L-[1-13C]苯丙氨酸呼气试验定量检测肝功能研究

为评价L-1- 13C]苯丙氨酸呼气试验检测肝功能的可行性和有效性,健康自愿者、代偿期肝硬化患者和失代偿期肝硬化患者各10名,口服100mg L-1- 13C]苯丙氨酸后进行呼气试验.应用气体同位素比值质谱仪测量服药前和服药后至360min各时间点气样中的13C丰度,得到了不同时间的13C的排除速率13CO2ERt (percentage 13C excretion rate) (% 13C剂量/h)和各时相内的累计13C排除率13Ccumt (percentage 13C cumulative excretion) (% 13C剂量).将呼气试验参数30 min 13C排除速率13CO2ER30和75min累计13C排除率13Ccum75在正常对照组、肝硬化代偿组、肝硬化失代偿组之间进行两两比较,并分别与各肝功能临床生化指标进行相关性分析.结果显示,13CO2ER30(肝硬化代偿组7.4% 13C剂量/h±1.0% 13C剂量/h;肝硬化失代偿组3.5% 13C剂量/h±1.1% 13C剂量/h;正常对照组12.1% 13C剂量/h±2.1% 13C剂量/h)和13Ccum75(肝硬化代偿组7.0% 13C剂量±1.1% 13C剂量;肝硬化失代偿组3.8% 13C剂量±1.0% 13C剂量;正常对照组10.6% 13C剂量±1.6% 13C剂量)在各组之间差异均具有显著性(P<0.001);13CO2ER30和13Ccum75与部分肝功能生化指标存在显著相关性(P<0.05).表明口服L-1- 13C]苯丙氨酸呼气试验是一种简便、灵敏、特异、定量的肝功能即时检测方法;13CO2ER30和13Ccum75是有效的肝功能评价参数.

A quantitative assessment of liver function using L-[1-13C]phenylalanine breath test

The purpose of this study is to evaluate the feasibility and validity of the breath test with L-1-13C]phenylalanine orally administrated in assessing liver function quantitatively. L-1-13C]phenylalanine breath tests were performed in 10 patients with compensated liver cirrhosis, 10 patients with decompensated liver cirrhosis and 10 normal subjects. Breath samples were taken before oral administration and at different time intervals within 360 minutes after administration of L-1-13C]phenylalanine (100mg / case) and the enrichment of breath 13CO2 was measured by an isotope ratio mass spectrometer. The percentage of 13C excretion rate at 30 minute (13CO2ER30) and the percentage of 13C cumulative excretion within 75 minutes (13Ccum75) were studied among the above groups and were compared to clinical liver function tests. Result showed that 13CO2ER30 were 7.4% 13C dose/h ?.0% 13C dose/h and 3.5% 13C dose/h ?.1% 13C dose/h in patients with compensated liver cirrhosis and patients with decompensated liver cirrhosis, both were significantly lower than that of normal subjects (12.1% 13C dose/h 2.1% 13C dose/h, P<0.001, respectively). 13Ccum75 were 7.0% 13C dose ?.1% 13C dose and 3.8 13C dose ?.0% 13C dose in patients with compensated liver cirrhosis and patients with decompensated liver cirrhosis, and both were also significantly lower than that of normal subjects (10.6% 13C dose ?.6% 13C dose, P<0.001, respectively). These two parameters signifi-cantly correlated with some clinical liver function tests (P<0.05). The present results seem to indicate that oral L-1-13C]phenylalanine breath test is a simple, sensitive, specific and quantitative test for the measurement of instant liver function, whereas 13CO2ER30 and 13Ccum75 are two useful parameters for evaluation.