Neutrophil-lymphocyte ratio is associated with all-cause mortality among critically ill patients with acute kidney injury

• Published in: Clinica chimica acta 2019-03, Vol.490, p.207-213
• Main Authors: Fan, Lai Lai, Wang, Yi Jun, Nan, Cun Jin, Chen, Ying He, Su, Hong Xia
• Format: Article
• Language: English
• Subjects: Acute kidney injury; Acute Kidney Injury - diagnosis; Acute Kidney Injury - immunology; Acute Kidney Injury - mortality; Aged; AKI; Critical Illness; Female; Humans; ICU; Intensive care unit; Lymphocyte Count; Lymphocytes - cytology; Male; Mortality; Neutrophil-lymphocyte ratio; Neutrophils - cytology; NLR; Prognosis; Retrospective Studies
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2018.09.014

Inflammation plays a critical role in the development of acute kidney injury (AKI). Neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation used to predict the prognostic outcome of several diseases. We conducted a retrospective cohort study to investigate if NLR can be used as a biomarker to predict the mortality of AKI. Records of critically ill patients with AKI were extracted from the Medical Information Mart for Intensive Care Database III version 1.3 (MIMIC-III v1.3). The primary outcome was 30-day mortality and the two secondary outcomes were in hospital and 90-day mortality. We used the Cox proportional hazards models to assess the association between different categories of NLR and outcomes. This analysis included data for 13,678 eligible subjects, with a total of 2,588 30-day, 2,224 in-hospital and 3,545 90-day deaths during the follow-up period. For 30-day mortality, an increased risk of mortality was associated with a higher level of NLR. The HR (95% confidence interval [CI]) of upper tertile (NLR > 12.14) was 1.37 (1.17-1.60) in a multivariate model when compared with that of the lower tertile (NLR  17.4) of 1.35 (1.08, 1.69) in a multivariate model compared to the first quintile (NLR  17.4) showed a slight decrease. Our analysis indicates that a higher level of NLR is associated with increased risk of 30-day and 90-day mortality in AKI patients. The similar upward trend is not detected in analysis of in-hospital mortality. •This is the first study to investigate if the neutrophil-lymphocyte ratio (NLR) can be used as a biomarker to predict the mortality of patients with acute kidney injury.•We include sufficient numbers of participants of 13,678.•Our analysis indicates that a higher level of NLR is associated with increased risk of 30-day and 90-day mortality in AKI patients.