Eosinophiluria in atheroembolic renal disease

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Pathology

Background:

• Atheroembolic renal disease (AERD) is a significant cause of acute and chronic renal failure, particularly in elderly patients with atherosclerosis or those undergoing aortic/arterial interventions.
• Diagnosis of AERD typically relies on renal biopsy, which is often not feasible for acutely ill patients.
• Previous research suggested AERD is associated with inactive urinary sediment and a lack of urine eosinophils.

Purpose of the Study:

• To investigate the presence and significance of eosinophiluria in patients with biopsy-proven atheroembolic renal disease (AERD).
• To determine if eosinophiluria can serve as a diagnostic marker for AERD, especially when renal biopsy is not possible.

Main Methods:

• Retrospective review of 24 patients with renal biopsy-proven AERD over a 4-year period.
• Focused evaluation of urine eosinophils using Hansel's stain in nine patients presenting with renal deterioration.
• Correlation of urine eosinophil findings with clinical presentation, vascular disease evidence, and procedural history.

Main Results:

• Eight out of nine patients evaluated showed positive results for eosinophiluria using Hansel's stain.
• Six of these eight patients had eosinophils constituting more than 5% of their urinary white blood cell count.
• The high prevalence of eosinophiluria suggests previous studies may have underestimated its presence due to the staining method used (e.g., Wright's stain vs. Hansel's stain).

Conclusions:

• Eosinophiluria, detected by Hansel's stain, is a notable finding in atheroembolic renal disease (AERD).
• The presence of eosinophils in urine should be considered as a potential indicator of AERD in patients with acute renal insufficiency.
• This finding expands the diagnostic considerations for eosinophiluria beyond acute interstitial nephritis to include AERD.