Abstract:
Background. The prevalence of acute kidney injury (AKI) reaches ~30% in neonates admitted to a tertiary level
neonatal intensive care unit. Novel urinary biomarkers are useful for the prediction and diagnosis of AKI. The objective
of this work was to determine the predictive and diagnostic value of urinary protein biomarkers for AKI in critically
sick full-term newborns.
Materials and methods. A prospective cohort study of 150 full-term neonates was performed. Group I included 55
healthy newborns, group II – 50 critically ill newborns without AKI, group III – 45 critically ill newborns with AKI.
Creatinine levels in serum (SCr), urinary concentration of total protein (UTPr), urinary albumin (UAlb), urinary immunoglobulin G (UIgG), urinary α1-microglobulin (Uα1-MG) and β2-microglobulin (Uβ2-MG) were measured on the
3rd day of life. In case the data were available, 2×2 tables were constructed to derive sensitivity (Se), specificity (Sp),
positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood
ratio (NLR) and cut-off level of urinary protein biomarkers. The area under the receiver operating characteristic (AUROC) curve was used to deduce the diagnostic accuracies of them.
Results. Considering AUROC values, the results of the conducted statistical analysis demonstrated that the
biggest diagnostic value concerning AKI determination in critically ill term newborns was peculiar for the model
with determination of UIgG level (AUROC 0.79; 95% СІ 0.69-0.88, р<0.001 with сut-off level ≥ 5.1 mg/L). Similar
diagnostic value was found in the models with determination of Uα1-MG (AUROC 0.73; 95% СІ 0.64-0.84, р<0.05
with сut-off level ≥ 42 mg/L) and UTPr (AUROC 0.73; 95% СІ 0.62-0.83, р<0.05 with сut-off level ≥ 186 mg/L).
The model with determination of UAlb (AUROC 0.64; 95% СІ 0.53-0.76, р<0.05 with сut-off level ≥ 23.0 mg/L) possessed the least diagnostic value. The laboratory test with determination of Uβ2-MG level demonstrated the absence
of diagnostic value concerning AKI determination in term newborns (AUROC 0.56; 95% СІ 0.5-0.68, р>0.05 with
сut-off level ≥ 2.95 mg/L).
Conclusions: 1. A comprehensive clinical-paraclinical examination should be performed for timely diagnostics of
AKI in critically ill term newborns with determination of early markers of renal dysfunction including urinary protein biomarkers. 2. Considering the values of AUROC the level of diagnostic value of the presented biomarkers concerning
detection of AKI was determined: UIgG > Uα1-MG, UTPr > UAlb with absent diagnostic value of Uβ2-MG. 3. None
of the presented diagnostic models demonstrated high discriminating ability with high values of Se and Sp at the same
time concerning detection of AKI in critically ill newborns.
Description:
Department of Pediatrics, Neonatology and Perinatal Medicine, Higher State Educational Establishment of Ukraine“Bukovinian State Medical University”, Chernivtsi, Ukraine