RISK-FACTORS IN THE DEVELOPMENT OF EARLY RENAL CORTICAL DEFECTS IN CHILDREN WITH URINARY-TRACT INFECTION

OEJECTIVE. Defects seen on early cortical scintigrams of the renal cor tex in children with urinary tract infection may represent acute infla mmatory change or established scar. The purpose of this study was to d etermine the relationship between these defects and age, sex, the pres ence and grade of vesicoureteral reflux, and infective organism in a c ohort of children examined after their first proved urinary tract infe ction. SUBJECTS AND METHODS. We prospectively examined 193 consecutive patients less than 5 years old who were seen at the ambulatory pediat ric department during a 3-year period and had a first proved urinary t ract infection. Children with obstructed or solitary kidneys were excl uded. All patients were imaged with scintigraphy of the renal cortex a nd radiographic voiding cystourethrography within 15 days of diagnosis . The association of age, sex, the presence and grade of vesicouretera l reflux, and infective organism with a defect (acute pyelonephritis o r a renal scar) seen on a cortical renal scan was studied. RESULTS. Th e prevalence of cortical defects was greater in the kidneys of patient s less than 2 years old (96/290, 33%) than in older children (16/96, 1 7%) and greater in those with vesicoureteral reflux (41/92, 45%) than in those without it (71/294, 24%). Vesicoureteral reflux was absent in 63% (71/112) of kidneys with a cortical defect. No association with s ex or infective organism was established. As well as having a greater prevalence of cortical defects, 145 (75%) of the 193 urinary tract inf ections included in the study were in children less than 2 years old. The kidneys of these younger patients also had a greater severity and prevalence of vesicoureteral reflux (74/290, 26%) than did those of ol der children (18/96, 19%).