Objective Predicting vesicoureteral reflux (VUR) after a first febrile urinary tract infection (FUTI) in children would allow the avoidance of unnecessary cystourethrographies. Procalcitonin has been validated to be a strong and sensitive predictor of VUR in patients with a first FUTI diagnosed by positive urine culture alone. However, early DMSA scan is the gold standard examination for acute pyelonephritis. Our aim was to study the relationship between VUR and procalcitonin in children with a first FUTI confirmed by an early DMSA scan.
Methods This secondary analysis of prospective published series included children aged 1 month to 4 years with a first FUTI and a positive early DMSA scan.
Results 203 patients (62 boys, mean age of 13.3 months, VUR in 29%) were included in five European centres. The median value of procalcitonin increased significantly with the grade of VUR (p = 0.005), but was not significantly higher in children with versus without VUR: 2.3 versus 1.5 ng/ml (p = 0.2). After dichotomisation around the previously defined 0.5 ng/ml threshold, there was a significant association between high-grade VUR and high procalcitonin (odds ratio 14.6, 95% CI 1.6 to 247, p = 0.004). However, this relationship between all-grade VUR and high procalcitonin did not remain statistically significant (p = 0.8). The sensitivity of high procalcitonin was 78% (95% CI 66 to 87) for all-grade VUR and 100% (95% CI 88 to 100) for high-grade VUR, both with 21% specificity (95% CI 15 to 28).
Conclusions Among patients with a first FUTI confirmed by early DMSA scan, a high serum procalcitonin concentration is a significant and sensible predictor of high-grade VUR.