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1.
Vet Res ; 52(1): 2, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397461

RESUMO

Porcine epidemic diarrhea (PED) is a coronavirus disease characterized by the rapid spread of severe diarrhea among pigs. PED virus (PEDV) infects and replicates mainly in the epithelial cells of the duodenum, jejunum, ileum and colon. Serum or mucosal IgA antibody levels have been used to predict both vaccine efficacy and the level of protective immunity to enteric infectious diseases in individuals or herds. Details of the B-cell immune response upon PEDV infection, such as the systemic and mucosal PEDV IgA antibody response, the distribution of IgA antibody-secreting cells (ASCs), and their role in virus clearance are not yet clear. In this experimental infection study, we observed similar fluctuations in PEDV IgA antibody levels in serum and intestinal contents of the upper and lower jejunum and ileum, but not fecal samples, over the 4-week experimental course. ASCs that actively secrete PEDV IgA antibody without in vitro stimulation were distributed mainly in the upper jejunum, whereas memory B cells that showed enhanced PEDV IgA antibody production upon in vitro stimulation were observed in mesenteric lymph nodes and the ileum. Our findings will contribute to the development of effective vaccines and diagnostic methods for PEDV.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína , Doenças dos Suínos/virologia , Animais , Chlorocebus aethiops , Infecções por Coronavirus/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Fezes/química , Fezes/virologia , Imunoglobulina A/sangue , Imunoglobulina A/química , Imunoglobulina A/metabolismo , Imunoglobulina G/sangue , Mucosa Intestinal/metabolismo , RNA Viral , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/imunologia , Células Vero
2.
J Infect Dis ; 223(1): 62-71, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33175145

RESUMO

BACKGROUND: At the COVID-19 spring 2020 pandemic peak in Spain, prevalence of SARS-CoV-2 infection in a cohort of 578 randomly selected health care workers (HCWs) from Hospital Clínic de Barcelona was 11.2%. METHODS: A follow-up survey 1 month later (April-May 2020) measured infection by rRT-PCR and IgM, IgA, and IgG to the receptor-binding domain of the spike protein by Luminex. Antibody kinetics, including IgG subclasses, was assessed until month 3. RESULTS: At month 1, the prevalence of infection measured by rRT-PCR and serology was 14.9% (84/565) and seroprevalence 14.5% (82/565). We found 25 (5%) new infections in 501 participants without previous evidence of infection. IgM, IgG, and IgA levels declined in 3 months (antibody decay rates 0.15 [95% CI, .11-.19], 0.66 [95% CI, .54-.82], and 0.12 [95% CI, .09-.16], respectively), and 68.33% of HCWs had seroreverted for IgM, 3.08% for IgG, and 24.29% for IgA. The most frequent subclass responses were IgG1 (highest levels) and IgG2, followed by IgG3, and only IgA1 but no IgA2 was detected. CONCLUSIONS: Continuous and improved surveillance of SARS-CoV-2 infections in HCWs remains critical, particularly in high-risk groups. The observed fast decay of IgA and IgM levels has implications for seroprevalence studies using these isotypes.


Assuntos
Anticorpos Antivirais/sangue , Pessoal de Saúde , Adulto , Estudos Transversais , Feminino , Seguimentos , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Cinética , Masculino , Pessoa de Meia-Idade , Soroconversão , Estudos Soroepidemiológicos , Espanha/epidemiologia
3.
J Med Virol ; 93(2): 803-811, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32667733

RESUMO

The development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests is massive. The external validation of their performance is needed before use in clinical routine practice. Our study aims at assessing the analytical and clinical performance of two enzyme-linked immunosorbent assay tests detecting antibodies directed against the virus nucleocapsid protein: The NovaLisa SARS-CoV-2 immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) test (NovaTec) allowing a separate detection of each antibody and the Platelia SARS-CoV-2 Total Ab test (Bio-Rad) detecting total antibodies (IgM, IgA, and IgG). Two-hundred and eight coronavirus disease 2019 samples from 48 quantitative reverse transcription-polymerase chain reaction (RT-qPCR) confirmed patients were used to perform the sensitivity analysis. Non-SARS-CoV-2 sera (n = 79) with a potential cross-reaction to SARS-CoV-2 immunoassays were included in the specificity analysis. In addition, using receiver operator characteristic curves, adapted cut-off for improvement of the performances were proposed. The kinetics of these antibodies was also assessed over 8 weeks. Two weeks after the RT-qPCR positive detection, the NovaLisa test shows a sensitivity and specificity of 94.9% (95% confidence interval [CI]: 83.1%-98.6%) and 96.2% (95% CI: 89.4%-98.7%) for IgG, of 89.7% (95% CI: 76.4%-95.9%) and 98.7% (95% CI: 93.2%-98.8%) for IgA, and of 48.7% (95% CI: 33.9%-63.8%) and 98.7% (95% CI: 93.2%-99.8%) for IgM. With the Platelia system, the specificity and sensitivity were 97.4% (95% CI: 92.1%-99.7%) and 94.9% (95% CI: 87.7%-98.0%) for total antibodies using the adapted cut-offs. The NovaLisa and the Platelia tests have satisfactory analytical performances. The clinical performances are excellent for IgG, IgA, and total antibodies especially if the cut-off is optimized.


Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/normas , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , /imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , /mortalidade , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Análise de Sobrevida
4.
J Med Virol ; 93(2): 1154-1157, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32710647

RESUMO

To verify reliability of antibody detection and investigate population immunity to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) in the local Chinese population. A cross-sectional study was conducted in Shenzhen to detect anti-coronavirus antibodies including, immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA). In the COVID-19 group, nine patients were enrolled after diagnosis. In the control group, 1589 individuals without clinical symptoms (cough, fever, and fatigue) and returning from outside Shenzhen were enrolled. The first study enrollment occurred at the end of February 2020; the final study visit was 18 March 2020. In the COVID-19 group, the seven of nine patients were positive for IgM, IgG, and IgA. Meanwhile, six of the 1589 healthy individuals were found to be weakly positive for IgG. According to SARS-CoV-2 nucleic acid tests, the six individuals were all negative. Strong supplemental support for clinical information can be provided by antibody detection, especially for IgA. According to comparison with overseas reports, the infection rate of the Chinese population outside Shenzhen, China, is significantly low, so most of the population in China is still susceptible. Hence, social distancing measures are still inevitable until a vaccine is developed successfully.


Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , China/epidemiologia , Estudos Transversais , Feminino , Voluntários Saudáveis , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Adulto Jovem
5.
Biosens Bioelectron ; 172: 112765, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33126179

RESUMO

To accurately diagnose COVID-19 infection and its time-dependent progression, the rapid, sensitive, and noninvasive determination of immunoglobulins A specific to SARS-CoV-2 (IgA) in saliva and serum is needed to complement tests that detect immunoglobulins G and M. We have developed a dual optical/chemiluminescence format of a lateral flow immunoassay (LFIA) immunosensor for IgA in serum and saliva. A recombinant nucleocapsid antigen specifically captures SARS-CoV-2 antibodies in patient specimens. A labelled anti-human IgA reveals the bound IgA fraction. A dual colorimetric and chemiluminescence detection enables the affordable and ultrasensitive determination of IgA to SARS-CoV-2. Specifically, a simple smartphone-camera-based device measures the colour signal provided by nanogold-labelled anti-human IgA. For the ultrasensitive chemiluminescence transduction, we used a contact imaging portable device based on cooled CCD, and measured the light signal resulting from the reaction of the HRP-labelled anti-human IgA with a H2O2/luminol/enhancers substrate. A total of 25 serum and 9 saliva samples from infected and/or recovered individuals were analysed by the colorimetric LFIA, which was sensitive and reproducible enough for the semi-quantification of IgA in subjects with a strong serological response and in the early stage of COVID-19 infection. Switching to CL detection, the same immunosensor exhibited higher detection capability, revealing the presence of salivary IgA in infected individuals. For the patients included in the study (n = 4), the level of salivary IgA correlated with the time elapsed from diagnosis and with the severity of the disease. This IgA-LFIA immunosensor could be useful for noninvasively monitoring early immune responses to COVID-19 and for investigating the diagnostic/prognostic utility of salivary IgA in the context of large-scale screening to assess the efficacy of SARS-CoV-2 vaccines.


Assuntos
Anticorpos Antivirais/análise , Técnicas Biossensoriais/instrumentação , /diagnóstico , /imunologia , Especificidade de Anticorpos , Técnicas Biossensoriais/métodos , /virologia , Colorimetria/instrumentação , Colorimetria/métodos , Desenho de Equipamento , Humanos , Imunoglobulina A/sangue , Imunoglobulina A Secretora/análise , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Saliva/imunologia
6.
J Virol Methods ; 288: 114025, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33227340

RESUMO

Large-scale serosurveillance of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) will only be possible if serological tests are sufficiently reliable, rapid and affordable. Many assays are either labour-intensive and require specialised facilities (e.g. virus neutralization assays), or are expensive with suboptimal specificity (e.g. commercial ELISAs and RDTs). Bead-based assays offer a cost-effective alternative and allow for multiplexing to test for antibodies against multiple antigens and against other pathogens. Here, we compare the performance of spike (S) and nucleocapsid (NP) antigens for the detection of SARS-CoV-2 specific IgG, IgM and IgA antibodies in a panel of sera that includes recent (up to six weeks after symptom onset, severe n = 44; and mild cases n = 52) and old infections (five months after symptom onset, mild n = 104), using a Luminex-bead based assay and comparison to a virus neutralization test. While we show that neutralizing antibody levels are significantly lower in mild than in severe cases, we demonstrate that a combination of the recombinant nucleocapsid protein (NP) and receptor-binding domain (RBD) results in highly specific (99 %) IgG antibody detection five months after infection in 96 % of cases. Although most severe Covid-19 cases developed a clear IgM and IgA response, titers fell below the detection threshold in more than 20 % of mild cases in our bead-based assay. In conclusion, our data supports the use of RBD and NP for the development of SARS-CoV-2 serological IgG bead-based assays.


Assuntos
Anticorpos Antivirais/imunologia , Imunoensaio , Proteínas do Nucleocapsídeo/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Neutralizantes , /virologia , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Testes de Neutralização , Curva ROC
7.
Front Immunol ; 11: 596684, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362779

RESUMO

Background: The current outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses an unprecedented health crisis. The most common chronic illness among patients infected with SARS-CoV-2 is hypertension. Immune dysregulation plays an important role in SARS-CoV-2 infection and in the development of hypertension; however, the dynamic immunological characteristics of COVID-19 patients with hypertension remain largely unclear. Methods: In total, 258 hypertensive patients infected with SARS-CoV-2 were included in this study. CD38+HLA-DR+ and CD38+PD-1+ CD8+ T cells, IFNγ+CD4+ and IFNγ+CD8+ T cells, the titers of IgG, IgM, and IgA against SARS-CoV-2 spike protein, and SARS-CoV-2 throat viral loads were measured weekly over 4 weeks after the onset of symptoms. Clinical outcomes were also monitored. Findings: CD4+ T lymphopenia was observed in 100% of the severe and critical cases. Compared with the surviving patients, the patients with fatal outcomes exhibited high and prolonged expression of CD38+HLA-DR+ and CD38+PD-1+ on CD8+ T cells, low expression of SARS-CoV-2-specific IFNγ+CD4+ and IFNγ+CD8+ T cells, low titers of IgG, IgM, and IgA against SARS-CoV-2 spike protein, and high SARS-CoV-2 viral load during the illness. In the surviving patients, the viral load was significantly inversely correlated with SARS-CoV-2-specific IFNγ+CD8+and IFNγ+CD4+ T cells, IgG, IgM, and IgA. Interpretation: T lymphopenia is common in critical or severe COVID-19 cases with hypertension. Prolonged activation and exhaustion of CD8+ T cells were associated with severe disease. The delayed SARS-CoV-2-specific antibody responses may be insufficient for overcoming severe SARS-CoV-2 infection in the absence of SARS-CoV-2-specific cellular responses.


Assuntos
Anticorpos Antivirais/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Hipertensão/patologia , /imunologia , /patologia , Estado Terminal , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Interferon gama/sangue , Linfopenia/sangue , Estudos Retrospectivos , Glicoproteína da Espícula de Coronavírus/imunologia , Carga Viral
8.
Cells ; 9(12)2020 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322797

RESUMO

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leads to an adaptive immune response in the host and the formation of anti-SARS-CoV-2 specific antibodies. While IgG responses against SARS-CoV-2 have been characterized quite well, less is known about IgA. IgA2 activates immune cells and induces inflammation and neutrophil extracellular trap (NET) formation which may contribute to organ injury and fatal outcome in SARS-CoV-2-infected patients. SARS-CoV-2 spike protein specific antibody levels were measured in plasma samples of 15 noninfected controls and 82 SARS-CoV-2-infected patients with no or mild symptoms, moderate symptoms (hospitalization) or severe disease (intensive care unit, ICU). Antibody levels were compared to levels of C-reactive protein (CRP) and circulating extracellular DNA (ecDNA) as markers for general inflammation and NET formation, respectively. While levels of SARS-CoV-2-specific IgG were similar in all patient groups, IgA2 antibodies were restricted to severe disease and showed the strongest discrimination between nonfatal and fatal outcome in patients with severe SARS-CoV-2 infection. While anti-SARS-CoV-2 IgG and IgA2 levels correlated with CRP levels in severely diseased patients, only anti-SARS-CoV-2 IgA2 correlated with ecDNA. These data suggest that the formation of anti-SARS-CoV-2 IgA2 during SARS-CoV-2 infection is a marker for more severe disease related to NET formation and poor outcome.


Assuntos
Anticorpos Antivirais/sangue , Armadilhas Extracelulares/imunologia , Imunoglobulina A/sangue , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa/imunologia , Estudos de Casos e Controles , Ácidos Nucleicos Livres/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto Jovem
9.
Viruses ; 12(12)2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33260809

RESUMO

The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , /imunologia , Adulto , /patologia , /imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Estudos Longitudinais , Masculino , Faringe/virologia , Fosfoproteínas/imunologia , RNA Viral/genética , RNA Viral/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/imunologia
10.
Science ; 370(6522): 1339-1343, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33159009

RESUMO

Zoonotic introduction of novel coronaviruses may encounter preexisting immunity in humans. Using diverse assays for antibodies recognizing SARS-CoV-2 proteins, we detected preexisting humoral immunity. SARS-CoV-2 spike glycoprotein (S)-reactive antibodies were detectable using a flow cytometry-based method in SARS-CoV-2-uninfected individuals and were particularly prevalent in children and adolescents. They were predominantly of the immunoglobulin G (IgG) class and targeted the S2 subunit. By contrast, SARS-CoV-2 infection induced higher titers of SARS-CoV-2 S-reactive IgG antibodies targeting both the S1 and S2 subunits, and concomitant IgM and IgA antibodies, lasting throughout the observation period. SARS-CoV-2-uninfected donor sera exhibited specific neutralizing activity against SARS-CoV-2 and SARS-CoV-2 S pseudotypes. Distinguishing preexisting and de novo immunity will be critical for our understanding of susceptibility to and the natural course of SARS-CoV-2 infection.


Assuntos
Anticorpos Antivirais/sangue , Imunidade Humoral , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Animais , Mapeamento de Epitopos , Feminino , Células HEK293 , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/química , /imunologia , Adulto Jovem
11.
PLoS One ; 15(11): e0242598, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253290

RESUMO

Detection of IgA antibody against Mycobacterium avium complex (MAC) glycopeptidolipid (GPL) has recently been shown to improve the diagnosis of MAC pulmonary disease but has yet to be tested in disseminated Non-tuberculous mycobacteria (NTM) infection. In this study, we address the diagnostic efficacies of an anti-GPL-core ELISA kit in disseminated lymphadenopathy patients positive for NTM culture and anti-IFN-γ autoantibodies. The study was conducted in a tertiary referral center in northeastern Thailand and patients with NTM, tuberculosis, melioidosis, and control subjects were enrolled. Plasma immunoglobulin A (IgA) and G (IgG) antibodies against GPL-core were detected in the subjects and the specificity and sensitivity of the assay was assessed. Anti-GPL-core IgA and IgG levels were significantly higher in NTM patients than other groups (p < 0.0001). Diagnostic efficacy for NTM patients using anti-GPL-core IgA cut-off value of 0.352 U/ml showed good sensitivity (91.18%) and intermediate specificity (70.15%). Using a cut-off value of 4.140 AU/ml for anti-GPL-core IgG showed the same sensitivity (91.18%) with increased specificity (89.55%) and an 81.58% positive predictive value. Most patients with moderate levels (4.140-7.955 AU/ml) of anti-GPL-core IgG had rapidly growing mycobacteria (RGM) infection. Taken together, the detection of anti-GPL-core antibodies could provide a novel option for the diagnosis and management of disseminated NTM infected patients.


Assuntos
Anticorpos Antibacterianos/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Complexo Mycobacterium avium/imunologia , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Feminino , Glicopeptídeos/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Complexo Mycobacterium avium/isolamento & purificação , Infecção por Mycobacterium avium-intracellulare/sangue , Infecção por Mycobacterium avium-intracellulare/epidemiologia , Infecção por Mycobacterium avium-intracellulare/imunologia , Tailândia/epidemiologia , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-33139618

RESUMO

Systemic presence of arthritis autoantibodies (AAb) is specific for rheumatoid arthritis (RA). AAb initiation might be triggered by chronic mucosal inflammation, such as in inflammatory bowel disease (IBD). We assessed the prevalence of anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF) in ulcerative colitis (UC) and Crohn's disease (CD) patients, with regard to the prevalence of joint complaints in AAb+ versus AAb- IBD patients. RA patients and healthy subjects (HC) served as controls. Serum was collected from 226 UC, 165 CD and 86 RA patients, and 36 HCs. One-hundred-and-ten UC (48.7%) and 76 CD (46.1%) patients were seropositive for at least one autoantibody, compared to 4 (13.9%) HCs and 81 (94.2%) RA patients. Eighty-three (37%) UC and 52 (32%) CD patients were seropositive for the anti-cyclic citrullinated protein antibody (anti-CCP2) of the immunoglobulin A type (IgA anti-CCP2), compared to 1 (2.8%) HC and 64 (74%) RA patients. RF of the immunoglobulin G type (IgG RF) and IgA RF seropositivity in UC and CD patients was comparable to HCs and low compared to RA patients. Arthralgia was reported by 34 (18.7%) UC and 50 (33.1%) CD patients, but presence of arthralgia was not increased in AAb+ patients. AAbs are frequently present in IBD patients, supporting the hypothesis that inflammation of intestinal mucosa induces low systemic levels of ACPA.


Assuntos
Anticorpos Anti-Proteína Citrulinada/metabolismo , Artrite Reumatoide/sangue , Autoanticorpos/imunologia , Colite Ulcerativa/sangue , Doença de Crohn/sangue , Fator Reumatoide/imunologia , Adulto , Idoso , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Estudos de Casos e Controles , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/imunologia , Doença de Crohn/diagnóstico , Doença de Crohn/epidemiologia , Doença de Crohn/imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Doenças Inflamatórias Intestinais/sangue , Pessoa de Meia-Idade , Prevalência , Fator Reumatoide/sangue
13.
J Clin Virol ; 133: 104681, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33160178

RESUMO

In 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic. Disease diagnosis, appropriate clinical management and infection control are all important factors in controlling the spread of SARS-CoV-2. The QIAreach™ Anti-SARS-CoV-2 Total Test (Anti-CoV2) is a rapid, qualitative serological test, using proprietary nanoparticle fluorescence technology to detect total antibody (IgA, IgM, and IgG) against SARS-CoV-2. Here we report the results of the US Food and Drug Administration (FDA) clinical agreement study. Thirty positive plasma or serum samples were taken from consenting individuals with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection ≥14 days from symptom onset. Seventy-five samples from before the believed circulation of SARS-CoV-2 (November 1, 2019) were used to assess specificity. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated along with the corresponding exact two-sided 95 % confidence intervals (CI) using an FDA Emergency Use Authorized PCR test as the reference method. Anti-CoV2 was shown to have 100 % sensitivity (PPA; 95 % CI 88.4-100 %) and 100 % specificity (NPA; 95 % CI 95.2-100 %). Against 157 pre-pandemic samples, no cross-reactivity was observed with seasonal coronaviruses or other respiratory pathogens tested. Additionally, no interference was observed when samples were spiked with: conjugated bilirubin 0.4 mg/ml; unconjugated bilirubin 0.4 mg/ml; hemoglobin 5 mg/ml; prednisolone 0.12 mg/ml; triglycerides 15 mg/ml. In conclusion, Anti-CoV2 provides accurate qualitative detection of total antibodies against SARS-CoV-2.


Assuntos
Anticorpos Antivirais/sangue , /diagnóstico , Fluorescência , Nanopartículas , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Sensibilidade e Especificidade , Estados Unidos , United States Food and Drug Administration/legislação & jurisprudência
14.
PLoS One ; 15(11): e0241164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33227020

RESUMO

The COVID-19 pandemic and the fast global spread of the disease resulted in unprecedented decline in world trade and travel. A critical priority is, therefore, to quickly develop serological diagnostic capacity and identify individuals with past exposure to SARS-CoV-2. In this study serum samples obtained from 309 persons infected by SARS-CoV-2 and 324 of healthy, uninfected individuals as well as serum from 7 COVID-19 patients with 4-7 samples each ranging between 1-92 days post first positive PCR were tested by an "in house" ELISA which detects IgM, IgA and IgG antibodies against the receptor binding domain (RBD) of SARS-CoV-2. Sensitivity of 47%, 80% and 88% and specificity of 100%, 98% and 98% in detection of IgM, IgA and IgG antibodies, respectively, were observed. IgG antibody levels against the RBD were demonstrated to be up regulated between 1-7 days after COVID-19 detection, earlier than both IgM and IgA antibodies. Study of the antibody kinetics of seven COVID 19 patients revealed that while IgG levels are high and maintained for at least 3 months, IgM and IgA levels decline after a 35-50 days following infection. Altogether, these results highlight the usefulness of the RBD based ELISA, which is both easy and cheap to prepare, to identify COVID-19 patients even at the acute phase. Most importantly our results demonstrate that measuring IgG levels alone is both sufficient and necessary to diagnose past exposure to SARS-CoV-2.


Assuntos
Anticorpos Antivirais/imunologia , /diagnóstico , Imunoglobulina G/imunologia , Pandemias , Domínios Proteicos/imunologia , /imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , /virologia , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Adulto Jovem
15.
PLoS One ; 15(11): e0242917, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33232382

RESUMO

BACKGROUND: The viral load and tissue distribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain important questions. The current study investigated SARS-CoV-2 viral load, biodistribution and anti-SARS-CoV-2 antibody formation in patients suffering from severe corona virus disease 2019 (COVID-19) induced acute respiratory distress syndrome (ARDS). METHODS: This is a retrospective single-center study in 23 patients with COVID-19-induced ARDS. Data were collected within routine intensive care. SARS-CoV-2 viral load was assessed via reverse transcription quantitative polymerase chain reaction (RT-qPCR). Overall, 478 virology samples were taken. Anti-SARS-CoV-2-Spike-receptor binding domain (RBD) antibody detection of blood samples was performed with an enzyme-linked immunosorbent assay. RESULTS: Most patients (91%) suffered from severe ARDS during ICU treatment with a 30-day mortality of 30%. None of the patients received antiviral treatment. Tracheal aspirates tested positive for SARS-CoV-2 in 100% of the cases, oropharyngeal swabs only in 77%. Blood samples were positive in 26% of the patients. No difference of viral load was found in tracheal or blood samples with regard to 30-day survival or disease severity. SARS-CoV-2 was never found in dialysate. Serologic testing revealed significantly lower concentrations of SARS-CoV-2 neutralizing IgM and IgA antibodies in survivors compared to non-survivors (p = 0.009). CONCLUSIONS: COVID-19 induced ARDS is accompanied by a high viral load of SARS-CoV-2 in tracheal aspirates, which remained detectable in the majority throughout intensive care treatment. Remarkably, SARS-CoV-2 RNA was never detected in dialysate even in patients with RNAemia. Viral load or the buildup of neutralizing antibodies was not associated with 30-day survival or disease severity.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , /complicações , /etiologia , /imunologia , Idoso , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , /virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Alemanha/epidemiologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Domínios Proteicos/imunologia , RNA Viral/genética , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glicoproteína da Espícula de Coronavírus/imunologia , Carga Viral/genética
16.
Front Immunol ; 11: 584241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33178218

RESUMO

Background: Critically ill patients with coronavirus disease 2019 (COVID-19) have a profound hypercoagulable state and often develop coagulopathy which leads to organ failure and death. Because of a prolonged activated partial-thromboplastin time (aPTT), a relationship with anti-phospholipid antibodies (aPLs) has been proposed, but results are controversial. Functional assays for aPL (i.e., lupus anticoagulant) can be influenced by concomitant anticoagulation and/or high levels of C reactive protein. The presence of anti-cardiolipin (aCL), anti-beta2-glycoprotein I (anti-ß2GPI), and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies was not investigated systematically. Epitope specificity of anti-ß2GPI antibodies was not reported. Objective: To evaluate the prevalence and the clinical association of aPL in a large cohort of COVID-19 patients, and to characterize the epitope specificity of anti-ß2GPI antibodies. Methods: ELISA and chemiluminescence assays were used to test 122 sera of patients suffering from severe COVID-19. Of them, 16 displayed major thrombotic events. Results: Anti-ß2GPI IgG/IgA/IgM was the most frequent in 15.6/6.6/9.0% of patients, while aCL IgG/IgM was detected in 5.7/6.6% by ELISA. Comparable values were found by chemiluminescence. aPS/PT IgG/IgM were detectable in 2.5 and 9.8% by ELISA. No association between thrombosis and aPL was found. Reactivity against domain 1 and 4-5 of ß2GPI was limited to 3/58 (5.2%) tested sera for each domain and did not correlate with aCL/anti-ß2GPI nor with thrombosis. Conclusions: aPL show a low prevalence in COVID-19 patients and are not associated with major thrombotic events. aPL in COVID-19 patients are mainly directed against ß2GPI but display an epitope specificity different from antibodies in antiphospholipid syndrome.


Assuntos
Anticorpos Anticardiolipina/imunologia , Síndrome Antifosfolipídica/imunologia , /imunologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Anticardiolipina/sangue , Síndrome Antifosfolipídica/sangue , /virologia , Estado Terminal , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Medições Luminescentes , Masculino , Pessoa de Meia-Idade , Fosfatidilserinas/imunologia , Protrombina/imunologia , Trombose/imunologia , beta 2-Glicoproteína I/imunologia
17.
Nat Commun ; 11(1): 5703, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177504

RESUMO

Compared to adults, children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have predominantly mild or asymptomatic infections, but the underlying immunological differences remain unclear. Here, we describe clinical features, virology, longitudinal cellular, and cytokine immune profile, SARS-CoV-2-specific serology and salivary antibody responses in a family of two parents with PCR-confirmed symptomatic SARS-CoV-2 infection and their three children, who tested repeatedly SARS-CoV-2 PCR negative. Cellular immune profiles and cytokine responses of all children are similar to their parents at all timepoints. All family members have salivary anti-SARS-CoV-2 antibodies detected, predominantly IgA, that coincide with symptom resolution in 3 of 4 symptomatic members. Plasma from both parents and one child have IgG antibody against the S1 protein and virus-neutralizing activity detected. Using a systems serology approach, we demonstrate higher levels of SARS-CoV-2-specific antibody features of these family members compared to healthy controls. These data indicate that children can mount an immune response to SARS-CoV-2 without virological confirmation of infection, raising the possibility that immunity in children can prevent the establishment of SARS-CoV-2 infection. Relying on routine virological and serological testing may not identify exposed children, with implications for epidemiological and clinical studies across the life-span.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/transmissão , Citocinas/sangue , Pneumonia Viral/transmissão , Saliva/imunologia , Adulto , Anticorpos Antivirais/imunologia , Austrália , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Criança , Pré-Escolar , Infecções por Coronavirus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Pandemias , Pais , Pneumonia Viral/imunologia , Testes Sorológicos , Glicoproteína da Espícula de Coronavírus/imunologia
18.
PLoS One ; 15(11): e0237828, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33137138

RESUMO

There is an urgent need for an accurate antibody test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have developed 3 ELISA methods, trimer spike IgA, trimer spike IgG, and nucleocapsid IgG, for detecting anti-SARS-CoV-2 antibodies. We evaluated their performance along with four commercial ELISAs, EDI™ Novel Coronavirus COVID-19 ELISA IgG and IgM, Euroimmun Anti-SARS-CoV-2 ELISA IgG and IgA, and one lateral flow assay, DPP® COVID-19 IgM/IgG System (Chembio). Both sensitivity and specificity were evaluated and the probable causes of false-positive reactions were determined. The assays were evaluated using 300 pre-epidemic samples and 100 PCR-confirmed COVID-19 samples. The sensitivities and specificities of the assays were as follows: 90%/100% (in-house trimer spike IgA), 90%/99.3% (in-house trimer spike IgG), 89%/98.3% (in-house nucleocapsid IgG), 73.7%/100% (EDI nucleocapsid IgM), 84.5%/95.1% (EDI nucleocapsid IgG), 95%/93.7% (Euroimmun S1 IgA), 82.8%/99.7% (Euroimmun S1 IgG), 82.0%/91.7% (Chembio nucleocapsid IgM), 92%/93.3% (Chembio nucleocapsid IgG). The presumed causes of false positive results from pre-epidemic samples in commercial and in-house assays were mixed. In some cases, assays lacked reproducibility. In other cases, reactivity was abrogated by competitive inhibition (spiking the sample with the same antigen that was used for coating ELISAs prior to performing the assay), suggesting positive reaction could be attributed to the presence of antibodies against these antigens. In other cases, reactivity was consistently detected but not abrogated by the spiking, suggesting positive reaction was not attributed to the presence of antibodies against these antigens. Overall, there was wide variability in assay performance using our samples, with in-house tests exhibiting the highest combined sensitivity and specificity. The causes of "false positivity" in pre-epidemic samples may be due to plasma antibodies apparently reacting with the corresponding antigen, or spurious reactivity may be directed against non-specific components in the assay system. Identification of these targets will be essential to improving assay performance.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/metabolismo , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Nucleocapsídeo/imunologia , Pneumonia Viral/diagnóstico , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Curva ROC , Reprodutibilidade dos Testes
19.
J Clin Microbiol ; 59(1)2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33067270

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of an ongoing pandemic that has infected over 36 million and killed over 1 million people. Informed implementation of government public health policies depends on accurate data on SARS-CoV-2 immunity at a population scale. We hypothesized that detection of SARS-CoV-2 salivary antibodies could serve as a noninvasive alternative to serological testing for monitoring of SARS-CoV-2 infection and seropositivity at a population scale. We developed a multiplex SARS-CoV-2 antibody immunoassay based on Luminex technology that comprised 12 CoV antigens, mostly derived from SARS-CoV-2 nucleocapsid (N) and spike (S). Saliva and sera collected from confirmed coronavirus disease 2019 (COVID-19) cases and from the pre-COVID-19 era were tested for IgG, IgA, and IgM to the antigen panel. Matched saliva and serum IgG responses (n = 28) were significantly correlated. The salivary anti-N IgG response resulted in the highest sensitivity (100%), exhibiting a positive response in 24/24 reverse transcription-PCR (RT-PCR)-confirmed COVID-19 cases sampled at >14 days post-symptom onset (DPSO), whereas the salivary anti-receptor binding domain (RBD) IgG response yielded 100% specificity. Temporal kinetics of IgG in saliva were consistent with those observed in blood and indicated that most individuals seroconvert at around 10 DPSO. Algorithms employing a combination of the IgG responses to N and S antigens result in high diagnostic accuracy (100%) by as early as 10 DPSO. These results support the use of saliva-based antibody testing as a noninvasive and scalable alternative to blood-based antibody testing.


Assuntos
Anticorpos Antivirais/análise , Anticorpos Antivirais/sangue , /imunologia , Saliva/imunologia , /métodos , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Glicoproteína da Espícula de Coronavírus/imunologia
20.
Clin Chim Acta ; 511: 28-32, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33002475

RESUMO

BACKGROUND AND AIMS: A novel coronavirus (SARS-CoV-2) was isolated from the respiratory samples of patients with pneumonia as showed by the sequence analysis of the virus genomes obtained in Wuhan, China. The antibody response to SARS-CoV-2 is not well understood yet, but the availability of sensitive and specific serological assays will be crucial for the early diagnosis of infection, for epidemiological studies and for defining the presence of neutralizing antibodies in response to a possible vaccine. MATERIALS AND METHODS: We tested and compared the performances of one chemiluminescent immunoassay (CLIA), two enzyme-linked immunosorbent assay (ELISA) and an electrochemiluminescence immunoassay (ECLIA). RESULTS: The ECLIA serological assay performed best and may be a valid screening method for SARS-COV-2 infection. The IgA detected by the ELISA assay might be a more reliable and stable early serological marker than IgM. Instead, IgGs, as expected, showed stable level after 10 days from symptoms onset. CONCLUSION: The ECLIA method could be used as screening test, considering both the excellent performance and the cost per single test; while ELISA assay for IgG and IgA, which are present at a higher level than IgM and last longer, might be used as confirmatory test.


Assuntos
/métodos , /sangue , Imunoglobulina A/sangue , /isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes
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