Nephritis, Acute Interstitial

Key Features

• Characterized by diffuse or focal inflammation and edema of the renal interstitium and secondary involvement of the tubules

• Most commonly drug related (eg, β-lactam–containing antibiotics or nonsteroidal anti-inflammatory drugs), but infectious etiologies, including Epstein-Barr virus, also occur

Clinical Findings

• Fever, rash, and eosinophilia may occur in drug-associated cases

• Association between tubulointerstitial nephritis and uveitis is occasionally seen in childhood

Diagnosis

• Urinalysis usually reveals leukocyturia and mild hematuria and proteinuria

• Hansel staining of the urinary sediment often demonstrates eosinophils

• The inflammation can cause significant deterioration of renal function and systemic hypertension

• Renal biopsy may be performed to demonstrate the characteristic tubular and interstitial inflammation

Treatment

• Immediate identification and removal of the causative agent whenever possible is imperative and may be all that is necessary

• Corticosteroids are helpful in patients with progressive kidney disease or associated nephrotic syndrome

• Dialysis support is occasionally required