Application of isoxanthopterin as a new pterin marker in the differential diagnosis of hyperphenylalaninemia

作     者：Pei-Zhong Bao Jun Ye Lian-Shu Han Wen-Juan Qiu Hui-Wen Zhang Yong-Guo Yu Jian-Guo Wang Xue-Fan Gu 

作者机构：Department of Endocrinology and GeneticsShanghai Institute of PediatricsXinhua HospitalShanghai Jiaotong University School of Medicine1665 Kong Jiang RoadShanghai 200092China 

出 版 物：《World Journal of Pediatrics》 (世界儿科杂志（英文版）)

年 卷 期：2019年第15卷第1期

页      面：66-71页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：supported by the National Key Research and Development Program of China 

主　　题：6-Pyruvoyltetrahydropterin synthase Hyperphenylalaninemia Isoxanthopterin Phenylalanine hydroxylase Pterin 

摘      要：Background This study aimed to explore the value of applying a new pterin marker (isoxanthopterin) to the traditional urine pterin analysis to reduce the rate of mis-diagnosis of 6-pyruvoyltetrahydropterin synthase deficiency (PTPSD) and improve the accuracy of *** We compared the urine neopterin (N),biopterin (B),isoxanthopterin (Iso),B% and Iso% levels between patients with phenylalanine hydroxylase deficiency and those with PTPSD,and found the most specific pterin biomarkers by ROC analysis.A positive cut-off value of urine pterins was *** effect of combined Iso% + B + B% in reducing PTPSD mis-diagnosis was evaluated,and the different urine pterin levels in PTPSD and false PTPSD (FPTPSD) were *** concordance of PTPSD diagnosis by the new pterin scheme and gene mutation analysis was *** (1) Urinary B,B%,Iso and Iso% were significantly lower in PTPSD than those in phenylalanine hydroxylase-deficiency group (P 0.01);(2) Iso%,B%,and B were the most specific markers;(3) The positive cut-off values of B,B%,Iso% for PTPSD were 0.17 mmoL/moLCr, 5.0%,and 9.5%,respectively;(4) urinary B +B% + Iso% scheme significantly reduced the false-positive rate of PTPSD compared to traditional *** Iso% levels in FPTPSD group were higher than the ones in PTPSD group;(5) an accuracy of diagnosis for PTPSD was increased by 9-19% when Iso% was introduced to urinary pterin *** Iso% is helpful to reduce the rate of misdiagnosis of PTPSD in the diagnosis by urinary pterin analysis for hyperphenylalaninemias and improve the accuracy of *** approach is worthy of further development and increased utilization.