Influence of hemolysis, icterus and lipemia on coagulation tests as performed on Cobas t511 new analyzer.

Abstract

: In the coagulation laboratory, spurious hemolysis, icterus and lipemia (HIL) in test samples represent by far the leading diagnostic prenalytical challenges. The aim of this study was to assess the performance of the preanalytical module on the new hemostasis analyser Cobas Roche t511. We assessed the influence of HIL on prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), antithrombin and D-dimer on plasma pools aliquots with different interference degrees. Moreover, we evaluated spontaneous hemolysis by comparing results on 50 paired samples (hemolysed versus nonhemolysed). Spurious hemolysis interference studies highlight the absence of a clinical significant impact on PT, APTT and antithrombin test results at all hemoglobin concentration investigated. For Fib and D-dimer assays a clinically significant difference was observed in the most hemolysed aliquot for Fib and in the two most hemolysed aliquots for D-dimer. Spontaneous hemolysis interference studies showed no clinical significant differences for PT and antithrombin assays, instead for APTT, Fib and D-dimer we found significant statistical and clinical differences between hemolysed and non hemolysed specimens. Bilirubin interference studies and lipemic samples interference studies enable us to confirm that the differences in the results obtained between the different aliquots and reference pool is not clinically significant for all assays. HIL check preanalytical module of Cobas Roche t511 analyzer displaied excellent performance for routine use in clinical laboratories. Regardless of analytical considerations, the type of interference encountered with spurious HIL is substantially different and requires different approaches.