[Interstitial nephropathy due to chronic bacterial pyelonephritis].

Chronic renal infection (Chronic bacterial pyelonephritis) is a cause of tubulo-interstitial nephropathy (nephritis); TIN. The disorder causes end-stage renal failure in about 2% of the patients who are treated by dialysis. However, Chronic bacterial pyelonephritis is a relatively benign condition that seldom leads to renal function loss. The affected kidney shows non-specific histological pictures similar to that seen with other diseases producing TIN. Clinical symptoms are of ten vague. Obstructive uropathy (eg, stones, benign prostatic hyperplasia) is frequently present. The affected kidney, which is almost unilateral, shows atrophy and scarring of variable degree. Significant pyuria and bacteriuria may or may not be found. Depending on the stage of the disease, the serum creatinine and blood urea nitrogen may be normal or elevated. Contributing obstructive uropathy should be corrected. The patients must be followed closely, urinary tract infection must be controlled and complications (eg, hypertension, azotemia) must be identified promptly and treated adequately.