No abstract

This study describes the pattern of urinary tract infections (UTI) in 87 females prospectively followed for a median of 23 years from their first recognized symptomatic infection in childhood. At 16 years of age they were selected for follow-up into adulthood because of renal scarring (reflux nephropathy) in 45 and recurrent UTI in 42. The attack rate (number of urinary tract infections per individual per observation year) was highest during the 1st year of life (1.9), with a gradual decrease to the lowest rate (0.2) at age 11-15 years. A moderately increased attack rate (0.4), was seen in the late teens, extending through to the mid twenties. The proportion of infections having a pyelonephritic character decreased with age and number of infection episodes, but not in females with severe renal scarring. Pyelonephritic infections were correlated with vesicoureteric reflux, and renal scarring to low age at the index infection, total number of pyelonephritic episodes and reflux. Females with renal scarring continued to have a high proportion of pyelonephritic recurrences after 10 years of age, implying that they risk progressive renal disease and should be closely followed into adulthood.

The renal findings on intravenous urography (IVU) are reported in 306 children (73 boys, 233 girls) from eight European centres entered into an international study comparing medical and surgical management of children with urinary tract infection and severe vesico-ureteric reflux followed for 5 years. One hundred and fifty-five children were randomly allocated to medical and 151 to surgical treatment. Protocol and investigative techniques were standardised and randomisation, data collection and analysis were performed centrally in Essen, Germany. At entry 149 (49%) has established renal scarring (79 medical, 70 surgical). Children with normal kidneys (105), areas of thinned parenchyma (52) and grade of reflux were also evenly distributed. IVU was repeated at 6, 18 and 54 months and serial urine culture, 99mtechnetium-dimercaptosuccinic acid scans and plasma creatinine estimations were performed. Two hundred and seventy-two children (89%) completed this follow-up. In 174 children (57%), (90 medical, 84 surgical) there was renal growth without morphological change. New renal scars developed in 19 children treated medically and 20 surgically; 12 (5 medical, 7 surgical) developed in previously normal kidneys. Six followed post-operative obstruction. No significant difference in outcome was found between medical or surgical management in terms of the development of new renal lesions or the progression of established renal scars.

This study describes blood pressure and renal function, as well as indices of renal disease, in females with and without renal scarring followed from their first urinary tract infection (UTI) in childhood. Of the 111 patients with a median follow-up time of 15 years, 54 had renal scarring (reflux nephropathy) on urography, which was severe in 19 and moderate in 35. The glomerular filtration rate was lower in patients with severe renal scarring and correlated with renal area on urography. However, the filtration rate was decreased below the lower reference limit in only 7 patients, with a lowest value of 70 ml/min per 1.73 m2. The diastolic blood pressure was higher in women with severe scarring. Hypertension of at least 140/90 mmHg was diagnosed in 3 of 54 (5.5%) females with renal scarring, 2 before and 1 at the follow-up examination. The excretion of albumin in urine was low and not correlated to filtration rate. Tubular enzymes in urine were similar in all groups. Thus the renal function was well preserved and the incidence of hypertension low. Within this range of renal function, the level of albumin in urine did not predict the degree of renal scarring.

The normal range of variation of the parenchymal thickness in well defined parts of the kidney was determined in children (0 to 15 years). The values were correlated with the distance between the superior surface of L1 and the inferior surface of L3. The ratio between the parenchymal thickness on the right side and the left side was also determined. The results are compiled in two nomograms.