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1.
Front Immunol ; 12: 614436, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33790892

RESUMEN

The novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic of the coronavirus disease 2019 (COVID-19), which elicits a wide variety of symptoms, ranging from mild to severe, with the potential to lead to death. Although used as the standard method to screen patients for SARS-CoV-2 infection, real-time PCR has challenges in dealing with asymptomatic patients and those with an undetectable viral load. Serological tests are therefore considered potent diagnostic tools to complement real-time PCR-based diagnosis and are used for surveillance of seroprevalence in populations. However, the dynamics of the antibody response against SARS-CoV-2 currently remain to be investigated. Here, through analysis of plasma samples from 84 patients with COVID-19, we observed that the response of virus-specific antibodies against three important antigens, RBD, N and S, dynamically changed over time and reached a peak 5-8 weeks after the onset of symptoms. The antibody responses were irrespective of sex. Severe cases were found to have higher levels of antibody response, larger numbers of inflammatory cells and C-reactive protein levels. Within the mild/moderate cases, pairwise comparison indicated moderate association between anti-RBD vs. anti-N, anti-RBD vs. anti-S1S2, and anti-N vs. anti-S1S2. Furthermore, the majority of cases could achieve IgM and IgG seroconversion at 2 weeks since the disease onset. Analysis of neutralizing antibodies indicated that these responses were able to last for more than 112 days but decline significantly after the peak. In summary, our findings demonstrate the longitudinally dynamic changes in antibody responses against SARS-CoV-2, which can contribute to the knowledge of humoral immune response after SARS-CoV-2 infection and are informative for future development of vaccine and antibody-based therapies.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , /inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Beijing , China , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Fosfoproteínas/inmunología , Dominios Proteicos/inmunología , Seroconversión , Índice de Severidad de la Enfermedad , Centros de Atención Terciaria
2.
BMC Infect Dis ; 21(1): 325, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33827460

RESUMEN

BACKGROUND: Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. METHODS: Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. RESULTS: Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78-100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. CONCLUSIONS: The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.


Asunto(s)
Anticuerpos Antivirales/sangre , Formación de Anticuerpos , /inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Humanos , Immunoblotting , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Pandemias , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Seroconversión , Pruebas Serológicas
3.
J Transl Med ; 19(1): 132, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33789686

RESUMEN

Coronavirus disease 2019 (COVID-19) global pandemic has created unique challenges to healthcare systems throughout the world. Ensuring subjects' safety is mandatory especially in oncology, in consideration of cancer patients' particular frailty. We examined the proportion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgM and/or IgG positive subjects in three different groups from Istituto Nazionale Tumori - IRCCS "Fondazione G. Pascale" in Naples (Campania region, Italy): cancer patients treated with Innovative Immunotherapy (Immune Checkpoint Inhibitors, ICIs), cancer patients undergoing standard Chemotherapies (CHTs) and healthcare providers. 9 out of 287 (3.1%) ICIs patients resulted positive, with a significant lower percentage in respect to CHTs patients (39 positive subjects out of 598, 6.5%) (p = 0.04). There was no statistically significant difference between ICIs cohort and healthcare providers, 48 out of 1050 resulting positive (4.6%). Performing a Propensity Score Matching based on gender and tumor stage, the effect of treatment on seropositivity was analyzed through a regression logistic model and the ICIs treatment resulted to be the only protective factor significantly (p = 0.03) associated with positivity (odds ratio-OR: 0.41; 95% confidence interval-CI 0.18-0.91). According to these preliminary data, ICIs would appear to be a protective factor against the onset of COVID-19 infection.


Asunto(s)
/prevención & control , Inmunoterapia , Neoplasias/terapia , Anciano , Anticuerpos Antivirales/sangre , Antineoplásicos/uso terapéutico , /inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Italia/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/inmunología , Pandemias , Estudios Retrospectivos , Investigación en Medicina Traslacional
4.
PLoS One ; 16(4): e0238088, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33793556

RESUMEN

BACKGROUND: COVID-19 seroprevalence data, particularly in less developed countries with a relatively low incidence, has been scant. We aimed to explore the seroprevalence of hospital staff in the area with zero confirmed COVID-19 case to shed light on the situation of COVID-19 infection in zero or low infection rate countries where mass screening was not readily available. METHODS: A locally developed rapid immunoglobulin M (IgM)/immunoglobulin G (IgG) test kit was used for hospital staff screening of Ranong hospital which is located in a province with zero COVID-19 prevalence in Thailand from 17th April to 17th May 2020. All staff was tested, 100 of which were randomly invited to have a repeating antibody test in one month. (Thai Clinical Trials Registry: TCTR20200426002). RESULTS: Of 844 hospital staff, 82 were tested twice one month apart (response rate for repeating antibody test 82%). Overall, 0.8% of the participants (7 of 844) had positive IgM, none had positive IgG. Female staff had 1.0% positive IgM (95% CI: 0.5-2.1%) while male had 0.5% positive IgM (95% CI: 0.1-2.6%). No participants with a history of travel to the high-risk area or close contact with PCR-confirmed COVID-19 case developed SARS-CoV-2 antibodies. Among 844 staff, 811 had no symptoms and six of them developed IgM seropositive (0.7%) while 33 had minor symptoms and only one of them developed IgM seropositive (3.0%). No association between SARS-CoV-2 IgM status and gender, history of travel to a high-risk area, close contact with PCR-confirmed or suspected COVID-19 case, presence of symptoms within 14 days, or previous PCR status was found. None of the hospital staff developed SARS-CoV-2 IgG. CONCLUSIONS: COVID-19 antibody test could detect a considerable number of hospital staff who could be potential silent spreaders in a province with zero COVID-19 cases. Accurate antibody testing is a valuable screening tool, particularly in asymptomatic healthcare workers. Trial registration: This study was approved by the Institutional Review Board of Chulalongkorn University (IRB No.236/63) and the Institutional Review Board of Ranong Hospital. (Thai Clinical Trials Registry: TCTR20200426002).


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Personal de Hospital/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Tailandia/epidemiología
5.
Nat Commun ; 12(1): 2037, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795692

RESUMEN

The hallmarks of COVID-19 are higher pathogenicity and mortality in the elderly compared to children. Examining baseline SARS-CoV-2 cross-reactive immunological responses, induced by circulating human coronaviruses (hCoVs), is needed to understand such divergent clinical outcomes. Here we show analysis of coronavirus antibody responses of pre-pandemic healthy children (n = 89), adults (n = 98), elderly (n = 57), and COVID-19 patients (n = 50) by systems serology. Moderate levels of cross-reactive, but non-neutralizing, SARS-CoV-2 antibodies are detected in pre-pandemic healthy individuals. SARS-CoV-2 antigen-specific Fcγ receptor binding accurately distinguishes COVID-19 patients from healthy individuals, suggesting that SARS-CoV-2 infection induces qualitative changes to antibody Fc, enhancing Fcγ receptor engagement. Higher cross-reactive SARS-CoV-2 IgA and IgG are observed in healthy elderly, while healthy children display elevated SARS-CoV-2 IgM, suggesting that children have fewer hCoV exposures, resulting in less-experienced but more polyreactive humoral immunity. Age-dependent analysis of COVID-19 patients, confirms elevated class-switched antibodies in elderly, while children have stronger Fc responses which we demonstrate are functionally different. These insights will inform COVID-19 vaccination strategies, improved serological diagnostics and therapeutics.


Asunto(s)
Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , /inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , /inmunología , Niño , Preescolar , Reacciones Cruzadas/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Persona de Mediana Edad , Receptores de IgG/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto Joven
6.
Sci Rep ; 11(1): 6614, 2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33758278

RESUMEN

There is a plethora of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) serological tests based either on nucleocapsid phosphoprotein (N), S1-subunit of spike glycoprotein (S1) or receptor binding domain (RBD). Although these single-antigen based tests demonstrate high clinical performance, there is growing evidence regarding their limitations in epidemiological serosurveys. To address this, we developed a Luminex-based multiplex immunoassay that detects total antibodies (IgG/IgM/IgA) against the N, S1 and RBD antigens and used it to compare antibody responses in 1225 blood donors across Greece. Seroprevalence based on single-antigen readouts was strongly influenced by both the antigen type and cut-off value and ranged widely [0.8% (95% CI 0.4-1.5%)-7.5% (95% CI 6.0-8.9%)]. A multi-antigen approach requiring partial agreement between RBD and N or S1 readouts (RBD&N|S1 rule) was less affected by cut-off selection, resulting in robust seroprevalence estimation [0.6% (95% CI 0.3-1.1%)-1.2% (95% CI 0.7-2.0%)] and accurate identification of seroconverted individuals.


Asunto(s)
Antígenos/inmunología , Pruebas Serológicas/métodos , Adolescente , Adulto , Anciano , Anticuerpos Antivirales/sangre , /inmunología , Femenino , Humanos , Inmunoensayo , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto Joven
7.
Virol J ; 18(1): 52, 2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-33750394

RESUMEN

BACKGROUND: Efficient monitoring and control of coronavirus disease 2019 (COVID-19) require access to diagnostic tests, and serological diagnostic testing is desirable. In the current study, antibodies were investigated in patients recently diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Cross-sectional data were obtained from 245 patients in whom SARS-CoV-2 infection had been confirmed via real-time reverse transcriptase-polymerase chain reaction between March and October 2020. Serum samples were acquired between 2 and 60 days following the onset of COVID-19 symptoms or the first detection of SARS-CoV-2 in asymptomatic patients. All specimens were tested simultaneously using an IgM/IgG rapid diagnostic test (RDT), IgG nucleocapsid protein-based chemiluminescent microparticle immunoassay (CMIA), IgG, and IgA spike protein-based enzyme-linked immunosorbent assays (ELISAs). Blood donor samples obtained in 2018 were used as negative controls. RESULTS: The sensitivity and specificity of the RDT IgG were compared with the IgG immunoassays as standards. The RDT IgG exhibited 97.5% sensitivity and 89.4% specificity compared with a CMIA IgG, 98.4% sensitivity, and 78.8% specificity compared with an ELISA IgG. IgM, IgG, and IgA seropositivity rates were low between 1 and 2 weeks after COVID-19 symptom onset or the detection of SARS-CoV-2 RNA. IgM seropositivity rate began decreasing after 4 weeks, whereas IgG and IgA seropositivity rate remained at appreciable levels over the 8-week study period. No cross-reactivity with seasonal coronaviruses was detected. CONCLUSIONS: IgG RDT alone or combined with molecular diagnostic tests may be useful for identifying recent SARS-CoV-2 infection.


Asunto(s)
Anticuerpos Antivirales/sangre , /diagnóstico , /aislamiento & purificación , Antígenos Virales/inmunología , Infecciones Asintomáticas/epidemiología , /normas , Estudios Transversales , Humanos , Inmunoensayo , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , /inmunología
8.
Methods Mol Biol ; 2259: 143-151, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33687712

RESUMEN

The versatility of protein microarrays provides researchers with a wide variety of possibilities to address proteomic studies. Therefore, protein microarrays are becoming very useful tools to identify candidate biomarkers in human body fluids for disease states such as rheumatoid arthritis (RA). In RA serum, there is a high prevalence of rheumatoid factor (RF), which is an antibody with high specificity against Fc portion of IgG. The presence of RF, in particular RF-IgM, has the great potential to interfere with antibody-based immunoassays by nonspecifically binding capture antibodies. Because of this concern, we describe a procedure to reduce the interference of RF-IgM on RA serum protein profiling approaches based on multiplexed antibody suspension bead arrays.


Asunto(s)
Artritis Reumatoide/sangre , Proteómica/métodos , Anticuerpos Inmovilizados/química , Artritis Reumatoide/diagnóstico , Biomarcadores/análisis , Biomarcadores/sangre , Humanos , Inmunoglobulina M/análisis , Inmunoglobulina M/sangre , Factor Reumatoide/análisis , Factor Reumatoide/sangre
9.
Acta Med Port ; 34(2): 87-94, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33641702

RESUMEN

INTRODUCTION: The aim of this study was to estimate and describe the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies (immunoglobulin M and/or immunoglobulin G) in Portugal in May-July 2020. MATERIAL AND METHODS: A cross-sectional seroepidemiological survey was developed after the peak of the first epidemic wave on a sample of 2301 Portuguese residents, aged 1 year or older. Survey sample was selected using a two-stage stratified non-probability sampling design (quota sampling). SARS-CoV-2 immunoglobulin M and immunoglobulin G antibodies were measured in serum samples by enzyme-linked immunosorbent assay. Seroprevalence estimates of immunoglobulin M and/or immunoglobulin G and 95% confidence intervals were stratified by sex, age group, health region and education. RESULTS: Overall, seroprevalence was 2.9% (95% confidence interval: 2.0% - 4.2%). Higher prevalence rates were observed in male (4.1%, 95% confidence interval: 2.6% - 6.6%) and those with secondary education (6.4%, 95% confidence interval: 3.2% - 12.5%). Differences in seroprevalence by age group and region were not statistically significant. DISCUSSION: The estimated seroprevalence of SARS-CoV-2 was higher than the cumulative incidence reported by the National Surveillance System but far from necessary to reach herd immunity. CONCLUSION: Our results support limited extent of infection by SARS-CoV-2 in the study population possibly due to early lockdown measures implemented in Portugal and support the need to continue monitoring of SARS-CoV-2 seroprevalence in order to increase our knowledge about the evolution of the epidemic and to estimate the proportion of the susceptible population over time.


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , /inmunología , Adolescente , Adulto , Distribución por Edad , Anciano , Niño , Preescolar , Intervalos de Confianza , Estudios Transversales , Escolaridad , Epidemias , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Portugal/epidemiología , Prevalencia , Estudios Seroepidemiológicos , Distribución por Sexo , Adulto Joven
10.
Nat Commun ; 12(1): 1383, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33654063

RESUMEN

In this study, we investigate the seroprevalence of SARS-CoV-2 antibodies among blood donors in the cities of Wuhan, Shenzhen, and Shijiazhuang in China. From January to April 2020, 38,144 healthy blood donors in the three cities were tested for total antibody against SARS-CoV-2 followed by pseudotype SARS-CoV-2 neutralization tests, IgG, and IgM antibody testing. Finally, a total of 398 donors were confirmed positive. The age- and sex-standardized SARS-CoV-2 seroprevalence among 18-60 year-old adults (18-65 year-old in Shenzhen) was 2.66% (95% CI: 2.24%-3.07%) in Wuhan, 0.033% (95% CI: 0.0029%-0.267%) in Shenzhen, and 0.0028% (95% CI: 0.0001%-0.158%) in Shijiazhuang, respectively. Female sex and older-age were identified to be independent risk factors for SARS-CoV-2 seropositivity among blood donors in Wuhan. As most of the population of China remained uninfected during the early wave of the COVID-19 pandemic, effective public health measures are still certainly required to block viral spread before a vaccine is widely available.


Asunto(s)
/patogenicidad , Anticuerpos Antivirales/sangre , Donantes de Sangre/estadística & datos numéricos , /epidemiología , China/epidemiología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Pruebas de Neutralización , Prevalencia , Factores de Riesgo , /inmunología
11.
Nat Commun ; 12(1): 1806, 2021 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-33753733

RESUMEN

Better diagnostic tools are needed to combat the ongoing COVID-19 pandemic. Here, to meet this urgent demand, we report a homogeneous immunoassay to detect IgG antibodies against SARS-CoV-2. This serological assay, called SATiN, is based on a tri-part Nanoluciferase (tNLuc) approach, in which the spike protein of SARS-CoV-2 and protein G, fused respectively to two different tNLuc tags, are used as antibody probes. Target engagement of the probes allows reconstitution of a functional luciferase in the presence of the third tNLuc component. The assay is performed directly in the liquid phase of patient sera and enables rapid, quantitative and low-cost detection. We show that SATiN has a similar sensitivity to ELISA, and its readouts are consistent with various neutralizing antibody assays. This proof-of-principle study suggests potential applications in diagnostics, as well as disease and vaccination management.


Asunto(s)
Anticuerpos Antivirales/sangre , /diagnóstico , Inmunoensayo/métodos , Luciferasas/metabolismo , /aislamiento & purificación , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/inmunología , /virología , Ensayo de Inmunoadsorción Enzimática , Células HEK293 , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Glicoproteína de la Espiga del Coronavirus/inmunología
12.
J Med Microbiol ; 70(3)2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33734961

RESUMEN

In this work, we studied the profile of IgM and IgG antibody responses to SARS-CoV-2 in 32 patients with COVID-19 from day 1 to day 24. IgM remained measurable for a much shorter period than IgG, suggesting that IgG antibody may represent the primary immune response.


Asunto(s)
Anticuerpos Antivirales/sangre , /inmunología , Adulto , Anciano , /inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Cinética , Masculino , Persona de Mediana Edad , Fosfoproteínas/inmunología , ARN Viral/análisis , /aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/inmunología
13.
PLoS One ; 16(3): e0248729, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33725025

RESUMEN

BACKGROUND: As COVID-19 vaccines become available, screening individuals for prior COVID-19 infection and vaccine response in point-of-care (POC) settings has renewed interest. We prospectively screened at-risk individuals for SARS-CoV-2 spike and nucleocapsid protein antibodies in a POC setting to determine if it was a feasible method to identify antibody from prior infection. METHODS: Three EUA-approved lateral flow antibody assays were performed on POC finger-stick blood and compared with serum and a CLIA nucleocapsid antibody immunoassay. Variables including antibody class, time since PCR, and the assay antigen used were evaluated. RESULTS: 512 subjects enrolled, of which 104 had a COVID-19 history and positive PCR. Only three PCR-positive subjects required hospitalization, with one requiring mechanical ventilation. The POC results correlated well with the immunoassay (93-97% sensitivity) and using serum did not improve the sensitivity or specificity. CONCLUSIONS: Finger-stick, POC COVID-19 antibody testing was highly effective in identifying antibody resulting from prior infections in mildly symptomatic subjects. Using high-complexity serum immunoassays did not improve the screening outcome. Almost all individuals with COVID-19 infection produced detectable antibodies to the virus. POC antibody testing is useful as a screen for prior COVID-19 infection, and should be useful in assessing vaccine response.


Asunto(s)
/diagnóstico , Sistemas de Atención de Punto , Adulto , Anciano , Anticuerpos Antivirales/sangre , Femenino , Humanos , Inmunoensayo , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Nucleocápside/inmunología , Juego de Reactivos para Diagnóstico , /aislamiento & purificación , Sensibilidad y Especificidad , Adulto Joven
14.
Acta Biomed ; 92(1): e2021070, 2021 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-33682801

RESUMEN

BACKGROUND AND AIM: The COVID-19 is an infectious disease caused by the novel coronavirus SARS-CoV-2, declared a public health emergency by the World Health Organization. In this study, we evaluated the seroconversion of SARS-CoV-2 antibodies to find predictors of infection in terms of symptoms, health status, and professions. METHODS: Serological samples of 341 volunteers in a cohort in Marche Region, Italy, were analyzed for the presence of IgM and/or IgG immunoglobulins specific for the SARS-CoV-2. Contextually, an anamnestic questionnaire was administered. The binary logistic regression analysis was used to find the predictors of seroconversion. RESULTS: Forty-nine subjects (14.4 %) were found positive, without significant differences between gender and age groups. The predictors identified inside the variable categories "symptoms," "risk factors" (smoking habit and established pathologies), and "professions" were the loss of taste and smell (OR, 8.563), cardiovascular diseases (OR, 2.912), and policeman profession (OR, 3.875), respectively. CONCLUSIONS: Although the limited number of subjects recruited in this study, our results could give important findings to be considered for planning preventive strategies in the view of the next COVID-19 waves.


Asunto(s)
Anticuerpos Antivirales/sangre , /inmunología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Italia/epidemiología , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Adulto Joven
15.
J Infect Dev Ctries ; 15(2): 237-241, 2021 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-33690206

RESUMEN

INTRODUCTION: We aim to describe the performance of combined IgM and IgG point-of-care antibody test (POC-Ab) (Wondfo®) compared to real-time reverse transcriptase (rRT-PCR) (Allplex™ 2019-nCoV Assay) in detecting coronavirus disease 2019 (COVID-19). METHODOLOGY: We compared POC-Ab with rRT-PCR results among patients in a tertiary hospital from January to March 2020 in Bandung, Indonesia. We selected presumptive COVID-19 patients with positive rRT-PCR consecutively and 20 patients with negative rRT-PCR results were selected randomly from the same group of patients as controls. We described the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) with corresponding 95% confidence interval using serum and capillary blood samples. We also tested POC-Ab using non-COVID-19 (confirmed dengue and typhoid) patients' sera. RESULTS: Twenty-seven patients with positive rRT-PCR result and 20 negative controls were included (68.1% males, mean age 46 (SD: 15.4)). Using the serum, the sensitivity of the POC-Ab was 63.0% (42.4-80.6), specificity was 95.0% (75.1-99.9), PPV was 94.4% (72.7-99.8), NPV was 65.5% (45.7-82.1). A subset of 20 patients was tested using a capillary blood sample. The accuracy of the capillary blood sample is lower compared to serum (50.0% vs. 78.7%). None of the non-COVID-19 sera tested were reactive. CONCLUSIONS: POC-Ab for COVID-19 has a high specificity with no false-positive result in non-COVID-19 sera. Therefore, it can be used to guide diagnostic among symptomatic patients in resource limited settings. Given its low sensitivity, patients with high suspicion of COVID-19 but non-reactive result should be prioritized for rRT-PCR testing.


Asunto(s)
/métodos , Adulto , Anciano , /etiología , Reacciones Falso Positivas , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Indonesia , Masculino , Persona de Mediana Edad , Nasofaringe/virología , Sistemas de Atención de Punto , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Sensibilidad y Especificidad , Centros de Atención Terciaria
16.
Talanta ; 227: 122207, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33714475

RESUMEN

Since December 2019, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused millions of deaths and seriously threatened the safety of human life; indeed, this situation is worsening and many people are infected with the new coronavirus every day. Therefore, it is very important to understand patients' degree of infection and infection history through antibody testing. Such information is useful also for the government and hospitals to formulate reasonable prevention policies and treatment plans. In this paper, we develop a lateral flow immunoassay (LFIA) method based on superparamagnetic nanoparticles (SMNPs) and a giant magnetoresistance (GMR) sensing system for the simultaneously quantitative detection of anti-SARS-CoV-2 immunoglobulin M (IgM) and G (IgG). A simple and time-effective co-precipitation method was utilized to prepare the SMNPs, which have good dispersibility and magnetic property, with an average diameter of 68 nm. The Internet of Medical Things-supported GMR could transmit medical data to a smartphone through the Bluetooth protocol, making patient information available for medical staff. The proposed GMR system, based on SMNP-supported LFIA, has an outstanding advantage in cost-effectiveness and time-efficiency, and is easy to operate. We believe that the suggested GMR based LFIA system will be very useful for medical staff to analyze and to preserve as a record of infection in COVID-19 patients.


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoensayo/métodos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , /inmunología , Animales , Anticuerpos Inmovilizados/química , Anticuerpos Inmovilizados/inmunología , Anticuerpos Antivirales/inmunología , Bovinos , Teléfono Celular , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Internet de las Cosas , Límite de Detección , Fenómenos Magnéticos
17.
Medicine (Baltimore) ; 100(11): e25195, 2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33726012

RESUMEN

ABSTRACT: The present study was conducted with an attempt to explore the correlation of serum resistin level and other metabolic hormones and immune function in neonatal umbilical cord blood.The levels of umbilical cord blood resistin, adiponectin, insulin, growth hormone, leptin, thyrotropin, thyroid hormone (T3, T4), lgM, lgA, lgG, CD4, and CD8 were measured in 180 full-term newborns delivered in hospital from October 2018 to November 2019. The delivery mode, weight, height, and gender at birth were recorded.The levels of resistin, insulin, and growth hormone in umbilical cord blood of newborns delivered vaginally were significantly higher than those born by cesarean section (P < .05), while the levels of adiponectin, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 were comparable between the 2 groups (P > .05). The levels of resistin, adiponectin, insulin, growth hormone, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 in cord blood of male and female newborns were comparable (P > .05). The newborns with birth weight ≥ 3501 g reported comparable results in the levels of resistin and growth hormone compared with those with birth weight of 3000 to 3500 g (P > .05), but were significantly higher than those with birth weight ≤ 2999 g (P < 0.05). In addition, the levels of adiponectin, insulin, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 were comparable among the 3 groups (P > .05). Based on Pearson correlation analysis, neonatal umbilical cord blood resistin was positively correlated with adiponectin, leptin, growth hormone, T3, and T4 (r = 0.281, 0.287, 0.321, 0.276, 0.269, P < .05). However, there was no significant correlation between neonatal umbilical cord blood resistin and insulin, TST, lgM, lgA, lgG, CD4, and CD8.The level of serum resistin in neonatal umbilical cord blood was associated with the delivery mode and birth weight, and positively correlated with adiponectin, leptin, growth hormone, T3, and T4. However, no correlation was observed between serum resistin in neonatal umbilical cord blood and insulin, TST, lgM, lgA, lgG, CD4, and CD8.


Asunto(s)
Adipoquinas/sangre , Peso al Nacer , Parto Obstétrico/estadística & datos numéricos , Sangre Fetal/química , Hormona de Crecimiento Humana/sangre , Hormonas Tiroideas/sangre , Adiponectina/sangre , Femenino , Sangre Fetal/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Recién Nacido , Insulina/sangre , Leptina/sangre , Recuento de Linfocitos , Masculino , Embarazo , Resistina/sangre , Nacimiento a Término/sangre , Tirotropina/sangre
18.
PLoS One ; 16(3): e0247797, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33661960

RESUMEN

Since the initial identification of the novel coronavirus SARS-CoV-2 in December of 2019, researchers have raced to understand its pathogenesis and begun devising vaccine and treatment strategies. An accurate understanding of the body's temporal immune response against SARS-CoV-2 is paramount to successful vaccine development and disease progression monitoring. To provide insight into the antibody response against SARS-CoV-2, plasma samples from 181 PCR-confirmed COVID-19 patients collected at various timepoints post-symptom onset (PSO) were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies via lateral flow. Additionally, 21 donors were tracked over time to elucidate patient-specific immune responses. We found sustained levels of anti-SARS-CoV-2 antibodies past 130 days PSO, with 99% positivity observed at 31-60 days PSO. By 61-90 days PSO, the percentage of IgM-/IgG+ results were nearly equal to that of IgM+/IgG+ results, demonstrating a shift in the immune response with a decrease in IgM antibody levels. Results from this study not only provide evidence that the antibody response to COVID-19 can persist for over 4 months, but also demonstrates the ability of Easy Check™ to monitor seroconversion and antibody response of patients. Easy Check was sufficiently sensitive to detect antibodies in patient samples as early as 1-4 days PSO with 86% positivity observed at 5-7 days PSO. Further studies are required to determine the longevity and efficacy of anti-SARS-CoV-2 antibodies, and whether they are protective against re-infection.


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , /inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/inmunología , /instrumentación , Diseño de Equipo , Femenino , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Adulto Joven
19.
PLoS One ; 16(3): e0247711, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33661990

RESUMEN

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The repeatability and within-laboratory precision were obviously good in validations, following to the CLSI document EP15-A3. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this new automated method for detecting antibody against both N and S proteins of SARS-CoV-2 is sufficient for use in laboratory testing.


Asunto(s)
Anticuerpos Antivirales/sangre , /diagnóstico , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , /aislamiento & purificación , Anticuerpos Antivirales/inmunología , /epidemiología , /inmunología , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Japón/epidemiología , Mediciones Luminiscentes/métodos , Fosfoproteínas/inmunología , Fosfoproteínas/aislamiento & purificación , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/aislamiento & purificación
20.
Lancet Child Adolesc Health ; 5(4): 256-264, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33571450

RESUMEN

BACKGROUND: The extent to which very young children contribute to the transmission of SARS-CoV-2 is unclear. We aimed to estimate the seroprevalence of antibodies against SARS-CoV-2 in daycare centres that remained open for key workers' children during a nationwide lockdown in France. METHODS: Children and staff who attended one of 22 daycare centres during a nationwide lockdown in France (between March 15 and May 9, 2020) were included in this cross-sectional, multicentre, seroprevalence study. Hospital staff not occupationally exposed to patients with COVID-19, or to children, were enrolled in a comparator group. The primary outcome was SARS-CoV-2 seroprevalence in children, daycare centre staff, and the comparator group. The presence of antibodies against SARS-CoV-2 in capillary whole blood was measured with a rapid chromatographic immunoassay. We computed raw prevalence as the percentage of individuals with a positive IgG or IgM test, and used Bayesian smoothing to account for imperfect sensitivity and specificity of the assay. This study is registered with ClinicalTrials.gov, NCT04413968. FINDINGS: Between June 4 and July 3, 2020, we enrolled 327 children (mean age 1·9 [SD 0·9] years; range 5 months to 4·4 years), 197 daycare centre staff (mean age 40 [12] years), and 164 adults in the comparator group (42 [12] years). Positive serological tests were observed for 14 children (raw seroprevalence 4·3%; 95% CI 2·6-7·1) and 14 daycare centre staff (7·7%; 4·2-11·6). After accounting for imperfect sensitivity and specificity of the assay, we estimated that 3·7% (95% credible interval [95% CrI] 1·3-6·8) of the children and 6·8% (3·2-11·5) of daycare centre staff had SARS-CoV-2 infection. The comparator group fared similarly to the daycare centre staff; nine participants had a positive serological test (raw seroprevalence 5·5%; 95% CI 2·9-10·1), leading to a seroprevalence of 5·0% (95% CrI 1·6-9·8) after accounting for assay characteristics. An exploratory analysis suggested that seropositive children were more likely than seronegative children to have been exposed to an adult household member with laboratory-confirmed COVID-19 (six [43%] of 14 vs 19 [6%] of 307; relative risk 7·1 [95% CI 2·2-22·4]). INTERPRETATION: According to serological test results, the proportion of young children in our sample with SARS-CoV-2 infection was low. Intrafamily transmission seemed more plausible than transmission within daycare centres. Further epidemiological studies are needed to confirm this exploratory hypothesis. FUNDING: Assistance Publique-Hôpitaux de Paris; Mairie de Paris, Conseil Départemental de Seine Saint Denis. TRANSLATIONS: For the French translation of the abstract see Supplementary Materials section.


Asunto(s)
Anticuerpos Antivirales/sangre , Jardines Infantiles , /inmunología , Adulto , Preescolar , Estudios Transversales , Francia/epidemiología , Humanos , Inmunoensayo , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Lactante , Estudios Seroepidemiológicos
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