As is well-known today, one of key factors of a pathogeny of severe forms of a koronavirusny infection, development of system inflammation is. Increase in level of markers of inflammation is the critical moment which is the cornerstone of system processes of a vasculitis and pathologies of process of a blood coagulation which cause the most part of damages of a parenchyma of vitals.
Now enough the facts demonstrating increase in level of markers of inflammation at COVID-19 is established. For example, according to researches, the S-jet Protein (SJP) was considerably raised at the initial stage of a course of a disease at patients with a severe form of COVID-19, even to identification of characteristic disturbances on KT. It is important to remember that SRB indicates progressing of a disease and is an early marker of a severe form of COVID-19. During the correlation analysis it is also revealed that SRB, SOE and the relation of granulocytes to lymphocytes positively correlated with weight assessment on KT.
Immunological biomarkers, such as SILT-6 and serumal ferritin are considerably raised at patients with a lethal outcome in comparison with the recovered patients and when comparing a severe and not severe form of a disease. Substantial increase of inflammatory cytokines, such as SILT-6, is connected with a so-called tsitokinovy storm, against the background of acute injury of lungs and ORDS, and can lead to further damage of fabrics and multiorgan insufficiency. Such strong system inflammation is connected with a lymphopenia and indicates high severity of a disease. Carry IL-6, IL-2, IL-7, the factor of a necrosis of tumors (FNT) to the main markers of inflammation an alpha, ИФНγ-индуцируемый protein (IP) - 10, monocytic hemoattraktantny protein-1 (MCP-1), macrophagic protein of inflammation (MIP) of a 1-alf, a granulotsitarny colony stimulating factor (G-CSF), SRB, pro-calcitonin (PKT) and ferritin.
Some of above-mentioned indicators indicate not only severity of a course of a disease, but also risk of a lethal outcome. During a series of retrospective clinical trials at late the died patients higher IL-6 levels, ferritin and SRB in comparison with the recovered patients were observed. By results of clinical practice it is recommended to determine the levels IL-6, D-dimer, LDG and transaminase in addition to standard laboratory analyses for stratification of patients with high risk and identifications of patients which can be helped by the immunotherapy inhibiting activity of SILT-6 with use of a totsilizumab.
In addition to a subject about biomarkers at COVID-19, it would be desirable to tell several words about pro-calcitonin. Pro-calcitonin (PKT) — the pro-peptide deprived of hormonal activity. In normal conditions it is developed by S-cells of a thyroid gland. Pro-calcitonin is not found in healthy people (less than 0.1 ng/ml). During a heavy infection (bacterial, parasitic and fungal) with system manifestations the level of pro-calcitonin can grow over 100 ng/ml and is developed generally in fabrics outside a thyroid gland. In spite of the fact that its biological mechanism of action mostly is not studied, the sequence homology between pro-calcitonin and other human cytokines, for example, family the FNO-alpha, SILT-6 and so forth, supports a hypothesis that pro-calcitonin is an inflammation mediator.
Synthesis of PKT can increase at the expense of endotoxins and/or cytokines (for example, SILT-6, the FNO-alpha and SILT-1 a beta). It is revealed that ekstratireoidny synthesis of PKT happens in a liver, a pancreas, kidneys, lungs, intestines and in leukocytes. However it was shown that synthesis of PKT is suppressed in the absence of a bacterial infection. At the system inflammatory answer to virus or noninfectious incentives the PKT level either remains invariable, or increases only slightly. Therefore PKT values were more indicative, than values of leukocytes and SRB, for establishment of difference of a bacterial infection from other inflammatory process.
As for patients with COVID-19, at more severe forms of a course of a disease more noticeable increase in the PKT level in comparison with not severe forms was observed. Slight increase of the PKT level (much lower than 0.5 ng/ml) is the important indicator of difference of patients from SARS-CoV-2 and patients without SARS-CoV-2. PKT values remain within the range of referensny values with patients with the uncomplicated course of an infection of SARS-CoV-2; and any significant increase indicates accession of a bacterial infection, development of a severe form of a disease and more difficult clinical picture.