Renal sarcoidosis with limited lung manifestations expressing propionibacterium acnes antigens in the affected tubulointerstitium

摘要

Sarcoidosis is a granulomatous multisystemic disorder of unknown origin that can affect the kidneys. Previous reports from Japan and Europe have indicated a link between Propionibacterium acnes infections and sarcoidosis. Here, we present the case of a 68-year-old woman with hypercalcemia and renal failure. A kidney biopsy was performed, which showed granulomatous tubulointerstitial nephritis with a large nonnecrotic nodule that contained mononuclear inflammatory cells and multinucleated giant cells. Subsequent immunohistochemical analysis revealed intracytoplasmic structures, which strongly indicated the presence of the P acnes antigen. Treatment with methylprednisolone ameliorated the patients hypercalcemia and renal failure. This case report emphasizes the potential of chronic P acnes infection to cause sarcoidosis.