title: Neutrophil-to-Lymphocyte Ratio Is Associated with Impaired Interferon-Gamma Release to Phytohemagglutinin.
abstract: OBJECTIVE
  The neutrophil-to-lymphocyte ratio (NLR) has been shown to predict adverse outcomes in several pathologic conditions. The majority of indeterminate interferon (IFN)-γ release assays were due to inadequate IFN-γ response to the phytohemagglutinin. We sought to study the value of NLR to predict an indeterminate result of QuantiFERON-TB Gold In-Tube (QFT-GIT) performed in routine laboratory practice.
  
  
  METHODS
  Results from 2,773 QFT-GIT assays were analyzed. Data collection included demographic data, the level of IFN-γ to nil, mitogen, and TB antigen of QFT-GIT, total WBC, and a differential count. We calculated the absolute neutrophil count, lymphocyte count, and NLR.
  
  
  RESULTS
  Of the total, 224 (8.1%) indeterminate results were observed. Twelve (1.8%) showed indeterminate results in the NLR range from 1.71 to 2.84, but 132 (19.2%) had indeterminate results in NLR ≥ 5.18 (p < 0.0001). The likelihood ratio for indeterminate results were 2.70 (95% CI, 2.36-3.08) in NLR ≥ 5.18 and 1.93 (95% CI, 1.64-2.27) in lymphocyte count ≤ 1050/μL. NLR and neutrophil count were independent predictors for indeterminate QFT-GIT result in multiple regression analysis. The IFN-γ response to PHA was negatively associated with NLR (r = -0.33, p < 0.001).
  
  
  CONCLUSIONS
  We showed that the NLR is an independent predictor of indeterminate QFT-GIT result. Low frequency of indeterminate results in group with normal NLR may imply the importance of a balance between two cellular compartments in physiological and pathological conditions.
authors.affiliation: Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
authors.forename: Kwang-Sook
authors.initials: KS
authors.lastname: Woo
authors.affiliation: Department of Preventive Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
authors.forename: Byoung-Gwon
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
authors.forename: Jae-Lim
authors.initials: JL
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
authors.forename: Kyeong-Hee
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000097:blood; D007958:Leukocyte Count; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D012372:ROC Curve
chemical_list: D010835:Phytohemagglutinins; D007371:Interferon-gamma