两种尿蝶呤谱检测方法的比较及在高苯丙氨酸血症中的应用

Comparison of two urinary purine spectrum detection methods and their application in phenylketonuria

目的对碘(I_(2))氧化法和二氧化锰(MnO_(2))氧化法两种前处理方法在尿蝶呤谱检测进行方法学评价,提高尿蝶呤谱在高苯丙氨酸血症(HPA)诊断及分型准确率。方法分别用I_(2)氧化法和MnO_(2)氧化法处理65例尿液样本,通过定量分析尿液中新蝶呤(N)和生物蝶呤(B)含量、比较两种方法的最低检测限、精密度和回收率,以及分析两种方法在HPA的诊断符合率。结果I_(2)氧化法和MnO_(2)氧化法处理苯丙酮尿症(PKU)、四氢生物蝶呤缺乏症(BH4D)和正常儿童尿液样本,诊断符合率均达100%。I_(2)氧化法检测的N和B浓度均高于MnO_(2)氧化法,差异有统计学意义(P<0.05)。两种方法N的检测限[I_(2)氧化法:(0.00063±0.00027)μg/L;MnO_(2)氧化法:(0.00076±0.00032)μg/L];B的检测限[I_(2)氧化法:(0.00084±0.00035)μg/L;MnO_(2)氧化法:(0.00081±0.00033)μg/L],I_(2)氧化法优于MnO_(2)氧化法。两种方法的批内精密度(CV)均较好(I_(2)氧化法和MnO_(2)氧化法N:2.54%、3.51%,B:2.43%、3.26%);批间CV I_(2)氧化法优于MnO_(2)氧化法(I_(2)氧化法和MnO_(2)氧化法N:2.26%、6.25%,B:2.75%、7.32%)。低浓度标准品回收试验,I_(2)氧化法的N回收率较差(I_(2)氧化法和MnO_(2)氧化法N:128.19%、85.7%;B:93.49%、87.55%);中、高浓度标准品回收试验N和B的回收率均良好(中、高浓度回收率分别是I_(2)氧化法N:109.90%、99.59%,B:97.57%、103.29%;MnO_(2)氧化法N:94.71%、98.41%,B:95.43%、100.5%)。两种方法在0.01~2.00μg/L范围内均有良好线性。结论I_(2)氧化法和MnO_(2)氧化法能有效鉴别PKU和BH4D,两者能满足临床检测需求;I_(2)氧化法优于MnO_(2)氧化法。

Objective To evaluate two pre-processing methods,iodine(I_(2))oxidation method and manganese dioxide(MnO_(2))oxidation method,in urinary purine spectrum detection to improve the accuracy of phenylketonuria(PKU)diagnosis and classification.Methods A total of 65 urine samples were processed using I_(2) oxidation and MnO_(2) oxidation methods.Quantitative analysis of the content of neopterin(N)and biopterin(B)in urine,comparison of the two methods in terms of the lowest detection limit,precision,recovery rate,and analysis of the diagnostic compliance rate in PKU were conducted.ResultsThe diagnostic compliance rates for PKU,tetrahydrobiopterin deficiency(BH4D),and normal children urine samples were all 100%for both I_(2) oxidation and MnO_(2) oxidation methods.The concentrations of N and B detected by the I_(2) oxidation method were higher than those by the MnO_(2) oxidation method,with statistical significance(P<0.05).The detection limits for both N[I_(2) oxidation method:(0.00063±0.00027)μg/L;MnO_(2) oxidation method:(0.00076±0.00032)μg/L]and B[I_(2) oxidation method:(0.00084±0.00035)μg/L;MnO_(2) oxidation method:(0.00081±0.00033)μg/L]were better for the I_(2) oxidation method.Both methods showed good within-batch precision(CV)for N(I_(2) oxidation method and MnO_(2) oxidation method:2.54%,3.51%)and B(I_(2) oxidation method and MnO_(2) oxidation method:2.43%,3.26%).The between-batch CV was better for the I_(2) oxidation method(N:2.26%,6.25%;B:2.75%,7.32%)compared to the MnO_(2) oxidation method.In the low concentration standard recovery test,the N recovery rate for the I_(2) oxidation method was poor(N:128.19%,85.7%;B:93.49%,87.55%),while in the middle and high concentration standard recovery test,the recovery rates for N and B were good for both methods(N:109.90%,99.59%;B:97.57%,103.29%for the I_(2) oxidation method;N:94.71%,98.41%;B:95.43%,100.5%for the MnO_(2) oxidation method).Both methods exhibited good linearity within the range of 0.01~2.00μg/L.Conclusion Both the I_(2) oxidation method and MnO_(2) oxidation method can effectively differentiate PKU and BH4D and meet clinical testing needs,with the I_(2) oxidation method performing better.