Four options: Russian scientists have created high-precision test systems for antibodies to coronavirus

The team of the Institute of Bioorganic Chemistry. Academicians M.M. Shemyakina and Yu.A. Ovchinnikov RAS (IBCh RAS) created high-precision test systems for the detection of patients with SARS-CoV-2 coronavirus. This was reported to RT by one of the developers, engineer of the separation and purification workshop of the IBCh RAS Georgy Scriabin.

In the course of the study, the scientists isolated the antigens that are inherent only to SARS-CoV-2 proteins - antigens - necessary for creating tests. Then, based on them, a complex of antigens was obtained to detect antibodies to coronavirus both in serum and in human blood plasma. 

An experimental batch of test systems has been clinically tested in the red zone of the Central Clinical Hospital of the Russian Academy of Sciences on the sera of more than 400 patients with coronavirus infection, the developers said.

Test systems are presented in four versions: a general screening test and three systems for determining a specific class of antibodies.

“First, a general screening for antibodies is needed to get a yes or no answer. If they are found, this means that the virus either still exists or has already been in the body. And in this case, an extended analysis is needed, ”explained Georgy Scriabin in an interview with RT.

In the case of a positive screening test, it is necessary to detect the presence in the body of each of the three classes of antibodies: IgA, IgG and IgM (immunoglobulin A, G and M). Checking for the presence of these antibodies gives doctors an understanding of what is happening in the patient’s body. So, IgM antibodies appear in the early days of the disease. IgA antibodies are markers of current or recent coronavirus infection, which can occur without manifestations, in mild form or in the form of severe bilateral pneumonia. The IgG class tells doctors about the presence of immunity, since these antibodies appear in the blood about 20 days after infection.

A comparison of the volume of presence of these three classes of antibodies in the body allows the presence of coronavirus in the body, the stage of development and the intensity of the disease to be detected. If the coronavirus "has left", then the tests will show how long it happened, will allow to determine the severity of the disease and the strength of the developed immunity.

George Skryabin noted that effective test systems for antibodies to coronavirus already exist on the market. The peculiarity and uniqueness of the new system is that it covers three classes of antibodies and, in his words, works “well and accurately”.

“During clinical trials, we took conditional 50 sera with confirmed antibodies and 50 without antibodies. In our sample, the test system has never made a mistake, ”said RT Scriabin.

Currently, the kit for testing patients for IgG antibodies has passed state registration, and the registration of the remaining three sets is in the final stage. According to the IBCh RAS, a patent application is also being filed for this development.