Abstract

occurs particularly because of reflux and infections. The relationship between renal parenchymal injury and reflux is well-known. The common reason of chronic renal failure in children and adult, the rate of 24%, is the vesicoureteral reflux. However, the rate of 90% of the hypertension among this population of patient, is due to the renal insufficiency, and also the reflux nephropathy is determined in the rate of 50% of them. In urological practice, creatinine clearance, blood urine nitrogen (BUN) and the protein levels of the urine are used to evaluate the failure of the renal function due to the reflux and the urinary infection. But the proteinuria has been confirmed at the late period of the renal insufficiency.

Increased urine protein level is a good, but late indicator of the renal parenchymal injury. Increased excretion of the low molecular weight proteins and renal tubular enzymes indicate early tubular injury. N-Acetyl β-D-Glycosaminidase is a lysosomal enzyme which indicates early tubular injury. In this study, we researched the relationship between the levels of NAG and NAG excretion rate in urine and renal parenchymal injury in patients who had urinary infection history.

Materials and Methods: 55 children with urinary infections and 13 healthy children, who addressed to the outpatient Nephrology Department of the SSK Ankara Pediatric Hospital, have been assessed. For every children routine urine analysis, urine culture, renal ultrasonography, intravenous pyelography, voiding cystourethrography and renal scintigraphy with Tc99m dimercaptosuccinic acid (DMSA) were performed. In urine specimens, the levels of NAG, albumin, and creatinin have been determined. The study group has been evaluated as urinary infection free status at least 3 months (for this reason urine NAG, BM and LDH levels have been not effected) if infection determined only the trimethoprime- sulphametaxazole has been used however, the proteinuria and the hypertension have not confirmed.

Results: 28 of 55 patients who have urinary infections history had VUR. 14 of 28 patients had renal scar. 7 of 27 patients without VUR had renal scar. Patients with renal scarring have been graded. The excreation of NAG in urine, not changed during the day so the spot urine evaluation has been performed. However, the NAG value has been divided to creatinine to decrease the effect of the diuresis. In all patients mean urinary NAG/creatinin ratio was higher than the control group (p<0.05). In patients with renal scar with or without VUR urinary NAG/creatinin ratio was significantly higher than the patients without scar or the control group (p<0.05). Between VUR (+) and VUR (-) patients who have not renal scar, had NAG/creatinine ratio which was not statistically significant (p>0.05).

Conclusion: We concluded that increased NAG levels in urinary tract infections may be an early finding for renal parenchymal injury. The excreation of the enzyme and microprotein have been not affected by the VUR or the degree of VUR without the present of the renal scar.