Prognostic Implications of Relative Eosinophil Counts in Nephrosclerosis

Background: The interplay between atherosclerosis and chronic inflammation has gained considerable recognition, with elevated eosinophil counts identified as a risk factor for cardiovascular diseases. Nonetheless, the effect of eosinophils on the kidney prognosis of patients with nephrosclerosis remains unclear. Methods: This retrospective observational study was conducted in a single hospital. Patients diagnosed with nephrosclerosis via kidney biopsy between January 2010 and December 2023 were included in the study. Clinical data were extracted from hospital records at the time of biopsy to evaluate the association between blood relative eosinophil count (REC; percentage of eosinophil in WBC) and renal outcomes. Logarithmic transformation was performed for continuous variables to make data conform more closely to the normal distribution. The primary endpoint was dialysis initiation during follow-up. Patients were categorized into three groups based on their REC levels (REC grade 1, lower group [0.7-2.6%]; 2, middle group [2.7-4.0%]; and 3, higher group [4.2-20.5%]), and a log-rank test was performed. Cox regression analysis was conducted and adjusted for REC, age, sex, BMI, and mean arterial pressure. Results: The cohort comprised 76 patients (median age 54.9 years, 81.6% male, with a median follow-up duration of 68.7 months [interquartile range 21.8-106.8]). Fifteen patients (19.7%) underwent dialysis. Kaplan-Meier curves with the log-rank test for time to events showed no significant difference (Log-rank p = 0.07; Figure 1). However, Cox regression analysis demonstrated that REC, as a continuous variable, was significantly associated with the initiation of dialysis (hazard ratio 1.41, 95% confidence interval 1.21-13.9). Conclusion: Eosinophil counts may serve as a significant prognostic marker for kidney outcomes in patients with nephrosclerosis.Figure 1