Orotic acid quantification in dried blood spots and biological fluids by hydrophilic interaction liquid chromatography tandem mass spectrometry
Orotic acid quantification in dried blood spots and biological fluids by hydrophilic interaction liquid chromatography tandem mass spectrometry
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DOI：
10.1002/jssc.200900758
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发表时间：
2010-04-01
影响因子：
3.1
通讯作者：
Corso, Gaetano
中科院分区：
文献类型：
--
作者：
D'Apolito, Oceania;Garofalo, Daniela;Corso, Gaetano
乳清酸(ORA)是嘧啶核苷酸途径的中间代谢产物，其尿液排泄有助于诊断遗传性口腔性酸尿症和某些尿素循环酶及氨基酸转运体的高氨性遗传缺陷。ORA分析是基于稳定同位素稀释的GC-MS或LC-MS/MS方法。建立了一种利用亲水作用LC-MS/MS快速测定干血斑、血浆和尿液中ORA的方法。血浆、DBS和尿液三个质控水平的日内和日间分析不精密度(CV%)为0.8~14.1%，而不精密度为13.5~9.4%。健康儿童(n=20)血浆ORA<0.69 mU/M，DBS<0.82 mU/M，尿肌酐0.2~1.4 mmol/mol。1例瓜氨酸血症患者血浆ORA水平为133 mU M，DBS为39 mU M。1例hyperammonemia-hyperornithinemia-homocitrullinemia(HHH)综合征患者尿ORA水平为9.1mmoL/m o l肌酐。该方法有可能区分受影响的患者和参考对象；临床验证应该扩大到更多的患者。
Orotic acid (ORA) is an intermediate metabolite in the pathway of pyrimidine nucleotides; its urinary excretion is useful to diagnose the hereditary orotic aciduria and some hyperammonemic inherited defects of urea cycle enzymes and amino acid transporters. ORA analysis is based on stable isotope dilution by GC-MS or LC-MS/MS methods. We developed a fast assay that measures the ORA in dried blood spots (DBS), plasma and urine using hydrophilic interaction LC-MS/MS. Within- and between-day analytical imprecision (CV%) of three quality control levels, in plasma, DBS and urine, ranged from 0.8 to 14.1%, while the inaccuracy ranged from 13.5 to 9.4%. In healthy children (n = 20), ORA concentrations were less than 0.69 mu M in plasma, less than 0.82 mu M in DBS and from 0.2 to 1.4 mmol/mol of creatinine in urine. A patient with citrullinemia showed ORA levels of 133 mu M in plasma and 39 mu M in DBS. A patient with hyperammonemia-hyperornithinemia-homocitrullinemia (HHH) syndrome presented a urinary ORA level of 9.1 mmol/mol of creatinine. The method is potentially able to discriminate affected patients from reference subjects; the clinical validation should be expanded on a higher number of patients.