论文部分内容阅读
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 evaluate the diagnostic value of this method in the differential diagnosis of hyperphenylalaninemia in patients with hyperphenylalaninemia by oral administration of tetrahydrobiopterin (BH4). Methods Totally 73 neonates with hyperphenylalaninemia (47 males and 26 females) with positive neonatal screening and clinical diagnosis were enrolled. The median age was 1.93 months. Oral BH4 stress test (20 mg / kg) was performed. In which phenylalaninePhe concentration <600μmol / L were given orally PheBH4 combined load test, simultaneous determination of urinary pteridine, erythrocyte dihydrobiopterin reductase determination. Results In the BH4 stress test or PheBH4 combined stress test, the blood Phe24h of the patients with classical phenylketonuria (PKU) did not respond to BH4; the blood Phe24h of moderate PKU caused by phenylalanine hydroxylase deficiency decreased by 32.8% ; BH4 deficiency patients with BH4 blood Phe showed a characteristic decline rapidly, 4h reduced to normal levels, and maintained until 24h. Combined with other test results, 22 cases were diagnosed as classic PKU, 39 cases of moderate PKU, 12 cases of BH4 deficiency. Conclusions Hyperphenylalaninemia is caused by a deficiency of phenylalanine hydroxylase or BH4 deficiency. Early differential diagnosis is very important. BH4 load test is a quick and easy in vivo diagnostic test, safe and reliable, with a high differential diagnostic value.