title: Usefulness of neutrophil to lymphocyte ratio in patients with chronic obstructive pulmonary disease: a prospective observational study.
abstract: OBJECTIVE
  Neutrophil to lymphocyte ratio (NLR) in peripheral blood is a useful systemic inflammatory response biomarker. However, NLR has not been studied in patients with chronic obstructive pulmonary disease (COPD). This study was aimed to evaluate the usefulness of NLR in patients with COPD.
  
  
  METHODS
  NLR was prospectively measured and compared in patients with COPD exacerbation (n = 59), patients with stable COPD (n = 61), and healthy controls (n = 28). NLR in patients with COPD exacerbation was repeatedly measured in the convalescent period. The correlation between NLR and clinical parameters was evaluated, and the predictors for respiratory hospitalization were analyzed by multivariate logistic regression.
  
  
  RESULTS
  NLR values were significantly higher in patients with COPD exacerbation compared with stable COPD patients and controls (12.4 ± 10.6, 2.4 ± 0.7, 1.4 ± 0.5, respectively; p < 0.001). NLR was significantly decreased during the convalescent period in patients with COPD exacerbation (4.5 ± 4.6 vs. 11.5 ± 8.8, p < 0.001). NLR exhibited a significant correlation with the body mass index, degree of airway obstruction, dyspnea, and exercise capacity (BODE) index, the 6-minute walk test, and the modified Medical Research Council scale. NLR ≥ 2.8 was an independent predictor with a borderline significance for respiratory hospitalization (odds ratio, 2.083; p = 0.079). Body mass index and forced expiratory volume in 1 second were independent predictors for respiratory hospitalization.
  
  
  CONCLUSIONS
  NLR is a straightforward and effective biomarker of COPD exacerbation that may serve as a predictor for respiratory hospitalization in patients with COPD.
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Hyang Rae
authors.initials: HR
authors.lastname: Lee
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Lee
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Sunmi
authors.initials: S
authors.lastname: Ju
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Sujin
authors.initials: S
authors.lastname: Lim
authors.affiliation: Division of Hematology and Oncology, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Se-Il
authors.initials: SI
authors.lastname: Go
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jung-Wan
authors.initials: JW
authors.lastname: You
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Yu Ji
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Division of Hematology and Oncology, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Gyeong-Won
authors.initials: GW
authors.lastname: Lee
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Yi Yeong
authors.initials: YY
authors.lastname: Jeong
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ho Cheol
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jong Deog
authors.initials: JD
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006760:Hospitalization; D006801:Humans; D007249:Inflammation / Q000097:blood; D007958:Leukocyte Count; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood*
chemical_list: D015415:Biomarkers
keywords: Neutrophil to lymphocyte ratio; Pulmonary disease, chronic obstructive; Respiratory hospitalization; Usefulness