[Comparative study of C-reactive protein and procalcitonin in the severity diagnosis of pyelonephritis in children].

Objective: The aim of this study is to compare two biologic parameters; C-reactive protein (CRP) and procalcitonin (PCT) in the detection of acute renal lesions assessed by DMSA scintigraphy in the urinary tract infection in child.

Design: In a prospective study, serum PCT, CRP and leukocyte counts were measured for children admitted, between January and December 2010, with a first episode of febrile urinary tract infection.

Results: Seventy-five children were enrolled in the study. Thirty-three patients had renal lesions (group A) and 42 had a normal DMSA scintigraphy (group B). The mean PCT level was significantly higher in group A than in group B (8.81 ng/mL versus 1.7 ng/mL, P=0.01). In this study, using receiver operating characteristic (ROC) curve, we identified that the optimal cut-off value with ideal sensitivity and specificity for PCT in detection of renal lesions was 0.76 ng/mL and for CRP, it was 70 mg/L. The sensitivity, the negative predictive value and the indice of Youden of the cut-off value of PCT were significantly higher than CRP (82% versus 70%; 84% versus 70% and 0.58 versus 0.25).

Conclusions: This study confirmed that the serum PCT level was more sensitive and specific than the CRP in the detection of renal lesions in the first urinary tract infection in child.