VIR-CoV-S is a novel, state-of-art test, to detect and localize infected organs during acute Covid-19 disease delivering highly valuable information to clinicians, transferable and applicable to other viral infections.
The option to diagnose SARS-CoV-2 infections are PCR-based and antigen-based assays sampled from nasopharyngeal swabs. All these test systems do not provide any information where the virus replicates and which organs have been infected and potentially damaged through SARS-Cov-2 such as lungs, brain, heart, kidney and endothelium. These information are of significant clinical value because Covid-19 disease with mild symptoms can lead to tremendous organ damages.
The extrapulmonary spread of a SARS-CoV-2 infection is causing organ damages and is decisive for the course and recovery from Covid-19 disease (see also section 2.3). In order to initiate disease tailored therapies (for example myocardial insufficiencies because of heart damage) and specific monitoring (for example if known that the kidney has been affected) to follow-up of the patients. Such a test system is not available.
Virus-infected cells release exosomes carrying virus protein on their surface. In proof-of-concept studies we demonstrated by means of fluorescence flow cytometry that ExoMag-positive extracellular vesicles carry SARS-CoV-2 spike protein on their surface (see Figure below). For the first time we show applying our methodology that extracellular vesicles released from infected cells in blood of Covid-19 patients contain SARS-CoV-2 protein.
Legend: Detection of SARS-CoV-2 spike antigen on exosomes in blood of Covid-19 patients (right upper quadrant). Both Covid-19 patients were tested PCR positive Control show the upper right quadrant empty.
Our technology enables to identify exosomes released from infected organs by applying organ-specific markers. Thus, we can diagnose the affected organs such as heart, endothelium or kidney and provide this information to clinicians to initiate appropriate treatment or monitoring follow-up.
Our developed method forms the basis of VIR-CoV, to determine through high-resolution phenotyping of SARS-CoV-2 microvesicles the localization of infected organs during acute Covid-19 disease.
By means of flow cytometry analysis of SARS-CoV-2 carrying exosomes, we will apply antibodies, to identify the origin e.g. which cells and organs released these exosomes (see Figure below).
Legend: Schematic presentation of the approach: SARS-CoV-2 infected various organs (left), which released exosomes with specific cell surface markers. Simultaneous detection of SARS-CoV-2 on exosomes and organ-specific markers will enable to identify the infected organs during Covid-19 disease (right).