Research progress of neutrophil-lymphocyte ratio in common lung diseases

Neutrophil-to-lymphocyte ratio (NLR) refers to the ratio of neutrophil to lymphocyte in peripheral blood.NLR is a new inflammation index which has attracted more and more attention in recent years.It reflects the dynamic balance between neutrophil and lymphocyte in peripheral blood and has been applied to the diagnosis, severity and prognosis of many diseases.This article reviews the research progress of NLR in common pulmonary diseases in order to improve clinicians′understanding of NLR. Key words: Lung diseases; Neutrophil-to-lymphocyte ratio