 nucleic acid. METHODS: We simultaneously performed both serological and molecular tests with a consecutive series of 191 symptomatic patients. The results provided by a new rapid serological colorimetric test for analyzing IgM/IgG expression were compared with those of RT-PCR testing for SARS-CoV-2 detection. RESULTS: Of the 191 subjects, 70 (36.6%) tested positive for SARS-CoV-2 based on RT-PCR results, while 34 (17.3%) tested positive based on serological IgM/IgG expression. Additionally, 13 (6.8%) subjects tested positive based on serological test results, but also tested negative based on RT-PCR results. The rapid serological test had a sensitivity of 30% and a specificity of 89% compared to the standard RT-PCR assay. Interestingly, the performance of both assays improved 8 days after symptom appearance. After 10 days had passed since symptom appearance, the predictive value of the rapid serological test was higher than that of the standard molecular assay (proportion of positive results: 40% vs 20%). Multivariate analysis showed that age >58 years (P<.01) and period of >15 days after symptom onset (P<.02) were significant and independent factors associated with serological test positivity. CONCLUSIONS: The rapid serological test analyzed in this study seems limited in terms of usefulness when diagnosing SARS-CoV-2 infection. However, it may be useful for providing relevant information on people's immunoreaction to COVID-19 exposure.


Assuntos
Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Testes Sorológicos/métodos , Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Feminino , Humanos , Imunoglobulina G/análise , Imunoglobulina G/imunologia , Imunoglobulina M/análise , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Sensibilidade e Especificidade
10.
Clin Chim Acta ; 510: 790-795, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32956703

RESUMO

BACKGROUND: While the diagnosis of SARS-CoV-2 infection is primarily based on detection of viral RNA, the detection of SARS-CoV-2 antibodies is useful for assessing past prevalence of the disease, and in corroborating a current infection in challenging cases. Sensitive and specific immunoassays provide the ability to identify exposure to SARS-CoV-2, to determine seroconversion, to confirm eligibility for donation of convalescent plasma as well as play an essential part in epidemiological studies. We report on the validation of the Ansh Laboratories SARS-CoV-2 IgG and SARS-CoV-2 IgM ELISA immunoassays. These assays were evaluated for detection of anti-SARS-CoV-2 IgG and IgM antibodies for clinical use in our hospital as part of an orthogonal testing algorithm recommended by the CDC. METHODS: Diagnostic specificity and sensitivity of the IgG and IgM ELISA assays were tested using samples confirmed to be negative or positive for COVID-19 by RT-PCR. We also evaluated precision, analytical interference, and cross-reactivity with known cases of infection with other viruses. Additionally, we validated concordance with molecular and other serological testing and evaluated seroconversion in our patient population. RESULTS: The IgG and IgM ELISA assays showed acceptable precision, were robust to analytical interference and did not exhibit cross reactivity with specimens positive for common respiratory viruses. Both assays exhibited 95% agreement with a primary screening serological assay utilized at our institution as well as with a reference laboratory semi-quantitative method. Concordance with RT-PCR was excellent > 6 days after symptom onset (100%). CONCLUSIONS: The Ansh SARS-CoV-2 ELISA assays have good analytical performance suitable for clinical use.


Assuntos
Betacoronavirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/análise , Imunoglobulina M/análise , Epitopos/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia
11.
Nat Metab ; 2(10): 1021-1024, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32879473

RESUMO

Here we report a case where the manifestations of insulin-dependent diabetes occurred following SARS-CoV-2 infection in a young individual in the absence of autoantibodies typical for type 1 diabetes mellitus. Specifically, a 19-year-old white male presented at our emergency department with diabetic ketoacidosis, C-peptide level of 0.62 µg l-1, blood glucose concentration of 30.6 mmol l-1 (552 mg dl-1) and haemoglobin A1c of 16.8%. The patient´s case history revealed probable COVID-19 infection 5-7 weeks before admission, based on a positive test for antibodies against SARS-CoV-2 proteins as determined by enzyme-linked immunosorbent assay. Interestingly, the patient carried a human leukocyte antigen genotype (HLA DR1-DR3-DQ2) considered to provide only a slightly elevated risk of developing autoimmune type 1 diabetes mellitus. However, as noted, no serum autoantibodies were observed against islet cells, glutamic acid decarboxylase, tyrosine phosphatase, insulin and zinc-transporter 8. Although our report cannot fully establish causality between COVID-19 and the development of diabetes in this patient, considering that SARS-CoV-2 entry receptors, including angiotensin-converting enzyme 2, are expressed on pancreatic ß-cells and, given the circumstances of this case, we suggest that SARS-CoV-2 infection, or COVID-19, might negatively affect pancreatic function, perhaps through direct cytolytic effects of the virus on ß-cells.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Diabetes Mellitus Tipo 1/complicações , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Betacoronavirus/imunologia , Biomarcadores , Infecções por Coronavirus/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Antígenos HLA-D/genética , Antígenos HLA-D/imunologia , Humanos , Imunoglobulina M/imunologia , Insulina/metabolismo , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/imunologia , Masculino , Pandemias , Pneumonia Viral/imunologia , Adulto Jovem
12.
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
13.
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
14.
Cell ; 183(4): 1024-1042.e21, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-32991844

RESUMO

Analysis of the specificity and kinetics of neutralizing antibodies (nAbs) elicited by SARS-CoV-2 infection is crucial for understanding immune protection and identifying targets for vaccine design. In a cohort of 647 SARS-CoV-2-infected subjects, we found that both the magnitude of Ab responses to SARS-CoV-2 spike (S) and nucleoprotein and nAb titers correlate with clinical scores. The receptor-binding domain (RBD) is immunodominant and the target of 90% of the neutralizing activity present in SARS-CoV-2 immune sera. Whereas overall RBD-specific serum IgG titers waned with a half-life of 49 days, nAb titers and avidity increased over time for some individuals, consistent with affinity maturation. We structurally defined an RBD antigenic map and serologically quantified serum Abs specific for distinct RBD epitopes leading to the identification of two major receptor-binding motif antigenic sites. Our results explain the immunodominance of the receptor-binding motif and will guide the design of COVID-19 vaccines and therapeutics.


Assuntos
Anticorpos Neutralizantes/imunologia , Mapeamento de Epitopos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Anticorpos Antivirais/sangue , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Reações Antígeno-Anticorpo , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Betacoronavirus/metabolismo , Sítios de Ligação , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Epitopos/química , Epitopos/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Cinética , Simulação de Dinâmica Molecular , Pandemias , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Ligação Proteica , Domínios Proteicos/imunologia , Estrutura Quaternária de Proteína , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
15.
PLoS One ; 15(9): e0238855, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32976540

RESUMO

BACKGROUND: Early recognition and diagnosis of allergic bronchopulmonary aspergillosis (ABPA) is critical to improve patient symptoms, and antifungal therapy may prevent or delay progression of bronchiectasis and development of chronic pulmonary aspergillosis. OBJECTIVE: A recently commercialized lateral flow assay (Aspergillus ICT) (LDBio Diagnostics, Lyons, France) detects Aspergillus-specific antibodies in <30 minutes, requiring minimal laboratory equipment. We evaluated this assay for diagnosis of ABPA compared to diseased (asthma and/or bronchiectasis) controls. METHODS: ABPA and control sera collected at the National Aspergillosis Centre (Manchester, UK) and/or from the Manchester Allergy, Respiratory and Thoracic Surgery research biobank were evaluated using the Aspergillus ICT assay. Results were read both visually and digitally (using a lateral flow reader). Serological Aspergillus-specific IgG and IgE, and total IgE titres were measured by ImmunoCAP. RESULTS: For 106 cases of ABPA versus all diseased controls, sensitivity and specificity for the Aspergillus ICT were 90.6% and 87.2%, respectively. Sensitivity for 'proven' ABPA alone (n = 96) was 89.8%, and 94.4% for 'presumed' ABPA (n = 18). 'Asthma only' controls (no bronchiectasis) and 'bronchiectasis controls' exhibited 91.4% and 81.7% specificity, respectively. Comparison of Aspergillus ICT result with Aspergillus-specific IgG and IgE titres showed no evident immunoglobulin isotype bias. Digital measurements displayed no correlation between ImmunoCAP Aspergillus-specific IgE level and ICT test line intensity. CONCLUSIONS: The Aspergillus ICT assay exhibits good sensitivity for ABPA serological screening. It is easy to perform and interpret, using minimal equipment and resources; and provides a valuable simple screening resource to rapidly distinguish more serious respiratory conditions from Aspergillus sensitization alone.


Assuntos
Anticorpos Antifúngicos/sangue , Aspergilose Broncopulmonar Alérgica/diagnóstico , Aspergillus/imunologia , Imunoensaio/métodos , Testes Sorológicos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antifúngicos/imunologia , Aspergilose Broncopulmonar Alérgica/epidemiologia , Aspergilose Broncopulmonar Alérgica/microbiologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reino Unido/epidemiologia , Adulto Jovem
16.
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
17.
Pain Physician ; 23(4S): S381-S390, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32942795

RESUMO

BACKGROUND: The interventional pain management community saw the COVID-19 pandemic decimate elective interventional procedures and new patient visits across the United States until the reopening of America and the restarting of interventional procedures and elective surgical procedures began again. Health care providers, along with essential workers and patients, continue to be concerned about functioning in a safe and responsible manner. Consequently, a level of comfort is created by the testing health care workers with long exposure to new patients and patients undergoing interventions in high risk environments. As the United States and the world suffers from an ongoing infodemic, there are substantial amounts of misinformation, and some appropriate information being produced on molecular, antigen and antibody testing. Consequently, this manuscript is undertaken to describe the value and validity of coronavirus antibody testing. METHODS: Literature review. RESULTS: Antibody tests detect antibodies or immunoglobulins that are produced as the human immune response to SARS-CoV-2 infection. A positive result suggests that the individual has potentially been exposed to SARS-CoV-2. When immunoglobulins M (IgM) antibodies are present, they can indicate an active or recent infection, whereas immunoglobulin G (IgG) antibodies show up later in the infection process and can often indicate a past infection, but does not exclude recently infected patients who can still be contagious, especially when IgM antibodies are also concurrently detected. While past knowledge indicates that for viral infections, IgG antibodies usually persist longer than IgM antibodies and provide immunity from re-infection, it is not clearly known if that is true for COVID-19. LIMITATIONS: A narrative review with paucity of literature. CONCLUSION: Antibody tests have been developed to detect IgG only, both IgG and IgM, or total antibodies. At present, multiple antibody tests are available for use in the United States. In a review of 54 available studies through the end of April, mostly from China, the accuracy of pooled results for combination IgG/IgM tests was 91.4% (95% CI, 87.0 - 96.6) for 15 to 21 days post-symptom onset. Thus, antibody tests provide a promise and a peril in the ongoing Covid-19 pandemic.


Assuntos
Anticorpos Antivirais/sangue , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Anticorpos Antivirais/imunologia , Betacoronavirus , China , Infecções por Coronavirus/sangue , Infecções por Coronavirus/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , Sensibilidade e Especificidade
18.
Iran J Kidney Dis ; 14(5): 389-398, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32943594

RESUMO

INTRODUCTION: Seven months after the emergence of SARS-COV-2 virus, there is paucity of data regarding the epidemiology of the virus in hemodialysis patients. We aim to present the results of the screening program implied after outbreak of COVID-19 in a referral hemodialysis ward. METHODS: We started clinical screening and obligatory mask wearing for dialysis patients and personnel on 20-Feb-2020. However 11 symptomatic COVID-19 patients emerged till day +36. On days +39 and +40 a screening program was implied including measurement of SARS-COV-2 PCR and immunoglobulin G and M (IgG/IgM) and chest computerized tomography (CCT) scan. The results of CCT scan, classified according to the coronavirus disease 2019 (COVID-19) Reporting and Data System (CO-RADS) classification; as with very low (grade 1-normal), low, indeterminate, high, and very high likelihood of COVID-19 (grades 2, 3, 4, and 5; respectively), were used for compartmentalization of patients. RESULTS: Among 178 patients (68.2% male, mean age = 58.7 ± 16.6 years), 11 got COVID-19 before screening, two of whom died. CCT scans were normal in 71.3% and grade 2, 3, 4, and 5 in 7.9%, 4.5%, 5.6%, and 10.7%; respectively. PCR and IgG and/or IgM were positive in 27 and 32 patients. Eighty-three patients had evidence of COVID-19 infection, who were significantly older (62.2 ± 16.6 vs. 56.1 ± 16.02, P < .05). There was no difference in the rate of infection considering gender, diabetes mellitus, hypertension and different blood groups. CONCLUSION: Asymptomatic SARS- COV 2 infection may affect a large number of dialysis patients. We highly recommend a screening strategy whenever the number of patients is increasing.


Assuntos
Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Pessoal de Saúde , Unidades Hospitalares de Hemodiálise , Falência Renal Crônica/terapia , Pulmão/diagnóstico por imagem , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Betacoronavirus/genética , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/complicações , Infecções por Coronavirus/imunologia , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Incidência , Irã (Geográfico)/epidemiologia , Falência Renal Crônica/complicações , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/imunologia , Diálise Renal , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tomografia Computadorizada por Raios X , Adulto Jovem
19.
Diagn Microbiol Infect Dis ; 98(3): 115140, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829098

RESUMO

INTRODUCTION: SARS-CoV-2 seroconversion is important for epidemiological studies as well as contact tracing. MATERIAL AND METHODS: The antibody response against SARS-CoV-2 was examined in 111 patients with a positive qRT-PCR. Seroconversion was assessed using the Elecsys from Roche, the Liaison S1/S2 IgG from Diasorin, the IgG and IgA from Euroimmun, as well as the VIDAS IgG and IgM. Specificity was estimated based on the measurement of SARS-CoV-2 antibodies in 96 residual samples collected during a non-pandemic period. RESULTS: The highest overall sensitivity for detecting seroconversion was obtained using the Elecsys (81.1%), the Euroimmun with a combined detection of IgG/IgA (86.5%), and the VIDAS with a simultaneous measurement of IgG/IgM (78.4%).The Elecsys and the VIDAS IgG/IgM demonstrated a specificity as well as a positive predictive value of 100%. CONCLUSIONS: The Elecsys and the VIDAS methods with a combination of IgG/IgM measurement demonstrated a high sensitivity with no false positive results.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Feminino , Humanos , Imunoensaio/métodos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Reação em Cadeia da Polimerase , Soroconversão , Testes Sorológicos/métodos , Adulto Jovem
20.
Diagnosis (Berl) ; 7(4): 395-400, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-32827394

RESUMO

Objectives Clinical laboratories plays a key role in screening, diagnosis and containment of the Coronavirus 2019 infection epidemic. The etiological diagnosis presupposes the isolation of virus genetic material in the patient's biological sample but laboratory diagnostics also make use of searching possibility for immunoglobulin (Ig)G, IgM classes antibodies. The characteristics of the antibody response are not yet completely clear. Methods This study describes a serological monitoring of subjects, elderly nursing care residence guests, interested by a very large infection outbreak. After first nasopharyngeal swab, all the positive subjects (43) were monitored for the persistence of the virus infection through nasopharyngeal swab after 20 days (16-24), 32 days (28-36) and after 49 days (47-50). At the same time, during the second (day 32) and third (day 49) follow up, all the guests were investigated for IgM and IgG anti SARS-CoV-2 antibodies, by using a quantitative chemiluminescence method. Results Thirty two days after performing the first diagnostic swab, 39 of 43 patients (90%) had IgG higher than the cut off value. After 49 days the four patients with negative IgG were still negative. The comparison of the levels of IgG-Ab between the controls shows a significant decrease in concentrations (-10%). Conclusions Our study confirms that in most patients affected by COVID-19 there is a typical antibody response with IgG-Ab present in 90% of nursing care COVID-19 positive residence guests. For IgM-Ab only 23% of tested subjects were positive on the 32nd and 49th day of illness, always in parallel with the IgG-Ab positivity.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Monitorização Imunológica/métodos , Pneumonia Viral/imunologia , Vírus da SARS/imunologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Assistência de Longa Duração , Medições Luminescentes/métodos , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia
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