Immuno-allergic interstitial nephritis related to fluindione: first biopsy proven cases.

Case 1. A 72-year-old man was admitted to our unit for acute renal failure (serum creatinine 353 mmol/l vs 107mmol/l at baseline). He had started fluindione for atrial fibrillation five weeks before. Clinical examination was normal. There was no eosinophilia. Urine protein/creatinine ratio was 25mg/mmol, containing low molecular weight protein without albumin. There was no haematuria or pyuria. Renal ultrasonography was normal. Fluindione was stopped at admission. Transjugular renal biopsy disclosed interstitial lymphocytic infiltration with severe tubulitis. Immunofluorescent studies revealed no immune deposits. The renal function returned to baseline level 2 weeks after fluindione was stopped, without corticosteroid therapy.