[Renal insufficiency caused by chronic granulomatous interstitial nephritis in Löfgren's syndrome]

The authors report the case of a woman with Löfgren's syndrome who developed renal failure associated with abnormalities of acidification and concentration of the urine. In the absence of a phosphate-calcium metabolic disturbance, these signs were attributed to a granulomatous interstitial nephropathy demonstrated on renal biopsy. These abnormalities regressed completely with steroid therapy. Secondary renal failure due to an isolated granulomatous interstitial nephropathy is exceptionally rare in sarcoidosis and has never been previously reported in Löfgren's syndrome.