Neutrophils to Lymphocytes Ratio and the Prognosisof the COVID-19 Patients

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new pandemic virus, a global concern, and has threatened human health. This virus binds to the Angiotensin-Converting Enzyme 2 (ACE2) that is expressed on different cells, especially on the alveolar cells. So the virus can enter the lung cells and causes respiratory syndromes. In Coronavirus Disease 2019 (COVID-19) that is caused by SARS-CoV-2, respiratory failure, and acute inflammation is the main cause of death. According to several reports, multiple factors, such as Neutrophils to Lymphocytes Ratio (NLR) have prognostic potentials in COVID-19. This study aims to review this parameter to have a better prediction about the condition of the patients and their treatments. According to this review, the NLR ratio that is related to the innate immune responses and inflammation can be helpful in the discrimination of severe from non-severe cases of COVID-19 patients.