Urinary Levels of Cathepsin B in Preterm Newborns

Increased investment in perinatal health in developing countries has improved the survival of preterm newborns, but their significant multiorgan immaturity is associated with short and long-term adverse consequences. Cathepsin B, as a protease with angiogenic properties, may be related to the process of nephrogenesis. A total of 88 neonates (60 premature children, 28 healthy term children) were included in this prospective study. We collected urine samples on the first or second day of life. In order to determine the concentration of cathepsin B in the urine, the commercially available enzyme immunoassay was used. The urinary concentrations of cathepsin B normalized with the urinary concentrations of creatinine (cathepsin B/Cr.) in newborns born at 30–34, 35–36, and 37–41 (the control group) weeks of pregnancy were (median, Q1–Q3) 4.00 (2.82–5.12), 3.07 (1.95–3.90), and 2.51 (2.00–3.48) ng/mg Cr, respectively. Statistically significant differences were found between the group of newborns born at 30–34 weeks of pregnancy and the control group (p < 0.01), and between early and late preterm babies (PTB) (p < 0.05). The group of children born at 35–36 weeks of pregnancy and the control group did not differ significantly. This result suggests that the elevated urinary cathepsin B/Cr. level may be the result of the kidneys’ immaturity in preterm newborns

Protein Biomarkers in Chronic Kidney Disease in Children—What Do We Know So Far?

Chronic kidney disease (CKD) in children is a major concern of medical care and public health as it is related to high morbidity and mortality due to progression to end-stage kidney disease (ESKD). It is essential to identify patients with a risk of developing CKD to implement therapeutic interventions. Unfortunately, conventional markers of CKD, such as serum creatinine, glomerular filtration rate (GFR) and proteinuria, have many limitations in serving as an early and specific diagnostic tool for this condition. Despite the above, they are still the most frequently utilized as we do not have better. Studies from the last decade identified multiple CKD blood and urine protein biomarkers but mostly assessed the adult population. This article outlines some recent achievements and new perspectives in finding a set of protein biomarkers that might improve our ability to prognose CKD progression in children, monitor the response to treatment, or even become a potential therapeutic target

Is Urinary Netrin-1 a Good Marker of Tubular Damage in Preterm Newborns?

There is a lack of a good marker for early kidney injury in premature newborns. In recent publications, netrin-1 seems to be a promising biomarker of kidney damage in different pathological states. The study aimed to measure the urinary level of netrin-1 depending on gestational age. A prospective study involved 88 newborns (I-60 premature newborns, II-28 healthy term newborns). Additionally, premature babies were divided for 2 groups: IA-28 babies born between 30–34 weeks of gestation and IB-32 born at 35–36 weeks. The median urinary concentration of netrin-1 was: IA-(median, Q1–Q3) 63.65 (56.57–79.92) pg/dL, IB-61.90 (58.84–67.17) pg/dL, and II-60.37 (53.77–68.75) pg/dL, respectively. However urinary netrin-1 normalized by urinary concentration of creatinine were IA-547.9 (360.2–687.5) ng/mg cr., IB-163.64 (119.15–295.96) ng/mg cr., and II-81.37 (56.84–138.58) ng/mg cr., respectively and differ significantly between the examined groups (p = 0.00). The netrin-1/creatinine ratio is increased in premature babies. Further studies examining the potential factors influencing kidney function are necessary to confirm its potential value in the diagnosis of subclinical kidney damage in premature newborns

Reference Data on Neonatal Serum N-Acetyl-β-hexosaminidase Activity

Background. Determination of neonate serum’s N-acetyl-β-hexosaminidase (HEX) activity and correlation results with Apgar scale and factors routinely determined in newborn serum. Aims. Providing reference values of neonates serum HEX activities, and indicate their diagnostic significance. Study design. The study was performed using random serum samples of 111 infants (53 ♂/58 ♀), aged 1–30 days. The activity of HEX was determined colorimetrically and expressed in nKat/L. Results. Serum HEX activity of 111 newborns was 360.5 ± 114.0 nKat/L and significantly positively correlated with gestation week at the day of delivery, birth weight, weight on day of blood collection, sex, and serum CRP. Conclusions. Reference values presented for neonatal serum activities of HEX may be used in neonatal diagnostics, for example, to detect inflammation and other diseases or for early assessment of the risk of Tay-Sachs and Sandhoff diseases