化学发光法检测血清胰岛素的现状分析

Analysis of current status of serum insulin determination by different chemiluminescence immunoassay systems

目的探讨目前较为广泛应用的几种化学发光检测系统测定血清胰岛素(insulin,INS)水平的可比性,并进一步探讨不受方法学影响的通用参数的可行性。方法选择100名做胰岛素释放试验的患者(均未使用外源性胰岛素治疗),共500份血清样本。同时使用5种化学发光免疫分析系统(分别为CLIA、ECLIA、CMIA、CLEIA1和CLEIA2)测定其血清INS水平,并计算每位患者服糖后各时间点INS水平与其空腹的比值(简称"比值")。结果分时段比较,总体上血清INS水平在不同的检测系统间差异有统计学意义(P均为0.000)。两两比较显示,空腹时ECLIA同CLIA、CMIA同CLIA间差异无统计学意义(P>0.05)。ECLIA同CLIA餐后3 h INS水平差异无统计学意义(P>0.05)。对校正后的INS比值而言,除CLEIA1分别与其他各检测系统的散点图比校正前更加发散外,其余各检测系统间则更为集中。分时段比较显示,各检测系统间总体差异有统计学意义(P均为0.000)。CLEIA2同ECLIA相比,其餐后0.5 h差异无统计学意义(P>0.05);CLEIA2同CMIA比,餐后1.0、2.0和3.0 h均无差异(P>0.05)。而其余各时间点、任意2个系统间比值均差异显著(P均<0.05)。结论血清INS水平在不同检测系统间差异很大,虽均具有很好的相关性,但多数情况不能通用,仅部分检测系统间空腹或餐后3.0 h可以通用。口服葡萄糖耐量试验(oral glucose tolerance test,OGTT)中服糖后各时间点的"比值"也与INS水平类似,仅部分时段、部分检测系统间校正后的"比值"可以互相替代,且转换为比值后,可增强大部分检测系统间的可比性,有利于不同方法学之间的比较。

Objective To investigate the comparability of serum insulin level detected by five widely used chemiluminescence immunoassay systems, and to further investigate the feasibility of a common parameter not influenced by detection systems. Methods One hundred patients were included who had done insulin release test （no exogenous insulin therapy） , and insulin concentrations of the same individual at different time points in oral glucose tolerance test （OGTF） were measured simultaneously by 5 different chemiluminescence y systems （CLIA, ECLIA, CMIA, CLEIA1 and CLEIA2, respectively）, and the ratio of serum insulin levels after meal at each time point to corresponding fasting levels （Ratio） was calculated. Results Temporally compared , there is overall significant difference for serum insulin level among all systems at any time point（ all P=0. 000） ; further comparison between any two systems revealed that there was no significant difference for fasting level between the following systems： ECLIA and CLIA, CMIA and CLIA（P〉0.05）. Similarity was also found between ECLIA and CLIA at 3 h after meal（P〉0.05 ）. For Ratio, apart from the more scattered diagram between CLEIA1 and anyone of the other systems, more gathered scatter diagrams were found between any two of the other systems. There was no significant difference between the Ratio by systems of CLEIA2 and ECLIA at 0.5 h after meal（ P〉0.05 ）, and similar phenomena were found between CLEIA2 and CMIA at 1.0 h, 2.0 h,and 3.0 h after meal（ P〉0.05 ）. There were significant differences between any other two systems at any time point（all P〈0. 05. Conclusion Serum insulin levels measured by different chemil immunoassay systems differ a lot from one another, and could hardly be interoperable though either two systems highly correlated with each other. Nevertheless, between certain two systems, and at certain temporal point, the absolute value of serum insulin or Ratios were able to substitute one for another. The conversion to Ratio from insulin level might help to increase the comparability among different systems.