NEITHER CLINICAL NOR BIOLOGICAL DATA CAN PREDICT RENAL INVOLVEMENT IN INFANTS WITH FEBRILE URINARY TRACT INFECTION

INTRODUCTION: 99m Tc-dimercaptosuccinic acid (DMSA) scintigraphy is accepted as the gold standard in the diagnosis of acute pyelonephritis. OBJECTIVE: In an attempt to reduce the number of investigations after urinary tract infections (UTIs), with this prospective study we aimed to evaluate the diagnostic value of acute-phase reactants in identifying renal involvement in infants with febrile UTI. METHODS: Fifty-four infants (36 male, 18 female) aged 1 to 12 months were studied. For all infants, clinical findings such as duration and height of fever before antibiotic administration and laboratory parameters such as leukocytosis (white blood cell count of >15.000/μL), elevated erythrocyte sedimentation rate (ESR) (>20 mm/hour), and high levels of C-reactive protein (>10 mg/mL) were compared with the results of the DMSA scan obtained within 72 hours after referral. RESULTS: Regarding microbial agents, Escherichia coli was identified in 42 (78%) of the 54 infants, and 16 (29.5%) of the 54 of infants were febrile for >2 days before diagnosis of UTI. Leukocytosis, elevated ESR, and high levels of C-reactive protein were present in 14 (26%), 41 (76%), and 38 (70%) infants, respectively. Acute-phase DMSA showed renal involvement in 10 (18.5%) infants. Vesicoureteral reflux was found in 16 (29.5%) infants. Gender, duration of fever before antibiotic administration, leukocytosis, elevated ESR, and high levels of C-reactive protein were not related to the severity of renal damage, as shown by DMSA. Only fever of >39°C was slightly correlated with an abnormal DMSA scan result (r = 0.3; P = .032). CONCLUSIONS: Acute-phase DMSA scintigraphy remains superior to clinical and laboratory data for predicting renal involvement in infants with febrile UTIs.