Comparative efficacies of procalcitonin and conventional inflammatory markers for prediction of renal parenchymal inflammation in pediatric first urinary tract infection.

OBJECTIVES: To compare the reliability of procalcitonin (PCT) with conventional laboratory parameters in predicting for renal parenchymal inflammation (RPI). METHODS: The study cohort consisted of 57 children who were admitted for a first-episode urinary tract infection. All patients underwent measurement of the leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum PCT. RPI was evaluated by technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. If the first DMSA findings were abnormal, another analysis was performed 6 months later. The cutoff points for ESR, CRP, and PCT were established by comparing the areas under their receiver operating characteristic curves. Statistical analysis was performed using 1-way analysis of variance. RESULTS: Of the 57 children, 27 were diagnosed with RPI on the basis of positive DMSA results. The ESR, CRP, and PCT levels were significantly greater (P < .001) in the patients with RPI than in those without RPI. In contrast, the leukocyte count was the same in both groups (P > .05). PCT was a more sensitive and specific marker for differentiating upper and lower urinary tract infection than ESR and CRP. Persistent lesions at the site of previous RPI were found in 12 patients in the follow-up DMSA analysis, with total regression evident in the remaining 15. The PCT levels were significantly greater in those with persistent renal lesions than in those with total regression (P = .005). CONCLUSIONS: Serum PCT is a more reliable biologic marker than the ESR, CRP, or leukocyte count for the early prediction of RPI in children with a first episode of urinary tract infection. In addition, the greater the elevation of PCT at admission, the more positive the correlation for subsequent permanent renal damage.

Procalcitonin for the early prediction of renal parenchymal involvement in children with UTI: preliminary results.

In order to establish the most reliable marker for distinguishing urinary tract infections (UTI) with and without renal parenchymal involvement (RPI), we recorded the clinical features and admission leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum procalcitonin (PCT) in 57 children (including 43 girls) aged 2-108 months admitted with a first episode of UTI. RPI was evaluated by Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. To establish cut-off points for ESR, CRP, and PCT, we used receiver operating characteristics curves and compared the area under the curve for ESR, CRP, and PCT. Twenty-seven children were diagnosed as having RPI based on positive renal scintigraphy. A body temperature of >38 degrees C, a history of diarrhea, and poor oral intake were more common in patients with RPI. ESR, CRP, and PCT, but not leukocyte count, were significantly higher in patients with RPI (P < 0.001). PCT was more sensitive and specific for the diagnosis of upper versus lower UTI than ESR and CRP. Using a cut-off value of 0.85 ng/ml, PCT had the best performance, with sensitivity, specificity, and positive and negative predictive values of 89%, 97%, 96%, and 91% respectively. Serum PCT is a better marker than ESR, CRP, and leukocyte count for the early prediction of RPI in children with a first episode of UTI.