Gregory Cria O, Yu Chunli, Singh Rani H
Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia, USA.
Genet Med. 2007 Nov;9(11):761-5. doi: 10.1097/GIM.0b013e318159a355.
Blood phenylalanine monitoring is critical for the management of phenylketonuria. We compared three methods for measuring blood phenylalanine concentration: the amino acid analyzer, high-performance liquid chromatography with fluorometric detection, and tandem mass spectrometry.
We studied 22 female patients with phenylketonuria, ages 12-48 years, who attended our Metabolic Camp. Blood was collected into heparinized tubes (for analysis by the amino acid analyzer) or filter paper (for analysis by high-performance liquid chromatography with fluorometric detection and tandem mass spectrometry).
Blood phenylalanine concentrations of plasma measured by the amino acid analyzer were significantly higher than those obtained from whole blood on filter paper by high-performance liquid chromatography (difference: 102 microM; 95% confidence interval: 23, 181) and tandem mass spectrometry (difference: 137 microM; 95% confidence interval: 58, 216). Phenylalanine concentrations from high-performance liquid chromatography and tandem mass spectrometry were not significantly different (P = 0.5).
When monitoring blood phenylalanine concentrations for dietary compliance, clinicians should be mindful of the method being used; analyses of whole blood on filter paper were consistently approximately 15% lower than analyses of plasma.
血液苯丙氨酸监测对于苯丙酮尿症的管理至关重要。我们比较了三种测量血液苯丙氨酸浓度的方法：氨基酸分析仪、荧光检测高效液相色谱法和串联质谱法。
我们研究了22名年龄在12至48岁之间的苯丙酮尿症女性患者，她们参加了我们的代谢营。血液采集到肝素化管中（用于氨基酸分析仪分析）或滤纸上（用于荧光检测高效液相色谱法和串联质谱法分析）。
氨基酸分析仪测得的血浆中血液苯丙氨酸浓度显著高于荧光检测高效液相色谱法（差异：102微摩尔/升；95%置信区间：23，181）和串联质谱法（差异：137微摩尔/升；95%置信区间：58，216）从滤纸上全血测得的浓度。荧光检测高效液相色谱法和串联质谱法测得的苯丙氨酸浓度无显著差异（P = 0.5）。
在监测血液苯丙氨酸浓度以评估饮食依从性时，临床医生应注意所使用的方法；滤纸上全血的分析结果始终比血浆分析结果低约15%。
