Association of peripheral eosinophil count with chronic kidney disease progression risk: a retrospective cohort study

Abstract

Abstract Background: Eosinophilia is common in renal diseases; however, the role of peripheral eosinophils in chronic kidney disease (CKD) requires further evaluation. Therefore, we aimed to determine whether an eosinophil count increase is related to the occurrence of end-stage renal disease (ESRD). Methods: This single-center, observational, retrospective study was conducted between January 2016 and December 2018 in Hangzhou, China. The study included 3163 patients, categorized into four groups according to peripheral eosinophil count (PEC) quartile values (Q1 PEC, ≤0.0625×109/L; Q2, 0.0625–0.1223×109/L; Q3, 0.1224–0.212×109/L; Q4, ≥0.212×109/L). The main outcome was ESRD development during follow-up. We evaluated the relationship between serum eosinophil count, demographic and clinical information, and ESRD incidence. Cox proportional hazards models were used to examine the association between the PEC and risk of progression to ESRD. Kaplan-Meier survival curves were compared between Q1 and Q4 PECs using the log-rank test. Results: A total of 3163 patients with CKD were included in this cohort, of whom 1254 (39.6%) were female individuals and the median (interquartile range [IQR]) age was 75 [64, 85] years and the median (IQR) estimated glomerular filtration rate was 55.16 [45.19, 61.19] mL/min/1.73 m2. The median PEC was 0.1224×109/L (IQR, 0.0625–0.212). Among the 3163 patients with CKD, 273 (8.6%) developed ESRD during a median follow-up time of 443.8 [238.8, 764.9] days. Individuals in the highest PEC quartile had a 66.2% higher ESRD risk than those in the lowest quartile (hazard ratio, 1.662; 95% confidence interval, 1.165–2.372). The results from the Kaplan-Meier survival curves confirmed the conclusion. Conclusions: Alongside traditional risk factors, patients with CKD and an elevated PEC are more likely to develop ESRD. Therefore, more attention should be paid to those patients with CKD who have a high PEC.