Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram

Abstract EN

Allergic interstitial nephritis (AIN) is an underdiagnosed cause of acute kidney injury (AKI).

Guidelines suggest that AIN should be suspected in a patient who presents with an elevated serum creatinine and a urinalysis that shows white cells, white cell casts, or eosinophiluria.

Drug-induced AIN is suspected if AKI is temporally related to the initiation of a new drug.

However, patients with bland sediment and normal urinalysis can also have AIN.

Currently, a definitive diagnosis of AIN is made by renal biopsy which is invasive and fraught with risks such as bleeding, infection, and hematoma.

Additionally, it is frequently unclear when a kidney biopsy should be undertaken.

We describe a biopsy proven case of allergic interstitial nephritis which manifested on contrast enhanced Magnetic Resonance Imaging (MRI) as a striated nephrogram.

Newer and more stable macrocyclic gadolinium contrast agents have a well-demonstrated safety profile.

Additionally, in the presentation of AKI, gadolinium contrast agents are safe to administer in patients who demonstrate good urine output and a downtrending creatinine.

We propose that the differential for a striated nephrogram may include AIN.

In cases in which the suspicion for AIN is high, this diagnostic consideration may be further characterized by contrast enhanced MRI.