Refer quantity of leukocytes, lymphocytes, neutrophils, the relation of neutrophils to lymphocytes and also quantity of thrombocytes and eosinophils to hematologic markers on which distinguish risk groups from patients with COVID-19.
In work of Yang et al. it was reported about a lymphopenia at 80% of seriously ill patients of patients with COVID-19 while at Chen et al. the lymphopenia is found in 25% of patients with a moderate current of COVID-19. These observations indicate that the lymphopenia can be connected with weight of a course of a disease. Qin et al. analysed the markers connected with dysregulation of an immune response in a cohort of 450 patients with the confirmed COVID-19 and revealed that are characteristic of a severe disease the lowered level of lymphocytes, the increased quantity of leukocytes and the high relation of neutrophils to lymphocytes and also low percentage of monocytes, eosinophils and basophiles, in comparison with patients with a moderate current. The same way, in work of Henry et al. the conclusion in meta-analysis of 21 researches which included 3377 patients with the confirmed COVID-19 that at patients with a severe disease and deadly outcomes very high level of leukocytes and low level of lymphocytes and thrombocytes, in comparison with patients with not heavy disease and the recovered patients were observed is also drawn.
Patients with the confirmed COVID-19 have contents T-helperov and T-suppressors were below norm, and the T-helperov level is lower, the disease is heavier. Moreover, in hard cases percentage intact T-helperov was increased, and T-helperov memories decreased. At patients with COVID-19 the level of regulatory T-cells which will be more possibly damaged in hard cases is also lowered. Cytotoxic lymphocytes, such as cytotoxic T lymphocytes and natural killers, are necessary for control of a viral infection, and functional exhaustion of cytotoxic lymphocytes correlates with progressing of a disease. In the confirmed COVID-19 cases laboratory analyses showed that the average content of lymphocytes was below norm.
At a research in which 32 patients with COVID-19 participated the lowered level of eosinophils was revealed at 66% of patients. Between the level of eosinophils and level of lymphocytes there is a direct dependence. In other research in which 140 patients with COVID-19 participated the eosinopenia was found in 52.9%, and there was a direct correlation between the level of eosinophils and level of lymphocytes at the moderate course and the heavy course of an infection. Authors of Du et al. reported about very low level of eosinophils at 81.2% of patients at receipt that can serve as a marker of the adverse forecast. Liu et al. also reported about low values of eosinophils at the beginning of hospitalization which returned then to norm before an extract on the basis of what it is possible to draw a conclusion that increase in level of eosinophils can be the indicator of improvement of clinical picture COVID-19. However by results of the systematic overview of literature, "the eosinopenia can be not connected with an adverse current of COVID-19". In this regard the diagnostic value of an eosinopenia at COVID-19 demands additional studying with participation of bigger number of patients for establishment of sensitivity and specificity of level of eosinophils.
The relation of neutrophils to lymphocytes calculated by the simple attitude of quantity of neutrophils towards quantity of lymphocytes is an inflammation marker which can predict the probability of a lethal outcome at patients with various cardiovascular diseases. Moreover, during meta-analysis the relation of neutrophils to lymphocytes was revealed as a predictive biomarker at patients with sepsis. For patients with COVID-19 the relation of neutrophils to lymphocytes is independent risk factor of transition of disease to a severe form. At fifty (75.8%) during hospitalization the relation of neutrophils to lymphocytes made patients with progressing of a disease 2.973 that can indicate weight of a current of COVID-19. When using binary logistic regression the increased values of the relation of neutrophils to lymphocytes as an independent factor of a failure were revealed at COVID-19 that was confirmed during meta-analysis which showed that the relation of neutrophils to lymphocytes was considerably raised at patients with a severe form of COVID-19. Increase in the relation of neutrophils to lymphocytes can be result of disturbance of regulation of an expression of the inflammatory cytokines, abnormal growth of pathological neutrophils of low density and gene activation participating in death of lymphocytes as a result of action of an infection of SARS-CoV-2.
As the maintenance of thrombocytes represents a simple, cheap and available biomarker, and it is an independent exponent of weight of a course of a disease and a lethal outcome in resuscitation, it began to be used quickly as a potential biomarker for patients with COVID-19. At patients with COVID-19 considerable decrease in number of thrombocytes was noted, and it was lower at the died patients in comparison with recovered. Low level of thrombocytes is connected with the increased risk of a severe form of a disease and a lethal outcome for patients with COVID-19 and can act as the indicator of deterioration in patients during hospitalization.