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1.
J Med Virol ; 94(1): 178-185, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34428312

RESUMO

Many aspects of the humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), such as its role in protection after natural infection, are still unclear. We evaluated IgA and IgG response to spike subunits 1 and 2 (S1 and S2) and Nucleocapsid proteins of SARS-COV-2 in serum samples of 109 volunteers with viral RNA detected or seroconversion with different clinical evolution (asymptomatic, mild, moderate, and severe coronavirus disease 2019), using the ViraChip® Test Kit. We observed that the quantification of antibodies to all antigens had a positive correlation to disease severity, which was strongly associated with the presence of comorbidities. Seroreversion was not uncommon even during the short (median of 77 days) observation, occurring in 15% of mild-asymptomatic cases at a median of 55 days for IgG and 46 days for IgA. The time to reach the maximal antibody response did not differ significantly among recovered and deceased volunteers. Our study illustrated the dynamic of anti-S1, anti-N, and anti-S2 IgA and IgG antibodies, and suggests that high production of IgG and IgA does not guarantee protection to disease severity and that functional responses that have been studied by other groups, such as antibody avidity, need further attention.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/imunologia , Soroconversão , Adulto Jovem
2.
Front Immunol ; 12: 772239, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804064

RESUMO

This contribution explores in a new statistical perspective the antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 141 coronavirus disease 2019 (COVID-19) patients exhibiting a broad range of clinical manifestations. This cohort accurately reflects the characteristics of the first wave of the SARS-CoV-2 pandemic in Italy. We determined the IgM, IgA, and IgG levels towards SARS-CoV-2 S1, S2, and NP antigens, evaluating their neutralizing activity and relationship with clinical signatures. Moreover, we longitudinally followed 72 patients up to 9 months postsymptoms onset to study the persistence of the levels of antibodies. Our results showed that the majority of COVID-19 patients developed an early virus-specific antibody response. The magnitude and the neutralizing properties of the response were heterogeneous regardless of the severity of the disease. Antibody levels dropped over time, even though spike reactive IgG and IgA were still detectable up to 9 months. Early baseline antibody levels were key drivers of the subsequent antibody production and the long-lasting protection against SARS-CoV-2. Importantly, we identified anti-S1 IgA as a good surrogate marker to predict the clinical course of COVID-19. Characterizing the antibody response after SARS-CoV-2 infection is relevant for the early clinical management of patients as soon as they are diagnosed and for implementing the current vaccination strategies.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , COVID-19/sangue , Imunoglobulina A/sangue , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/imunologia , Feminino , Células HEK293 , Hospitalização , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
J Korean Med Sci ; 36(43): e294, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34751011

RESUMO

BACKGROUND: In Korea, the first community outbreak of coronavirus disease 2019 (COVID-19) occurred in Daegu on February 18, 2020. This study was performed to investigate the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies in healthcare workers (HCWs) at 6 major hospitals in Daegu. METHODS: Blood specimens of 2,935 HCWs at 6 major hospitals in Daegu from January 2021 to February 2021 were collected. Every specimen was tested for antibody against SARS-CoV-2 using both Elecsys Anti-SARS-CoV-2 electrochemiluminescence immunoassay (Roche Diagnostics, Rotkreuz, Switzerland) and R-FIND COVID-19 IgG/M/A enzyme-linked immunosorbent assay kit (SG medical Inc., Seoul, Korea) as screening tests. If 1 or more of these screening test results was positive, 2 additional antibody tests were performed using Abbott Anti-SARS-CoV-2 IgG assay (Abbott, Abbott Park, IL, USA) and cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript USA Inc., Piscataway, NJ, USA). If 2 or more of the total 4 test results were positive, it was determined as positive for the antibody against SARS-CoV-2. RESULTS: According to the criteria of SARS-CoV-2 antibody positivity determination, 12 subjects were determined as positive. The overall positive rate of the SARS-CoV-2 antibody was 0.41% (12/2,935). Of the 12 subjects determined as positive, 7 were diagnosed with COVID-19, and the remaining 5 were nondiagnosed cases of COVID-19. CONCLUSION: In early 2021, the overall seroprevalence of SARS-CoV-2 antibody among HCW located in Daegu was 0.41%, and 0.17% excluding COVID-19 confirmed subjects. These results were not particularly high compared with the general public and were much lower than HCWs in other countries.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/diagnóstico , COVID-19/imunologia , Pessoal de Saúde/estatística & dados numéricos , Imunoglobulina G/sangue , Adulto , Idoso , Anticorpos Neutralizantes , Especificidade de Anticorpos , COVID-19/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitais , Humanos , Imunoglobulina A/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Prevalência , República da Coreia/epidemiologia , SARS-CoV-2
4.
Microbiol Spectr ; 9(2): e0087021, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34612689

RESUMO

The first case of SARS-CoV-2 was discovered in Israel in late February 2020. Three major outbreaks followed, resulting in over 800,000 cases and over 6,000 deaths by April 2021. Our aim was characterization of a serological snapshot of Israeli patients and healthy adults in the early months of the COVID-19 pandemic. Sera from 55 symptomatic COVID-19 patients and 146 healthy subjects (early-pandemic, reverse transcription-quantitative PCR [qRT-PCR]-negative), collected in Israel between March and April 2020, were screened for SARS-CoV-2-specific IgG, IgM, and IgA antibodies, using a 6-plex antigen microarray presenting the whole inactivated virus and five viral antigens: a stabilized version of the spike ectodomain (S2P), spike subunit 1 (S1), receptor-binding-domain (RBD), N-terminal-domain (NTD), and nucleocapsid (NC). COVID-19 patients, 4 to 40 days post symptom onset, presented specific IgG to all of the viral antigens (6/6) in 54 of the 55 samples (98% sensitivity). Specific IgM and IgA antibodies for all six antigens were detected in only 10% (5/55) and 4% (2/55) of the patients, respectively, suggesting that specific IgG is a superior serological marker for COVID-19. None of the qRT-PCR-negative sera reacted with all six viral antigens (100% specificity), and 48% (70/146) were negative throughout the panel. Our findings confirm a low seroprevalence of anti-SARS-CoV-2 antibodies in the Israeli adult population prior to the COVID-19 outbreak. We further suggest that the presence of low-level cross-reacting antibodies in naive individuals calls for a combined, multiantigen analysis for accurate discrimination between naive and exposed individuals. IMPORTANCE A 6-plex protein array presenting the whole inactivated virus and five nucleocapsid and spike-derived SARS-CoV-2 antigens was used to generate a serological snapshot of SARS-CoV-2 seroprevalence and seroconversion in Israel in the early months of the pandemic. Our findings confirm a very low seroprevalence of anti-SARS-CoV-2 antibodies in the Israeli adult population. We further propose that the presence of low-level nonspecific antibodies in naive individuals calls for a combined, multiantigen analysis for accurate discrimination between naive and exposed individuals enabling accurate determination of seroconversion. The developed assay is currently applied to evaluate immune responses to the Israeli vaccine during human phase I/II trials.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/epidemiologia , Análise em Microsséries/métodos , SARS-CoV-2/imunologia , Adulto , Idoso , Antígenos Virais/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Humanos , Imunoensaio/métodos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/imunologia , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
5.
Front Immunol ; 12: 743422, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659239

RESUMO

Elderly residents of long-term care facilities (LTCFs) have long been underrepresented in studies on vaccine efficacy, particularly in light of currently emerging variants of concern (VOCs). In this prospective observational cohort study, we analyzed serological immune responses in 190 individuals before, 3 weeks after 1st and 3 weeks after 2nd vaccination with BNT162b2. Unvaccinated COVID-19-convalescent subjects served as reference. End points comprised serum anti-spike IgG and IgA titers as well as neutralization capacities against unmutated and mutated SARS-CoV-2 receptor binding domains including B.1.1.7, B.1.351 and P.1. We found that antibody titers and neutralization capacities up to 3 weeks after 2nd vaccination with BNT162b2 were significantly higher in COVID-19-convalescent as compared to COVID-19-naive vaccinees. Moreover, pre-vaccination anti-NCP IgG titers, but not age or gender, had a high impact on the strength and kinetics of post-vaccination neutralization capacity development. Most importantly, BNT162b2-induced neutralization capacity was cross-reactive with VOCs. In contrast to unvaccinated convalescents, vaccinated convalescent individuals of all ages acquired strong neutralizing capacities against current VOCs. The present study suggests that COVID-19-convalescent individuals with a broad age range between 18 and 98 years benefit from BNT162b2 vaccination by developing strong and broad neutralizing immune responses against SARS-CoV-2 including current VOCs.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/prevenção & controle , Convalescença , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Assistência de Longa Duração , Pessoa de Meia-Idade , Estudos Prospectivos , Vacinação , Adulto Jovem
6.
PLoS One ; 16(10): e0258759, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34662351

RESUMO

The endocervix, the primary site of Chlamydia trachomatis (Ct) infection in women, has a unique repertoire of locally synthesized IgG and secretory IgA (SIgA) with contributions from serum IgG. Here, we assessed the ability of genital and serum-derived IgG and IgA from women with a recent positive Ct test to neutralize Ct elementary bodies (EBs) and inhibit inclusion formation in vitro in human endocervical epithelial cells. We also determined if neutralization was influenced by the major outer membrane protein (MOMP) of the infecting strain, as indicated by ompA gene sequencing and genotyping. At equivalent low concentrations of Ct EB (D/UW-3/Cx + E/UW-5/Cx)-specific antibody, genital-derived IgG and IgA and serum IgA, but not serum IgG, significantly inhibited inclusion formation, with genital IgA being most effective, followed by genital IgG, then serum IgA. The well-characterized Ct genotype D strain, D/UW-3/Cx, was neutralized by serum-derived IgG from patients infected with genotype D strains, genital IgG from patients infected with genotype D or E strains, and by genital IgA from patients infected with genotype D, E, or F strains. Additionally, inhibition of D/UW-3/Cx infection by whole serum, rather than purified immunoglobulin, was associated with levels of serum EB-specific IgG rather than the genotype of infecting strain. In contrast, a Ct genotype Ia clinical isolate, Ia/LSU-56/Cx, was neutralized by whole serum in a genotype and genogroup-specific manner, and inhibition also correlated with EB-specific IgG concentrations in serum. Taken together, these data suggest that (i) genital IgA most effectively inhibits Ct infection in vitro, (ii) human antibody-mediated inhibition of Ct infection is significantly influenced by the ompA genotype of the infecting strain, (iii) the genital antibody repertoire develops or matures differently compared to systemic antibody, and (iv) ompA genotype-specificity of inhibition of infection by whole serum can be overcome by high concentrations of Ct-specific IgG.


Assuntos
Anticorpos Neutralizantes/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Colo do Útero/imunologia , Infecções por Chlamydia/imunologia , Chlamydia trachomatis/imunologia , Adulto , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/metabolismo , Anticorpos Neutralizantes/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Linhagem Celular , Colo do Útero/citologia , Colo do Útero/virologia , Chlamydia trachomatis/genética , Células Epiteliais/citologia , Células Epiteliais/imunologia , Células Epiteliais/virologia , Feminino , Genótipo , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/metabolismo , Imunoglobulina G/sangue , Imunoglobulina G/metabolismo , Filogenia , Análise de Sequência de DNA , Adulto Jovem
7.
mSphere ; 6(5): e0075221, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34643417

RESUMO

During the progression of coronavirus disease 2019 (COVID-19), immune response and inflammation reactions are dynamic events that develop rapidly and are associated with the severity of disease. Here, we aimed to develop a predictive model based on the immune and inflammatory response to discriminate patients with severe COVID-19. COVID-19 patients were enrolled, and their demographic and immune inflammatory reaction indicators were collected and analyzed. Logistic regression analysis was performed to identify the independent predictors, which were further used to construct a predictive model. The predictive performance of the model was evaluated by receiver operating characteristic curve, and optimal diagnostic threshold was calculated; these were further validated by 5-fold cross-validation and external validation. We screened three key indicators, including neutrophils, eosinophils, and IgA, for predicting severe COVID-19 and obtained a combined neutrophil, eosinophil, and IgA ratio (NEAR) model (NEU [109/liter] - 150×EOS [109/liter] + 3×IgA [g/liter]). NEAR achieved an area under the curve (AUC) of 0.961, and when a threshold of 9 was applied, the sensitivity and specificity of the predicting model were 100% and 88.89%, respectively. Thus, NEAR is an effective index for predicting the severity of COVID-19 and can be used as a powerful tool for clinicians to make better clinical decisions. IMPORTANCE The immune inflammatory response changes rapidly with the progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and is responsible for clearance of the virus and further recovery from the infection. However, the intensified immune and inflammatory response in the development of the disease may lead to more serious and fatal consequences, which indicates that immune indicators have the potential to predict serious cases. Here, we identified both eosinophils and serum IgA as prognostic markers of COVID-19, which sheds light on new research directions and is worthy of further research in the scientific research field as well as clinical application. In this study, the combination of NEU count, EOS count, and IgA level was included in a new predictive model of the severity of COVID-19, which can be used as a powerful tool for better clinical decision-making.


Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/imunologia , Regras de Decisão Clínica , Índice de Gravidade de Doença , Adulto , Idoso , Biomarcadores/sangue , COVID-19/sangue , Tomada de Decisão Clínica/métodos , Progressão da Doença , Eosinófilos/metabolismo , Feminino , Humanos , Imunoglobulina A/sangue , Inflamação/sangue , Inflamação/diagnóstico , Inflamação/virologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Valor Preditivo dos Testes , Prognóstico , Sensibilidade e Especificidade
8.
Sci Rep ; 11(1): 21308, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34716391

RESUMO

The aim of this study was to present and evaluate novel oral vaccines, based on self-amplifying RNA lipid nanparticles (saRNA LNPs), saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum, to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) variants alpha and delta. After invitro evaluation of the oral vaccines on HEK293T/17 cells, we found that saRNA LNPs, saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum could express S-protein at both mRNA and protein levels. In the next step, BALB/c mice were orally vaccinated with saRNA LNPs, saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum at weeks 1 and 3. Importantly, a high titer of IgG and IgA was observed by all of them, sharply in week 6 (P < 0.05). In all study groups, their ratio of IgG2a/IgG1 was upper 1, indicating Th1-biased responses. Wild-type viral neutralization assay showed that the secreted antibodies in vaccinated mice and recovered COVID-19 patients could neutralize SARS-COV-2 variants alpha and delta. After oral administration of oral vaccines, biodistribution assay was done. It was found that all of them had the same biodistribution pattern. The highest concentration of S-protein was seen in the small intestine, followed by the large intestine and liver.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , Lactobacillus plantarum/genética , Lipídeos/química , Nanopartículas/química , SARS-CoV-2/imunologia , Transfecção/métodos , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Administração Oral , Adulto , Animais , COVID-19/sangue , COVID-19/virologia , Vacinas contra COVID-19/farmacocinética , Feminino , Células HEK293 , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Intestino Delgado/metabolismo , Lactobacillus plantarum/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Modelos Animais , Testes de Neutralização , RNA Mensageiro/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Distribuição Tecidual
9.
Front Immunol ; 12: 690322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34497602

RESUMO

A convalescent, non-severe, patient with COVID-19 was enrolled as a hyper-immune plasma voluntary donor by the Immuno-Hematology and Transfusion Unit of the Regina Elena National Cancer Institute in Rome, under the TSUNAMI national study criteria. During a nearly 6-month period (May-October 2020), the patient was closely monitored and underwent four hyperimmune plasma collections. Serum SARS-CoV-2 (anti-S + anti-N) IgG and IgM, anti-S1 IgA, and neutralizing titers (NTs) were measured. Anti-SARS-CoV-2 antibody levels steadily decreased. No correlation was found between anti-S/anti-N IgG and IgM levels and viral NT, measured by either a microneutralization test or the surrogate RBD/ACE2-binding inhibition test. Conversely, NTs directly correlated with anti-S1 IgA levels. Hyperimmune donor plasma, administered to five SARS-CoV-2 patients with persistent, severe COVID-19 symptoms, induced short-term clinical and pathological improvement. Reported data suggest that high NTs can persist longer than expected, thus widening hyperimmune plasma source, availability, and potential use. In vitro RBD/ACE2-binding inhibition test is confirmed as a convenient surrogate index for neutralizing activity and patients' follow-up, suitable for clinical settings where biosafety level 3 facilities are not available. IgA levels may correlate with serum neutralizing activity and represent a further independent index for patient evaluation.


Assuntos
Anticorpos Neutralizantes/administração & dosagem , Anticorpos Antivirais/administração & dosagem , COVID-19/terapia , SARS-CoV-2/imunologia , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Doadores de Sangue , COVID-19/imunologia , COVID-19/virologia , Humanos , Imunização Passiva , Imunoglobulina A/administração & dosagem , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo , Resultado do Tratamento
10.
BMJ Open Respir Res ; 8(1)2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34561239

RESUMO

OBJECTIVE: To determine clinical and ethnodemographic correlates of serological responses against the SARS-CoV-2 spike glycoprotein following mild-to-moderate COVID-19. DESIGN: A retrospective cohort study of healthcare workers who had self-isolated due to COVID-19. SETTING: University Hospitals Birmingham NHS Foundation Trust, UK (UHBFT). PARTICIPANTS: 956 healthcare workers were recruited by open invitation via UHBFT trust email and social media between 27 April 2020 and the 8 June 2020. INTERVENTION: Participants volunteered a venous blood sample that was tested for the presence of anti-SARS-CoV-2 spike glycoprotein antibodies. Results were interpreted in the context of the symptoms of their original illness and ethnodemographic variables. RESULTS: Using an assay that simultaneously measures the combined IgG, IgA and IgM response against the spike glycoprotein (IgGAM), the overall seroprevalence within this cohort was 46.2% (n=442/956). The seroprevalence of immunoglobulin isotypes was 36.3%, 18.7% and 8.1% for IgG, IgA and IgM, respectively. IgGAM identified serological responses in 40.6% (n=52/128) of symptomatic individuals who reported a negative SARS-CoV-2 PCR test. Increasing age, non-white ethnicity and obesity were independently associated with greater IgG antibody response against the spike glycoprotein. Self-reported fever and fatigue were associated with greater IgG and IgA responses against the spike glycoprotein. The combination of fever and/or cough and/or anosmia had a positive predictive value of 92.3% for seropositivity in self-isolating individuals a time when Wuhan strain SARS-CoV-2 was predominant. CONCLUSIONS AND RELEVANCE: Assays employing combined antibody detection demonstrate enhanced seroepidemiological sensitivity and can detect prior viral exposure even when PCR swabs have been negative. We demonstrate an association between known ethnodemographic risk factors associated with mortality from COVID-19 and the magnitude of serological responses in mild-to-moderate disease.


Assuntos
Anticorpos Antivirais/sangue , Formação de Anticorpos , COVID-19 , Adulto , COVID-19/imunologia , Feminino , Pessoal de Saúde , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estudos Soroepidemiológicos , Reino Unido
11.
Sci Rep ; 11(1): 18984, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556736

RESUMO

Serological diagnostic of the severe respiratory distress syndrome coronavirus 2 (SARS-CoV-2) is a valuable tool for the determination of immunity and surveillance of exposure to the virus. In the context of an ongoing pandemic, it is essential to externally validate widely used tests to assure correct diagnostics and epidemiological estimations. We evaluated the performance of the COVID-19 ELISA IgG and the COVID-19 ELISA IgM/A (Vircell, S.L.) against a highly specific and sensitive in-house Luminex immunoassay in a set of samples from pregnant women and cord blood. The agreement between both assays was moderate to high for IgG but low for IgM/A. Considering seropositivity by either IgG and/or IgM/A, the technical performance of the ELISA was highly imbalanced, with 96% sensitivity at the expense of 22% specificity. As for the clinical performance, the negative predictive value reached 87% while the positive predictive value was 51%. Our results stress the need for highly specific and sensitive assays and external validation of diagnostic tests with different sets of samples to avoid the clinical, epidemiological and personal disturbances derived from serological misdiagnosis.


Assuntos
Teste Sorológico para COVID-19/métodos , Ensaio de Imunoadsorção Enzimática/métodos , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , COVID-19/diagnóstico , Teste Sorológico para COVID-19/tendências , Feminino , Sangue Fetal/imunologia , Humanos , Imunoensaio/métodos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pandemias , Gravidez , Sensibilidade e Especificidade , Testes Sorológicos/métodos
12.
Sci Rep ; 11(1): 18285, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521900

RESUMO

Serological assays intended for diagnosis, sero-epidemiologic assessment, and measurement of protective antibody titers upon infection or vaccination are essential for managing the SARS-CoV-2 pandemic. Serological assays measuring the antibody responses against SARS-CoV-2 antigens are readily available. However, some lack appropriate characteristics to accurately measure SARS-CoV-2 antibodies titers and neutralization. We developed an Enzyme-linked Immunosorbent Assay (ELISA) methods for measuring IgG, IgA, and IgM responses to SARS-CoV-2, Spike (S), receptor binding domain (RBD), and nucleocapsid (N) proteins. Performance characteristics of sensitivity and specificity have been defined. ELISA results show positive correlation with microneutralization and Plaque Reduction Neutralization assays with infectious SARS-CoV-2. Our ELISA was used to screen healthcare workers in Louisville, KY during the first wave of the local pandemic in the months of May and July 2020. We found a seropositive rate of approximately 1.4% and 2.3%, respectively. Our analyses demonstrate a broad immune response among individuals and suggest some non-RBD specific S IgG and IgA antibodies neutralize SARS-CoV-2.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/epidemiologia , SARS-CoV-2/imunologia , Área Sob a Curva , COVID-19/sangue , COVID-19/virologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Kentucky/epidemiologia , Pandemias , Fosfoproteínas/imunologia , Curva ROC , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia
13.
Microbiol Spectr ; 9(2): e0073121, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34523985

RESUMO

COVID-19 patients produce circulating and mucosal antibodies. In adults, specific saliva antibodies have been detected. Nonetheless, seroprevalence is routinely investigated, while little attention has been paid to mucosal antibodies. We therefore assessed SARS-CoV-2-specific antibody prevalence in serum and saliva in children in the Netherlands. We assessed SARS-CoV-2 antibody prevalence in serum and saliva of 517 children attending medical services in the Netherlands (irrespective of COVID-19 exposure) from April to October 2020. The prevalence of SARS-CoV-2 spike (S), receptor binding domain (RBD), and nucleocapsid (N)-specific IgG and IgA were evaluated with an exploratory Luminex assay in serum and saliva and with the Wantai SARS-CoV-2 RBD total antibody enzyme-linked immunosorbent assay in serum. Using the Wantai assay, the RBD-specific antibody prevalence in serum was 3.3% (95% confidence interval [CI]. 1.9 to 5.3%). With the Luminex assay, we detected heterogeneity between antibodies for S, RBD, and N antigens, as IgG and IgA prevalence ranged between 3.6 and 4.6% in serum and between 0 and 4.4% in saliva. The Luminex assay also revealed differences between serum and saliva, with SARS-CoV-2-specific IgG present in saliva but not in serum for 1.5 to 2.7% of all children. Using multiple antigen assays, the IgG prevalence for at least two out of three antigens (S, RBD, or N) in serum or saliva can be calculated as 3.8% (95% CI, 2.3 to 5.6%). Our study displays the heterogeneity of the SARS-CoV-2 antibody response in children and emphasizes the additional value of saliva antibody detection and the combined use of different antigens. IMPORTANCE Comprehending humoral immunity to SARS-CoV-2, including in children, is crucial for future public health and vaccine strategies. Others have suggested that mucosal antibody measurement could be an important and more convenient tool to evaluate humoral immunity compared to circulating antibodies. Nonetheless, seroprevalence is routinely investigated, while little attention has been paid to mucosal antibodies. We show the heterogeneity of SARS-CoV-2 antibodies, in terms of both antigen specificity and differences between circulating and mucosal antibodies, emphasizing the additional value of saliva antibody detection next to detection of antibodies in serum.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , SARS-CoV-2/imunologia , Saliva/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , COVID-19/diagnóstico , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Fosfoproteínas/imunologia , Prevalência , Sensibilidade e Especificidade , Estudos Soroepidemiológicos
14.
Front Immunol ; 12: 668974, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539623

RESUMO

Objectives: This aim of this study was to determine whether neutrophil extracellular traps (NETs) are involved in the pathogenesis of IgA vasculitis (IgAV) and investigate whether the circulating NETs levels are associated with disease activity in children. Methods: We performed a case-control study and collected blood samples from 193 children with different stages of IgAV (61 were at the onset stage, 64 at the remission stage, 43 at the active stage, and 25 were undergoing drug withdrawal). A total of 192 healthy children were recruited as controls. Circulating cell free DNA (cf-DNA) was obtained from the plasma and quantified by using the Quant-iT PicoGreen DNA quantification kit. NETs-associated myeloperoxidase-DNA (MPO-DNA), citrullinated-histone H3 (cit-H3), neutrophil elastase (NE), and the deoxyribonuclease I (DNase I) concentrations were measured using enzyme-linked immunosorbent assays. The presence of NETs in the kidney and gastrointestinal tissues of onset and active IgAV patients was determined by multiple immunofluorescence staining in 15 IgAV nephritis patients and 9 IgAV patients without IgAV nephritis, respectively. NETs degradation potency of collected sera samples from IgAV patients were checked in vitro. Relationships between circulating levels of cf-DNA with MPO-DNA, NE, and DNase I and the patients were analyzed. Results: Circulating levels of cf-DNA in onset and active IgAV patients were significantly higher than those in remission and drug withdrawal patients as well as healthy controls. The results were similar for MPO-DNA and NE. The levels of circulating cf-DNA correlated significantly with MPO-DNA, NE and DNase I. A significantly decreased degradation of NETs from the onset and active IgAV patients was observed, but was normal in healthy controls. Furthermore, presence of NETs was also confirmed in all renal and gastrointestinal tissues obtained from the onset and active IgAV patients but not control samples. Conclusions: Our data showed that NETs were released into the circulation of IgAV patients and are involved in the disease activity. The circulating levels of NETs maybe used to assess disease severity in children with IgAV.


Assuntos
Armadilhas Extracelulares/metabolismo , Imunoglobulina A/sangue , Neutrófilos/metabolismo , Biomarcadores/sangue , Estudos de Casos e Controles , Ácidos Nucleicos Livres/sangue , Criança , Pré-Escolar , DNA/sangue , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Humanos , /diagnóstico , Rim/imunologia , Rim/metabolismo , Masculino , Ativação de Neutrófilo , Neutrófilos/imunologia , Índice de Gravidade de Doença
15.
Front Immunol ; 12: 737083, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539673

RESUMO

mRNA-based vaccines effectively induce protective neutralizing antibodies against SARS-CoV-2, the etiological agent of COVID-19. Yet, the kinetics and compositional patterns of vaccine-induced antibody responses to the original strain and emerging variants of concern remain largely unknown. Here we characterized serum antibody classes and subclasses targeting the spike receptor-binding domain of SARS-CoV-2 wild type and α, ß, γ and δ variants in a longitudinal cohort of SARS-CoV-2 naïve and COVID-19 recovered individuals receiving the mRNA-1273 vaccine. We found that mRNA-1273 vaccine recipients developed a SARS-CoV-2-specific antibody response with a subclass profile comparable to that induced by natural infection. Importantly, these antibody responses targeted both wild type SARS-CoV-2 as well as its α, ß, γ and δ variants. Following primary vaccination, individuals with pre-existing immunity showed higher induction of all antibodies but IgG3 compared to SARS-CoV-2-naïve subjects. Unlike naïve individuals, COVID-19 recovered subjects did not mount a recall antibody response upon the second vaccine dose. In these individuals, secondary immunization resulted in a slight reduction of IgG1 against the receptor-binding domain of ß and γ variants. Despite the lack of recall humoral response, vaccinees with pre-existing immunity still showed higher titers of IgG1 and IgA to all variants analyzed compared to fully vaccinated naïve individuals. Our findings indicate that mRNA-1273 vaccine triggered cross-variant antibody responses with distinct profiles in vaccinees with or without pre-existing immunity and suggest that individuals with prior history of SARS-CoV-2 infection may not benefit from the second mRNA vaccine dose with the current standard regimen.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/prevenção & controle , Convalescença , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Estudos Longitudinais , Masculino , Espanha , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação
16.
Mil Med Res ; 8(1): 47, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465396

RESUMO

SARS-CoV-2 is a newly identified member of the coronavirus family that has caused the Coronavirus disease 2019 (COVID-19) pandemic. This rapidly evolving and unrelenting SARS-CoV-2 has disrupted the lives and livelihoods of millions worldwide. As of 23 August 2021, a total of 211,373,303 COVID-19 cases have been confirmed globally with a death toll of 4,424,341. A strong understanding of the infection pathway of SARS-CoV-2, and how our immune system responds to the virus is highly pertinent for guiding the development and improvement of effective treatments. In this review, we discuss the current understanding of neutralising antibodies (NAbs) and their implications in clinical practice. The aspects include the pathophysiology of the immune response, particularly humoral adaptive immunity and the roles of NAbs from B cells in infection clearance. We summarise the onset and persistence of IgA, IgM and IgG antibodies, and we explore their roles in neutralising SARS-CoV-2, their persistence in convalescent individuals, and in reinfection. Furthermore, we also review the applications of neutralising antibodies in the clinical setting-from predictors of disease severity to serological testing to vaccinations, and finally in therapeutics such as convalescent plasma infusion.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , COVID-19/terapia , Imunidade Humoral , SARS-CoV-2/imunologia , Anticorpos Neutralizantes/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , Humanos , Imunização Passiva , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pandemias , Glicoproteína da Espícula de Coronavírus/imunologia
17.
Sci Rep ; 11(1): 17534, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475438

RESUMO

The COVID-19 pandemic threatens indigenous peoples living in suburban areas of large Brazilian cities and has thus far intensified their pre-existing socio-economic inequalities. We evaluated the epidemiological situation of SARS-CoV-2 infection among residents of the biggest urban multiethnic indigenous community of the Amazonas state, Brazil. Blood samples of 280 indigenous people living in the surrounding area of Manaus were tested for the presence of anti-SARS-CoV-2 IgA or IgG antibodies. The risk factors and sociodemographic information were assessed through an epidemiological questionnaire. We found a total positivity rate of 64.64% (95% CI 59.01-70.28) for SARS-CoV-2 infection. IgA and IgG were detected in 55.71% (95% CI 49.89-61.54) and 60.71% (95% CI 54.98-66.45) of the individuals, respectively. Over 80% of positive individuals were positive for both IgA and IgG.No significant difference in positivity rates between genders or age groups was observed. Moreover, the age group ≥ 60 years old showed the highest antibody ratios (IgA mean ratio = 3.080 ± 1.623; IgG mean ratio = 4.221 ± 1.832), while the age groups 13-19 and 20-29 showed the lowest IgA (mean ratio = 2.268 ± 0.919) and IgG ratios (mean ratio = 2.207 ± 1.246), respectively. Individuals leaving the home more frequently were at higher risk of infection (Odds ratio (OD) 2.61; 95% CI 1.00-1.49; p = 0.048). Five or more individuals per household increased fivefold the risk of virus transmission (OR 2.56; 95% CI 1.09-6.01; p = 0.019). The disproportionate dissemination of SARS-CoV-2 infection observed among the study population might be driven by typical cultural behavior and socioeconomic inequalities. Despite the pandemic threat, this population is not being targeted by public policies and appears to be chronically invisible to the Brazilian authorities.


Assuntos
Teste Sorológico para COVID-19 , COVID-19 , Povos Indígenas , Pandemias , SARS-CoV-2/metabolismo , Adolescente , Adulto , Anticorpos Antivirais/sangue , Brasil/epidemiologia , Brasil/etnologia , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/etnologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade
18.
Front Immunol ; 12: 723585, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34489974

RESUMO

Objectives: Our objective was to determine the antibody and cytokine profiles in different COVID-19 patients. Methods: COVID-19 patients with different clinical classifications were enrolled in this study. The level of IgG antibodies, IgA, IgM, IgE, and IgG subclasses targeting N and S proteins were tested using ELISA. Neutralizing antibody titers were determined by using a toxin neutralization assay (TNA) with live SARS-CoV-2. The concentrations of 8 cytokines, including IL-2, IL-4, IL-6, IL-10, CCL2, CXCL10, IFN-γ, and TNF-α, were measured using the Protein Sample Ella-Simple ELISA system. The differences in antibodies and cytokines between severe and moderate patients were compared by t-tests or Mann-Whitney tests. Results: A total of 79 COVID-19 patients, including 49 moderate patients and 30 severe patients, were enrolled. Compared with those in moderate patients, neutralizing antibody and IgG-S antibody titers in severe patients were significantly higher. The concentration of IgG-N antibody was significantly higher than that of IgG-S antibody in COVID-19 patients. There was a significant difference in the distribution of IgG subclass antibodies between moderate patients and severe patients. The positive ratio of anti-S protein IgG3 is significantly more than anti-N protein IgG3, while the anti-S protein IgG4 positive rate is significantly less than the anti-N protein IgG4 positive rate. IL-2 was lower in COVID-19 patients than in healthy individuals, while IL-4, IL-6, CCL2, IFN-γ, and TNF-α were higher in COVID-19 patients than in healthy individuals. IL-6 was significantly higher in severe patients than in moderate patients. The antibody level of anti-S protein was positively correlated with the titer of neutralizing antibody, but there was no relationship between cytokines and neutralizing antibody. Conclusions: Our findings show the severe COVID-19 patients' antibody levels were stronger than those of moderate patients, and a cytokine storm is associated with COVID-19 severity. There was a difference in immunoglobulin type between anti-S protein antibodies and anti-N protein antibodies in COVID-19 patients. And clarified the value of the profile in critical prevention.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/imunologia , Citocinas/sangue , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , COVID-19/classificação , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologia
19.
Indian J Pathol Microbiol ; 64(3): 484-489, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34341258

RESUMO

Background and Aims: An early correct diagnosis of celiac disease (CD) is fundamental to reversal of symptoms and prevention of complications in pediatric patients. Our aim was to evaluate the role of duodenal bulb biopsy by studying the degree of mucosal damage in the duodenal bulb (D1) and second part of the duodenum (D2) and correlating the findings with serum IgA anti-tTG levels. Settings and Design: Pediatric patients (age <18 years) with clinical suspicion of CD and positive IgA anti-tTG titers were consecutively enrolled over a period of one year. Demographic variables, anthropometry, clinical history, laboratory values and endoscopic findings were studied. Endoscopic biopsies obtained from D1 and D2 were evaluated and assigned histopathologic grades that were correlated with serology. Statistical Analysis Used: Descriptive statistics were employed. Results: A total of 37 clinically suspected cases of pediatric CD were studied. The mean age was 6.7 years and the M:F ratio was 1:1.3. Thirty-two (32) children had varying degrees of growth impairment. Eight (8) children had only extra-intestinal symptoms. Thirty (30) children were anemic, hypoalbuminemia was seen in five (5) children while transaminitis was seen in two (2) children. IgA anti-tTG >300 U/ml was associated with Marsh-Oberhuber Grade 3 morphology at atleast one site. Conclusions: Low positive serology values should be confirmed by histopathology. Biopsies should be taken even in the absence of endoscopic abnormality. Additional D1 biopsies placed in a separate container can increase the diagnostic yield.


Assuntos
Doença Celíaca/complicações , Doença Celíaca/imunologia , Duodeno/patologia , Imunoglobulina A/sangue , Abdome/patologia , Adolescente , Biópsia , Doença Celíaca/diagnóstico , Doença Celíaca/patologia , Criança , Pré-Escolar , Duodeno/anatomia & histologia , Feminino , Humanos , Mucosa Intestinal/patologia , Masculino
20.
Clin Chem Lab Med ; 59(11): 1878-1884, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34348424

RESUMO

OBJECTIVES: Numerous analytical systems, rapidly made available on the market throughout the SARS-CoV-2 pandemic, aim to detect COVID-19, and to continuously update and improve the same systems. Medical laboratory professionals have also developed in-house analytical procedures in order to satisfy the enormous volume of requests for tests. These developments have highlighted the need control the analytical procedures used in order to guarantee patient safety. The External Quality Assessment (EQA) Scheme, an important quality assurance tool, aims to guarantee high standard performance for laboratory and analytical procedures. The aim of the present study was to report on the results collected in an experimental EQA scheme for the serological diagnosis of SARS-CoV-2. METHODS: All qualitative results collected in the different EQA surveys were summarized in order to identify the percentage of laboratory results in relation to typology of antibodies, results and samples. RESULTS: A total of 4,867 data sets were collected. The analysis of EQA data made, demonstrates a better agreement among laboratories results for total Ig than single immunoglobulins (IgG, IgM, IgA) in the case samples positive for SARS-CoV-2, and a wide divergence between IgM results for positive samples (only 34.9% were correct). Results for negative controls and specificity controls demonstrated a better overall agreement than results for positive samples. CONCLUSIONS: Working in collaboration with the IVD manufacturers, laboratory professionals must strive to achieve harmonization of results, and to develop well-defined protocols complying with the ISO 15189 requirements.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/diagnóstico , SARS-CoV-2/imunologia , Testes Sorológicos/métodos , Anticorpos Antivirais/sangue , COVID-19/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/metabolismo , Imunoglobulina G/sangue , Imunoglobulina G/metabolismo , Imunoglobulina M/sangue , Imunoglobulina M/metabolismo , Projetos Piloto , Garantia da Qualidade dos Cuidados de Saúde , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença
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