Evaluation of diagnostic value of procalcitonin in pediatric acute pyelonephritis

Urinary tract infection (UTI) in children is among the prevalent infections of childhood, which occurs due to growth of bacteria in the urinary tract. The aim of this study was to evaluate the usefulness of procalcitonin (PCT) as a reliable marker for distinguishing urinary tract infection (UTI) with or without renal parenchyma (cystitis). Eighty children, who were suspicious of having UTI and had been referred to Ali Ibne Abitaleb hospital (in Zahedan) or pediatric clinics (June 2007- Oct 2009) were included in the study after their urine culture revealed their infection. Besides, their clinical and lab symptoms including erythrocyte sedimentation rate (ESR), C– reactive protein (CRP), serum WBC, and serum procalcitonin (PCT) were recorded. The patients were divided into two groups based on their lab clinical symptoms and radio-isotope scans, namely acute pyelonephritis and acute cystitis (lower UTI). Serum procalcitonin was measured in these cases in a semi-quantitative manner. Fifty children with mean age of 4.89±3.50 years were compared with 30 children with mean age of 5.20±3.07 years. ESR, WBC, and PCT were significantly higher in patients with upper UTI (P<0.001), but CRP was not significantly different in the two groups. PCT, which was semi-quantitatively measured, when lower than 0.5 had a relationship with sensitivity, specificity, positive predictive value, and negative value of 72%, 83.3%, 87.8%, and 64.1% respectively. When PCT was more than 2, the relationship with the mentioned features was 50%, 96.6%, 96.2%, and 53.7%, respectively. The relationships in these two domains can both be assistant in differentiating pyelonephritis from cystitis. PCT was more sensitive and specific for the diagnosis of upper versus lower UTI compared with CRP, and it can be a better marker than CRP for early prediction of febrile pyelonephritis in children.