Tag: COVID-19

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SARS-CoV-2 ELISA Used in Recent Study

by Eagle Biosciences

COVID-19 IgG and IgA ELISA Feature in Recent Study Analyzing Antibody Response to SARS-CoV-2 Exposure and Symptom Onset

A study has been published in Viruses titled Persisting Neutralizing Activity to SARS-CoV-2 over Months in Sera of COVID-19 Patients by B, Flehming et al. This study takes a look at the long term presences of SARS-CoV-2 RNA and IgG and IgA antibodies in three patients diagnosed with COVID-19 over a six month period. This research utilized the COVID-19 Nucleocapsid IgG Quantitative ELISA Assay Kit and the Anti-SARS-CoV-2 IgA (S1 RBD) ELISA Assay offered by Eagle Biosciences. The results of this study indicate that immunity to the virus may persist for a couple of months after onset of symptoms. These findings are consistent with some other studies done with larger cohorts of COVID-19 patients, however similar longitudinal studies should be done in the future to corroborate these findings.

Abstract

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

Click here for the full text.

To view Eagle Biosciences’ extensive collection of SARS-CoV-2 Assays and other products click here. 

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Angiopoietin-2 is Predictive for ICU Admission of COVID Patients

by Eagle Biosciences

Studies show that Angiopoietin-2 is a strong predictor in COVID-19 patients

Two research teams find that increased levels of the proinflammatory cytokine Angiopoietin-2 predicts transfer to the ICU and is responsible for hypercoagulation observed in critically ill COVID-patients.

Studies:

Angiopoietin-2 as a marker of endothelial activation is a good predictor factor for intensive care unit admission of COVID-19 patients. Smadja DM et al., Angiogenesis, 2020;1-10. Full text

Elevated Angiopoietin-2 inhibits thrombomodulin-mediated anticoagulation in critically ill COVID-19 patients. Hultstrom M et al., MedRxiv preprint server, 2021. Full text

Click here for a summary of the findings.

Background

SARS-CoV-2 is the causative agent of the coronavirus respiratory disease COVID-19. It has a diverse range of symptoms and may cause severe illness, in particular in patients with cardiovascular risk factors (1).

Endothelial damage and inflammation in SARS-CoV-2 infection

The inflammatory cytokine storm occurring in COVID-19 patients, leads to the recruitment of leukocytes which damage the capillary endothelium. The endothelial damage and inflammation in several organs in SARS-CoV-2 infection is a direct consequence of viral involvement and of the host inflammatory response (2).
Despite the routine thrombosis prophylaxis as standard of care treatment, the major COVID-19 complication is the hyperactivation of the coagulation system indicating a poor prognosis among COVID-19 patients in intensive care (3).

Angiopoietin-2 (ANG2) is a soluble marker of endothelial activation

Angiopoietin-2 is an angiogenesis regulator that can be rapidly released by the activated endothelium upon thrombin or inflammatory cytokines. ANG2 induces inflammation and vascular hyperpermeability and correlates with adverse outcomes in several critical care syndromes (4, 5).

Angiopoietin-2 is a crucial factor to predict transfer to the ICU

In COVID-19 patients, ANG2 was recently reported by Smadja and colleagues to be a relevant factor to predict transfer to the ICU as it was associated with poor lung compliance (6). Thus, showing that endothelial activation reinforces the hypothesis of a COVID-19-associated microvascular dysfunction.

Angiopoietin-2 inhibits anticoagulation in critically ill COVID-19 patients

Hulstrom and colleagues recently demonstrated that ANG2 levels in critically ill COVID-19 patients correlate with disease severity, hypercoagulation, and mortality. In addition, the researchers provided novel in vivo evidence for a direct role for ANG2 in coagulation through binding to and inhibition of thrombomodulin-mediated anticoagulation. The scientists suggest that inhibition of ANG2 might be beneficial for treating critically ill COVID-19 patients, as well as other patients with hypercoagulation (7).

About the Angiopoietin ELISA

  • Low sample volume – only 10µl needed
  • Assay range optimized for clinical samples
  • Ready to use standards and 2 controls included
  • Highly specific epitope mapped capture and detection antibodies

The human Angiopoietin-2 ELISA kit was developed and manufactured by Biomedica

Literature

  1. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Zhou F et al., Lancet, 2020; 395(10229):1054-1062.
  2. Endotheliitis in COVID-19. Varga S. Der Pathologe, 2020; 41(Suppl 2):99-102.
  3. COVID-19 and coagulation: bleeding and thrombotic manifestations of SARS-CoV-2 infection. Al-Samkari H et al., Blood, 2020:136, 489-500.
    Role of Angiopoietin-2 in Vascular Physiology and Pathophysiology. Akwii RG et al., Cells, 2019; 8(5): 471.
  4. Circulating angiopoietin-2 and the risk of mortality in patients with acute respiratory distress syndrome: a systematic review and meta-analysis of 10 prospective cohort studies. Li F et al., Therapeutic advances in respiratory disease, 2020; 14, 1753466620905274.
  5. Angiopoietin-2 as a marker of endothelial activation is a good predictor factor for intensive care unit admission of COVID-19 patients. Smadja DM et al., Angiogenesis, 2020;1-10.
  6. Elevated Angiopoietin-2 inhibits thrombomodulin-mediated anticoagulation in critically ill COVID-19 patients. Hultstrom M et al., MedRxiv preprint server, 2021.
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Studies Show that Neuropilin-1 Could Play Role in Transmission of COVID-19

by Eagle Biosciences
Studies Show that Neuropilin-1 Could Play Role in Transmission of COVID-19

Eagle News

Two Independent Research Teams Find Possible Link Between Neuropilin-1 and SARS-CoV-2 Transmission

Neuropilin-1 (NRP1) is an essential transmembrane cell surface receptor acting primarily as a co-receptor for various ligands (i.e. VEGF, Semaphorins). Due to alternative splicing or shedding, the extracellular region can be released into circulation as soluble Neuropilin-1. NRP1 functions in many key biological processes including the neuronal, cardiovascular and the immune system. The virus SARS-CoV-2 is the causative agent of the coronavirus disease COVID-19 NRP1 is expressed in multiple cell types in the body but occurs primarily on cells in the lung, nose and brain (i.e. respiratory and olfactory epithelium as well as in the CNS). SARS CoV 2 enters the host cells by its spike proteins mainly through its binding to the angiotensin converting enzyme 2 (ACE2).

Click here for summary of findings.

Studies:

Neuropilin-1 facilitates SARS-CoV-2 cell entry and provides a possible pathway into the central nervous system. Cantuti-Castelvetri L et al., Science 13 Nov, 2020; Vol. 370, Issue 6518, pp. 856-860. Full publication.

Neuropilin-1 is a host factor for SARS-CoV-2 infection. Daly JL et al., Science, 13 Nov 2020; Vol. 370, Issue 6518, pp. 861-865. Full publication.

About the Neuropilin-1 ELISA:

  • Only assay that measures free and ligand bound soluble NRP1
  • Low sample volume – only 10µl needed
  • Highly specific using epitope mapped antibodies
  • Rigorously validated according to international guidelines

Contact us for more information about this or our other SARS-CoV-2 related products.

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How Does COVID-19 Effect Your Central Nervous System?

by Eagle Biosciences

A new article published by Nelly Kanberg, et al. titled Neurochemical evidence of astrocytic and neuronal injury commonly found in COVID-19 has set out to study how COVID-19 impacts the central nervous system. It’s already known how this novel coronavirus effects the respiratory system, but does the body’s inflammatory response to this virus cause lasting effects to the nervous system?

For this study, two biomarkers in human plasma were measured; neurofilament light chain protein (NfL) and glial fibrillary acidic protein (GFAP). The samples came from patients who had mild, moderate or severe cases of COVID-19 (n=47). Of those 47 patients, the ones who had a severe case of COVID-19 showed higher concentrations of GFAP and NfL.

Glial Fibrillary Acidic Protien, or GFAP for short, is a known biomarker in the central nervous system (CNS) that is typically studied in those with brain injuries. When a brain injury occurs (concussion, retinal stess, tumors, etc.), GFAP is released into the blood stream and helps determine the severity of the injury. The results of this study help support and determine the relationship between COVID-19 and potentially lasting neural injuries.

To read this article in full, click here.

To learn more about how to measure GFAP, click here or contact us with your questions

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Comparison of SARS-CoV-2 antibody assays

by Eagle Biosciences

Comparison of the Elecsys® Anti-SARS-CoV-2 immunoassay with the EDITM enzyme linked immunosorbent assays for the detection of SARS-CoV-2 antibodies in human plasma

Both of Epitope Diagnostics’ Anti-SARS-COV-2 antibody assays (IgG and IgM) have been featured in a head-to-head comparison against Elecsys® Anti-SARS-CoV-2. Elecsys® Anti-SARS-CoV-2 is manufactured by Roche Diagnostics and has been the gold-standard in the diagnostics industry for automated assays.

Abstract: Recently, Roche Diagnostics (Rotkreuz, Switzerland) has launched the IVD CE-marked Elecsys® Anti-SARS-CoV-2 assay for the qualitative detection of SARS-CoV-2 antibodies on the cobas e immunoassay analyzers. The aim of this study was to compare the clinical performance of the Elecsys® Anti-SARS-CoV 2 assay with the EDITM SARS-CoV-2 IgM and IgG enzyme linked immunosorbent assays (ELISA), which we have recently established in our laboratory.

Read and Learn More Here

Coronavirus COVID-19 IgG ELISA Assay

Coronavirus COVID-19 IgM ELISA Assay Kit

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Expanded COVID-19 Assay Selection

by Eagle Biosciences

We, at Eagle Biosciences, Inc. are rapidly expanding our selection of Coronavirus Assays by welcoming two new research kits! With the ongoing pandemic, it’s more important now than ever that we continue to offer the highest quality assays to our customers. Here are our newest additions;

Anti-SARS-CoV-2 S1 (RBD) IgG ELISA Assay
Catalog Number: E111

The Anti-SARS-CoV-2 S1 (RBD) IgG ELISA Assay Kit is manufactured in Germany by Mediagnost. This assay is a highly specific enzyme immunoassay for the detection of IgG antibodies directed against SARS-CoV-2-S1 Receptor Binding Domain (RBD) in human blood. In this assay the recombinant Receptor Binding Domain (RBD) of SARS-CoV-2 S1 spike protein, which binds the ACE2 receptor, is used. The use of RBD increases the specificity of the assay since the domain is identical with SARS-CoV but not with MERS-CoV for example. Antibodies directed against the RBD neutralize both virus strains SARS-CoV and SARS-CoV-2.

Size: 1×96 wells
Incubation Time: 2 hours 40 minutes
Sample Type: Serum and Plasma
Sample Size: 100 µl
Controls Included

To learn more about the Anti-SARS-CoV-2 S1 (RBD) IgG ELISA Assay click here*

Anti-SARS-CoV-2 (S1, S2, N) IgG ELISA Assay Kit
Catalog Number: 3940

The Anti-SARS-CoV-2 (S1, S2, N) IgG ELISA Assay Kit is manufactured in Germany by Generic Assays. This assay is a module based Enzyme Immunoassay for the confirmation of positive IgG antibodies against SARS coronavirus 2 (SARS-CoV-2) in the first screening. The Anti-SARS-CoV-2 (S1, S2, N) IgG ELISA Assay Kit determines the specificity of antibodies against the main immunodominant antigens (Spike Glycoprotein 1, Spike Glycoprotein 2, Nucleocapsid) of SARS-CoV-2 in human serum or plasma. This test kit consists of modules separately coated with the major antigens of the virus as seen in the illistration below:

Size: 96 wells (24 samples x 4)
Incubation Time: 2 hours
Sample Type: Serum or Plasma
Number Of Tests Per Kit: 24 (22 samples + controls)
Sample Size: 50 µl
Controls Included

To learn more about the Anti-SARS-CoV-2 (S1, S2, N) IgG ELISA Assay Kit click here*

 

Check out our entire Coronavirus Series here or contact us with any questions or inquires

 

*These kits are for research use only and should not be used for diagnostic procedures.

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MHC Tools For COVID-19 Immune Monitoring

by Eagle Biosciences

Eagle News

Immune Monitoring COVID-19

Cells infected with SARS-CoV-2 are only visible to CD8+ T cell after virus proteins have been processed and presented by MHC class I molecules – and only then are the CD8+ T cell able to eradicate the infection. While antibodies against the COVID-19 virus are important to prevent or minimize infection, CD8+ T cells are responsible for clearing the virus from the body. Hence, the identification of peptides being presented by MHC class I is essential to:

  • Design potent vaccines eliciting a persistent response and
  • Using MHC class I tetramers to monitor cellular immune responses
  • Assessments of vaccine induced cellular immunity

immunAware allows researchers pursuing novel COVID-19 vaccines to generate tetramers and monitor immune responses. In the current pandemic scenario it is essential not to only focus on a few ALA allotypes; rather it is essential to be able to monitor as many allotypes as possible to ensure a novel vaccine targets a broad range of allotypes.

The easYmer reagents can also be used to validate the binding of predicted epitopes to further stratify the selection of potential COVID-19 vaccine targets.

As the US distributor for immunAware, Eagle Biosciences offer their extensive catalog of MHC tetramer products, including:

HLA-A*29:02 (WYMWLGARY) Class I Tetramer

See our full list of immunAware products here. If you have questions or for assistance with a specific product, please contact us.

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COVID-19 IgG and IgM ELISA’s Now Available

by Eagle Biosciences

Eagle Biosciences, Inc. is excited to announce the launch of two new assays to help with the growing epidemic of the COVID-19 virus that is spreading worldwide. The COVID-19 IgG and IgM ELISA’s are successfully validated assays for the qualitative detection of novel coronavirus infected pneumonia cases, suspected clustering cases, and other new coronaviruses in serum or plasma samples (COVID-19) through measurement of the COVID-19 IgM or IgG antibodies.

Assay Background
2019 novel coronavirus (COVID-19) is a single-stranded RNA coronavirus. Comparisons of the genetic sequences of is virus have shown similarities to SARS-CoV and bat coronaviruses. In humans, coronaviruses cause respiratory infections. Coronaviruses are composed of several proteins including the spike (S), envelope (E), membrane (M), and nucleocapsid (N). Results suggest that the spike protein retains sufficient affinity to the Angiotensin converting enzyme 2 (ACE2) receptor to use it as a mechanism of cell entry. Human to human transmission of coronaviruses is primarily thought to occur among close contacts via respiratory droplets generated by sneezing and coughing. IgM is the first immunoglobulin to be produced in response to an antigen and will be primarily detectable during the early onset of the disease.

Assay Principle
These COVID-19 IgG and IgM ELISA assay kits are designed, developed, and produced for the qualitative measurement of the COVID-19 IgM or COVID-19 IgG antibody in serum. The assays utilizes the “IgM capture” or “IgG capture” methods on microplate based enzyme immunoassay technique.

Assay controls and samples are added to the microtiter wells of a microplate that was coated with an anti-human IgM or IgG specific antibodies. After the first incubation period, the unbound protein matrix is removed with a subsequent washing step. A horseradish peroxidase (HRP) labeled recombinant COVID-19 antigen is added to each well. After an incubation period, an immunocomplex of Anti-hIgM or Anti-hIgG antibody – human COVID-19 IgM or IgG antibody – HRP labeled COVID-19 antigen is formed if there is novel coronavirus IgM or IgG antibody present in the tested materials. The unbound tracer antigen is removed by the subsequent washing step. HRP-labeled COVID-19 antigen tracer bound to the well is then incubated with a substrate solution in a timed reaction and then measured in a spectrophotometric microplate reader. The enzymatic activity of the tracer antigen bound to the coronavirus IgM of IgG on the wall of the microtiter well is proportional to the amount of the coronavirus IgM or IgG antibody level in the tested materials

To learn more, view assay’s here or contact us for questions! 
Novel Coronavirus COVID-19 IgM ELISA Kit
Novel Coronavirus COVID-19 IgG ELISA Kit