Urine biomarkers predict the need for surgery in babies with congenital urinary tract obstruction
Urine biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (CyC), can help predict the need for early surgical intervention in infants with congenital urinary tract obstruction (UTO), a new study reveals.
The study included 37 infants with congenital UTO (mean age at surgery, 5 months) who were divided into three: those with grade III unilateral hydro(uretero)nephrosis (n=14), grade III bilateral hydro(uretero)nephrosis (n=13) and low UTO (n=10). Among the renal biomarkers assessed were NGAL, serum and urine CyC, serum creatinine, and kidney injury molecule-1 (KIM-1).
Across all patient subgroups, surgical intervention largely led to drops in all urinary biomarkers. NGAL, for instance, dropped by 82.4 percent while retinol-binding protein (RBP) declined by 67.3 percent. Other urine biomarkers decreased by at least 50 percent after surgery.
RBP was the best individual biomarker for predicting surgical indication in the low UTO group, achieving a sensitivity of 76.2 percent and specificity of 91.8 percent. The same was true for the bilateral hydro(uretero)nephrosis subgroup (sensitivity: 83.3 percent; specificity: 94.7 percent). In the unilateral hydro(uretero)nephrosis group, KIM-1 (sensitivity: 62.5 percent; specificity: 82.1 percent) and NGAL (sensitivity: 63.3 percent; specificity: 96.7 percent) emerged as the best predictors.
Notably, NGAL, either alone (area under the curve [AUC], 0.801) or in combination with serum CyC (AUC, 0.881) was the strongest predictor of the need for surgery.
“It is clear that a search for one … candidate biomarker, as a new suitable noninvasive diagnostic tool, gives modest results. The combination of two or three of the best performing biomarkers, as suggested here, is a more realistic option in the quest for a simple, routinely available and bedside reliable biomarker kit,” said researchers.