Detection of urographic scars in girls with pyelonephritis followed for 13-38 years

We report the detection and progression of renal scars in girls prospectively followed from their first recognized urinary tract infection. There were 107 infection-prone subjects with a median age of 7.1 years at the first and 21.7 years at the last urography. Of 51 females who ultimately had lesions, 38 had established scars at the first urography. In 18 subjects, new scars were found in previously undamaged kidneys, 5 already with unilateral scarring. There had been a normal urography after the 5th birthday in 8 of those with later scarring. Worsening of scarring was seen in 10 of the 38 subjects with established scars. The renal damage was in most cases slight or moderate. By stepwise logistic regression analysis, grade of reflux and number of pyelonephritic attacks correlated with scarring, and number of pyelonephritic attacks with new scars and worsening of the lesions. In summary, of the females who ultimately had renal lesions, one-third developed new scars. In most of those with established scars at the first urography, the focal character of lesions suggests that most were also acquired. Since reflux and number of pyelonephritic attacks were identified as risk factors, prevention of renal deterioration should be possible.