甜菜碱对血清酶ALT活性的稳定作用及其基质效应的研究

目的 研究甜菜碱(betaine)在不同温度下对人血清中ALT酶活性的稳定作用,并评估添加甜菜碱的人血清在各检测系统中的基质效应.方法 血清中添加终浓度为1 mol/L的甜菜碱,检测37 ℃、25 ℃、4 ℃、-20 ℃下放置不同时间的血清中的ALT酶活力.根据美国临床和实验室标准协会(CLSI)EP14-A文件进行基质效应实验,以4个被评价检测系统为被比较系统,以罗氏公司试剂-日立仪器检测系统为比较系统,用比较系统和被评价系统检测40个患者血清样品以及添加了1 mol/L甜菜碱的3个血清(高、中、低浓度)样本的ALT酶活力;用直线回归方法统计数据,以回归直线的(-Y)估计值(^/Y)的95%可信区间估计这3个添加了甜菜碱的样品在4种检测系统中的基质效应.结果 37 ℃添加甜菜碱的血清48 h后ALT酶活力稳定为99%,对照血清降至42%;25 ℃添加甜菜碱的血清4 d后ALT酶活力稳定为98%,对照血清降至86%;4 ℃添加甜菜碱的血清4周后ALT酶活力稳定为97%,对照血清1周后已降至71%;-20 ℃添加甜菜碱的血清4个月后ALT酶活力稳定为99%,对照血清1个月后已降至79%.添加了甜菜碱的3个样本的值均在回归直线的(-Y)估计值(^/Y)的95%可信区间内,即其在4个被评价系统和比较系统中均无明显基质效应.结论 甜菜碱可作为一个较好的血清ALT酶活力的稳定剂用于血清酶ALT的校准品的研制中.

Abstract：

Objective To investigate the stabilization of betaine on the enzyme activity of ALT in human serum at different temperatures, and to evaluate the matrix effects of human serum with betaine among different analytical systems. Methods The enzyme activity of ALT in human serums with l mol/L betaine stored at 37 ℃, 25 ℃, 4 ℃ and - 20 ℃ respectively were measured. The matrix effect experiment was carried out according to the procedures specified in Clinical and Laboratory Standards Institute (CLSI)document EP14-A. Four analytical systems were the candidates for evaluation, and Roche Diagnostics (Roche)-Hitachi analytical system served as the reference system. The enzyme activity of ALT of 40 patient specimens and 3-level specimens ( high, medium and low) with 1 mol/L betaine were measured using the evaluated methods and the reference method respectively. The linear regression analysis was performed to compare the mean y value of 3-level specimens with the statistically defined limits ( the two-tailed 95% prediction interval) derived from 40 patient specimen data. Results The enzyme activity of ALT could be stabilized with betaine in serum, which remained to be 99% for 48 h at 37 ℃, 98% for4 d at 25 ℃, 97%for 4 weeks at 4 ℃, and 99% for 4 months at - 20 ℃. The enzyme activity of control serum decreased to 42%, 86%, 71%, 79% respectively. The mean y values of three specimens with the betaine were within the 95% prediction interval of the estimated mean y values, which suggested no obvious matrix effects in serum. Conclusion Betaine can be used in the development of enzyme ALT calibrator as its stabilizer.

Study of stabilization of the enzyme activity of ALT and the matrix effects of betaine

Objective To investigate the stabilization of betaine on the enzyme activity of ALT in human serum at different temperatures, and to evaluate the matrix effects of human serum with betaine among different analytical systems. Methods The enzyme activity of ALT in human serums with l mol/L betaine stored at 37 ℃, 25 ℃, 4 ℃ and - 20 ℃ respectively were measured. The matrix effect experiment was carried out according to the procedures specified in Clinical and Laboratory Standards Institute (CLSI)document EP14-A. Four analytical systems were the candidates for evaluation, and Roche Diagnostics (Roche)-Hitachi analytical system served as the reference system. The enzyme activity of ALT of 40 patient specimens and 3-level specimens ( high, medium and low) with 1 mol/L betaine were measured using the evaluated methods and the reference method respectively. The linear regression analysis was performed to compare the mean y value of 3-level specimens with the statistically defined limits ( the two-tailed 95% prediction interval) derived from 40 patient specimen data. Results The enzyme activity of ALT could be stabilized with betaine in serum, which remained to be 99% for 48 h at 37 ℃, 98% for4 d at 25 ℃, 97%for 4 weeks at 4 ℃, and 99% for 4 months at - 20 ℃. The enzyme activity of control serum decreased to 42%, 86%, 71%, 79% respectively. The mean y values of three specimens with the betaine were within the 95% prediction interval of the estimated mean y values, which suggested no obvious matrix effects in serum. Conclusion Betaine can be used in the development of enzyme ALT calibrator as its stabilizer.