Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.698
Filtrar
1.
Nat Commun ; 12(1): 2055, 2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33824342

RESUMEN

Identification of protective T cell responses against SARS-CoV-2 requires distinguishing people infected with SARS-CoV-2 from those with cross-reactive immunity to other coronaviruses. Here we show a range of T cell assays that differentially capture immune function to characterise SARS-CoV-2 responses. Strong ex vivo ELISpot and proliferation responses to multiple antigens (including M, NP and ORF3) are found in 168 PCR-confirmed SARS-CoV-2 infected volunteers, but are rare in 119 uninfected volunteers. Highly exposed seronegative healthcare workers with recent COVID-19-compatible illness show T cell response patterns characteristic of infection. By contrast, >90% of convalescent or unexposed people show proliferation and cellular lactate responses to spike subunits S1/S2, indicating pre-existing cross-reactive T cell populations. The detection of T cell responses to SARS-CoV-2 is therefore critically dependent on assay and antigen selection. Memory responses to specific non-spike proteins provide a method to distinguish recent infection from pre-existing immunity in exposed populations.


Asunto(s)
Antivirales/farmacología , /virología , Reacciones Cruzadas/inmunología , Inmunoensayo/métodos , Linfocitos T/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Proliferación Celular , Citocinas/metabolismo , Células HEK293 , Personal de Salud , Humanos , Inmunoglobulina G/inmunología , Memoria Inmunológica , Interferón gamma/metabolismo , Pandemias , Péptidos/metabolismo , /efectos de los fármacos
2.
Int J Nanomedicine ; 16: 1901-1911, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33707945

RESUMEN

Purpose: Developing a sensitive SERS-based method to quantitatively detect serum biomarkers (Aß1-42 and P-Tau-181) for the early diagnosis of Alzheimer's disease (AD). Methods: In this study, a novel SERS-based sandwich immunoassay, which consists of tannin-capped silver nanoparticles and magnetic graphene oxide (Fe3O4@GOs), was developed. We firstly applied this method for the detection of protein standards in buffer solution, obtaining the regression equation. Then, its potential value on real serum samples of AD was further explored. Results: The detection linear range of Aß1-42 and P-Tau-181 protein standards were observed to range from 100 pg mL-1 to 10 fg mL-1, 100 pg mL-1 to 1 fg mL-1 respectively. We finally explored clinical application of the proposed method in 63 serum samples. As a result, P-tau-181 differentiated AD from non-AD dementia patients (AUC = 0.770), with a more favored ROC than Aß1-42 (AUC = 0.383). Conclusion: The developed SERS-based immunoassay is successfully applied to the determination of Aß1-42 and P-Tau-181 in human serum specimens, which provides a promising tool for the early diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/sangre , Inmunoensayo/métodos , Sondas Moleculares/química , Plata/química , Espectrometría Raman/métodos , Péptidos beta-Amiloides/sangre , Benzoatos/química , Calibración , Femenino , Grafito/química , Humanos , Límite de Detección , Masculino , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Compuestos de Sulfhidrilo/química , Difracción de Rayos X , Proteínas tau/sangre
3.
Biosens Bioelectron ; 180: 113088, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33647790

RESUMEN

Serial measurement of a large panel of protein biomarkers near the bedside could provide a promising pathway to transform the critical care of acutely ill patients. However, attaining the combination of high sensitivity and multiplexity with a short assay turnaround poses a formidable technological challenge. Here, the authors develop a rapid, accurate, and highly multiplexed microfluidic digital immunoassay by incorporating machine learning-based autonomous image analysis. The assay has achieved 12-plexed biomarker detection in sample volume <15 µL at concentrations < 5 pg/mL while only requiring a 5-min assay incubation, allowing for all processes from sampling to result to be completed within 40 min. The assay procedure applies both a spatial-spectral microfluidic encoding scheme and an image data analysis algorithm based on machine learning with a convolutional neural network (CNN) for pre-equilibrated single-molecule protein digital counting. This unique approach remarkably reduces errors facing the high-capacity multiplexing of digital immunoassay at low protein concentrations. Longitudinal data obtained for a panel of 12 serum cytokines in human patients receiving chimeric antigen receptor-T (CAR-T) cell therapy reveals the powerful biomarker profiling capability. The assay could also be deployed for near-real-time immune status monitoring of critically ill COVID-19 patients developing cytokine storm syndrome.


Asunto(s)
/inmunología , Citocinas/análisis , Procesamiento de Imagen Asistido por Computador/métodos , Inmunoensayo/métodos , Aprendizaje Automático , Análisis por Micromatrices/métodos , Técnicas Analíticas Microfluídicas/métodos , Síndrome de Liberación de Citoquinas , Humanos , Inmunoterapia Adoptiva , Redes Neurales de la Computación
4.
Mikrochim Acta ; 188(3): 105, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33651173

RESUMEN

Severe acute respiratory syndrome SARS-CoV-2 has caused a global pandemic starting in 2020. Accordingly, testing is crucial for mitigating the economic and public health effects. In order to facilitate point-of-care diagnosis, this study aims at presenting a label-free electrochemical biosensor as a powerful nanobiodevice for SARS-CoV-2 spike protein detection. Utilizing the IgG anti-SARS-CoV-2 spike antibody onto the electrode surface as a specific platform in an ordered orientation through staphylococcal protein A (ProtA) is highly significant in fabricating the designed nanobiodevice. In this sense, the screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provide a large surface area in a very small space, was applied in order to increase the ProtA loading on the electrode surface. Accordingly, the sensitivity and stability of the sensing platform significantly increased. The electrochemical evaluations proved that there is a very good linear relationship between the charge transfer resistance (Rct) and spike protein contents via a specific binding reaction in the range 0.25 fg mL-1 to 1 µg mL-1. Moreover, the assay when tested with influenza viruses 1 and 2 was performed in 20 min with a low detection limit of 0.04 fg mL-1 for spike protein without any cross-reactivity. The designed nanobiodevice exhibited an average satisfactory recovery rate of ~ 97-103% in different artificial sample matrices, i.e., saliva, artificial nasal, and universal transport medium (UTM), illustrating its high detection performance and practicability. The nanobiodevice was also tested using real patients and healthy samples, where the results had been already obtained using the standard polymerase chain reaction (PCR) procedure, and showed satisfactory results. Graphical abstract.


Asunto(s)
Técnicas Biosensibles/métodos , /diagnóstico , Cobre/química , Técnicas Electroquímicas/métodos , Nanoestructuras/química , Glicoproteína de la Espiga del Coronavirus/análisis , Anticuerpos Antivirales/metabolismo , Electrodos , Humanos , Inmunoensayo/métodos , Inmunoglobulina G/metabolismo , Unión Proteica , Sensibilidad y Especificidad , Proteína Estafilocócica A/química , Propiedades de Superficie
5.
Biosensors (Basel) ; 11(3)2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33670852

RESUMEN

The diagnosis of respiratory viruses of zoonotic origin (RVsZO) such as influenza and coronaviruses in humans is crucial, because their spread and pandemic threat are the highest. Surface-enhanced Raman spectroscopy (SERS) is an analytical technique with promising impact for the point-of-care diagnosis of viruses. It has been applied to a variety of influenza A virus subtypes, such as the H1N1 and the novel coronavirus SARS-CoV-2. In this work, a review of the strategies used for the detection of RVsZO by SERS is presented. In addition, relevant information about the SERS technique, anthropozoonosis, and RVsZO is provided for a better understanding of the theme. The direct identification is based on trapping the viruses within the interstices of plasmonic nanoparticles and recording the SERS signal from gene fragments or membrane proteins. Quantitative mono- and multiplexed assays have been achieved following an indirect format through a SERS-based sandwich immunoassay. Based on this review, the development of multiplex assays that incorporate the detection of RVsZO together with their specific biomarkers and/or secondary disease biomarkers resulting from the infection progress would be desirable. These configurations could be used as a double confirmation or to evaluate the health condition of the patient.


Asunto(s)
/diagnóstico , Inmunoensayo/métodos , Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Espectrometría Raman/métodos , /instrumentación , Diseño de Equipo , Humanos , Inmunoensayo/instrumentación , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Espectrometría Raman/instrumentación
6.
Methods Mol Biol ; 2265: 265-276, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33704721

RESUMEN

Liquid biopsy has emerged as the next generation target for diagnostics and therapeutic monitoring of many diseases including cancer. Liquid biopsy offers noninvasive analysis of aberrant biomolecular changes (e.g., aberrant protein expression, DNA mutation) which can provide crucial information on disease stages and therapy responses. As a diagnostically important biomarker for melanoma, the detection of the BRAFV600E aberration at the DNA and protein level in liquid biopsies confers an attractive option. This method describes the preparation and operation of an integrated multimolecular sensor (IMMS) for simultaneous detection of the BRAFV600E aberration in both molecular forms from circulating melanoma cells in liquid biopsy. IMMS integrates specific melanoma cell capture, cell release, cell lysis, and electrochemical BRAFV600E detection on a single device. IMMS is demonstrated for a sample-to-answer workflow of plasma spiked with melanoma cells.


Asunto(s)
Técnicas Biosensibles/métodos , Inmunoensayo/métodos , Dispositivos Laboratorio en un Chip , Melanoma/metabolismo , Microfluídica/instrumentación , Microfluídica/métodos , Proteínas Proto-Oncogénicas B-raf/metabolismo , Neoplasias Cutáneas/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Técnicas Biosensibles/instrumentación , Técnicas de Cultivo de Célula/métodos , Humanos , Inmunoensayo/instrumentación , Biopsia Líquida/métodos , Melanoma/genética , Melanoma/patología , Mutación , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patología , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología
7.
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
8.
Molecules ; 26(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670468

RESUMEN

Lateral flow assays (lateral flow immunoassays and nucleic acid lateral flow assays) have experienced a great boom in a wide variety of early diagnostic and screening applications. As opposed to conventional examinations (High Performance Liquid Chromatography, Polymerase Chain Reaction, Gas chromatography-Mass Spectrometry, etc.), they obtain the results of a sample's analysis within a short period. In resource-limited areas, these tests must be simple, reliable, and inexpensive. In this review, we outline the production process of antibodies against drugs of abuse (such as heroin, amphetamine, benzodiazepines, cannabis, etc.), used in lateral flow immunoassays as revelation or detection molecules, with a focus on the components, the principles, the formats, and the mechanisms of reaction of these assays. Further, we report the monoclonal antibody advantages over the polyclonal ones used against drugs of abuse. The perspective on aptamer use for lateral flow assay development was also discussed as a possible alternative to antibodies in view of improving the limit of detection, sensitivity, and specificity of lateral flow assays.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Inmunoensayo/métodos , Detección de Abuso de Sustancias , Animales , Técnicas de Visualización de Superficie Celular , Humanos , Valor Predictivo de las Pruebas , Proyectos de Investigación
9.
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
10.
J Korean Med Sci ; 36(9): e64, 2021 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-33686810

RESUMEN

BACKGROUND: In Korea, there were issues regarding the use of immunoassays for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies to detect infection. So, we compared antibody results of eight kinds of commercial immunoassays using clinical remnant specimens. METHODS: We compared the results of several immunoassay kits tested on 40 serum samples from 15 confirmed patients and 86 remnant serum samples from clinical laboratory. Eight kinds of IVD kits-four enzyme-linked immunosorbent assay, two lateral flow rapid immunochromatographic assays, and two chemiluminescent immunoassays with one RUO kit were tested. RESULTS: Among 40 serum samples from 15 coronavirus disease 2019 (COVID-19) patients, 35 yielded at least one positive result for detecting antibodies in the combined assessment. There were inconsistent results in 12 (28%) samples by single immunoassay. Forty samples collected in 2019 before the first COVID-19 Korean case showed negative results except for one equivocal result. CONCLUSION: The discrepant results obtained with different immunoassay kits in this study show that serological assessment of SARS-CoV-2 by a single immunoassay requires caution not only in detecting infection but also in assessing immunologic status.


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoensayo/métodos , /inmunología , /virología , Hospitalización , Humanos , Inmunoglobulina G/sangre , Juego de Reactivos para Diagnóstico , /aislamiento & purificación
11.
Food Chem ; 352: 129415, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33711728

RESUMEN

Furazolidone (FZD) and its metabolite called 3-amino-2-oxazolidinone (AOZ) would induce carcinogenic and mutagenic effects to human. In this work, to develop a novel, stable, and simple point of care testing (POCT) with a potential to social applied for FZD detection, we utilized the aspect of protein staining of coomassie brilliant blue (CBB) to exploit a new CBB-LFIA strategy free of NPs. Only one mixing step is needed during the probe manufacturing process, which requires just 2 h and is a great time saving strategy compared with other methods (requiring 4-33 h for probe preparation). Besides, the cost of CBB-LFIA is 300 times lesser than other LFIA with respect to obtaining the label. The developed CBB-LFIA was successfully applied to detect AOZ with a detection limit of 2 ng mL-1, without any influence from other potential interfering compounds. The proposed CBB-LFIA exhibited prominent practical application, and possesses considerable utilization potential in the related field.


Asunto(s)
Costos y Análisis de Costo , Furazolidona/análisis , Furazolidona/química , Inmunoensayo/economía , Inmunoensayo/métodos , Sistemas de Atención de Punto/economía , Colorantes de Rosanilina/química , Humanos , Límite de Detección , Factores de Tiempo
12.
Bioanalysis ; 13(3): 161-167, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33538622

RESUMEN

Aim: Several automated immunoassays have been validated on serum/plasma to evaluate the presence of significant levels of anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) antibodies, signs of a present or past infection, but the use of dried blood spots (DBS) would facilitate sampling, shipping and storage. Objective: The aim of this project was to give proof of concept of the possibility to use of the automatized Elecsys® anti-SARS-CoV-2 immunoassay with a volumetric DBS device. Results: Linearity and correlation were satisfactory between volumetric DBS and plasma. A cut-off value was suggested and should be validated with more samples. Conclusion: this study strongly support the possibility to work with volumetric DBS instead of serum/plasma to test for anti-SARS-CoV-2 antibodies.


Asunto(s)
/diagnóstico , Inmunoensayo/métodos , Anticuerpos Antivirales/sangre , Pruebas con Sangre Seca , Humanos , Mediciones Luminiscentes , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , /aislamiento & purificación
13.
Int J Nanomedicine ; 16: 715-724, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33542626

RESUMEN

Objective: The coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is now rapidly spreading globally. Serological tests are an important method to assist in the diagnosis of COVID-19, used for epidemiological investigations. In this study, we aimed to investigate the impact of different types of vacuum collection tubes on the detection of SARS-CoV-2 IgM and IgG antibodies, using the colloidal gold immunochromatographic assay (GICA). Patients and Methods: A total of 112 patients with COVID-19 and 200 healthy control subjects with no infection were enrolled in this study. Their serum and plasma were collected into four different types of vacuum blood collection tubes. SARS-CoV-2 IgM and IgG specific antibodies in the plasma and serum were then detected by GICA and chemiluminescence assay (CA), respectively. In addition, the particle sizes of different colloidal gold solutions in the presence of different anticoagulants and coagulants were evaluated by both laser diffraction (Malvern) and confocal laser microscope, respectively. Results: Our results revealed that anticoagulated plasma with EDTA-K2 improved the positive detection rate of SARS-CoV-2 IgM antibodies. Furthermore, our results shown that the detection results by GICA and CA were highly consistent, especially, the results of EDTA-K2 anticoagulated plasma detected by GICA was more consistent with CA results. We confirmed that EDTA-K2 could improve the detection sensitivity of SARS-CoV-2 IgG antibodies by chelating excessive colloidal gold compared with sodium citrate or lithium heparin, these methodologies did not appear to cause false positives. Colloidal gold particles could be chelated and aggregated by EDTA-K2, but not by sodium citrate, lithium heparin and coagulants. Conclusion: GICA is widely used to detect antibodies for the advantages of convenient, fast, low cost, suitable for screening large sample and require minimal equipment. In this study, we found that EDTA-K2 amplified the positive antibody signal by chelating colloidal gold and improved the detection sensitivity of SARS-CoV-2 IgM and IgG antibodies when using the GICA. Therefore, we suggested that EDTA-K2 anticoagulated plasma was more suitable for the detection of SARS-CoV-2 antibodies.


Asunto(s)
Anticuerpos Antivirales/aislamiento & purificación , Quelantes/química , Ácido Edético/química , Oro Coloide/química , Inmunoensayo/métodos , Inmunoglobulina G/aislamiento & purificación , Inmunoglobulina M/aislamiento & purificación , /inmunología , Adulto , Anticuerpos Antivirales/sangre , Especificidad de Anticuerpos/inmunología , /inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Peso Molecular , Tamaño de la Partícula , Polímeros/química , Sensibilidad y Especificidad
14.
J Immunol Methods ; 492: 112996, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33582147

RESUMEN

Dried blood spots (DBS) are routinely used in screening newborns for treatable disorders. Immunoglobulin extraction from DBS, serum or other biological fluids loaded on filter paper cards could represent a valuable method of specimen preservation in monitoring immune response against pathogens as well as vaccination efficiency. In this study using different sources including serum, and monoclonal antibodies we established parameters for antibody extraction from the filter cards to assess antibody reactivity against Helicobacter pylori, measles virus (MV) and the novel coronavirus SARS-CoV-2 antigens. We demonstrated that DBS and dried undiluted serum result in completely preserved antibody activity for immunoassays, including in virus neutralization assays against MV. Extraction efficiency was determined by IgG concentration measurements. The plaque-reduction neutralization titer 50% of dried human serum spots remained stable after more than 10-day storage - 1:359 vs. 1:345 for the corresponding frozen sample. DBSs could be used to monitor immune response to bacterial and viral antigens following natural exposure or immunization. Mice immunized with recombinant spike protein receptor-binding domain of SARS-CoV-2 developed a strong antibody response by day 14 and reached titers above 1:64,000 on day 21 following the secondary boost immunization as measured on DBS samples in antigen-mediated ELISA. Variability in IgG concentration of eluted DBS could be influenced by factors involved in sample application, extraction process and sample characteristics. Adjustment of antibody specific activity to the eluted IgG concentration can increase accuracy of the result interpretation, including in SARS-CoV-2 serological diagnostics.


Asunto(s)
Anticuerpos Antivirales/aislamiento & purificación , Pruebas con Sangre Seca , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/fisiología , Inmunoensayo/métodos , Virus del Sarampión/fisiología , Sarampión/diagnóstico , Monitorización Inmunológica/métodos , /fisiología , Animales , Anticuerpos Monoclonales , Formación de Anticuerpos , Pruebas con Sangre Seca/métodos , Femenino , Humanos , Inmunidad Humoral , Ratones , Ratones Endogámicos BALB C , Pruebas Serológicas , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunación
15.
Diagn Microbiol Infect Dis ; 100(1): 115313, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33548855

RESUMEN

OBJECTIVES: To evaluate the diagnostic performances of four SARS-CoV-2 IgG antibody immunoassays. METHODS: Following immunoassays were studied: Abbott's SARS-CoV-2 IgG assay, Diasorin's Liaison SARS-CoV-2 S2/S2 IgG assay, Euroimmun's Anti-SARS-CoV-2 IgG ELISA, and Roche's Elecsys Anti-SARS-CoV-2 assay. Specificity was retrospectively evaluated with 38 samples from 2019. Sensitivity samples (n = 147) were taken from SARS-CoV-2 real-time PCR-positive patients who developed COVID-19 symptoms ten days earlier. RESULTS: Mean specificity was 96.6%. Mean sensitivity was 62.7% from ten days after onset of symptoms, 84.4% from 15 days after onset of symptoms, and 87.5% from 20 days after onset of symptoms. CONCLUSIONS: Specificity was high, while Abbott and Roche were 100% specific. Sensitivity increased over time, with Abbott and Roche having the highest sensitivity at all time points with ≥90% from 20 days after symptoms' onset. These findings may assist in selecting SARS-CoV-2 IgG antibody immunoassays for additional diagnostics, epidemiological research, and vaccine development.


Asunto(s)
Anticuerpos Antivirales/sangre , Inmunoensayo/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Infecciones por Virus de Epstein-Barr/sangre , Infecciones por Virus de Epstein-Barr/virología , Femenino , Humanos , Inmunoglobulina G/sangre , Lactante , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto Joven
16.
Medicina (Kaunas) ; 57(2)2021 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-33562085

RESUMEN

Background and objective: Serologic testing is a useful additional method for the diagnosis of COVID-19. It is also used for population-based seroepidemiological studies. The objective of the study was to determine SARS-CoV-2 seroprevalence in healthcare workers of Kaunas hospitals and to compare two methods for specific SARS-CoV-2 antibody testing. Materials and Methods: A total of 432 healthcare workers in Kaunas hospitals were enrolled in this study. Each participant filled a questionnaire including questions about their demographics, contact with suspected or confirmed COVID-19, acute respiratory symptoms, and whether they contacted their general practitioner, could not come to work, or had to be hospitalized. Capillary blood was used to test for SARS-CoV-2 specific immunoglobulin G (IgG) and immunoglobulin M (IgM) a lateral flow immunoassay. Serum samples were used to test for specific IgG and IgA class immunoglobulins using semiquantitative enzyme-linked immunosorbent assay (ELISA) method. Results: 24.77% of study participants had direct contact with a suspected or confirmed case of COVID-19. A total of 64.81% of studied individuals had at least one symptom representing acute respiratory infection, compatible with COVID-19. Lateral flow immunoassay detected SARS-CoV-2 specific IgG class immunoglobulins in 1.16% of the tested group. Fever, cough, dyspnea, nausea, diarrhea, headache, conjunctivitis, muscle pain, and loss of smell and taste predominated in the anti-SARS-CoV-2 IgG-positive group. Using ELISA, specific IgG were detected in 1.32% of the tested samples. Diarrhea, loss of appetite, and loss of smell and taste sensations were the most predominant symptoms in anti-SARS-CoV-2 IgG-positive group. The positive percent agreement of the two testing methods was 50%, and negative percent agreement was 99.66%. Conclusions: 1.16% of tested healthcare workers of Kaunas hospitals were anti-SARS-CoV-2 IgG-positive. The negative percent agreement of the lateral flow immunoassay and ELISA exceeded 99%.


Asunto(s)
/epidemiología , Inmunoglobulina G/sangre , Personal de Hospital , /inmunología , Adulto , Anciano , /diagnóstico , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoensayo/métodos , Inmunoglobulina M/sangre , Lituania/epidemiología , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Estudios Seroepidemiológicos
17.
Nat Commun ; 12(1): 740, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33531472

RESUMEN

The COVID-19 pandemic affects more than 81 million people worldwide with over 1.7 million deaths. As the population returns to work, it is critical to develop tests that reliably detect SARS-CoV-2-specific antibodies. Here we present results from a multiplex serology test for assessing the antibody responses to COVID-19. In an initial large cohort, this test shows greater than 99% agreement with COVID-19 PCR test. In a second outpatient cohort consisting of adults and children in Colorado, the IgG responses are more robust in positive/symptomatic participants than in positive/asymptomatic participants, the IgM responses in symptomatic participants are transient and largely fall below the detection limit 30 days after symptom onset, and the levels of IgA against SARS-CoV-2 receptor binding domain are significantly increased in participants with moderate-to-severe symptoms compared to those with mild-to-moderate symptoms or asymptomatic individuals. Our results thus provide insight into serology profiling and the immune response to COVID-19.


Asunto(s)
/inmunología , Inmunoensayo/métodos , /patogenicidad , Adulto , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , Niño , Estudios de Cohortes , Colorado , Femenino , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Masculino , Persona de Mediana Edad , Pandemias/estadística & datos numéricos , Reacción en Cadena de la Polimerasa , Pruebas Serológicas
18.
Talanta ; 225: 121898, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33592692

RESUMEN

The current situation of the Covid-19 pandemic is indicated by a huge number of infections, high lethality, and rapid spread. These circumstances have stopped the activity of almost the entire world, affecting severely the global economy. A rapid diagnosis of the Covid-19 and a generalized testing protocol is essential to fight against the pandemic and to maintain health control in the population. Principal biosensing and diagnostic technologies used to monitor the spread of the SARS-CoV-2 are based on specific genomic analysis and rapid immune tests, both with different technology platforms that include advantages and disadvantages. Most of the in vitro diagnosis companies are competing to be the first on validating under different regulations their technology for placing their platforms for Covid-19 detection as fast as possible in this big international market. A comprehensive analysis of the commercialized technologies for the genomic based sensing and the antibody/antigen detection methods devoted to Covid-19 diagnosis is described in this review, which have been detailed and listed under different countries regulations. The effectiveness of the described technologies throughout the different stages of the disease and a critical comparison of the emerging technologies in the market to counterattack this pandemic have been discussed.


Asunto(s)
/diagnóstico , Inmunoensayo/métodos , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , /aislamiento & purificación , Anticuerpos Antivirales/inmunología , Antígenos Virales/inmunología , /virología , Humanos , Pandemias , /fisiología , Sensibilidad y Especificidad
19.
J Virol Methods ; 291: 114111, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33640374

RESUMEN

Rapid, sensitive, and precise multiplexed assays for serological analysis during candidate COVID-19 vaccine development would streamline clinical trials. The VaxArray Coronavirus (CoV) SeroAssay quantifies IgG antibody binding to 9 pandemic, potentially pandemic, and endemic human CoV spike antigens in 2 h with automated results analysis. IgG antibodies in serum bind to the CoV spike protein capture antigens printed in a microarray format and are labeled with a fluorescent anti-species IgG secondary label. The assay demonstrated excellent lower limits of quantification ranging from 0.3 to 2.0 ng/mL and linear dynamic ranges of 76 to 911-fold. Average precision of 11 % CV and accuracy (% recovery) of 92.5 % over all capture antigens were achieved over 216 replicates representing 3 days and 3 microarray lots. Clinical performance on 263 human serum samples (132 SARS-CoV-2 negatives and 131 positives based on donor-matched RT-PCR and/or date of collection) produced 98.5 % PPA and 100 % NPA.


Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Coronavirus/diagnóstico , Coronavirus/aislamiento & purificación , Análisis por Micromatrices/métodos , Pruebas Serológicas/métodos , Antígenos Virales/inmunología , /inmunología , Coronavirus/inmunología , Infecciones por Coronavirus/inmunología , Humanos , Inmunoensayo/métodos , Inmunoglobulina G/sangre , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología
20.
Food Chem ; 351: 129270, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33640770

RESUMEN

Small molecules are immunochemically classified as hapten that lacking of at least two epitopes, usually using competitive format for establishing immunoassays. However, theoretically, noncompetitive immunoassay format is more sensitive and has a wider analytical range. In the present study, a novel hapten of halofuginone was synthesized and used to produce a monoclonal antibody (mAb). By analyzing the binding kinetics, we found that the affinity of analyte-enzyme to mAb was much greater than that of analyte, which could result in a low sensitivity of competitive assay format. Based on this, we established a novel noncompetitive immunoassay by using a replacement approach. The noncompetitive format has obvious advantages in sensitivity and analytical range, which promoted approximately 3.5- and 5-fold, respectively, compared to the competitive immunoassay. Ultimately, the newly designed noncompetitive immunoassay in this work will provide insights as well as alternative method to traditional small molecule competitive assays.


Asunto(s)
Inmunoensayo/métodos , Límite de Detección , Piperidinas/análisis , Quinazolinonas/análisis , Anticuerpos Monoclonales/inmunología , Epítopos/inmunología , Haptenos/inmunología , Piperidinas/inmunología , Quinazolinonas/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...