Russians can measure the level of antibodies to coronavirus using various test systems, but each has its own sensitivity and measurement units. How not to get confused in your own indicators, the head of the scientific center for molecular genetic research of DNKOM Andrey Isaev explained to the Rosbalt correspondent.
“There are test systems of Russian production – Vector-Best, Hema, Alkor-Bio, Ecolab. There are American ones – Abbot, Beckman Coulter, Swiss – Roche, German – Siemens, Italian – Liason. Chinese Mindreys are also found, but they did not perform well. All these test systems have different sensitivity and their own units of measurement. The fact is that each test system is calibrated to a certain optical density, which calculates the concentration of antibodies in the blood. Some are measured in millimoles per liter, others in nanograms per milliliter or in conventional units. That is why the reference ranges are different in each system, ”the specialist explains.
According to him, sometimes it is a unit, sometimes – 10 cu. e. If the patient’s indicator is below the reference mark, it should be set to zero.
“If the level of antibodies is 11 with a reference mark of 10, we can talk about a borderline state. In fact, we do not know what will happen after the amount of antibodies drops below the threshold of the system, or how long it will stay at this threshold. There is no research on this topic. But, probably, when faced with a covid, the level of antibodies can jump, as the immune system “remembers” the virus and is activated, ”Isaev said.
The expert also emphasizes that each test system has its own sensitivity and specificity, which means that it can catch, for example, antibodies to seasonal coronaviruses, but not SARS-CoV-2. However, all test systems that have received a certificate of the Russian Federation can be used – it is still worth choosing them, focusing on the cost and production time, the expert is sure. In further measurements, in order to understand your own dynamics, it is necessary to use a test system of the same manufacturer so that you do not have to convert one measurement unit to another.
“Let me remind you that in no case should you spend money on express tests, better known as ‘Chinese strips’ – they catch antibodies very poorly,” Isaev warned.
Earlier, Rosbalt wrote why over time, after the transferred COVID-19, antibodies are becoming more and more.