STEROID-RESPONSIVE RENAL-INSUFFICIENCY DUE TO IDIOPATHIC GRANULOMATOUS TUBULOINTERSTITIAL NEPHRITIS

A 26-year-old male was admitted to our hospital having suffered from s ubfever, sterile pyuria and renal insufficiency for 1 year. There had been no apparent hematuria/proteinuria, and evidence of infection, all ergy or intoxication was not demonstrated. Open renal biopsy revealed severe tubulointerstitial changes with granuloma accompanied by neithe r caseous necrosis nor giant cells. Infiltrating cells mostly consiste d of CD4 and CD8 T cells, and some proximal tubular cells presented MH C class II antigen. Following the negative culture of biopsied specime n for acid-fast bacilli, diagnosis of idiopathic granulomatous tubuloi nterstitial nephritis was made, and steroid therapy was started. Two m onths later, pyuria disappeared and renal function improved significan tly, proving the effectiveness of steroid on idiopathic granulomatous tubulointerstitial nephritis.