Procalcitonin to reduce the number of unnecessary cystographies in children with a urinary tract infection: a European validation study.

Objective: To validate high serum procalcitonin (PCT) as a predictor of vesicoureteral reflux (VUR) in children with a first febrile urinary tract infection (UTI).
Study Design: This secondary analysis of prospective hospital-based cohort studies included children ages 1 month to 4 years with a first febrile UTI.
Results: Of the 398 patients included in 8 centers in 7 European countries, 25% had VUR. The median PCT concentration was significantly higher in children with VUR than in those without: 1.6 versus 0.7 ng/mL (P = 10(-4)). High PCT (> or =0.5 ng/mL) was associated with VUR (OR: 2.3; 95% CI, 1.3 to 3.9; P = 10(-3)). After adjustment for all cofactors, the association remained significant (OR: 2.5; 95% CI, 1.4 to 4.4; P = 10(-3)). The strength of the relation increased with the grade of reflux (P = 10(-5)). The sensitivity of procalcitonin was 75% (95% CI, 66 to 83) for all-grade VUR and 100% (95% CI, 81 to 100) for grade > or =4 VUR, both with 43% specificity (95% CI, 37 to 48).
Conclusions: High PCT is a strong, independent and now validated predictor of VUR that can be used to identify low-risk patients and thus avoid one third of the unnecessary cystourethrographies in children with a first febrile UTI.