Clinical correlates of eosinophiluria.

Area of Science:

• Nephrology
• Urology
• Clinical Pathology

Background:

• Eosinophiluria, the presence of eosinophils in urine, is observed in a subset of patients.
• Understanding the clinical significance of eosinophiluria is crucial for accurate diagnosis.

Purpose of the Study:

• To investigate the clinical correlates of eosinophils in urine.
• To determine the diagnostic utility of eosinophiluria, particularly in relation to acute interstitial nephritis.

Main Methods:

• Retrospective review of 65 patients with documented eosinophiluria.
• Analysis of urine sediment for eosinophil presence and percentage relative to total white blood cells.
• Correlation of eosinophiluria findings with clinical diagnoses, including urinary tract infections and acute interstitial nephritis.

Main Results:

• Eosinophils were present in the urine sediment of 16% of 470 patients examined.
• In patients with eosinophiluria, 85% had <5% eosinophils and 45% had <1% eosinophils relative to total urine white blood cells.
• Urinary tract infections accounted for 45% of conditions associated with eosinophiluria.
• Acute interstitial nephritis was diagnosed in 14% of patients with eosinophiluria.

Conclusions:

• Eosinophiluria is associated with diverse clinical conditions.
• Expressing urine eosinophils as a percentage of total white blood cells enhances diagnostic value.
• Low levels (<5%) of urine eosinophils may not strongly predict acute interstitial nephritis, whereas higher levels (>5%) may be more indicative.