[Role of procalcitonin in the diagnosis of acute pyelonephritis in children].

Objective: To study the role of procalcitonin (PCT) in the diagnosis of acute pyelonephritis (APN) in children.
Methods: Retrospective analysis was performed on the clinical records of children aged under 3 years who were diagnosed with primary urinary tract infection (UTI) from September 2011 to February 2012. These children were divided into those with upper UTI (UUTI) (APN) and those with lower UTI (LUTI) (non-APN) based on 99mTc-dimercaptosuccinic acid (DMSA) renal scan results as a gold standard. The UUTI and LUTI groups were compared in terms of serum levels of PCT and C-reactive protein (CRP). Receiver operating characteristic (ROC) curves were drawn to evaluate the diagnostic values of serum PCT and CRP.
Results: Sixty-five children with UTI, including 39 cases of APN and 26 cases of LUTI, were included in this study. The APN cases had significantly higher serum levels of PCT (3.08 ng/mL vs 0.37 ng/Ml; P<0.01) and CRP (6.25 mg/L vs 3.01 mg/L; P<0.01) than the LUTI cases. The sensitivity and specificity of serum PCT level for APN were 84.6% and 88.5%, respectively, with an area under the ROC curve (AUC) of 0.873 (95%CI=0.781-0.965) and an optimal threshold point of 1.03 ng/mL. The sensitivity and specificity of serum CRP level for APN were 71.8% and 69.2%, respectively, with an AUC of 0.735 (95%CI=0.612-0.858) and an optimal threshold point of 3.91 mg/L.
Conclusions: As a result of its high sensitivity and specificity for the disease, serum PCT can be used as a marker in the early diagnosis of APN in children.