Granulomatous interstitial nephritis in a patient with Crohn's disease†

Granulomatous interstitial nephritis (GIN) is an uncommon disorder, previously documented in the literature in asso-ciation with sarcoidosis, multiple medications, and infection. The coexistence of GIN and Crohn's disease has rarely been reported, and its true incidence is unknown. We describe a young female with Crohn's disease who was found to have an elevated serum creatinine with a normal urinalysis and autoimmune work-up. Kidney biopsy revealed granulomatous interstitial nephritis. She was treated with corticosteroids, cyclophosphamide, and mycophenolate mofetil. Her kidney function remains stable 2 years after diagnosis. This case report highlights the diagnosis and explores a novel treatment regimen.