Distinction of Degrees of Ischemic Kidney Parenchymal Injury in Children with Congenital Vesicoureteral Reflux (According to Enzymological Criteria)

Abstract

The objective: to evaluate the possibility of determining the levels of activity of N-acetyl-β-D-glucosaminidase B (NAG B) in urine as an enzymological marker of differentiation of ischemic damage to the renal parenchyma in children with congenital vesicoureteral reflux (VUR). Materials and methods. 49 children aged 1 to 15 years with a verified diagnosis of unilateral VUR and 25 practically healthy children were examined. NAG B activity in urine was determined before reconstructive treatment. The limits of the reference intervals of the levels of enzyme activity in the urine of healthy children were calculated by the formula M±1.5σ. According to the personalized analysis the patientswere divided into 3 groups: group 1 – 13 patients (the levels of NAG activity in the urine are registered from 0.8 to 2.3 units); group 2 – 14 patients (the levels of NAG activity in the urine – 2.4 to 4.5 units); group 3 – 22 patients (the levels of NAG activity in urine – 4.6 to 10.5 units. Results. In the urine of healthy children, the activity of NAG B averages 1.56±0.096 units, σ=0.48, reference levels are recorded from 0.8 to 2.3 units. In the urine of the 1st group, the levels of NAG B activity are equal to 1.61±0.13 units correspond to the control values and are evaluated as zero degree of ischemic damage of a renal parenchyma; in the urine of the 2nd group – 3.97±0.17 units exceed the average control values by 1.6–2.9 times and are assessed as moderate or I degree of ischemic damage to the renal parenchyma; in the urine of the 3rd group – 7.50±0.39 units exceed the average control values by 3 times or more and are assessed as severe or II degree of ischemic damage to the renal parenchyma (p2,3-1<0,001; p3-2<0.001). Conclusions. The expediency of determining the activity levels of N-acetyl-β-D-glucosaminidase B in the urine of children with congenital vesicoureteral reflux, as an enzyme with pronounced renospecific properties and as enzyme marker for differentiating the degrees of ischemic damage (0, I, II) of the renal parenchyma was established. Activity levels of NAG B can be used as well for timely prevention of the development and progression severe complications through the timely appointment of the appropriate optimal corrective therapy.