Background  Chronic kidney disease (CKD) has become a global health problem, how to delay the progression of the disease is of great importance. As a new inflammatory indicator, peripheral blood neutrophil/lymphocyte ratio (NLR) is rarely studied in predicting the progression of CKD.

  Objective  To analyze the value of neutrophil-to-lymphocyte ratio in predicting the progression of stage 4 chronic kidney disease.

  Methods  This was a single center retrospective study. Patients with stage 4 chronic kidney disease in nephrology department of Affiliated Hospital of Hebei University were included from December 2018 to December 2019. Demographic, clinical data and follow-up data were collected. The end point of the study was the initiation of renal replacement therapy (RRT) or progression to CKD5. All the patients were divided into HG group and LG group according to the median neutrophil-to-lymphocyte, and the clinical characteristics were compared between the two groups. Multivariate Cox regression model was used to analyze the influencing factors of disease progression in stage 4 chronic kidney disease.

  Results  A total of 218 subjects were included, with an average age of (60.8 ± 4.46) years, including 117 males (53.7%). The average follow-up period was 19.3 months, during which 39.6% of the patients reached to the study endpoint. Compared with LG group, more patients in HG group reached the end point (62.4% vs 33.6%, P=0.013) and had a history of hypertension (87.1% vs 73.2%, P=0.009), patients in HG group had lower serum albumin (3.75 ± 0.43 g/dL vs 3.93 ± 0.47 g/dL, P=0.001), and higher CRP (18.1 ± 11.2 mg/L vs 7.9 ± 4.4 mg/L, P<0.001). Kaplan Meier survival analysis showed that the mean renal survival reduced significantly in HG patients (9 months vs 15 months, P<0.001). Multivariate Cox regression model showed that the neutrophil-to-lymphocyte ratio had the most significant effect on the study endpoint (HR 95% CI=2.832 2.174-5.836, P=0.001).

  Conclusion  Neutrophil-to-lymphocyte ratio is an independent index to predict the renal end point, which can well reflect the prognosis of patients with stage 4 chronic kidney disease.