LC-MS/MS法监测系统性红斑狼疮患者血浆中霉酚酸谷浓度

Monitoring of trough concentration of mycophenolic acid in plasma of patients with systemic lupus erthematosus by LC-MS/MS

目的运用高效液相色谱串联质谱建立测定系统性红斑狼疮(SLE)患者血浆中霉酚酸谷浓度的分析方法。方法采用多反应监测,正离子模式,电喷雾离子化,监测离子对为m/z 321.2→159.0(霉酚酸)和m/z 327.2→270.0(内标)。50μL血浆加入内标后,再经蛋白沉淀处理,采用色谱柱Welch XB-C_(18)(50 mm×2.1 mm,5μm)进行液相分离,流动相为2 mmol·L^(-1)醋酸铵溶液(0.1%甲酸)-乙腈(0.1%甲酸),梯度洗脱,流速为0.8 mL·min^(-1),分析时长为3.5 min,进样量为3μL。20例SLE患者规律口服吗替麦考酚酯分散片达稳态后,于下一次服药前30 min内取全血并分离血浆,处理后进样分析。结果霉酚酸在0.25~20μg·mL^(-1)范围内线性良好(r=0.9970),各质控水平准确度为87.5%~114.7%,日内和日间相对标准偏差为4.4%~14.7%,提取回收率为93.7%~110.2%。20例SLE患者霉酚酸谷浓度波动在285~5297 ng·mL^(-1)范围内,剂量标准化后患者谷浓度介于285.4~5297 ng·mL^(-1)·g^(-1),变异系数高达95.9%。结论本方法专属性强、灵敏度高、耗时短、前处理简单,可高效精准地监测系统性红斑狼疮患者血浆中霉酚酸谷浓度。

Objective To establish a liquid chromatography-tandem mass spectrometry method for determining concentration of mycophenolic acid in plasma of patients with systemic lupus erythematosus(SLE).Methods Multiple reaction monitoring mode,positive ion scanning and electrospray ion source were applied with ion pairs of m/z 321.2→159.0(mycophenolic acid)and m/z 327.2→270.0(internal standard).50μL plasma sample was precipitated with acetonitrile after the addition of internal standard.The sample was separated with Welch XB-C_(18)(50 mm×2.1 mm,5μm),the mobile phase consisted of 2 mmol·L^(-1) ammonium acetate solution(0.1%formic acid)-acetonitrile(0.1%formic acid)with gradient elution at the flow rate of 0.8 mL·min^(-1),the injection volum was 3μL and analytical time was 3.5 min.After 20 patients with SLE were given regular oral doses of mycophenolate mofetil dispersive tablets to reach steady state,whole blood was taken and plasma was separated within 30 min before the next dose of drug,processed and analyzed.Results The linear range of mycophenolic acid was well accepted within 0.25-20μg·mL^(−1)(r=0.9970),the relative standard deviation of iner-and intra-day precision was 4.4%~14.7%with a accuracy of 87.5%~114.7%among each quality control level,the recovery was 93.7%-110.2%.The trough concentration of mycophenolic acid in 20 patients with SLE ranged from 285 to 5297 ng·ml^(-1).After dose standardization,the trough concentrations ranged from 285.4 to 5297 ng·ml-1·g^(-1),with the coefficient of variation as high as 95.9%.Conclusion This is a highly specific,high-sensitive,time-saving,and simple pre-treatment method and could be finely applied to monitoring the plasma concentration of mycophenolic acid in patients with SLE.