Brentuximab-Induced Acute Interstitial Nephritis: A Case Report

Area of Science:

• Nephrology
• Oncology
• Pathology

Background:

• Brentuximab vedotin is an anti-CD30 antibody-drug conjugate approved for treating mycosis fungoides, Hodgkin's lymphoma, and anaplastic large cell lymphoma.
• While generally well-tolerated, renal complications are infrequently reported.
• Acute kidney injury (AKI) is a rare but serious potential adverse reaction.

Purpose of the Study:

• To report a rare case of acute interstitial nephritis (AIN) secondary to brentuximab vedotin treatment.
• To describe the clinical presentation, diagnostic findings, and treatment outcome.
• To highlight a novel histopathologic finding in drug-induced AIN.

Main Methods:

• Case report of a 73-year-old male with mycosis fungoides.
• Monitoring of serum creatinine and estimated glomerular filtration rate (eGFR) before and after brentuximab vedotin cycles.
• Diagnosis of AKI, exclusion of other causes, and confirmation of AIN via kidney biopsy.
• Treatment with oral prednisone and subsequent taper.

Main Results:

• The patient developed severe AKI (SCr peak 1073 µmol/L) after his third brentuximab vedotin cycle.
• Kidney biopsy confirmed acute interstitial nephritis (AIN) with a tubulointerstitial inflammatory infiltrate.
• Treatment with prednisone led to partial recovery of renal function (SCr 156 µmol/L).
• The histopathology was consistent with AIN, a pattern typically seen with immune checkpoint inhibitors (ICIs), though brentuximab is not an ICI.

Conclusions:

• This case represents a rare renal complication of brentuximab vedotin, specifically acute interstitial nephritis.
• The histopathologic findings of AIN in this case are novel for a non-ICI medication.
• Physicians should be vigilant for renal adverse events in patients treated with brentuximab vedotin, even if rare.