A prognostic value of early urinary biomarkers NGAL and IL-18 in critically ill children: a 10-year literature review

Introduction. Acute kidney injury (AKI) is a life-threatening syndrome caused by a sudden and rapidly progressing impair-ment of renal function. It is a common and complicated clinical entity among hospi-talized children, occurring in 2%-4.5% of children treated in a pediatric intensive care unit. Mortality among such patients remains high (from 8% to 89%) despite improving patient care and technical pos-sibilities. The stage of renal damage is a reversible process, and its timely detection would prevent the progression of renal damage and thus reduce pediatric mor-tality rates. Therefore, modern medicine necessitates the identification of novel AKI biomarkers that would correlate with renal cell damage and could be detected ear-lier than a rise in serum creatinine (sCr). Neutrophil gelatinase-associated lipocalin (NGAL) and interleukin 18 (IL-18) are one of such early markers of AKI.Aim. To carry out a literature review of studies on changes in NGAL and IL-18 lev-els in the urine of critically ill patients and to determine a prognostic value of these biomarkers in the detection of renal injury and impact on disease outcomes. Material and methods. This literature review includes the publications of bio-medical studies assessing early biomark-ers of AKI in urine (uNGAL or uIL-18) of critically ill children, published in English during the 10-year period. Search for pub-lication was performed in the PubMed da-tabase.Results. Analysis included 10 studies that investigated early biomarkers of AKI (NGAL or IL-18) in urine of critically ill children and compared them with sCr. Among the biomedical studies analyzed in our literature review, 9 measured the NGAL level in urine or both in urine and serum, while 2measured IL-18 in urine. It was determined that uNGAL and uIL-18 were good early diagnostic biomarkers of AKI, which increased 48 h earlier than Cr in serum (P<0.005). The meta-analysis carried out by Haase et al. showed that uNGAL predicted the development of AKI better in critically ill children than in adults (OR, 25.4; ROC, 0.930 vs. OR, 10.6; ROC, 0.782). Three studies reported that the uNGAL level in study populations with AKI directly depended on disease severity and AKI degree (P<0.005). Four studies found that uNGAL and one study that uIL-18 are good predictive factors of mortality (P<0.005).Conclusions. uNGAL and uIL-18 are early predictive biomarkers of AKI in critically ill children. uNGAL and uIL-18 level cor-related well with disease severity and are independent predictive biomarkers of mortality.