Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 691
Filtrar
2.
Nat Commun ; 12(1): 1951, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33782398

RESUMO

Serological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests do not require special equipment, are read by eye, have short development times, low cost and can be applied at the Point of Care. Here we describe a quantitative Haemagglutination test (HAT) for the detection of antibodies to the receptor binding domain of the SARS-CoV-2 spike protein. The HAT has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. We will supply aliquots of the test reagent sufficient for ten thousand test wells free of charge to qualified research groups anywhere in the world.


Assuntos
Anticorpos Antivirais/análise , /diagnóstico , Testes de Hemaglutinação/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Testes de Aglutinação/métodos , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , /imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Soroconversão
3.
Emerg Infect Dis ; 27(4): 1155-1158, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33734962

RESUMO

Prospective serosurveillance of severe acute respiratory syndrome coronavirus 2 in 1,069 healthcare workers in London, UK, demonstrated that nucleocapsid antibody titers were stable and sustained for <12 weeks in 312 seropositive participants. This finding was consistent across demographic and clinical variables and contrasts with reports of short-term antibody waning.


Assuntos
Anticorpos Antivirais/sangue , Formação de Anticorpos/imunologia , Pessoal de Saúde/estatística & dados numéricos , Adulto , /epidemiologia , /métodos , Feminino , Humanos , Londres/epidemiologia , Masculino , Fosfoproteínas/imunologia , Soroconversão , Estudos Soroepidemiológicos
4.
Emerg Infect Dis ; 27(4): 1193-1195, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33754987

RESUMO

After experimental inoculation, severe acute respiratory syndrome coronavirus 2 infection was confirmed in bank voles by seroconversion within 8 days and detection of viral RNA in nasal tissue for up to 21 days. However, transmission to contact animals was not detected. Thus, bank voles are unlikely to establish effective transmission cycles in nature.


Assuntos
Arvicolinae , Transmissão de Doença Infecciosa , Doenças dos Roedores , Soroconversão , Eliminação de Partículas Virais , Animais , Anticorpos Antivirais , /transmissão , Modelos Animais de Doenças , Suscetibilidade a Doenças , Mucosa Nasal/virologia , Doenças dos Roedores/imunologia , Doenças dos Roedores/transmissão , Doenças dos Roedores/virologia
5.
Elife ; 102021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33724185

RESUMO

COVID19 is a heterogeneous medical condition involving diverse underlying pathophysiological processes including hyperinflammation, endothelial damage, thrombotic microangiopathy, and end-organ damage. Limited knowledge about the molecular mechanisms driving these processes and lack of staging biomarkers hamper the ability to stratify patients for targeted therapeutics. We report here the results of a cross-sectional multi-omics analysis of hospitalized COVID19 patients revealing that seroconversion status associates with distinct underlying pathophysiological states. Low antibody titers associate with hyperactive T cells and NK cells, high levels of IFN alpha, gamma and lambda ligands, markers of systemic complement activation, and depletion of lymphocytes, neutrophils, and platelets. Upon seroconversion, all of these processes are attenuated, observing instead increases in B cell subsets, emergency hematopoiesis, increased D-dimer, and hypoalbuminemia. We propose that seroconversion status could potentially be used as a biosignature to stratify patients for therapeutic intervention and to inform analysis of clinical trial results in heterogenous patient populations.


Assuntos
/epidemiologia , Soroconversão , Biomarcadores , /metabolismo , Comorbidade , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Hematopoese , Homeostase , Hospitalização , Humanos , Hipoalbuminemia , Interferons/metabolismo , Modelos Biológicos , Estudos Soroepidemiológicos , Transdução de Sinais
6.
J Immunol Res ; 2021: 6680337, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33644235

RESUMO

COVID-19 is a pandemic caused by SARS-CoV-2. In Chile, half a million people have been infected and more than 16,000 have died from COVID-19. As part of the clinical trial NCT04384588, we quantified IgG against S1-RBD of SARS-CoV-2 (anti-RBD) in recovered people in Santiago and evaluated their suitability as COVID-19 convalescent plasma donors. ELISA and a luminescent SARS-CoV-2 pseudotype were used for IgG and neutralizing antibody quantification. 72.9% of the convalescent population (468 of 639) showed seroconversion (5-55 µg/mL anti-RBD IgG) and were suitable candidates for plasma donation. Analysis by gender, age, and days after symptom offset did not show significant differences. Neutralizing activity correlated with an increased concentration of anti-RBD IgG (p < 0.0001) and showed a high variability between donors. We confirmed that the majority of the Chilean patients have developed anti-SARS-CoV-2 antibodies. The quantification of anti-RBD IgG in convalescent plasma donors is necessary to increase the detection of neutralizing antibodies.


Assuntos
/imunologia , /fisiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/sangue , Anticorpos Antivirais/uso terapêutico , Chile , Feminino , Humanos , Imunização Passiva/métodos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Soroconversão , Adulto Jovem
7.
BMJ ; 372: n616, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33731327

RESUMO

OBJECTIVES: To examine longitudinal changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and to determine the clustering of children who were seropositive within school classes in the canton of Zurich, Switzerland from June to November 2020. DESIGN: Prospective cohort study. SETTING: Switzerland had one of the highest second waves of the SARS-CoV-2 pandemic in Europe in autumn 2020. Keeping schools open provided a moderate to high exposure environment to study SARS-CoV-2 infections. Children from randomly selected schools and classes, stratified by district, were invited for serological testing of SARS-CoV-2. Parents completed questionnaires on sociodemographic and health related questions. PARTICIPANTS: 275 classes in 55 schools; 2603 children participated in June-July 2020 and 2552 in October-November 2020 (age range 6-16 years). MAIN OUTCOME MEASURES: Serology of SARS-CoV-2 in June-July and October-November 2020, clustering of children who were seropositive within classes, and symptoms in children. RESULTS: In June-July, 74 of 2496 children with serological results were seropositive; in October-November, the number had increased to 173 of 2503. Overall SARS-CoV-2 seroprevalence was 2.4% (95% credible interval 1.4% to 3.6%) in the summer and 4.5% (3.2% to 6.0%) in late autumn in children who were not previously seropositive, leading to an estimated 7.8% (6.2% to 9.5%) of children who were ever seropositive. Seroprevalence varied across districts (in the autumn, 1.7-15.0%). No significant differences were found among lower, middle, and upper school levels (children aged 6-9 years, 9-13 years, and 12-16 years, respectively). Among the 2223 children who had serology tests at both testing rounds, 28/70 (40%) who were previously seropositive became seronegative, and 109/2153 (5%) who were previously seronegative became seropositive. Symptoms were reported for 22% of children who were seronegative and 29% of children who were newly seropositive since the summer. Between July and November 2020, the ratio of children diagnosed with SARS-CoV-2 infection to those who were seropositive was 1 to 8. At least one child who was newly seropositive was detected in 47 of 55 schools and in 90 of 275 classes. Among 130 classes with a high participation rate, no children who were seropositive were found in 73 (56%) classes, one or two children were seropositive in 50 (38%) classes, and at least three children were seropositive in 7 (5%) classes. Class level explained 24% and school level 8% of variance in seropositivity in the multilevel logistic regression models. CONCLUSIONS: With schools open since August 2020 and some preventive measures in place, clustering of children who were seropositive occurred in only a few classes despite an increase in overall seroprevalence during a period of moderate to high transmission of SARS-CoV-2 in the community. Uncertainty remains as to whether these findings will change with the new variants of SARS-CoV-2 and dynamic levels of community transmission. TRIAL REGISTRATION: NCT04448717.


Assuntos
/epidemiologia , Estudantes/estatística & dados numéricos , Adolescente , Criança , Análise por Conglomerados , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Soroconversão , Estudos Soroepidemiológicos , Suíça/epidemiologia
8.
Sci Rep ; 11(1): 3461, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568715

RESUMO

Despite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.


Assuntos
/imunologia , Imunoglobulina G/imunologia , Interleucina-12/sangue , Interleucina-33/sangue , Soroconversão/fisiologia , Formação de Anticorpos , /diagnóstico , Humanos , Índice de Gravidade de Doença
9.
Nat Commun ; 12(1): 944, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574228

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits high levels of mortality and morbidity and has dramatic consequences on human life, sociality and global economy. Neutralizing antibodies constitute a highly promising approach for treating and preventing infection by this novel pathogen. In the present study, we characterize and further evaluate the recently identified human monoclonal MD65 antibody for its ability to provide protection against a lethal SARS-CoV-2 infection of K18-hACE2 transgenic mice. Eighty percent of the untreated mice succumbed 6-9 days post-infection, while administration of the MD65 antibody as late as 3 days after exposure rescued all infected animals. In addition, the efficiency of the treatment is supported by prevention of morbidity and ablation of the load of infective virions in the lungs of treated animals. The data demonstrate the therapeutic value of human monoclonal antibodies as a life-saving treatment for severe COVID-19 infection.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Antivirais/administração & dosagem , /imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Chlorocebus aethiops , Feminino , Imunoglobulina G/administração & dosagem , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , /fisiologia , Soroconversão , Células Vero , Carga Viral
10.
Lancet HIV ; 8(2): e77-e86, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33539761

RESUMO

BACKGROUND: The Ring Study, a phase 3 trial in 1959 sexually active women (randomised 2:1), showed a favourable safety profile and a 31% HIV-1 infection risk reduction for a vaginal ring containing 25 mg of dapivirine, compared with a placebo ring. We report here the DREAM study, which aimed to evaluate safety, adherence, and HIV-1 incidence in those using the dapivirine vaginal ring (DVR) in open-label use. METHODS: The DREAM study is an open-label extension of The Ring Study, done at five research centres in South Africa and one research centre in Uganda. Former participants from The Ring Study, who remained HIV-negative and who did not discontinue the study due to an adverse event or safety concern that was considered to be related to the investigational product, were eligible. Women who were pregnant, planning to become pregnant, or breastfeeding at screening for DREAM were excluded. All participants received the DVR for insertion at the enrolment visit. Participants attended a 1-month follow-up visit and could either proceed with visits once every 3 months or attend monthly visits up to month 3 and then continue with visits once every 3 months. At each visit, HIV testing and safety evaluations were done, and residual dapivirine measured in used rings (approximately 4 mg is released from the DVR over 28 days of consistent use). HIV-1 incidence was compared descriptively with the simulated incidence rate obtained from bootstrap sampling of participants in the placebo group of The Ring Study, matched for research centre, age, and presence of sexually transmitted infections at enrolment. This study is registered with ClinicalTrials.gov, NCT02862171. FINDINGS: Between July 12, 2016, and Jan 11, 2019, 1034 former participants from The Ring Study were screened, 941 were enrolled and 848 completed the trial. 616 (65·5%) of 941 participants reported treatment-emergent adverse events. Of these, six (0·6%) had events considered to be treatment-related. No treatment-related serious adverse events were reported. Measurements of monthly ring residual amounts in participants enrolled in both trials showed consistently lower mean values in DREAM than in The Ring Study. Arithmetic mean ring residual amounts of participants in The Ring Study DVR group who enrolled in DREAM were 0·25 mg lower (95% CI 0·03-0·47; p=0·027) than the mean ring residual amounts of these participants in The Ring Study. 18 (1·9%) HIV-1 infections were confirmed during DVR use, resulting in an incidence of 1·8 (95% CI 1·1-2·6) per 100 person-years, 62% lower than the simulated placebo rate. INTERPRETATION: Although efficacy estimation is limited by the absence of a placebo group, the observed low HIV-1 incidence and improved adherence observed in DREAM support the hypothesis that increased efficacy due to improved adherence occurs when women know the demonstrated safety and efficacy of the DVR. The feasibility of a visit schedule of once every 3 months was shown, indicating that the DVR can be used in a real-world situation in usual clinical practice. FUNDING: The Ministry of Foreign Affairs (MFA) Denmark, Flanders MFA, Irish Aid, Dutch MFA, UK Aid from the UK Government's Foreign, Commonwealth and Development Office, and the US President's Emergency Plan for AIDS Relief through the US Agency for International Development.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Dispositivos Anticoncepcionais Femininos , Infecções por HIV/prevenção & controle , Pirimidinas/uso terapêutico , Tenofovir/uso terapêutico , Administração Intravaginal , Adolescente , Adulto , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Pessoa de Meia-Idade , Cooperação do Paciente/estatística & dados numéricos , Segurança do Paciente , Soroconversão , África do Sul , Resultado do Tratamento , Uganda
11.
Lancet HIV ; 8(2): e87-e95, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33539762

RESUMO

BACKGROUND: Two phase 3 clinical trials showed that use of a monthly vaginal ring containing 25 mg dapivirine was well tolerated and reduced HIV-1 incidence in women by approximately 30% compared with placebo. We aimed to evaluate use and safety of the dapivirine vaginal ring (DVR) in open-label settings with high background rates of HIV-1 infection, an important step for future implementation. METHODS: We did a phase 3B open-label extension trial of the DVR (MTN-025/HIV Open-label Prevention Extension [HOPE]). Women who were HIV-1-negative and had participated in the MTN-020/ASPIRE phase 3 trial were offered 12 months of access to the DVR at 14 clinical research centres in Malawi, South Africa, Uganda, and Zimbabwe. At each visit (monthly for 3 months, then once every 3 months), women chose whether or not to accept the offer of the ring. Used, returned rings were tested for residual amounts of dapivirine as a surrogate marker for adherence. HIV-1 serological testing was done at each visit. Dapivirine amounts in returned rings and HIV-1 incidence were compared with data from the ASPIRE trial, and safety was assessed. This study is registered with ClinicalTrials.gov, NCT02858037. FINDINGS: Between July 16, 2016, and Oct 10, 2018, of 1756 women assessed for eligibility, 1456 were enrolled and participated in the study. Median age was 31 years (IQR 27-37). At baseline, 1342 (92·2%) women chose to take the DVR; ring acceptance was more than 79% at each visit up until 12 months and 936 (73·2%) of 1279 chose to take the ring at all visits. 12 530 (89·3%) of 14 034 returned rings had residual dapivirine amounts consistent with some use during the previous month (>0·9 mg released) and the mean dapivirine amount released was greater than in the ASPIRE trial (by 0·21 mg; p<0·0001). HIV-1 incidence was 2·7 per 100 person-years (95% CI 1·9-3·8, 35 infections), compared with an expected incidence of 4·4 per 100 person-years (3·2-5·8) among a population matched on age, site, and presence of a sexually transmitted infection from the placebo group of ASPIRE. No serious adverse events or grade 3 or higher adverse events observed were assessed as related to the DVR. INTERPRETATION: High uptake and persistent use in this open-label extension study support the DVR as an HIV-1 prevention option for women. With an increasing number of HIV-1 prophylaxis choices on the horizon, these results suggest that the DVR will be an acceptable and practical option for women in Africa. FUNDING: The Microbicide Trials Network and the National Institute of Allergy and Infectious Diseases, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute of Mental Health, all components of the US National Institutes of Health.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Dispositivos Anticoncepcionais Femininos , Infecções por HIV/prevenção & controle , Pirimidinas/uso terapêutico , Tenofovir/uso terapêutico , Administração Intravaginal , Adulto , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Malaui , Cooperação do Paciente/estatística & dados numéricos , Segurança do Paciente , Soroconversão , África do Sul , Resultado do Tratamento , Uganda , Zimbábue
12.
J Clin Virol ; 136: 104765, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33636554

RESUMO

BACKGROUND: Most SARS-CoV-2 infected patients develop IgG antibodies within 2-3 weeks after symptom onset. Antibody levels have been shown to gradually decrease in the first months after infection, but few data are available at six months or later. METHODS: A retrospective multi-center study was performed using 652 samples of 236 PCR-confirmed SARS-CoV-2 infected patients from 2 Belgian University hospitals. Patients were included if at least two samples were available (range 2-7 samples); including at least one sample collected 30 days or later after first positive PCR (range 0-240 days). Of those 236 patients, 19.1 % were classified as mild/asymptomatic (mild) and 80.9 % as moderate to critical (severe). IgG anti-nucleocapsid antibodies (anti-N) were measured using the Abbott Architect immunoassay. RESULTS: 22.2 % of mild and 2.6 % of severe COVID-19 cases never seroconverted (p < 0.001). Of the mild patients who seroconverted 0-59 days after PCR; 18.8 %, 40.0 % and 61.1 % were seronegative in the windows 60-119 days, 120-179 days and 180-240 days after PCR, respectively. In severe patients, these numbers were 1.9 %, 10.8 % and 29.4 % respectively (p < 0.05 each). Antibody levels were significantly higher in severe patients compared to mild patients in each 60 day window (p < 0.001 each). CONCLUSIONS: SARS-CoV-2 anti-N IgG antibody levels steadily decreased after 2 months up to 8 months post PCR. Of severe COVID-19 patients, 70.6 % remained positive up to eight months after infection. Antibody levels were significantly lower in mild SARS-CoV-2 infected patients and 61.1 % became seronegative within 6 months after the first positive PCR.


Assuntos
Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Nucleocapsídeo/imunologia , Soroconversão , Humanos , Estudos Longitudinais , Estudos Retrospectivos , Fatores de Tempo
13.
Immunobiology ; 226(2): 152054, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33524881

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide causing a pandemic with millions of infected people and deaths. Currently, the scientific community is working hard to develop a specific vaccine or treatment. However, since antibody production is an important part of the adaptive immune response, to develop vaccines and therapies, we must understand the antibody response to SARS-CoV-2 infection. In this work, we summarize the most important findings of antibody-mediated immunity against SARS-CoV-2 and highlight its role in the efficient use of plasma from convalescent patients and the direct application of antibodies as treatment.


Assuntos
Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , /imunologia , /fisiologia , Formação de Anticorpos , Humanos , Imunidade Humoral , Imunização Passiva , Soroconversão
14.
PLoS One ; 16(1): e0245382, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33497420

RESUMO

Antibody responses are important in the control of viral respiratory infection in the human host. What is not clear for SARS-CoV-2 is how rapidly this response occurs, or when antibodies with protective capability evolve. Hence, defining the events of SARS-CoV-2 seroconversion and the time frame for the development of antibodies with protective potential may help to explain the different clinical presentations of COVID-19. Furthermore, accurate descriptions of seroconversion are needed to inform the best use of serological assays for diagnostic testing and serosurveillance studies. Here, we describe the humoral responses in a cohort of hospitalised COVID-19 patients (n = 19) shortly following the onset of symptoms. Commercial and 'in-house' serological assays were used to measure IgG antibodies against different SARS-CoV-2 structural antigens-Spike (S) S1 sub-unit and Nucleocapsid protein (NP)-and to assess the potential for virus neutralisation mediated specifically by inhibition of binding between the viral attachment protein (S protein) and cognate receptor (ACE-2). Antibody response kinetics varied amongst the cohort, with patients seroconverting within 1 week, between 1-2 weeks, or after 2 weeks, following symptom onset. Anti-NP IgG responses were generally detected earlier, but reached maximum levels slower, than anti-S1 IgG responses. The earliest IgG antibodies produced by all patients included those that recognised the S protein receptor-binding domain (RBD) and were capable of inhibiting binding to ACE-2. These data revealed events and patterns of SARS-CoV-2 seroconversion that may be important predictors of the outcome of infection and guide the delivery of clinical services in the COVID-19 response.


Assuntos
Anticorpos Neutralizantes/imunologia , /imunologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Estudos de Coortes , Feminino , Hospitalização , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/química , Soroconversão , Glicoproteína da Espícula de Coronavírus/química , País de Gales
16.
Diagn Microbiol Infect Dis ; 99(4): 115300, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33388575

RESUMO

The clinical and public health utility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic testing requires a better understanding of the dynamics of the humoral response to infection. To track seroconversion of IgG and IgM antibodies in patients with SARS-CoV-2 infection and its association with patient and clinical factors and outcomes. Residual patient specimens were analyzed on the Abbott ARCHITECT i2000 instrument using the Abbott SARS-CoV-2 IgG assay and prototype SARS-CoV-2 IgM assay. Age, sex, comorbidities, symptom onset date, mortality, and specimen collection date were obtained from electronic medical records. Three hundred fifty-nine longitudinal samples were collected from 89 hospitalized patients 0 to 82 days postsymptom onset. Of all, 51.7% of the patients developed IgG and IgM antibodies simultaneously; 32.8% seroconverted for IgM before IgG. On average, patients seroconverted for IgG by 8 days and for IgM by 7 days postsymptom onset. All patients achieved IgG seropositivity by 19 days and IgM seropositivity by 17 days. Median time to IgG and IgM seroconversion was prolonged and initial levels of IgG were lower in immunocompromised patients and patients <65 years of age compared to immune competent patients and those ≥65 years of age. Immunocompromised patients also had persistently lower levels of IgM that peaked on day 17.6 and decreased thereafter compared to immune competent patients. IgM seroconversion in patients who died reached significantly higher levels later after symptom onset than in those who recovered. SARS-CoV-2 infected patients have similar time to seroconversion for IgG and IgM. However, differences in immune status and age alter time to seroconversion. These results may help guide serologic testing application in COVID-19 management.


Assuntos
Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Soroconversão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , /métodos , Feminino , Hospitalização , Humanos , Imunidade Humoral/imunologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Estados Unidos , Adulto Jovem
17.
Arch Virol ; 166(3): 881-884, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33433694

RESUMO

In the present study, we serosurveyed the exposure of 222 draft horses to different arboviruses in the city of Santa Fe, Argentina. Plaque reduction neutralization tests confirmed exposure to Fort Sherman virus (FSV), Saint Louis encephalitis virus (SLEV), West Nile virus (WNV), and Río Negro virus (RNV). Apparently, Western and Eastern equine encephalitis viruses did not circulate in the population tested. The confirmation of five seroconversions for WNV, FSV, and SLEV and the association between prevalence and age are indicative of recent circulation. These results highlight the importance of considering draft horses in arboviral surveillance in urban and rural areas of developing countries.


Assuntos
Infecções por Alphavirus/epidemiologia , Anticorpos Antivirais/sangue , Infecções por Bunyaviridae/epidemiologia , Encefalite de St. Louis/epidemiologia , Doenças dos Cavalos/epidemiologia , Febre do Nilo Ocidental/epidemiologia , Alphavirus/imunologia , Alphavirus/isolamento & purificação , Infecções por Alphavirus/veterinária , Animais , Argentina/epidemiologia , Infecções por Bunyaviridae/veterinária , Vírus da Encefalite de St. Louis/imunologia , Vírus da Encefalite de St. Louis/isolamento & purificação , Encefalite de St. Louis/veterinária , Doenças dos Cavalos/virologia , Cavalos , Orthobunyavirus/imunologia , Orthobunyavirus/isolamento & purificação , Soroconversão , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/isolamento & purificação
20.
J Immunol Methods ; 490: 112958, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33412174

RESUMO

The current Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) pandemic is a public health emergency of international concern. Sensitive and precise diagnostic tools are urgently needed. In this study, we developed a SARS-CoV-2 spike (S1) protein enzyme-linked immunosorbent assay (ELISA) to detect SARS-CoV-2-specific antibodies. The SARS-CoV-2 S1 ELISA was found to be specific [97.8% (95% CI, 96.7% - 98.5%)], reproducible and precise (intra-assay coefficient of variability (CV) 5.3%, inter-assay CV 7.9%). A standard curve and the interpolation of arbitrary ELISA units per milliliter served to reduce the variability between different tests and operators. Cross-reactivity to other human coronaviruses was addressed by using sera positive for MERS-CoV- and hCoV HKU1-specific antibodies. Monitoring antibody development in various samples of twenty-three and single samples of twenty-nine coronavirus disease 2019 (COVID-19) patients revealed seroconversion and neutralizing antibodies against authentic SARS-CoV-2 in all cases. The comparison of the SARS-CoV-2 (S1) ELISA with a commercially available assay showed a better sensitivity for the in-house ELISA. The results demonstrate a high reproducibility, specificity and sensitivity of the newly developed ELISA, which is suitable for the detection of SARS-CoV-2 S1 protein-specific antibody responses.


Assuntos
/métodos , Células Epiteliais/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Animais , Anticorpos Neutralizantes/sangue , Chlorocebus aethiops , Ensaios Enzimáticos , Ensaio de Imunoadsorção Enzimática , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soroconversão , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...