四氢生物蝶呤负荷试验在高苯丙氨酸血症鉴别诊断中的价值  

Tetrahydrobiopterin loading test in differential diagnosis among hyperphenylalaninemia patients

作　　者：张知新[1] 叶军[1] 邱文娟[1] 韩连书[1] 顾学范[1] 

机构地区：[1]上海第二医科大学附属新华医院

出　　处：《中华医学遗传学杂志》2005年第4期438-440,共3页Chinese Journal of Medical Genetics

基　　金：上海市教委(03BK12)~~

摘　　要：目的对高苯丙氨酸血症患者进行口服四氢生物蝶呤(tetrahydrobiopterin,BH4)负荷试验,了解该方法在高苯丙氨酸血症中的鉴别诊断价值。方法新生儿筛查阳性以及临床诊断的高苯丙氨酸血症患儿73例(男47例、女26例),中位数年龄1.93月,进行口服BH4负荷试验(20mg/kg)。对其中血苯丙氨酸(phenylalaninePhe)浓度<600μmol/L者给予口服PheBH4联合负荷试验,同时进行尿蝶呤谱分析,红细胞二氢生物蝶啶还原酶测定。结果在BH4负荷试验或PheBH4联合负荷试验中,经典型苯丙酮尿症(phenylketonuria,PKU)的血Phe对BH4无反应;苯丙氨酸羟化酶缺乏引起的中度PKU的血Phe24h下降32.8%;BH4缺乏症患者服BH4后血Phe表现出特征性的快速下降,4h降至正常水平,并且维持至24h。结合其他检测结果,22例诊断为经典型PKU,39例中度PKU,12例BH4缺乏症。结论高苯丙氨酸血症是由苯丙氨酸羟化酶缺乏或者BH4缺乏所引起,早期鉴别诊断十分重要。BH4负荷试验是快速、简便的体内诊断试验,安全可靠,有较高的鉴别诊断价值。Objective To perform tetrahydrobiopterin （BH4） loading test and to further understand its usefulness in differential diagnosis among hyperphenylalaninemia（HPA） patients. Methods BH4 loading test was carried out in 73 HPA patients, including the positive cases unveiled by neonatal screening and the clinically suspected cases. These patients, 47 males and 26 females, were at a mean age of 1.93 months. BH4（20 mg/kg） loading test was performed in all patients, and a combined phenylalanine （Phe）（ 100 mg/kg） and BH4 loading test was performed among the patient who had a basic blood Phe concentration less than 600 μmol/L. The urine pterine profile analysis and the dihydropteridine reductase activity in dry blood filter spot were tested simultaneously. Results During BH4 loading test or combined Phe and BH4 loading test, the patients with classic phenylketonuria showed no response to BH4, the patients with moderate HPA caused by Phe hydroxylase deficiency decreased 32.8% of blood Phe level and the patients with BI44 deficiency showed a prompt reduction in blood Phe level and it decreased to normal level at 4 h and lasted until 24 h. Twenty-two cases were diagnosed as classic phenylketonttria, 39 were moderate phenylketonuria and 12 were BH4 deficiency. Conclusion Hyperphenylalaninemia may be caused by deficiency of Phe hydroxylase or by deficiency of co-factor BH4. Early diagnosis is important. BH4 loading test is a safe and fast test in vivo. It is sensitive, easy-to-do, and is highly useful in differential diagnosis for suspected cases of HPA.

关 键 词：四氢生物蝶呤 负荷试验 高苯丙氨酸血症 鉴别诊断 苯丙酮尿症 

分 类 号：R725.8[医药卫生—儿科]