MILLIPLEX® assays for detection of human immunoglobulins against SARS-CoV-2 antigens
The SARS-CoV-2 coronavirus is the pathogenic cause of the human disease COVID-19. The virus particle consists of RNA encapsulated by the nucleocapsid (N) protein which is enveloped by a membrane (M) protein. The corona-like spike proteins surrounding this inner core consists of subunits S1 and S2, and the receptor binding domain (RBD) which binds to the human cellular angiotensin converting enzyme 2 (ACE2) receptor. Upon binding, the virus enters the cell, takes over the cellular machinery, reproduces, and the viral contagion continues. Viral structural proteins offer antigenic potential for an immune response. Upon viral infection, the humoral immune system responds first by producing the immunoglobulin IgM, followed later by IgG, which can convey long-lasting immunity. IgA, a mucosal immune response, is also found in blood.
By testing human serum and plasma for IgM, IgG, and IgA antibodies which bind to SARS-CoV-2 antigens, researchers may identify those who have been exposed to the SARS-CoV-2 virus and mounted some level of immune response. Researchers may further understand the immune response throughout infection and recovery from COVID-19.
Each of our three configurable 4-plex panels allow the researcher to select any or all the following viral antigens: SARS-CoV-2 Spike S1, Spike S2, RBD, and N protein.
Example Data
Reagent COVID-19 convalescent patient sample, detergent-solvent inactivated, was assayed internally according to protocol in each of the three MILLIPLEX® SARS-CoV-2 Antigen Panels for IgM, IgG, and IgA binding to the four SARS-CoV-2 antigens. Assay control beads C1, C2, C3 and Negative Control are shown in cyan. Note that the assay control beads for the IgG assay are shared components with our auto-antibody kits and are in reverse order of high, medium, and low IgG bound to bead. Antigen-beads for SARS-CoV-2 Spike S1, Spike S2, RBD, and N protein are shown in blue. (Mean, n=4 separate assays, +/- SD)
For Research Use Only. Not For Use In Diagnostic Procedures.
MILLIPLEX® assays for cytokine storm-related COVID-19 research
When the immune system overreacts to a pathogen or other immunogenic substance such as a drug, a hyperinflammatory response may trigger excess production of signaling molecules from immune cells. This is referred to as cytokine storm syndrome (CSS) or cytokine release syndrome (CRS). Acute or systemic inflammation results in fluid buildup in the lungs, respiratory distress, multiple organ failure, and can be fatal.
In response to SARS-CoV-2 viral infection of the lungs, a cytokine storm can result. Over-produced immune cells and their signaling molecules cause a local inflammatory response in the lungs leading to respiratory distress and reduced blood oxygen levels. A cytokine storm can contribute to severe clinical symptoms and poor patient outcomes.
Human Studies
Some early publications on the cytokine profile for COVID-19 have found increased levels of IL- 2, IL-7, G-CSF, IP-10, MCP-1, MIP-1α, TNFα, and Ferritin 1. In a separate study, IL-6 was also found to increase with SARS-CoV-2 infection 2. Tocilizumab, an immunosuppressive monoclonal antibody therapy that targets the IL-6 receptor (IL-6R) has been approved for Phase III clinical trials by the FDA to evaluate its effectiveness for the treatment of severe COVID-19 pneumonia as of March 26, 2020. IL-1β, IL- 1RA, IL-8, IL-9, IL-10, FGF-basic, GM-CSF, IFNγ, MIP-1β, PDGF, and VEGF have also been shown to be increased in COVID-19 patients compared to healthy subjects 3.
Non-Human Primate Studies
Research on SARS-CoV-2 is also being conducted in nonhuman primates such as rhesus macaques, which will allow researchers to test possible vaccines and antiviral medications/treatments in relevant animal models. A recent Nature publication used MILLIPLEX® Non-Human Primate assays to analyze serum over multiple time points in macaques with SARS-CoV-2 exposure for changes in cytokine and chemokine levels, and showed increases in IL-1RA, IL-6, IL-10, IL-15, MCP-1, MIP-1β, along with a decrease in TGFα 4.
Using MILLIPLEX® multiplex immunoassays to understand the immune response to COVID-19
Our MILLIPLEX® multiplex immunoassays offer researchers the ability to simultaneously quantitate numerous analytes critical to understanding the immune response in humans. Our 48-plex Human Cytokine/Chemokine/Growth Factor Panel A saves time and sample volume for a snapshot of analyte profiles during a cytokine storm, sepsis, or other disease states. We offer a wide array of MILLIPLEX® soluble protein panels and cell signaling kits to help elucidate the downstream signaling pathways when researching antiviral immune response. Our portfolio offers the widest range of analytes across the most species, including non-human primate panels for vaccine research.
Comparison of Sepsis vs. Normal Serum/Plasma Samples Using MILLIPLEX® Human Cytokine Panel A
Figure 1. Healthy control (n=20) and sepsis patients (n=16) serum/plasma samples (obtained from BioIVT, Discovery, and BioChemed) were tested neat (25 μL/well) in the HCYTA-60K panel. Shown here are a subset of the analytes which have been mentioned in recent publications to be increased in SARS-CoV-2 cytokine release syndrome (CRS).
For Research Use Only. Not For Use In Diagnostic Procedures.
MILLIPLEX® assays for emerging COVID-19 research areas
ACE and ACE2 play a role in the plasma kallikrein-kinin system (KKS), which controls the blood coagulation system, endothelial cell growth, angiogenesis, the complement pathway and the renin angiotensin system (RAS)5. Bradykinin, a kinin peptide, along with kallikreins and kininogens make up the KKS. ACE2 functions to decrease bradykinin, and when disrupted, higher bradykinin levels can increase systemic inflammation6. In addition to CCS, the disruption of the RAS/KKS may lead to severe complications in COVID-19. Moreover, the activation of bradykinin receptors mediates inflammation, leading to distinctly elevated cytokine levels. Our MILLIPLEX® multiplex immunoassays offer researchers the ability to simultaneously quantitate numerous analytes critical to understanding these mechanisms triggered by COVID-19, including complement components in our Human Complement Panel 1 and Panel 2, Renin, Kallikrein-6, and our Human Angiogenesis/Growth Factor Panel 1 and Human Angiogenesis Panel 2.
Coagulopathy is severe condition that has been associated with COVID-19, indicated by elevated D-dimer levels and extensive microthrombosis in lung autopsies7. Thrombotic complications are associated with multiorgan failure and a higher rate of mortality. Higher levels of acute phase proteins, such as CRP and fibrinogen, have been shown to correlate with this COVID-19 severity. Increased cytokine levels, a hallmark of disease noted previously, can lead to upregulation of adhesion molecules such as ICAM-1, VCAM-1, P-selectin, and e-Selectin8. With our MILLIPLEX® Human Cardiovascular Disease Panel 2, ICAM-1, VCAM-1, D-Dimer, and P-selectin can be quantitated simultaneously to study this critical condition.
Your research breakthroughs depend on reliable, high-performing products and services. Our MILLIPLEX® portfolio of immunoassays is the largest portfolio of multiplex biomarker assays, based on Luminex® xMAP® technology, offering you consistent, high-quality results, so you can do your best work while saving time, labor and cost.
For Research Use Only. Not For Use In Diagnostic Procedures.
COVID-19 On-Demand Webinars Featuring MILLIPLEX® Kits
View our on-demand webinars demonstrating how MILLIPLEX® multiplex assays have been used in COVID-19 research. In these webinars you will discover how the immune response in COVID-19 patients is assessed and how to successfully integrate multiplex immunoassays into your disease research workflow.
The Dynamics of Sars CoV 2 Specific Antibody Responses in COVID-19 Patients Presented by Prof. Dr. Christina S. Falk, Institute for Transplantation Immunology, Hannover
Immune Responses in Severe COVID-19 Patients Presented by Prof. Dexi Chen, Beijing Institute of Hepatology
MILLIPLEX® multiplex immunoassays for use in COVID-19 and cytokine storm research Presented by Brooke Gilliam, MilliporeSigma
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How to Cite Our Products in Your Paper
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How to cite MILLIPLEX® Assay kits:
- If you are based in the USA or Canada, state MilliporeSigma as the source of your assay.
- If you are based anywhere in the world besides the USA or Canada, state Merck KGaA, Darmstadt, Germany, as the source of your assay.
- Include the full MILLIPLEX® kit name and kit Catalog Number, also list the analytes you used from the kit.
- Include the species of samples you used, and how you diluted your samples.
Human and Mouse Procalcitonin available through our Custom Protein Immunoassay and Biomarker Development Services. For more information, visit our Custom Immunoassay Page.
MILLIPLEX® kits are manufactured in facilities which are ISO 9001:2015 compliant and are for research use only (RUO), not for use in clinical or for medical diagnostic purposes.
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