Biochemical predictors of chronic kidney disease in children recovering from acute kidney injury

Abstract

The pressing question today is to find early informative markers for kidney interstitial injury in reconvalescents of acute kidney injury (AKI). The aim of the study was to determine the informativeness of transferrin (TF), ceruloplasmin (CP) presence and activity level of lysosomal enzymes in urine as predictors of chronic kidney disease. Materials and methods. The contents of TF, CP and N-acetyl-β-Dgluosaminindase (NAG) and β-galactosidase (ß-GAL) in the urine of 41 children after AKI were determined. All patients were divided into 2 groups depending on the disease duration – group 1 included 22 patients with 12 months’ duration, group 2 – 19 children with the disease duration of 2 years and more. The control group consisted of 28 conditionally healthy children. Results. The levels of NAG and ß-GAL were 8 and 3 times increased, respectively, in the patients from group 1 in comparison with the control group (P < 0.001). In the group 2 children, the enzyme levels were 4 times higher than the control, and albuminuria was observed at normal GFR (P < 0.001). An inverse correlation was established between GFR indices and activity levels of NAG (r = -0.473) and ß-GAL (r = -0.333), and a direct correlation between activity indices of GAG and ß-GAL (r = 0.845). The presence and high levels of TF in 18.8 % of children in group 1 and in 21.0 % in group 2, as well as urine CP in 72.7 % of patients in group 1 and in 78.9 % in group 2, is indicative of a progressive damage to the kidney glomerular apparatus. Conclusions. The presence and increased quantitative parameters of TF and CP in the urine of children after AKI are early signs of damage to the kidney glomerular apparatus. Four times increased levels of the enzyme activity and albuminuria at unchanged GFR indicate an interstitial kidney injury (P < 0.001). The examinations conducted are non-invasive, relatively low cost and easy to use for children of all ages.