Ortho Clinical Diagnostics, Rochester, NY, USA.
Clin Chem. 2012 Feb;58(2):391-401. doi: 10.1373/clinchem.2011.172288. Epub 2011 Dec 13.
Standardized calibration does not change a creatinine measurement procedure's susceptibility to potentially interfering substances.
We obtained individual residual serum or plasma samples (n = 365) from patients with 19 different disease categories associated with potentially interfering substances and from healthy controls. Additional sera at 0.9 mg/dL (80 μmol/L) and 3.8 mg/dL (336 μmol/L) creatinine were supplemented with acetoacetate, acetone, ascorbate, and pyruvate. We measured samples by 4 enzymatic and 3 Jaffe commercially available procedures and by a liquid chromatography/isotope dilution/mass spectrometry measurement procedure against which biases were determined.
The number of instances when 3 or more results in a disease category had biases greater than the limits of acceptability was 28 of 57 (49%) for Jaffe and 14 of 76 (18%) for enzymatic procedures. For the aggregate group of 59 diabetes samples with increased β-hydroxybutyrate, glucose, or glycosylated hemoglobin (Hb A(1c)), the enzymatic procedures had 10 biased results of 236 (4.2%) compared with 89 of 177 (50.3%) for the Jaffe procedures, and these interferences were highly procedure dependent. For supplemented sera, interferences were observed in 11 of 24 (46%) of groups for Jaffe and 8 of 32 (25%) of groups for enzymatic procedures and were different at low or high creatinine concentrations.
There were differences in both magnitude and direction of bias among measurement procedures, whether enzymatic or Jaffe. The influence of interfering substances was less frequent with the enzymatic procedures, but no procedure was unaffected. The details of implementation of a method principle influenced its susceptibility to potential interfering substances.
标准化校准不会改变肌酐测量程序对潜在干扰物质的敏感性。
我们从 19 种不同疾病类别的患者和健康对照者中获得了个体残余血清或血浆样本（n=365）。在 0.9mg/dL（80μmol/L）和 3.8mg/dL（336μmol/L）肌酐的额外血清中添加了乙酰乙酸盐、丙酮、抗坏血酸和丙酮酸盐。我们使用 4 种酶法和 3 种 Jaffe 市售方法以及液相色谱/同位素稀释/质谱测量程序测量样本，并确定了偏差。
在 57 种疾病类别中有 3 种或更多种结果存在大于可接受偏差的偏倚的情况下，Jaffe 法有 28 种（49%），酶法有 14 种（18%）。对于 59 例糖尿病患者β-羟基丁酸、葡萄糖或糖化血红蛋白（HbA1c）升高的样本，酶法有 10 个偏倚结果（4.2%），而 Jaffe 法有 89 个（50.3%），这些干扰高度依赖于方法。对于补充的血清，在 Jaffe 法的 24 个组中有 11 个（46%）组和酶法的 32 个组中有 8 个（25%）组观察到干扰，并且在低或高肌酐浓度下干扰情况不同。
无论是酶法还是 Jaffe 法，在测量程序之间都存在偏差的大小和方向的差异。干扰物质的影响在酶法中较少见，但没有一种方法不受影响。方法原理的实施细节影响了其对潜在干扰物质的敏感性。
