Interstitial Eosinophilic Aggregates and Kidney Outcome in Patients with CKD
Koki Hattori, Yusuke Sakaguchi, Tatsufumi Oka, Yuta Asahina, Takayuki Kawaoka, Ryohei Yamamoto, Isao Matsui, Masayuki Mizui, Jun-Ya Kaimori, Yoshitaka Isaka- Transplantation
- Nephrology
- Critical Care and Intensive Care Medicine
- Epidemiology
Background:
Interstitial eosinophilic aggregates are observed in various kidney diseases, but their clinical implications remain unknown. We assessed the association between interstitial eosinophilic aggregates and kidney outcomes, and further analyzed the association between blood eosinophil count, as a surrogate for interstitial eosinophilic aggregates, and the risk of kidney failure in patients with advanced CKD.
Methods:
We analyzed datasets from two retrospective cohort studies: 1) The kidney biopsy cohort including 563 patients who underwent native kidney biopsy at Osaka University Hospital between 2009 and 2021, and 2) the retrospective CKD cohort including 2877 patients with an estimated glomerular filtration rate (eGFR) of 10-60 mL/min/1.73 m2 referred to the nephrology outpatient center at Osaka University Hospital between 2005 and 2018. Interstitial eosinophilic aggregates were defined as ≥5 interstitial eosinophils in the high-power field on Hematoxylin & Eosin staining. The study outcome was initiation of kidney replacement therapy (KRT) or ≥40% decline in eGFR.
Results:
In the kidney biopsy cohort, interstitial eosinophilic aggregates were found in 17% of patients, most frequently in those with diabetic nephropathy (50%). Interstitial eosinophilic aggregates were associated with a higher rate of the composite kidney outcome after adjustment for clinical and histological variables (hazard ratio, 3.61; 95% confidence interval, 2.47-5.29; P<0.001). LASSO revealed that blood eosinophil count was the strongest predictor of interstitial eosinophilic aggregates. In the retrospective CKD cohort, higher baseline and time-updated blood eosinophil counts were significantly associated with a higher rate of KRT initiation in Cox proportional hazards models and marginal structural models.
Conclusions:
Interstitial eosinophilic aggregates were associated with a higher risk of a composite of KRT initiation or ≥40% decline in eGFR.