A professor at Johns Hopkins University and one of the study's co-authors, stated that the use of commercial glucometers to quantitatively measure levels of disease-targeted antibodies "presents an innovative approach towards democratising the availability of immune protection data."
| Counting the amount of antibodies |
The diagnostic procedures for COVID-19 look for viral genetic material or proteins. On the other hand, tests that measure antibodies against SARS-CoV-2 can be used to determine previous exposure to the virus.
IgG antibodies, which make up the majority of the antibodies in blood, are among these antibodies. The production of an immune response against bacteria and viruses, particularly SARS-CoV-2, depends heavily on IgG antibodies.
The prognostic value of IgG antibody levels Trusted Source of the level of defence against a SARS-CoV-2 infection with symptoms. Therefore, assessing antibody levels in the community can aid in figuring out how long immunity to COVID-19 lasts following immunisation or a prior infection.
It is critical to evaluate the population's levels of immunological protection because the introduction of new SARS-CoV-2 strains has also increased concerns about decreasing immunity. Thus, measuring anti-SARS-CoV-2 antibody levels may aid in determining whether booster doses are necessary.
| How glucose meters are useful? |
In these tests, the enzyme invertase, which converts sucrose or sugar into glucose, is combined with antibodies or other detecting molecules. When a sucrose solution is added, the antibodies and invertase bind to the target protein in a sample and release glucose. A glucose meter can identify the amount of glucose produced, which is proportional to the quantity of the target protein.
However, combining antibodies with invertase has proven challenging. Through the use of intermediary substances like nanoparticles, researchers have inadvertently connected invertase with antibodies in several studies. However, this method can lead to variations in coupling strength and unreliable outcomes.
The genetic fusion of the antibody and invertase enzyme assures that a constant number of invertase molecules are bound to the antibody, unlike indirect coupling. All human IgG antibodies can be bound by these antibodies when combined with invertase.
The SARS-CoV-2 spike protein is put on a plastic strip for the new assay. The SARS-CoV-2-specific antibodies only attach to the spike proteins that cover the strip's surface when blood samples from people having a history of COVID-19 are added to the strip.
The strip is moved from a solution containing the antibody-invertase fusion protein to a sucrose solution after being rinsed to get rid of the non-specific antibodies.
The antibody-invertase fusion protein will thereafter be able to identify the SARS-CoV-2 specific IgG antibodies linked to the spike protein on the strip. Subsequently, the invertase enzyme converts sucrose into glucose, which can be measured with a glucose meter. The amount of SARS-CoV-2 specific IgG antibodies in the blood sample determines how much glucose is produced by the experiment.
| Possibilities of other diseases |
"This technology's immediate purpose is to increase production efficiency to enable widespread adoption.
We intend to correlate disease protection with antibody levels across a broad variety of people using emergent data from this platform, according to Dr. Spangler.
By covering the strip with a protein other than the wild-type SARS-CoV-2 spike protein, the assay might be used to different situations. To evaluate antibody levels against a particular SARS-CoV-2 variation, for instance, strips may be coated with the spike protein from that variety.