Abstract:
Currently, there are several international guidelines that clearly describe that infection with the SARS-CoV-2 virus
presents abnormalities of the hemocytometric indices, especially in severe forms. The prognostic values of these
biomarkers reflect the intensity of the hyperinflammatory response, mediated by cytokines, and are strongly
associated with a poor outcome of SARS-CoV-2 infection. In severe forms of COVID-19, leukocytes show
lymphocytopenia, decrease in the number of monocytes and eosinophils, significant increase in neutrophils and
neutrophil/lymphocyte ratio. These simple and feasible parameters can be used to predict and early identify patients
with severe and critical forms of COVID-19. Leukocytosis, neutrophilia, lymphocytopenia, thrombocytopenia and
the neutrophil/lymphocyte ratio were identified as independent factors for the poor clinical outcome in this category
of patients and can be called, with certainty, true prognostic markers of severity, mortality, with the need to admit
patients to the intensive care unit. The estimation of hematological laboratory parameters at hospitalization, capable
of differentiating severe cases from non-severe cases, cases with high or low risk of mortality, allows awareness,
supervision and timely treatment of patients with early improvement of the clinical outcomes. However, the
interpretation of these indicators in the surveillance of patients with COVID-19 must take into account the
administration of drug remedies (corticosteroids) and the occurrence of bacterial co-infection that could interfere
with the result. The assessment of the accuracy of hemocytometric biomarkers needs to be determined in further
research worldwide – more relevant studies with more accurate design, more rigorous execution and larger sample
size.
