Association of the Neutrophil-to-Lymphocyte Ratio with Lung Function and Exacerbations in Patients with Chronic Obstructive Pulmonary Disease.
BACKGROUND
The ratio of neutrophils to lymphocytes (NLR) is a widely available marker of inflammation. Several types of inflammatory cells and mediators have been found to be involved in the progression of chronic obstructive pulmonary disease (COPD). We sought to evaluate the association of the NLR with severity of airflow limitation and disease exacerbations in a COPD population.


METHODS
We analyzed 885 patients from the Korean COPD Subtype Study cohort that recruited subjects with COPD from 44 referral hospitals. We determined the relationship of NLR levels to severity of lung function using a linear regression model. In addition, we analyzed the experiences of COPD exacerbation according to the NLR quartiles.


RESULTS
NLR levels were inversely associated with severity of airflow limitation as measured by FEV1% predicted and absolute values after adjustments for age, gender, body mass index, pack-years of smoking, and the use of inhaled corticosteroid (P<0.001, respectively). In the multivariate binary regression model, the NLR 4th quartile (vs. 1st quartile) was found to be a significant predictor of exacerbations during 1-year follow-up (OR = 2.05, 95% CI = 1.03 to 4.06, P = 0.041). Adding an NLR to FEV1 significantly improved prediction for exacerbations during 1-year follow-up as measured by the net reclassification improvement (NRI = 7.8%, P = 0.032) and the integrated discrimination improvement (IDI = 0.014, P = 0.021).


CONCLUSIONS
The NLR showed a significant inverse relationship to airflow limitation and was a prognostic marker for future exacerbations in patients with COPD.
Department of Internal Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
Heock
H
Lee
Department of Internal Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
Soo-Jung
SJ
Um
Department of Internal Medicine, Pusan National University College of Medicine, Busan, Republic of Korea.
Yun Seong
YS
Kim
Department of Internal Medicine, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea.
Deog Kyeom
DK
Kim
Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea.
An Soo
AS
Jang
Department of Internal Medicine, Dongguk University Gyeongju Hospital, Gyeongju, Republic of Korea.
Hye Sook
HS
Choi
Department of Internal Medicine, Kyung Hee University Gangdong Hospital, Seoul, Republic of Korea.
Yee Hyung
YH
Kim
Department of Internal Medicine, Konkuk University College of Medicine, Seoul, Republic of Korea.
Tae Eun
TE
Kim
Department of Clinical Pharmacology, Konkuk University College of Medicine, Seoul, Republic of Korea.
Kwang Ha
KH
Yoo
Department of Internal Medicine, Hallym University College of Medicine, Anyang, Republic of Korea.
Ki-Suck
KS
Jung
D005260:Female; D006761:Hospitals; D006801:Humans; D008168:Lung / Q000502:physiology*; D008214:Lymphocytes / Q000166:cytology* / Q000502:physiology; D008297:Male; D009504:Neutrophils / Q000166:cytology* / Q000502:physiology; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000473:pathology / Q000503:physiopathology*