单次尿铜比值诊断儿童肝豆状核变性意义初探

Value of the single test of the ratio of urinary copper excretion in the diagnosis of Wilson's disease in children

目的探讨单次尿铜比值测定代替24h尿铜定量用于诊断肝豆状核变性(WD)的可行性。方法测定正常儿童24小时内多次尿标本的铜肌酐(Cu/Cr)、铜/锌(Cu/Zn)比值,了解其稳定性;收集15例肝病患儿(其中2例WD)的晨尿和24h尿,研究单次尿Cu/Cr、Cu/Zn值与24h尿铜相关性;测定9例初发WD患儿和22例其它肝病患儿的单次尿铜比值和24h尿铜,研究其诊断儿童肝病中的WD的敏感度和特异度。结果2例正常儿童24h内尿Cu/Cr值和Cu/Zn值的变异系数分别为12.5%、9.3%。单次尿Cu/Cr值和Cu/Zn值与24h尿铜的相关系数分别0.767和0.891(P<0.001)。24h尿铜定量诊断WD的敏感度55.5%、特异度77.3%;晨尿Cu/Zn值的敏感度77.8%、特异度86.4%。结论单次尿铜比值1d内波动小,尿Cu/Zn值与24h尿铜定量相关性好,诊断WD的敏感度和特异度较高,可望代替24h尿铜定量用于WD诊断。

Objective 24-hour urinary copper excretion is one of the most important indexes in the diagnosis of Wilson＇s disease. But it is diflqcult to collect with accuracy and the sample is easy to be polluted. This study is to test the feasibility of utilizing single measurement of urinary copper ratio instead of the 24 hr urinary copper quantification in the diagnosis of Wilson＇ s disease. Methods 1. Measured the ratio of urine copper/creatinine（Cu/Cr）, copperlzinc（CulZn） ratio in multiple samples during 24 hour sampling with 2 cases of healthy children to test the stability. 2. Collected samples of morning urine and 24 hour urine from 2 cases of new-diagnosed Wilson＇s disease children and 13 cases of children with other liver diseases, study the correlation coefficient between the single urinary Cu/Cr ratio, Cu/Zn ratio and the 24 hr urinary copper excretion. 3. Collected samples from 9 cases of new-diagnosed Wilson＇ s disease children and 22 cases of children with other liver diseases, compare the single urinary Cu/Zn ratio and the 24 hr urinary copper excretion, study the sensitivity and specificity in diagnosing WD in children with liver disease. Results in the 2 healthy children, coeflqcient variation（CV） of urinal Cu/Cr ratio and Cu/Zn ratio were 12.5 % and 9.3 %. Correlation coeflqcient between the single urine Cu/Cr ratio, Cu/Zn ratio and the 24 hr urinary copper excretion were 0.767 and 0. 891. In diagnosing WD, 24 hour urinary copper excretion method had sensitivity of 55.5 % and specificity of 77.3 %, while the morning urinary Cu/Zn ratio method had sensitivity of 77.8 % and specificity of 86.4 %. Conclusion Single urinary copper ratio has low variation over the day and urinary Cu/ Zn ratio has better relationship than Cu/Cr with 24 hr urinary copper excretion. Morning urinary Cu/Zn ratio has better sensitivity and specificity than 24 hr Cu excretion in diagnosing WD. It could be used to replace the 24 hr Cu excretion method to diagnose WD.