Abstract
SARS-CoV-2, the causative agent of coronavirus disease 19 (COVID-19), was identified in Wuhan, China. Since then, the novel coronavirus started to be compared to influenza. The haematological parameters and inflammatory indexes are associated with severe illness in COVID-19 patients. In this study, the laboratory data of 120 COVID-19 patients, 100 influenza patients and 61 healthy controls were evaluated. Lower lymphocytes, eosinophils, basophils, platelets and higher delta neutrophil index (DNI), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were found in COVID-19 and influenza groups compared to healthy controls. The eosinophils, lymphocytes and PLR made the highest contribution to differentiate COVID-19 patients from healthy controls (area under the curves (AUCs): 0.819, 0.817 and 0.716, respectively; P-value is <0.0001 for all). The NLR, the optimal cut-off value was 3.58, which resulted in a sensitivity of 30.8 and a specificity of 100 (AUC: 0.677, P < 0.0001). Higher leucocytes, neutrophils, DNI, NLR, PLR and lower lymphocytes, red blood cells, haemoglobin, haematocrit levels were found in severe patients at the end of treatment. Nonsevere patients showed an upward trend for lymphocytes, eosinophils and platelets, and a downward trend for neutrophils, DNI, NLR and PLR. However, there was an increasing trend for eosinophils, platelets and PLR in severe patients. In conclusion, NLR and PLR can be used as biomarkers to distinguish COVID-19 patients from healthy people and to predict the severity of COVID-19. The increasing value of PLR during follow-up may be more useful compared to NLR to predict the disease severity.
Highlights
In January 2020, the severe acute respiratory syndrome virus 2 (SARS-CoV-2) was identified in China and the disease was termed coronavirus disease 2019 (COVID-19) [1, 2]
The increase of C-reactive protein (CRP) was observed in COVID-19 and influenza groups compared to healthy controls (Table 1)
There were several significant differences, including lower lymphocytes, eosinophils, basophils and platelets, and higher delta neutrophil index (DNI), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were found in COVID-19 and influenza groups compared to healthy controls
Summary
In January 2020, the severe acute respiratory syndrome virus 2 (SARS-CoV-2) was identified in China and the disease was termed coronavirus disease 2019 (COVID-19) [1, 2]. Since this novel RNA beta-coronavirus began to be compared to the influenza virus. This novel RNA beta-coronavirus began to be compared to the influenza virus Both viruses that cause respiratory disease are transmitted by contact and droplets. It has been reported that haematological parameters and inflammatory indexes based on blood cell analysis had an important predictive value for the prognosis of infections, and many other diseases [4,5,6]. Haematological parameters and indexes such as the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were investigated as potential indicators of the severity of the COVID-19 [9, 10]
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