P0599THE LYSOSOMAL URINE ENZYMES ACTIVITY IN CHILDREN AFTER ACUTE KIDNEY INJURI

Abstract

Abstract Background and Aims The urgency of the problem of acute kidney injury (AKI) in children is due to the high risk of chronic kidney disease (CKD) as an outcome. Lysosomal enzymes in urine are considered to be informative markers of renal parenchyma damage. The aim of study was to determine the activity of lysosomal enzymes β-galactosidase (GAL) and N-acetyl-β-D-glucosamynidase (NAG) in urine as markers of CKD progression in children after AKI. Method 41 children were examined after AKI with achieving self-diuresis and clinical improvement. The functional state of the kidneys was evaluated by the glomerular filtration rate (Schwartz GFR), the level of albuminuria. Urine enzyme activity was determined and cross-linked to mmol urinary creatinine. The control (reference) group consisted of 28 children who were conditionally healthy, without kidney disease. Results The NAG activity was 8 times higher level than in the reference group of healthy children (87/46;193 vs. 15/11;18, p<0.001), and GAL was elevated in 3 times either (34/22;45 vs. 10/6;13, p<0.001) in patients with a disease period of up to 2 years after AKI. In patients with follow-up period 2 or more years enzyme activity levels decreased, but remained 4 times higher (NAG: 49/31;109, p <0.001 compared to control; GAL: 35/25;44, p <0.001 compared to control). The high levels of enzyme activity was documented in 73.2% of patients after one year of follow up, but the GFR decrease was found in 22.0%, and albuminuria - only in 34.1%. Conclusion The urine activity of NAG and GAL in children is an informative marker for diagnosing recovery after AKI or CKD progression with renal function decline. This method is non-invasive, inexpensive, and simple to conduct.