Abstract：
OBJECTIVE: Glycated albumin (GA) has potential value in the management of people with diabetes; however, to draw meaningful conclusions between clinical studies it is important that the GA values are comparable. This study investigates the standardization of the Norudia Glycated Albumin and Lucica Glycated Albumin-L methods.
METHODS: The manufacturer reported imprecision was verified by performing CLSI-EP15-A3 protocol using manufacturer produced controls. The Japanese Clinical Chemistry Reference Material (JCCRM)611-1 was measured 20 times to evaluate the accuracy of both methods. GA was also measured in 1,167 patient samples and results were compared between the methods in mmol/mol and %.
RESULTS: Maximum CV for Lucica was ≤0.6 % and for Norudia ≤1.8 % for control material. Results in mmol/mol and % of the JCCRM611-1 were within the uncertainty of the assigned values for both methods. In patient samples the relative difference in mmol/mol between the two methods ranged from -10.4 % at a GA value of 183 mmol/mol to +8.7 % at a GA value of 538 mmol/mol. However, the relative difference expressed in percentage units ranged from of 0 % at a GA value of 9.9 % to +1.7 % at a GA value of 30 %.
CONCLUSIONS: The results in mmol/mol between the two methods for the patient samples were significantly different compared to the results in %. It is not clear why patient samples behave differently compared to JCCRM611-1 material. Valuable lessons can be learnt from comparing the standardization process of GA with that of HbA1c.
METHODS: The manufacturer reported imprecision was verified by performing CLSI-EP15-A3 protocol using manufacturer produced controls. The Japanese Clinical Chemistry Reference Material (JCCRM)611-1 was measured 20 times to evaluate the accuracy of both methods. GA was also measured in 1,167 patient samples and results were compared between the methods in mmol/mol and %.
RESULTS: Maximum CV for Lucica was ≤0.6 % and for Norudia ≤1.8 % for control material. Results in mmol/mol and % of the JCCRM611-1 were within the uncertainty of the assigned values for both methods. In patient samples the relative difference in mmol/mol between the two methods ranged from -10.4 % at a GA value of 183 mmol/mol to +8.7 % at a GA value of 538 mmol/mol. However, the relative difference expressed in percentage units ranged from of 0 % at a GA value of 9.9 % to +1.7 % at a GA value of 30 %.
CONCLUSIONS: The results in mmol/mol between the two methods for the patient samples were significantly different compared to the results in %. It is not clear why patient samples behave differently compared to JCCRM611-1 material. Valuable lessons can be learnt from comparing the standardization process of GA with that of HbA1c.
摘要：
目的：糖化白蛋白（GA）在糖尿病患者的治疗中具有潜在价值；然而，为了在临床研究之间得出有意义的结论，重要的是GA值具有可比性。本研究调查了Norudia糖化白蛋白和Lucica糖化白蛋白-L方法的标准化。
方法：通过使用制造商生产的对照进行CLSI-EP15-A3方案，验证了制造商报告的不精确性。测量日本临床化学参考材料（JCCRM）611-120次，以评估两种方法的准确性。还在1,167名患者样品中测量了GA，并以mmol/mol和％为单位比较了两种方法之间的结果。
结果：对于对照材料，Lucica的最大CV≤0.6％，Norudia的最大CV≤1.8％。JCCRM611-1的mmol/mol和％的结果在两种方法的指定值的不确定度范围内。在患者样品中,两种方法之间的mmol/mol的相对差异范围为在183mmol/mol的GA值下的-10.4%至在538mmol/mol的GA值下的+8.7%。然而,以百分比单位表示的相对差异范围从GA值为9.9%时的0%到GA值为30%时的+1.7%。
结论：两种方法对患者样品的结果（以mmol/mol为单位）与以%为单位的结果相比有显著差异。尚不清楚为什么患者样品与JCCRM611-1材料相比表现不同。通过比较GA与HbA1c的标准化过程，可以获得宝贵的经验教训。
方法：通过使用制造商生产的对照进行CLSI-EP15-A3方案，验证了制造商报告的不精确性。测量日本临床化学参考材料（JCCRM）611-120次，以评估两种方法的准确性。还在1,167名患者样品中测量了GA，并以mmol/mol和％为单位比较了两种方法之间的结果。
结果：对于对照材料，Lucica的最大CV≤0.6％，Norudia的最大CV≤1.8％。JCCRM611-1的mmol/mol和％的结果在两种方法的指定值的不确定度范围内。在患者样品中,两种方法之间的mmol/mol的相对差异范围为在183mmol/mol的GA值下的-10.4%至在538mmol/mol的GA值下的+8.7%。然而,以百分比单位表示的相对差异范围从GA值为9.9%时的0%到GA值为30%时的+1.7%。
结论：两种方法对患者样品的结果（以mmol/mol为单位）与以%为单位的结果相比有显著差异。尚不清楚为什么患者样品与JCCRM611-1材料相比表现不同。通过比较GA与HbA1c的标准化过程，可以获得宝贵的经验教训。
