尿液AQP2在先天性肾积水患儿中的检测和意义

Significance and measurement of urinary aquaporins-2 in children with congenital hydronephrosis

目的研究单侧先天性肾盂输尿管连接处梗阻(pyeloureteric junction obstruction,PUJO)肾积水患儿尿液水通道蛋白2(Aquaporins-2,AQP2)测定在肾脏浓缩功能评价中的意义。方法选取12例正常儿童,26例单侧先天性PUJO肾积水患儿,其中轻度14例,重度12例,均经彩超、静脉肾盂造影证实,并排除其它泌尿系统疾病;在严格设定条件下,收集正常对照组术前和梗阻解除术后第3天患肾24h尿液,同时收集术中肾盂尿液,测定尿渗透压,并用酶联免疫吸附法(ELISA)测定尿液中AQP2。结果与正常对照组比较,积水组术中尿液AQP2和尿渗透压明显下降(P<0.05),且重度积水组术中尿液AQP2与轻度积水组相比,明显降低(P<0.05),但重度积水组和轻度积水组术中尿渗透压相比无显著差异(P>0.05);梗阻解除后,轻、重度积水组术中尿液AQP2与术后第3天相比,无显著差异(P>0.05),而术后第3天两组尿渗透压却明显下降(P<0.05),术后第3天重度积水组与轻度积水组尿液AQP2和尿渗透压相比较,显著下降(P<0.05);正常对照组与轻、重度积水组术后第3天尿液AQP2和尿渗透压之间存在一定相关性。结论小儿单侧先天性PUJO尿液AQP2和尿渗透压较正常对照组显著降低,且二者之间存在一定相关性。尿液中AQP2下降可能和尿液浓缩功能改变有关。

Objective To investigate the value of evaluating kidney concentration ability by detecting urinary aquaporins-2 in children with pyeloureteral junction obstruction （PUJO）.Methods Twelve healthy children and twenty-six hydronephrosis children with congenital unilateral PUJO were included in this study, which included fourteen mild hydronephrosis and twelve severe hydronephrosis. All were confirmed by color Doppler uhrasound and intravenous pyelogram（IVP）,and the other urinary system diseases were eliminated.In the strict control condition,24h-urine was collected separately from healthy children and affected kidney of releasing ureteral obstruction in the third day, and pelvis urine of operation also was collected. The urine osmolality was measured, and AQP2 levels were measured by using enzyme-linked immunosorbent assay （ELISA）. Results Comparing with the normal control, urinary AQP2 and osmolality were lower at operation （P 〈 0.05 ）,and urine AQP2 in severe hydronephrosis were lower than those of the mild hydronephrosis （P 〈 0.05 ）.However, there is no significant difference between the mild and severe hydronephrosis.After releasing obstruction, there is no statistic difference in urinary AQP2 between the miht and severe group, but urine osmolality reversed. Meanwhile, urinary AQP2 and osmolality in severe group were lower than the mild group in the third day after operation （P〈 0.05 ）; there was a positive correlation between osmolality and AQP2 levels in normal children and those of the third day after operation. Conclusions Comparing with the normal control ,urinary AQP2 and osmolality were lower than those of congenital PUJO hydronephrosis , which indicated that the decrease of AQP2 levels of urine may be related with impairment of concentrating ability of collecting duct.