Sarcoidosis associated with acute renal failure and increased levels of interleukin-6 in urine.

A 24-year-old man who had uveitis and showed intrathoracic lymph node swelling on a chest X-ray, was admitted to our hospital for further examination. Transbronchial lung biopsy specimens revealed non-caseating granulomas compatible to sarcoidosis. As the renal function became progressively worse, a specimen was obtained by renal biopsy. It showed a granuloma formation, and was diagnosed as renal sarcoidosis. A high level of interleukin (IL)-6 was detected in his urine. After oral administration of prednisolone, the renal function improved, and the urinary IL-6 level was reduced. These findings suggest that in sarcoidosis associated with renal failure, steroid therapy is effective and that IL-6 plays an important role in the pathogenesis of renal involvement of sarcoidosis.