title: What is the normal value of the neutrophil-to-lymphocyte ratio?
abstract: BACKGROUND
  Neutrophil-to-lymphocyte ratio (NLR) has proven its prognostic value in cardiovascular diseases, infections, inflammatory diseases and in several types of cancers. However, no cut-off has been proposed on the basis of reference values coming from healthy population.
  
  
  METHODS
  Routine blood samples were obtained (n = 413) from workers (age: median 38, range: 21-66 years) involved in a health care prevention program, to determine means, standard deviations (SDs), 95% confidence intervals (95% CI), percentiles P2.5 and P97.5. A second independent sample of healthy volunteers is compared (n = 29).
  
  
  RESULTS
  The mean NLR is 1.65 [±1.96 SD: 0.78-3.53] (95% CI [0.75-0.81] and [3.40-3.66]). In the second cohort (healthy control), the NLR values are in the same range, whichever the used analyzer. No NLR assessed in the validation series is out of the proposed limits.
  
  
  CONCLUSIONS
  We have identified that the normal NLR values in an adult, non-geriatric, population in good health are between 0.78 and 3.53. These data will help to define the normal values of the NLR.
authors.affiliation: Department of Anesthesiology, Cliniques Universitaires Saint-Luc, Institute of Neuroscience (pole CEMO), Université Catholique de Louvain, 1200, Brussels, Belgium. forgetpatrice@yahoo.fr.|Department of Anesthesiology and Perioperative Medicine, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan, 101, 1090, Brussels, Belgium. forgetpatrice@yahoo.fr.
authors.forename: Patrice
authors.initials: P
authors.lastname: Forget
authors.affiliation: Department of Anesthesiology, Cliniques Universitaires Saint-Luc, Institute of Neuroscience (pole CEMO), Université Catholique de Louvain, 1200, Brussels, Belgium.
authors.forename: Céline
authors.initials: C
authors.lastname: Khalifa
authors.affiliation: Department of Clinical Biology, Cliniques Universitaires Saint-Luc, 1200, Brussels, Belgium.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Defour
authors.affiliation: Department of Clinical Biology, Cliniques Universitaires Saint-Luc, 1200, Brussels, Belgium.
authors.forename: Dominique
authors.initials: D
authors.lastname: Latinne
authors.affiliation: CESI-Prévention et Protection ASBL, Brussels, Belgium.
authors.forename: Marie-Cécile
authors.initials: MC
authors.lastname: Van Pel
authors.affiliation: Department of Anesthesiology, Cliniques Universitaires Saint-Luc, Institute of Neuroscience (pole CEMO), Université Catholique de Louvain, 1200, Brussels, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: De Kock
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007249:Inflammation; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology*; D011379:Prognosis; D012016:Reference Values; D055815:Young Adult
keywords: Cells count; Laboratory testing; Neutrophil-to-lymphocyte ratio; Reference values