Background

Spuriously high results using the Abbott Architect enzymatic creatinine assay were noted to be particularly associated with very small sample volumes. This led us to query the effect of under-filling lithium heparin tubes on the measured enzymatic creatinine result.

Methods

Blood was provided by 5 laboratory personnel and then decanted into 5 x1.2 mL Sarstedt S-Monovette tubes, giving final blood volumes of 200, 400, 600, 800 and 1200 μL. Plasma was analysed using Abbott Architect Jaffe, enzymatic creatinine, Beckman Coulter (AU500) enzymatic creatinine and Roche (Cobas c702) enzymatic creatinine assays. Saline was also added to Sarstedt 1.2 mL and Teklab 2 mL tubes and analysed using the Abbott Jaffe and enzymatic creatinine methods.

Results

Increasing degrees of under-fill were associated with greater over-estimation of creatinine using the Abbott enzymatic assay, but no difference was noted using Jaffe methodology on the same platform or enzymatic assays provided by Roche or Beckman. On average, creatinine was 40.6% (+27.7 μmol/L) higher when only 200 μL of blood was present in the tube. Small volumes of saline added to lithium heparin tubes measured significant creatinine concentrations using the Abbott enzymatic method.

Conclusions

Lithium heparin directly interferes in the Abbott Architect enzymatic creatinine assay. Under-filling lithium heparin tubes can lead to clinically significant over-estimation of creatinine results by this assay. Users of this assay should be aware of the potential for spurious results in small sample volumes collected into lithium heparin tubes and implement robust procedures for identifying and reporting results on these samples.

中文翻译：

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Abbott 酶促肌酐测定中的肝素锂干扰：未满管的意义

背景

注意到使用 Abbott Architect 酶促肌酐测定的异常高结果与非常小的样本量特别相关。这导致我们质疑肝素锂管填充不足对测量的酶促肌酐结果的影响。

方法

血液由 5 名实验室人员提供，然后倒入 5 x1.2 mL Sarstedt S- Monovette管中，最终血液体积为 200、400、600、800 和 1200 μL  。使用 Abbott Architect Jaffe、酶促肌酐、 Beckman Coulter (AU500) 酶促肌酐和罗氏 (Cobas c702) 酶促肌酐测定。还将盐水添加到 Sarstedt 1.2 mL 和 Teklab 2 mL 试管中，并使用 Abbott Jaffe 和酶促肌酐方法进行分析。

结果

使用 Abbott 酶测定法时，未满程度的增加与更高的肌酐高估有关，但在同一平台上使用 Jaffe 方法或 Roche 或 Beckman 提供的酶法测定法没有发现差异。当试管中只有 200  μL 的血液时，肌酐平均高出 40.6% (+27.7  μmol / L)。添加到肝素锂管中的少量盐水使用 Abbott 酶法测量显着的肌酐浓度。

结论

肝素锂直接干扰 Abbott Architect 酶促肌酐测定。肝素锂管填充不足可导致该测定法对肌酐结果的临床显着高估。该检测的用户应该意识到收集到肝素锂管中的小样本量可能产生虚假结果，并实施可靠的程序来识别和报告这些样本的结果。