The Comparison of Manual and Automatic Interference Determination on Coagulometers ACL Top 750 CTS and Roche Cobas t511 for Routine Coagulation Tests

Background: Preanalytical issues are a major part of routine coagulation laboratory errors. Automation in detection of preanalytical problems, including hemolysis, icterus and lipemia (HIL) and undue clotting, has recently been implemented on specific hemostasis instruments. The aim of this study was to assess the added value of a new preanalytical module integrated into hemostasis analyzers compared to visual inspection of samples.

Methods: The detection of preanalytical issues was performed by visual or manual inspection of the samples and by the new preanalytical module integrated on the ACL TOP 750 and Roche Cobas t511. The routine coagulation tests (PT, aPTT, DDIM, dRVVT) were done to evaluate the interference of hemoglobin (Hb), bilirubin or triglycerides (TG). At the same time, the maximum value of interference for individual parameters was evaluated, which excluded detection coagulum formation due to excessive background.

Results: Visual or manual inspection detected statistically less samples with preanalytical issues than the new preanalytical module integrated on the ACL TOP 750 as well as on the Roche Cobas t511 (2,63% vs. 0,86% vs 0,86%, p < 0.001). HIL interferences appeared on assays when the concentration of Hb, bilirubin or TG exceeded a certain threshold that was analyzer and reagent dependent.

Conclusions: Automatic and standardized check of routine coagulation samples by ACL TOP 750 and Roche Cobas t511 increased the accuracy and consistency in detection of preanalytical issues as compared to visual inspection only. The main advantages were the detection of microclots and icteric samples that are not detected visually.

Supported by grant LF-2018-004 and MH CZ - DRO (FNOl, 00098892)

No conflict of interest has been declared by the author(s).