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

Abstract

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.

Severity of COVID-19 Respiratory Complications during Pregnancy are Associated with Degree of Lymphopenia and Neutrophil to Lymphocyte Ratio on Presentation: A Multicenter Cohort Study

“…NLR has been thought to reflect the balance between the innate immunity of the acute inflammatory response as reflected by neutrophils, and adaptive immunity as reflected by lymphocytes. 22 In patients with COVID-19, there is a neutrophilic response with a simultaneous lymphopenia. While the neutrophilic response is the expected innate response, the lymphopenia is thought to be due to sequestration of T-cells in the infected lungs and virally mediated lymphocyte apoptosis.…”

“…Therefore, a highly elevated NLR may represent a state of immunologic imbalance with unfavorable prognosis. 10,22 A meta-analysis of 10 published studies of pregnant women with COVID-19 found that 83.7% of cases had an elevated absolute neutrophil count, and 71.4% had a decreased absolute lymphocyte count. 26 Our data did not show an association of other inflammatory markers with disease severity.…”