Clinical value of early renal damage index in children hydronephrosis

Objective To explore urinary NAG, Cr, MA, α1-MG andβ2-MG as the early renal damage index in children hydronephrosis. Methods The clinical data of 206 patients in the Bayi Children′s Hospital Affiliated to the Seventh Medical Center of Chinese PLA General Hospital from May 2018 to January 2019 were analyzed retrospectively. Among them, 152 children with hydronephrosis were set as observation group, 54 children without hydronephrosis were set as control group. In the observation group, the age ranged from 1 month to 18 years old, and the median age was 2 years old. There were 123 cases of hydronephrosis caused by ureteropelvic junction obstruction (UPJO) and 29 cases of posterior urethral valve complicated with hydronephrosis. In the control group, the age ranged from 1 month to 15 years old, with a median age of 5 years. There were 18 hypospadias cases, 15 occult penis cases and 21 phimosis. All children with hydronephrosis underwent nuclear medicine renal dynamic imaging. Urine specimens were tested for urinary NAG, Cr, MA, α1-MG, and β2-MG. According to renal dynamic results, the observed components were the renal function injury group and the normal renal function group. The above indicators analyzed to judge the clinical value to find the early renal damage. Results The expression levels of urinary NAG, MA, α1-MG and β2-MG in the observation group were higher than those in the control group, and the difference was statistically significant. The expression of urinary Cr and the abnormal rate were no significant difference between any two groups(P=0.647, P=0.572). The expression levels of urinary NAG, MA, α1-MG and β2-MG were not significantly different between the normal renal hydronephrosis group and the renal function impairment group (P=0.365, P=0.448, P=0.379, P=0.338). The abnormal expression rate of Urine MA and β2-MG was not statistically significant in the patients with normal renal hydronephrosis and the renal function impairment group (P=0.436, P=0.478). MA got the highest sensitivity of (58.8%), and NAG had the highest specificity of 89.3% to detect early renal demage. Four indexes combined analysis, sensitivity, negative predictive rate, diagnostic coincidence rate improved obviously. Joint analysis of posterior urethral valves combined with hydronephrosis, the abnormal rate was 89.7%(26/29). The renal dysfunction of the posterior urethral valve showed that the renal dynamics dysfunction rate was only 37.9%(11/29). Conclusions The combined analysis of urinary NAG, MA, α1-MG and β2-MG can accurately predict early renal injury. The index of early renal loss may be the early evidence to judge whether the posterior urethral valve is complicated with upper urinary tract function injury. Key words: Hydronephrosis; Children; Early renal damage index; Clinical application