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1.
NeuroQuantology ; 20(10):2908-2915, 2022.
Article in English | EMBASE | ID: covidwho-2033475

ABSTRACT

Background: A severe antibody-mediated inflammatory demyelinating disease of the central nervous system is neuromyelitis optica spectrum disorder (NMOSD). Azathioprine (AZA) and Rituximab (RTX) were used to treat NMO-SD patients though not FDA approved yet. Aim of the study: To compare the effectiveness and safety of rituximab treatment versus azathioprine in treating individuals with NMOSDs. Methods: Seventy four Egyptian individuals with NMOSDs in this retrospective observational study and collecting their medical records from multiple sclerosis (MS) clinics, Neurology Departments, El-Maadi Military Hospital, and Cairo University hospitals. Fourty four patients received either treatment over two year duration, Group 1 (rituximab group) consisted of 19 patients, while group 2 (azathioprine group) consisted of 25 patients. Their full medical history, general and neurological examination, MRI brain and spinal cord results, and laboratory investigation were collected including immune assays and AQP-4 antibody. Results: There was no statistically significant difference between the groups in terms of brain MRI data at the baseline and outcomes. Between the two groups, there were statistically significant differences in last observer spinal MRI (p=0.025), annual relapse rate before treatment with RTX group (P=0.021), EDSS pretreatment (p=0.005), annual relapse rate post-treatment. When it came to the number of relapses after treatment, there was a high statistically significant difference between the two groups (p=0.016), with group 1 (RTX group) having zero relapses. There was a statistically significant decrease comparing EDDS scores pre-and post-treatment regarding the RTX group (p=0.003). Adverse events were Infusion rate reaction (5.3%) and pneumonic COVID (9.5%) of patients. Conclusion: RTX is more helpful and less harmful for NMO-SD patients than AZA.

2.
Frontiers in Immunology ; 13, 2022.
Article in English | EMBASE | ID: covidwho-2032775

ABSTRACT

DEAD-box RNA helicase 21 (DDX21), also known as RHII/Gu, is an ATP-dependent RNA helicase. In addition to playing a vital role in regulating cellular RNA splicing, transcription, and translation, accumulated evidence has suggested that DDX21 is also involved in the regulation of innate immunity. However, whether DDX21 induces or antagonizes type I interferon (IFN-I) production has not been clear and most studies have been performed through ectopic overexpression or RNA interference-mediated knockdown. In this study, we generated DDX21 knockout cell lines and found that knockout of DDX21 enhanced Sendai virus (SeV)-induced IFN-β production and IFN-stimulated gene (ISG) expression, suggesting that DDX21 is a negative regulator of IFN-β. Mechanistically, DDX21 competes with retinoic acid-inducible gene I (RIG-I) for binding to double-stranded RNA (dsRNA), thereby attenuating RIG-I-mediated IFN-β production. We also identified that the 217–784 amino acid region of DDX21 is essential for binding dsRNA and associated with its ability to antagonize IFN production. Taken together, our results clearly demonstrated that DDX21 negatively regulates IFN-β production and functions to maintain immune homeostasis.

3.
Journal of Hypertension ; 40(10):2022-2036, 2022.
Article in English | EMBASE | ID: covidwho-2032197

ABSTRACT

Objective:Biomarkers have become important in the prognosis and diagnosis of various diseases. High-throughput methods, such as RNA sequencing facilitate the detection of differentially expressed genes (DEGs), hence potential biomarker candidates. Individual studies suggest long lists of DEGs, hampering the identification of clinically relevant ones. Concerning preeclampsia - a major obstetric burden with high risk for adverse maternal and/or neonatal outcomes - limitations in diagnosis and prediction are still important issues. We, therefore, developed a workflow to facilitate the screening for biomarkers.Methods:On the basis of the tool DESeq2, a comprehensive workflow for identifying DEGs was established, analyzing data from several publicly available RNA-sequencing studies. We applied it to four RNA-sequencing datasets (one blood, three placenta) analyzing patients with preeclampsia and normotensive controls. We compared our results with other published approaches and evaluated their performance.Results:We identified 110 genes that are dysregulated in preeclampsia, observed in at least three of the studies analyzed, six even in all four studies. These included FLT-1, TREM-1, and FN1, which either represent established biomarkers at protein level, or promising candidates based on recent studies. For comparison, using a published meta-analysis approach, 5240 DEGs were obtained.Conclusion:This study presents a data analysis workflow for preeclampsia biomarker screening, capable of identifying promising biomarker candidates, while drastically reducing the numbers of candidates. Moreover, we were also able to confirm its performance for heart failure. This approach can be applied to additional diseases for biomarker identification, and the set of DEGs identified in preeclampsia represents a resource for further studies.

4.
HemaSphere ; 6:2790-2791, 2022.
Article in English | EMBASE | ID: covidwho-2032094

ABSTRACT

Background: Vaccination against COVID-19 commenced in England in December 2020, most haematology patients iwere included in the first wave as they are identified as extremely vulnerable. A second dose was administered 12 weeks after the initial dose, and booster doses became available in September 2021. Severely immune compromised patients started to be contacted in December 2021 to offer them a fourth dose of vaccine. With the availability of treatments there arose a need for early confirmation of presence or absence of antibodies against COVID-19 and testing for antibody was introduced into routine practice for patients about to commence chemotherapy, or those who had yet to complete the four-dose protocol. On the 1st of March most restrictions imposed during the pandemic were removed, in the expectation that the majority of people would have protective antibodies from vaccination. Aims: Over a period of six months from October 2021 to February 2022 we tested 90 patients attending routine haematology clinics, with a number of conditions, mainly malignancy under follow-up or recieving treatment. We reviewed the results of these tests, to assess degree of protection Methods: Retrospective analysis of all requests for SARS-Cov antibody tests carried out in our patient populations. Results: There were 55 males, and 35 females, with an average age of 65y (range 24-90) The majority attended clinic for management of haematological malignancy (Plasma cell disorders, Chronic Leukaemia, Lymphomas) with a smaller number of patients being managed for congenital or immune conditions. Diagnosis No detectable antibody Antibody<500 units Antibody > 500 units (Table Presented) Summary/Conclusion: Despite early availability of vaccines, and delivery of more than two doses to the majority of our patients, only half our patients had significant antibody response, and almost one quarter still had no detectable antibody. Although the number of new cases is reducing, in the vicinity of our Hospital there were 483 new cases per 100,000 on the last day of February, and during the six months of this study two fully vaccinated patients with CLL with no detectctable antibody died in Hospital with covid-19 pneumonitis. For some haematology patients particulalry those with CLL it is still not safe to come out.

5.
Clinical Immunology Communications ; 2022.
Article in English | ScienceDirect | ID: covidwho-2031198

ABSTRACT

Introduction: The AbC-19™ lateral flow immunoassay (LFIA) performance was evaluated on plasma samples from a SARS-CoV-2 vaccination cohort, WHO international standards for anti-SARS-CoV-2 IgG (human), individuals ≥2 weeks from infection of RT-PCR confirmed SARS-CoV-2 genetic variants, as well as microorganism serology. Methods: Pre-vaccination to three weeks post-booster samples were collected from a cohort of 111 patients (including clinically extremely vulnerable patients) from Northern Ireland. All patients received Oxford-AstraZeneca COVID-19 vaccination for the first and second dose, and Pfizer-BioNTech for the third (first booster). WHO international standards, 15 samples from 2 variants of concern (Delta and Omicron) and cross-reactivity with plasma samples from other microorganism infections were also assessed on AbC-19™. Results: All 80 (100%) participants sampled post-booster had high positive IgG responses, compared to 38/95 (40%) participants at 6 months post-first vaccination. WHO standard results correlated with information from corresponding biological data sheets, and antibodies to all genetic variants were detected by LFIA. No cross-reactivity was found with exception of one (of five) Dengue virus samples. Conclusion: These findings suggest BNT162b2 booster vaccination enhanced humoral immunity to SARS-CoV-2 from pre-booster levels, and that this antibody response was detectable by the LFIA. In combination with cross-reactivity, standards and genetic variant results would suggest LFIA may be a cost-effective measure to assess SARS-CoV-2 antibody status.

6.
Clinical Laboratory ; 2022.
Article in English | Web of Science | ID: covidwho-2025359

ABSTRACT

Background: To assess protective immunity among a general population against severe acute respiratory syndrome coronavirus 2, the correlation of the commercially available solid-phase assay (SPA) for SARS-CoV-2 IgG with a neutralization assay must be investigated. Methods: Both the neutralization assay and SPA were performed on samples of 143 recovered coronavirus disease 2019 (COVID-19) patients. SARS-CoV-2 IgG was measured using two SPAs for the chemiluminescence immunoassay principle with different target proteins: nucleocapsid and spike protein (Architect i2000SR [Abbott] and Liaison XL [DiaSorin], respectively). The plaque reduction neutralization test (PRNT) was conducted to obtain titers for the neutralizing antibody. Results: All patients had PRNT titers ranging from 10 to 2,560. Spike Ab SPA had greater sensitivity than nucleocapsid Ab SPA (81.1% [116/143] and 70.6% [101/143], respectively, p = 0.003). The values measured for both SPAs had a positive correlation with the PRNT titers (both R = 0.77, p < 0.001). To predict a high PRNT titer (>= 160), cutoff values of two SPAs were adjusted based on receiver-operating characteristics curve analysis. The nucleocapsid Ab SPA (cutoff index of 4.17) attained 90.3% sensitivity and 75.9% specificity, whereas the spike Ab SPA (cutoff value of 109 unit/mL) attained 87.1% sensitivity and 89.3% specificity. Therefore, the spike Ab SPA had greater specificity than the nucleocapsid Ab SPA (p = 0.003). Conclusions: The qualitative SPA for nucleocapsid Ab, as well as the quantitative SPA for spike Ab, had a modest positive correlation with the neutralization assay. However, spike Ab SPA was more suitable for neutralizing capacity.

7.
S Afr J Infect Dis ; 37(1):431, 2022.
Article in English | PubMed | ID: covidwho-2024689

ABSTRACT

BACKGROUND: Different diagnostic tools could improve early detection of coronavirus disease 2019 (COVID-19). A number of antibody-based serological point-of-care tests have been developed to supplement real-time reverse transcriptase polymerase chain reaction (RT-PCR)-based diagnosis. This study describes the validity of an antibody test, namely the immunoglobulin G (IgG)/immunoglobulin M (IgM) Rapid Test Cassette(®) (BNCP - 402 and BNCP402), manufactured by Spring Healthcare Services. METHODS: A prospective cohort validation study was undertaken at Chris Hani Baragwanath Academic Hospital between 16 July 2020 and 12 August 2020. A total of 101 patients admitted as COVID-19 cases under investigation were included in the study. They were divided into two categories depending on time since symptom onset: testing performed within seven days (early cohort) and after seven days (late cohort). The rapid antibody test was compared to the RT-PCR. RESULTS: Overall, the test has a sensitivity and specificity of 85.2% and 80.0%, respectively, for a combination of IgG and IgM. Sensitivity and specificity of IgG testing alone were 81.5% and 85%. Sensitivity improved for testing with increasing time from symptom onset;however, specifity was not significantly different. CONCLUSION: The study data adds to the body of evidence that because of relatively low sensitivity and specificity, there is a limited role for antibody-based point-of-care testing in the acute phase of COVID-19 infection, as was the case with this IgG/IgM Rapid Test Cassette (BNCP - 402 and BNCP402). There may exist a role for such testing in patients recovered from prior COVID-19 infection or in seroprevalence studies;however, additional evaluations at later timepoints from symptom onset are required.

8.
Journal of Clinical Medicine ; 11(17):5005, 2022.
Article in English | ProQuest Central | ID: covidwho-2023794

ABSTRACT

Background: Treatment with glucocorticoids (GCs) is associated with side effects. In contrast to the well-known negative impact on bone tissue exerted by oral GCs, few data are available regarding intravenous GCs. We investigated the influence of intravenous methylprednisolone (IVMP) on bone turnover markers (BTM): amino-terminal propeptide of type I procollagen (P1NP) and the C-terminal telopeptide of type I collagen (CTX), and on calcium metabolism parameters: 1,25-dihydroxyvitamin D (1,25(OH)2D), 25-hydroxyvitamin D (25(OH)D), calcium (Ca), phosphate (P), and intact parathormone (iPTH). Methods: In a prospective study, 23 consecutive subjects with Graves’ orbitopathy were included and treated with IVMP according to the European Group on Graves’ Orbitopathy recommendations. We evaluated effects on BTM occurring during the first 7 days after 0.5 g IVMP, and after the therapy with 12 IVMP pulses with a cumulative dose of 4.5 g. Results: We observed prompt but transient decrease of P1NP (p < 0.001) and the reduction of CTX (p = 0.02) after the first IVMP pulse. Following the full course of IVMP therapy, both P1NP and CTX were found decreased (p < 0.05 and p < 0.01, respectively). Conclusions: A single pulse of 0.5 g IVMP already decreases bone formation and resorption;however, this change is transient. The full therapy is associated with suppression of bone turnover.

9.
International Journal of Molecular Sciences ; 23(17):9991, 2022.
Article in English | ProQuest Central | ID: covidwho-2023754

ABSTRACT

Carbohydrate antigen 199 (CA199) is a serum biomarker which has certain value and significance in the diagnosis, prognosis, treatment, and postoperative monitoring of cancer. In this study, a lateral flow immunoassay based on europium (III) polystyrene time-resolved fluorescence microspheres (TRFM-based LFIA), integrated with a portable fluorescence reader, has been successfully establish for rapid and quantitative analysis of CA199 in human serum. Briefly, time-resolved fluorescence microspheres (TRFMs) were conjugated with antibody I (Ab1) against CA199 as detection probes, and antibody II (Ab2) was coated as capture element, and a “TRFMs-Ab1-CA199-Ab2” sandwich format would form when CA199 was detected by the TRFM-based LFIA. Under the optimal parameters, the detection limit of the TRFM-based LFIA for visible quantitation with the help of an ultraviolet light was 4.125 U/mL, which was four times lower than that of LFIA based on gold nanoparticles. Additionally, the fluorescence ratio is well linearly correlated with the CA199 concentration (0.00–66.0 U/mL) and logarithmic concentration (66.0–264.0 U/mL) for quantitative detection. Serum samples from 10 healthy people and 10 liver cancer patients were tested to confirm the performances of the point-of-care application of the TRFM-based LFIA, 20.0 U/mL of CA199 in human serum was defined as the threshold for distinguishing healthy people from liver cancer patients with an accuracy of about 60%. The establishment of TRFM-based LFIA will provide a sensitive, convenient, and efficient technical support for rapid screening of CA199 in cancer diagnosis and prognosis.

10.
International Journal of Molecular Sciences ; 23(16):9129, 2022.
Article in English | ProQuest Central | ID: covidwho-2023736

ABSTRACT

Current procedures for the assessment of chronic wound infection are time-consuming and require complex instruments and trained personnel. The incidence of chronic wounds worldwide, and the associated economic burden, urge for simple and cheap point-of-care testing (PoCT) devices for fast on-site diagnosis to enable appropriate early treatment. The enzyme myeloperoxidase (MPO), whose activity in infected wounds is about ten times higher than in non-infected wounds, appears to be a suitable biomarker for wound infection diagnosis. Herein, we develop a single-component foldable paper-based device for the detection of MPO in wound fluids. The analyte detection is achieved in two steps: (i) selective immunocapture of MPO, and (ii) reaction of a specific dye with the captured MPO, yielding a purple color with increasing intensity as a function of the MPO activity in infected wounds in the range of 20–85 U/mL. Ex vivo experiments with wound fluids validated the analytic efficiency of the paper-based device, and the results strongly correlate with a spectrophotometric assay.

11.
RMD Open ; 8(2), 2022.
Article in English | ProQuest Central | ID: covidwho-2020256

ABSTRACT

Immunocompromised patients treated with immunosuppressive drugs are at increased risk of adverse outcomes following SARS-CoV-2 infection.1 There is limited information on the effect of immunomodulatory therapies on the quality of SARS-CoV-2 vaccine-induced immunity in these populations.2 In a cohort of patients with immune-mediated inflammatory diseases (IMIDs) not treated with B-cell depleting agents or corticosteroids, we recently demonstrated that antibody levels and T cell responses showed greater waning by 3 months following the second dose of SARS-CoV-2 mRNA vaccine compared with healthy controls, emphasising the need for third doses of the vaccine.3 Here, we investigated immune responses in uninfected patients with IMID following a third dose of the Pfizer/BioNTech BNT162b2 or Moderna mRNA-1273 mRNA vaccine. NS, non-significant;RBD, receptor binding domain;FPR, false positive rate;PBMC, peripheral blood mononuclear cells;DMSO, dimethyl sulfoxide;SQRT, square root. Competing interests VP has no personal financial ties with any pharmaceutical company but has received honoraria for speaker and/or advisory board member roles from AbbVie, Almirall, Celgene, Janssen, Kyowa Kirin, LEO Pharma, Novartis, Pfizer, Sanofi, UCB and Union Therapeutics.

12.
Microbiol Spectr ; : e0212922, 2022.
Article in English | PubMed | ID: covidwho-2019796

ABSTRACT

The SARS-CoV-2 Omicron variant is characterized by substantial changes in the antigenic structure of the Spike (S) protein. Therefore, antibodies induced by primary Omicron infection lack neutralizing activity against earlier variants. In this study, we analyzed whether these antigenic changes impact the sensitivity of commercial anti-SARS-CoV-2 antibody assays. Sera from 37 unvaccinated, convalescent individuals after putative primary Omicron infection were tested with a panel of 20 commercial anti-SARS-CoV-2 immunoassays. As controls, we used samples from 43 individuals after primary infection with the SARS-CoV-2 ancestral wild-type strain. In addition, variant-specific live-virus neutralization assays were used as a reference for the presence of SARS-CoV-2-specific antibodies in the samples. Notably, in Omicron convalescents, there was a statistically significant reduction in the sensitivity of all antibody assays containing S or its receptor-binding-domain (RBD) as antigens. Furthermore, antibody levels quantified by these assays displayed a weaker correlation with Omicron-specific neutralizing antibody titers than with those against the wild type. In contrast, the sensitivity of nucleocapsid-protein-specific immunoassays was similar in wild-type and Omicron-infected subjects. In summary, the antigenic changes in the Omicron S lead to reduced immunoreactivity in the current commercial S- and RBD-specific antibody assays, impairing their diagnostic performance. IMPORTANCE This study demonstrates that the antigenic changes of the SARS-CoV-2 Omicron variant affect test results from commercial Spike- and RBD-specific antibody assays, significantly diminishing their sensitivities and diagnostic abilities to assess neutralizing antibodies.

13.
Journal of Thrombosis & Haemostasis ; : 1, 2022.
Article in English | Academic Search Complete | ID: covidwho-2019525

ABSTRACT

Background Objectives Methods Results Conclusions Vaccine‐induced immune thrombotic thrombocytopenia (VITT) is a prothrombotic, heparin‐induced thrombocytopenia (HIT)‐mimicking, adverse reaction caused by platelet‐activating anti‐platelet factor 4 (PF4) antibodies that occurs rarely after adenovirus vector‐based COVID‐19 vaccination. Strength of PF4‐dependent enzyme immunoassay (EIA) reactivity—judged by optical density (OD) measurements—strongly predicts platelet‐activating properties of HIT antibodies in a functional test. Whether a similar relationship holds for VITT antibodies is unknown.To evaluate probability for positive platelet activation testing for VITT antibodies based upon EIA OD reactivity;and to investigate simple approaches to minimize false‐negative platelet activation testing for VITT.All samples referred for VITT testing were systematically evaluated by semiquantitative in‐house PF4/heparin‐EIA (OD readings) and PF4‐induced platelet activation (PIPA) testing within a cohort study. EIA‐positive sera testing PIPA‐negative were retested following 1/4 to 1/10 dilution. Logistic regression was performed to predict the probability of a positive PIPA per magnitude of EIA reactivity.Greater EIA ODs in sera from patients with suspected VITT correlated strongly with greater likelihood of PIPA reactivity. Of 61 sera (with OD values >1.0) testing negative in the PIPA, a high proportion (27/61, 44.3%) became PIPA positive when tested at 1/4 to 1/10 dilution.VITT serology resembles HIT in that greater EIA OD reactivity predicts higher probability of positive testing for platelet‐activating antibodies. Unlike the situation with HIT antibodies, however, diluting putative VITT serum increases probability of a positive platelet activation assay, suggesting that optimal complex formation depends on the stoichiometric ratio of PF4 and anti‐PF4 VITT antibodies. [ FROM AUTHOR] Copyright of Journal of Thrombosis & Haemostasis is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

14.
IEEE Sensors Journal ; : 1-1, 2022.
Article in English | Scopus | ID: covidwho-2018960

ABSTRACT

The key to fight against a global pandemic such as COVID-19 is to have low-cost, reliable and fast response diagnostic tools. Electronic biosensors are preferred because of their ease of integration into current centralized health care networks and integration with modern point-of-care testing (POCT) devices. Printed electronic sensors provide a sensitive and reliable diagnostic platform to aid in controlling transmissible diseases. In this work, we demonstrate a fully printed capacitive biosensor. The sensor uses coplanar electrodes, coupled with capture antibodies immobilized on microporous Polyvinylidene-fluoride (PVDF) film to detect the SARS-CoV-2 spike protein in spiked buffer solutions. Antibody immobilization on PVDF surface is confirmed with confocal fluorescent imaging microscopy. Gold nanoparticle (GNP) tagged detection antibodies are also introduced to provide increased sensitivity. The gold nanoparticles provide a reflectance layer which leads to increased capacitance. This increased capacitance can be measured directly and has demonstrated the ability to screen for spiked samples with statistical significance. This fully printed capacitive immunoassay has the potential to be used as a transmissible disease screening and vaccine efficacy assessment tool for resource-limited areas. IEEE

15.
Analyst ; 2022.
Article in English | Web of Science | ID: covidwho-2016862

ABSTRACT

This article describes three novel electrochemical biosensing platforms developed to determine the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) spike antigen protein: glutaraldehyde, SARS-CoV-2 spike antibody and bovine serum albumin;N,N-dicyclohexyl carbodiimide/4-(dimethylamino)pyridine functionalised SARS-CoV-2 spike antibody and bovine serum albumin;and 1-ethyl-3-[3-dimethylaminopropyl]-carbodiimide hydrochloride/N-hydroxysuccinimide functionalised SARS-CoV-2 spike antibody and bovine serum albumin modified cysteine-based gold-flower modified glassy carbon electrodes. Two of the produced biosensors having better signals were used to determine the SARS-CoV-2 spike antigen in spiked-saliva and clinical samples containing gargle and mouthwash liquids and characterised using cyclic voltammetry, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The study provides highly significant information in terms of how coupling reagents ought to be used with linkers consisting of both amine and carboxylic acid terminals (i.e. cysteine). The electrochemical cathodic signals based on antibody-antigen protein interactions at approximately -270 mV were evaluated as a response using square wave voltammetry, and they increased in proportion to the SARS-CoV-2 spike antigen. The limit of detection values were 0.93 and 46.3 ag mL(-1) in a linear range from 1 ag mL(-1) to 100 pg mL(-1) and from 100 ag mL(-1) to 10 ng mL(-1) and the recovery and relative standard deviation values for spiked-saliva samples were 99.50% and 99.40%, and 3.87% and 0.13% for BSA/S-AB/GluAl/Cys/Au/GCE and BSA/S-AB/f-Cys/Au/GCE, respectively. The results showed that both biosensing platforms could be selectively and accurately used to diagnose COVID-19 in RT-PCR-approved clinical samples.

16.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 839-840, 2021.
Article in English | Scopus | ID: covidwho-2012958

ABSTRACT

In this study, an immuno-wall microdevice was developed to detect the spike protein of SARS-CoV-2 virus in saliva. We performed the immunoassay of the SARS-CoV-2 spike protein in saliva within 30 min without pretreatment. The assay time was about 6-time shorter than commercial ELISA (5 h) and the limit of detection (LOD) was 5 ng/mL, which was close to the commercial ELISA kit. This immuno-wall microdevice has a high promising future to be applied to the massive, low-cost, and rapid test for COVID-19. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

17.
Int J Infect Dis ; 122: 576-584, 2022 Jul 08.
Article in English | MEDLINE | ID: covidwho-2015433

ABSTRACT

OBJECTIVES: Observing the serological cross-reactivity between SARS-CoV-2 and dengue virus (DV), we aimed to elucidate its effect on dengue serodiagnosis and infectivity in a highly dengue-endemic city in India. METHODS: A total of 52 COVID-19 (reverse transcription-polymerase chain reaction [RT-PCR] positive) serum samples were tested in rapid lateral flow immunoassays and DV immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) to detect DV or SARS-CoV-2 IgG/immunoglobulin M. The COVID-19 antibody (Ab) positive samples were subjected to a virus neutralization test (Huh7 cells) using DV type 1 (DV1) clinical isolate. RESULTS: Most (93%) of the SARS-CoV-2 Ab-positive serum samples cross-reacted with DV in rapid or ELISA tests. All were DV RNA and nonstructural protein 1 (NS1) antigen-negative. COVID-19 serum samples that were DV cross-reactive neutralized DV1. Of these, 57% had no evidence of DV pre-exposure (DV NS1 Ab-negative). The computational study also supported potential interactions between SARS-CoV-2 Ab and DV1. CONCLUSION: DV serodiagnosis will be inconclusive in areas co-endemic for both viruses. The COVID-19 pandemic appears to impart a protective response against DV in DV-endemic populations.

18.
Braz J Microbiol ; 2022 Apr 14.
Article in English | MEDLINE | ID: covidwho-2014657

ABSTRACT

Immunological assays to detect SARS-CoV-2 Spike Receptor Binding Domain (RBD) antigen seroconversion in humans are important tools to monitor the levels of protecting antibodies in the population in response to infection and/or immunization. Here we describe a simple, low cost, and high throughput Ni2+ magnetic bead immunoassay to detect human IgG reactive to Spike S1 RBD Receptor Binding Domain produced in Escherichia coli. A 6xHis-tagged Spike S1 RBD was expressed in E. coli and purified by affinity chromatography. The protein was mobilized on the surface of Ni2+ magnetic beads and used to investigate the presence of reactive IgG in the serum obtained from pre-pandemic and COVID-19 confirmed cases. The method was validated with a cohort of 290 samples and an area under the receiver operating characteristic curve of 0.94 was obtained. The method was operated with > 82% sensitivity at 98% specificity and was also able to track human IgG raised in response to vaccination with Comirnaty at > 85% sensitivity. The IgG signal obtained with the described method was well-correlated with the signal obtained when pre fusion Spike produced in HEK cell lines was used as antigen. This novel low-cost and high throughput immunoassay may act as an important tool to investigate protecting IgG antibodies against SARS-CoV-2 in the human population.

19.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 1469-1470, 2021.
Article in English | Scopus | ID: covidwho-2012445

ABSTRACT

We present here a bead-based immunoassay which provides a sensitive direct electronic readout without the use of any intermediate optics. Analyte binding to antigen-coated microparticles is converted to probe-directed enzymatically amplified silver metallization on microparticle surfaces. The microparticles are then characterized in a high-throughput manner via electrical impedance spectra captured as they flow through a 3-D printed plastic micro-aperture. Metallized microparticles are found to have unique impedance signatures. This enables an electronic readout of the silver metallization density on microparticle surfaces and hence analyte concentration as well. Here we use this scheme to measure the antibody response to the viral nucleocapsid protein in convalescent COVID-19 patient serum. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

20.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 125-126, 2021.
Article in English | Scopus | ID: covidwho-2012421

ABSTRACT

The need to develop high-throughput diagnostic platforms for infectious diseases has never been more evident than with the emergence of SARS-CoV-2 and the ensued COVID-19 pandemic. Microfluidics, in tandem with its multiplexing capabilities, high sensitivity, and potential for automation, provides a unique advantage towards the development of high-throughput serological diagnostic platforms. Here, we present a microfluidic device that detects IgG or IgM raised against four SARS-CoV-2 antigens (spike, S;S1 subunit, S1;the receptor-binding domain, RBD;and nucleocapsid, N) from 50 serum samples in parallel. We validated the platform with a cross-sectional cohort of 66 samples from confirmed COVID-19 patients and a pre-pandemic control of 34 serum samples collected in 2018. The analysis of both antibodies against all four viral antigens provided a sensitivity of 90.4% and a specificity of 94.1%, with both parameters increasing to 100% in late-stage samples (21-30 days after symptoms onset). We expect our device to open the door to massive serological testing, impacting diagnostics, vaccine development, and epidemiological understanding of COVID-19. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

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