Evaluation of liver-type fatty acid binding protein (L-FABP) and interleukin 6 in children with renal cysts

Abstract

Background. Renal cysts, according to their etiology, can be divided into genetic and acquired cysts. This is of great importance in patients with cystic kidney disease with a possible poor prognosis to identify markers of early kidney damage. Objectives. The objective of this study was to evaluate the concentration of serum and urine liver-type fatty acid binding protein (L-FABP) and interleukin 6 (IL-6) in children with kidney cysts. Material and methods. The study was conducted on a group of 39 children with kidney cysts including 20 subjects with autosomal dominant polycystic kidney disease (ADPKD). Results. Serum and urine L-FABP concentration in children with renal cysts was significantly higher compared to the controls, regardless of the underlying type of cystic degeneration, number of cysts and gender. Also, serum and urinary IL-6 concentration was significantly higher than in the control group. There was a significant negative correlation between serum L-FABP concentration and standard deviation score (SDS) for diastolic blood pressure (DBP). A significant negative correlation was found between serum IL-6 concentration and systolic blood pressure (SBP), DBP and mean arterial pressure (MAP) values as well as SDS for SBP and DBP. In addition, a significant positive correlation was found between urinary IL-6 concentration and estimated glomerular filtration rate (eGFR). Conclusions. Higher concentration of L-FABP in serum and urine in children with kidney cysts indicates the early damage to the renal parenchyma, detectable before the onset of hypertension and other organ damage. Significantly higher serum and urinary IL-6 levels in children with cystic kidney disease compared to healthy children may suggest the role of this cytokine in chronic kidney disease development.

Renal biomarkers in cats: A review of the current status in chronic kidney disease

“… 135 , 140 In the clinical setting, uL‐FABP/Cr ratio is a biomarker of early tubular damage that can reflect the severity of tubulointerstitial injury, detect AKI, and predict CKD progression in humans. 141 , 142 , 143 , 144 , 145 , 146 , 147 Furthermore, L‐FABP has been shown to be renoprotective in small laboratory animals. 148 , 149 …”

“…135,140 In the clinical setting, uL-FABP/ Cr ratio is a biomarker of early tubular damage that can reflect the severity of tubulointerstitial injury, detect AKI, and predict CKD progression in humans. [141][142][143][144][145][146][147] Furthermore, L-FABP has been shown to be renoprotective in small laboratory animals. 148,149 A commercial feline L-FABP ELISA based on cross-reactivity with anti-human L-FABP has been used in research on cats and recently has been validated for feline serum and urine.…”

“…Ischemic injury and oxidative stress of the proximal tubules result in L‐FABP excretion into the urine in small laboratory animals and humans 135,140 . In the clinical setting, uL‐FABP/Cr ratio is a biomarker of early tubular damage that can reflect the severity of tubulointerstitial injury, detect AKI, and predict CKD progression in humans 141‐147 . Furthermore, L‐FABP has been shown to be renoprotective in small laboratory animals 148,149 …”

Urinary liver‐type fatty acid‐binding protein in clinically healthy elderly cats: Evaluation of its potential to detect IRIS stage 1 chronic kidney disease and borderline proteinuria

“…L‐FABP plays a role in free fatty acid metabolism and is expressed by proximal tubular cells and excreted into urine when tubular cells are injured (Xu et al., 2015 ). Urinary L‐FABP (uL‐FABP) is promising as an early biomarker of tubular damage in people with acute kidney injury (AKI) as well as with CKD (Plesiński et al., 2019 ; Susantitaphong et al., 2013 ). According to recent findings, uL‐FABP concentration increases in cats both with AKI and CKD (Katayama et al., 2019 ; Kongtasai et al., 2021 ).…”