Clinical utility of blood neutrophil-lymphocyte ratio in Japanese COPD patients

Kaori Sakurai, Shotaro Chubachi, Hidehiro Irie, Akihiro Tsutsumi, Naofumi Kameyama, Takashi Kamatani, Hidefumi Koh, Takeshi Terashima, Hidetoshi Nakamura, Koichiro Asano, Tomoko Betsuyaku

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20 Citations (Scopus)


Background: Neutrophil-to-lymphocyte ratio (NLR) is a biomarker of inflammation in chronic obstructive pulmonary disease (COPD) patients. But, a meaningful threshold and the longitudinal changes are unknown. We aimed to investigate the association between NLR and the clinical characteristics of COPD patients and to determine a meaningful threshold and the longitudinal changes for NLR. Methods: Keio University and its affiliate hospitals conducted an observational COPD cohort study over 3 years. We performed a blood examination and a pulmonary function test. Blood examination was completed at baseline and annually thereafter, at a time when the disease was stable. Two hundred seventy-four patients who had at least 3 blood examinations over 3 years were included. Results: Baseline NLR was correlated with baseline C-reactive protein (CRP) (r = 0.18, p = 0.003) and SAA (r = 0.34, p < 0.001). We defined an NLR score of 2.7 as the arbitrary cut-off value based on upper quartile points. COPD patients with NLR ≥ 2.7 were older (p = 0.037), had a lower BMI (p = 0.005) and a lower %FEV1 (p = 0.0003) compared to patients with NLR < 2.7. Receiver-operating-characteristic (ROC) curves showed the optimal cutoff for the baseline NLR in the predicting moderate/severe exacerbation to be 2.7, which was same as the upper quartile points. Follow-up analysis over 3 years revealed that the differences in the trends of NLR among the three groups based on the categories of exacerbations (moderate or severe, mild, no exacerbation) were significant (p = 0.006). Conclusions: NLR is associated with COPD severity and exacerbations. For predicting exacerbations, we estimated the threshold of NLR to be 2.7 at baseline.

Original languageEnglish
Article number65
JournalBMC Pulmonary Medicine
Issue number1
Publication statusPublished - 2018 May 2


  • Acute exacerbation
  • COPD
  • Comorbidity
  • NLR

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine


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