Nephrosis and papillary necrosis after pyelonephritis.

We present a case of nephrotic syndrome complicating acute pyelonephritis in a 45-year-old man. His first attack of acute bacterial pyelonephritis had two unusual features: transient nephrotic syndrome and chronic recurrent episodes of papillary necrosis. The former, which lasted for two weeks, was characterized by edema, excretion of 7.7 g of urinary protein per 24 hours and hypoproteinemia (1.8 g per 100 ml). A percutaneous renal biopsy two weeks after the height of the nephrotic state showed normal glomeruli by light and electron microscopy and immunohistologic studies. Interstitial changes were noted. Over two years the patient has passed approximately 50 fragments, characterized as necrotic tissue containing tubular structures. He has no evidence of diabetes mellitus, urinary-tract obstruction or ureteral reflux, analgesic abuse or atypical vasculitis. He is afebrile but has recurrent bacteriuria despite antibiotics. This case demonstrates that acute pyelonephritis must be added to the list of diseases causing the nephrotic state.