Prognostic value of elevated peripheral blood eosinophils for diabetic nephropathy

Objective To investigate the clinical value of peripheral eosinophil count (PEC) in predicting the outcome of diabetic nephropathy (DN). Methods A retrospective cohort trial was conducted on 220 DN patients identified by renal biopsy in Department of Nephrology of Second Affiliated Hospital from Army Medical University from March 2021 to March 2023. Clinical data, results of routine blood test and renal function were collected. X-tile bioinformatics software version 3.6.1 was used to determine the optimal cut-off value of PEC for predicting survival. Cox proportional hazards model and Kaplan-Meier survival analysis were applied to analyze the prognosis. Results The level of PEC in DN patients was positively correlated with the levels of serum creatinine (Scr) (r=0.245), blood urea nitrogen (BUN) (r=0.237) and blood uric acid (UA) (r=0.252), and negatively with estimated glomerular filtration rate (eGFR) (r=-0.236). According to the optimal PEC cut-off value, DN patients were divided into high-level group (>0.29×109/L, n=41) and low-level group (≤0.29×109/L, n=179). The levels of Scr (P < 0.001), BUN (P=0.001) and UA (P=0.005) were significantly higher, while the eGFR (P < 0.001) was obviously lower in the high-level group than the low-level group. Multivariate Cox regression analysis showed that the high level of PEC was associated with poor prognosis of DN (HR=2.20, 95%CI: 1.05~4.60, P=0.036). Kaplan-Meier survival analysis demonstrated that the incidence of end-stage renal disease (ESRD) was notably higher in the high-level group than the low-level group (P=0.024). Conclusion PEC level of DN patients is closely associated with the progression and prognosis of DN, and the count is a potential biomarker for predicting the prognosis of DN.