亚硝酸盐对焦酚红法检测24 h尿液总蛋白的干扰分析  

Analysis of interference effect of nitrites on total urinary protein assay by pyrogallol red molybdenum method

作　　者：杨帆[1] 董丹风 苏同轩 陆怡德[1] YANG Fan;DONG Danfeng;SU Tongxuan;LU Yide(Department of Clinical Laboratory,Ruijin Hospital,Shanghai Jiaotong University School of Medicine,Shanghai 200025,China)

机构地区：[1]上海交通大学医学院附属瑞金医院检验科,上海200025

出　　处：《临床检验杂志》2024年第4期241-245,共5页Chinese Journal of Clinical Laboratory Science

基　　金：上海市卫生健康委员会资助项目(20194Y0318)。

摘　　要：目的探讨亚硝酸盐对于焦酚红法检测24 h尿液总蛋白的干扰效应,并评估维生素C纠正干扰的可行性。方法根据美国临床和实验室标准协会(CLSI)EP7-A3文件,选取24 h尿液总蛋白定量结果为150 mg/L、500 mg/L和1000 mg/L的新鲜尿液标本作为对照样本,并配制含不同浓度亚硝酸钠的干扰物样本。利用配对差异实验确认亚硝酸盐的干扰作用,并通过剂量效应实验明确亚硝酸盐浓度与干扰程度的关系。在终浓度为200μg/mL亚硝酸钠存在的情况下,评估不同浓度维生素C纠正干扰的效果。同时收集61例亚硝酸盐阳性和40例亚硝酸盐阴性的临床标本,比较两组标本维生素C纠正前后的相对差值,评估其临床应用价值。结果配对差异实验中200μg/mL亚硝酸钠对150 mg/L和500 mg/L两个浓度的尿总蛋白测定分别存在-157.8%和-36.2%的相对干扰,显著大于1/2TEa(22%),而对于高浓度1000 mg/L的尿总蛋白虽存在-20.5%的负干扰,但在可接受范围内。剂量效应实验结果显示随着尿液中亚硝酸盐浓度的增加,尿总蛋白检测所受负干扰作用亦逐渐增大。在终浓度为200μg/mL亚硝酸钠存在的情况下,添加0.2 mg/mL的维生素C可分别将150 mg/L和500 mg/L的尿总蛋白纠正至148 mg/L(-1.1%)和402 mg/L(-19.5%),均处于可接受范围内。临床标本中亚硝酸盐阳性组通过维生素C纠正产生的相对差值显著高于亚硝酸盐阴性组(P<0.01)。结论亚硝酸盐对于焦酚红法检测尿液总蛋白存在负干扰,尤其是在尿总蛋白150 mg/L情况下,需引起临床实验室的关注。添加0.2 mg/mL维生素C可有效纠正低浓度尿总蛋白标本中亚硝酸盐的干扰作用,具有一定的临床应用价值。Objective To investigate the interference effect of nitrite on the determination of 24 h urine total protein by pyrogallol red method and evaluate the feasibility of using vitamin C to correct this interference.Methods According to the CLSI EP7-A3 document,fresh urine specimens with 24 h urine total protein concentrations of 150 mg/L,500 mg/L and 1000 mg/L were selected as control samples,and interfering samples containing different concentrations of sodium nitrite were prepared.The interference of nitrite was confirmed through paired difference experiments,and the relationship between nitrite concentration and interference level was clarified using dose-effect experiments.The effects of different concentrations of vitamin C on correcting the interference caused by 200μg/mL sodium nitrite were evaluated.Additionally,61 nitrite-positive and 40 nitrite-negative clinical specimens were collected to compare the relative differences before and after vitamin C correction to assess its clinical application value.Results In the paired difference experiments,200μg/mL sodium nitrite had relative interferences of-157.8%and-36.2%on the determination of urine total protein of 150 mg/L and 500 mg/L respectively,which were significantly greater than 1/2TEa(22%).Although there was a-20.5%negative interference for the high concentration of 1000 mg/L urine total protein,the interference was within the acceptable range.The doseeffect experiment results showed that as the nitrite concentration in urine increased,the negative interference on urine total protein detection also gradually increased.In the presence of 200μg/mL sodium nitrite as the final concentration,the addition of 0.2 mg/mL vitamin C corrected the urine total protein at 150 mg/L and 500 mg/L to 148 mg/L(-1.1%)and 402 mg/L(-19.5%),respectively,both within the acceptable range.The relative differences produced by vitamin C correction in the nitrite-positive clinical specimen group were significantly higher than those in the nitrite-negative group(P<0.01).Conclusions

关 键 词：24 h尿总蛋白 亚硝酸盐 干扰分析 维生素C 纠正试验 

分 类 号：R446[医药卫生—诊断学]