Tag: SARS-COV-2

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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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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.