A PROSPECTIVE-STUDY OF CORTICAL SCARRING IN ACUTE FEBRILE PYELONEPHRITIS IN ADULTS - CLINICAL AND BACTERIOLOGICAL CHARACTERISTICS

Previous reports have demonstrated lesions on computerized axial tomog raphy (CT), and nuclear scintigraphy (DMSA) in acute pyelonephritis (P N). We undertook a prospective study of all patients presenting to our hospital with PN over 40 months. Patients who fulfilled diagnostic cr iteria, were treated with intravenous antibiotics. Excluding two who w ere pregnant, all patients had imaging by intravenous urography (IVU), CT and DMSA during their admission. Urine samples were collected prio r to treatment. Patients without lVU evidence of cortical scarring but with parenchymal defects on CT and/or DMSA underwent a repeat DMSA th ree or more months after the acute episode. Of the 164 patients, 142 w ere female. E. coli was found in 116 patients. Forty-six patients had an abnormality on IVU. Of the 106 patients without IVU evidence of cor tical scarring, 59 had a defect on CT and/or DMSA. Late DMSA scans in 35 of these 59 patients showed a persistent abnormality in 77%. E. col i characteristics such as P-fimbriae and Type 1 fimbriae were not pred ictive of acute imaging abnormalities. Inhibition of E. coli growth by the addition of EDTA was highly predictive of acute CT and DMSA abnor malities with a sensitivity of 83.3% and a specificity of 82.8%. Acute pyelonephritis is often associated with acute CT and/or DMSA abnormal ities which may evolve into renal cortical scars. Acute scan abnormali ties can be predicted by the presence of E. coli which were susceptibl e to EDTA in culture. Late scarring could not be predicted by clincial features, response to treatment or antibiotic used.