da Fonseca-Wollheim F, Heinze K G, Lomsky K, Schreiner H
Zentrallaboratorium, Krankenhaus Zehlendorf, Berlin.
J Clin Chem Clin Biochem. 1988 Aug;26(8):523-5.
Serum, at neutral pH, was submitted to a simple filtration, using centrifugation in the disposable Centrisart. The ultrafiltrate was similar to serum in its creatinine content but was virtually free from proteins, including protein-bound bilirubin, haemoglobin and lipoproteins. The creatinine concentrations of anicteric serum specimens and the corresponding ultrafiltrates as determined with Jaffé and enzymic procedures show a high correlation and are convertible. With icteric sera the negative interference effect of bilirubin in a particular analytical procedure can be quantified using ultrafiltrate as the reference. It is suggested that ultrafiltration is useful in selected cases for eliminating elevated concentrations of bilirubin, haemoglobin and turbidity, which would interfere in the direct creatinine determination. Relative to the continuous flow methods with dialysis of the analyte, direct methods for creatinine are more susceptible to interference by endogenous factors like hyperbilirubinaemia, hypertriglyceridaemia and haemolysis (1). The negative interference by bilirubin is of special importance, since it interferes in some modifications of the kinetic Jaffé method (2) and in the chromogenic enzymatic method (3). As a simple alternative, we evaluated the use of serum ultrafiltrate for the accurate determination of creatinine by the Jaffé and enzymatic methods, free from interfering by the high-molecular serum matrix and compounds bound to it.
在中性pH条件下，将血清置于一次性使用的Centrisart离心机中进行简单过滤。超滤物的肌酐含量与血清相似，但几乎不含蛋白质，包括与蛋白质结合的胆红素、血红蛋白和脂蛋白。用Jaffé法和酶法测定的无黄疸血清标本及其相应超滤物的肌酐浓度显示出高度相关性且可相互转换。对于黄疸血清，在特定分析程序中胆红素的负干扰效应可以以超滤物为参比进行定量。建议在某些选定的情况下，超滤有助于消除胆红素、血红蛋白和浊度的升高浓度，这些会干扰肌酐的直接测定。相对于对分析物进行透析的连续流动方法，肌酐的直接测定方法更容易受到内源性因素如高胆红素血症、高甘油三酯血症和溶血的干扰(1)。胆红素的负干扰尤为重要，因为它会干扰动力学Jaffé法的某些改进方法(2)和比色酶法(3)。作为一种简单的替代方法，我们评估了使用血清超滤物通过Jaffé法和酶法准确测定肌酐，不受高分子血清基质及其结合化合物的干扰。
