A marker for monitoring kidney fibrosis risk in children with SFK
Kidneys are two bean-shaped organs at the core of the renal system. They have many crucial functions, notably maintaining overall fluid balance, regulating and filtering minerals from blood, filtering waste materials from food, medications and toxic substances, producing hormones to make red blood cells, and regulating blood pressure.
Among the congenital anomalies found in humans, Solitary Functioning Kidney (SFK) is characterized by the presence of one kidney instead of two in the individual. Most people with only one kidney have normal healthy lives. However, others may experience severe complications, including reduced kidney function and high blood pressure that could lead to chronic kidney disease (CDK).
The earlier SFK is identified during childhood, the more likely regular monitoring of the single kidney function can help identify abnormal consequences due to renal compensation. This includes the early development of kidney fibrosis.
SFK is generally identified in childhood using ultrasound and renal scintigraphy techniques. Biomarker quantification from urine samples is the preferred option for monitoring regular renal function. These biomarkers should reflect all aspects of normal kidney function or pathophysiology, including the first signs of fibrosis.
In this article, Katazyna Taranta-Janusz performed a prospective clinical study on a population of SFK children. Among biomarkers potentially useful for assessing kidney fibrosis, she demonstrated that procollagen type III aminoterminal propeptide (PIIINP) was the best candidate.
Correlation studies and Receiver Operating Characteristic (ROC) analysis for urinary PIIINP in SFK and control children are extremely convincing.
Lung, liver, and now kidney… increasing quantities of data showing the role of PIIINP for monitoring fibrosis progression are available in scientific literature.
Undoubtedly, PIIINP has taken its position as the best and most up-to-date biomarker for fibrosis assessment.
We aimed at evaluating urinary levels of procollagen III aminoterminal propeptide (PIIINP) and β-catenin and the relationship between these markers and clinical and laboratory variables in children with a solitary functioning kidney (SFK).
The study group consisted of 98 (M/F: 62/36) children with an SFK with a median age of 8 years. An age-matched control group contained 54 healthy peers. Urinary levels of procollagen III aminoterminal propeptide and β-catenin were measured using a commercially available immunoassay kit.
The urinary values of PIIINP (UPIIINP) were significantly increased in patients with SFK versus controls (p < 0.01). Our analysis revealed no significant differences in urinary β-catenin levels between the SFK patients and control subjects (p > 0.05). Only urinary PIIINP levels were correlated to renal function tests, such as serum creatinine, urea, uric acid, and estimated glomerular filtration rate (p<0.05). An increased urinary level of PIIINP may indicate early kidney impairment in children with SFK. Urinary β-catenin does not seem to play any important role as a marker of renal function in children with SFK. Further long-term studies are required in order to evaluate the clinical usefulness of these markers and their predictive value of chronic kidney disease (CKD) progression.
Advances in Medical Sciences. 2019 Feb 6;64(1):189-194.