Prognostic value of neutrophil-to-lymphocyte ratio dynamics in patients with septic acute kidney injury: a cohort study

Abstract

Background

Neutrophil-to-lymphocyte ratio (NLR) has been suggested to be a prognostic marker for various diseases, but whether NLR dynamics (ΔNLR) is related to mortality and disease severity in patients with septic acute kidney injury (AKI) has not been determined.

Methods

Between August 2013 and August 2021, septic AKI patients at our center were retrospectively enrolled. ΔNLR was defined as the difference between the NLR at septic AKI diagnosis and at hospital admission. The relationship between the ΔNLR and mortality was evaluated by Kaplan–Meier curves, Cox proportional hazards, and cubic spline analyses. The prediction values were compared by area under the receiver-operating characteristic curve (AUROC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) analyses.

Results

Of the 413 participants, the mean age was 63 ± 17 years, and 134 were female (32.4%). According to the median value, patients in the high-ΔNLR group had significantly greater 90-d mortality (74.4% vs. 46.6%, p < 0.001). After adjustment for potential confounders, high ΔNLR remained an independent predictor of 90-d mortality (HR = 2.80; 95% CI = 1.74–4.49, p < 0.001). Furthermore, ΔNLR had the highest AUROC for 90-d mortality (0.685) among the various biomarkers and exhibited an improved NRI (0.314) and IDI (0.027) when incorporated with PCT and CRP. For secondary outcomes, patients with high ΔNLR had increased risk of 30-d mortality (p = 0.004), need for renal replacement therapy (p = 0.011), and developing stage-3 AKI (p = 0.040) according to the adjusted models.

Conclusions

High ΔNLR is independently associated with increased risk of patient mortality and adverse outcomes. ΔNLR might be utilized to facilitate risk stratification and optimize septic AKI management.

Keywords:

• Septic acute kidney injury
• neutrophil-to-lymphocyte ratio dynamics
• prognosis
• mortality

Acknowledgments

None.

Informed consent statement

Patient informed consent was waived by the Institutional Review Board due to the retrospective design.

Author contributions

WW and YZ were responsible for literature research and manuscript drafting. LC, GS, and YL were responsible for literature research and data collection. JL, TY, BW, and YY were responsible for the statistical analysis. ML, LZ, FP, and ZY were responsible for the study design and data interpretation. All coauthors were involved in patient care and participated in manuscript revision.

Disclosure statement

The authors declare that there are no conflicts of interest.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This study was supported by the National Key Research and Development Program of China (2023YFC2411800), the Science and Technology Department of Sichuan Province (24GJHZ0169, MZGC20230017), Sichuan University (2023SCUH0065), and 135 Project for Disciplines of Excellence, West China Hospital, Sichuan University (2020HXFH014). The funding sources had no involvement in this study.