T and B lymphocyte subsets in fenoprofen nephropathy

Area of Science:

• Nephrology
• Immunology
• Pharmacology

Background:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) like fenoprofen are common causes of drug-induced kidney injury.
• Acute interstitial nephritis (AIN) and minimal-change glomerulopathy (MCG) are distinct renal pathologies.
• Combined AIN and MCG is a rare presentation of drug-induced renal disease.

Observation:

• Two patients developed renal failure following fenoprofen administration.
• Renal biopsies revealed concurrent AIN and MCG.
• Interstitial infiltrates showed a predominance of T lymphocytes over B lymphocytes (4:1 ratio).
• IgE-bearing B cells were prevalent, and cytotoxic/suppressor T cells outnumbered helper-inducer T cells (3:1 ratio).

Findings:

• Fenoprofen therapy was associated with a unique combination of AIN and MCG.
• The specific immune cell profile in the interstitial infiltrate suggests a T-cell-mediated hypersensitivity reaction.
• Steroid treatment led to clinical remission and resolution of renal pathology, including glomerular foot process restoration.

Implications:

• This case highlights fenoprofen as a potential cause of combined AIN and MCG.
• The findings suggest a specific immunopathogenic mechanism involving T and B lymphocytes in fenoprofen-induced nephrotoxicity.
• Understanding these immune responses may guide future therapeutic strategies for drug-induced kidney injury.