PB1134 - Determination and verification of reference intervals on the automated coagulation analyzer sthemO 301

Background: The sthemO 301 is a new medium-high throughput, fully automated coagulation analyzer developed by Diagnostica Stago (Asnières, France) to perform clotting, chromogenic and immunoassay methods.

Aims: These studies’ aim was to determine or verify reference intervals (RI) in healthy donors for the following parameters: fibrinogen, fibrin degradation products, D-Dimer, prothrombin time, activated partial prothrombin time, thrombin time, protein S clotting activity, free protein S, antithrombin, functional protein C and protein C clotting activity.

Methods: Inclusion criteria were healthy donors aged 18 to 65 years, not having any pathology nor taking drugs affecting blood coagulation. Blood collection was approved by the Maastricht University Medical Center’s medical ethical committees and performed after obtaining written informed consent. The blood, collected in 3.2% citrated tubes, was double centrifuged within two hours for preparation of platelet poor plasma. Fresh or frozen (-70°C) samples were tested. Verification of a published RI required a minimum of 60 samples whereas RI determination required a minimum of 120 samples, according to Clinical Laboratory Standard Institute (CLSI) EP28. Both men and women samples were included, at the exception of the functional Protein S and free Protein S that required a gender-dependent RI. Quality controls (QCs) for each coagulation assay were performed on each testing day.

Results: RI results for verification studies (number of samples, minimum and maximum age of donors) are presented in table 1. RI results for determination studies are presented in table 2. QCs standard deviations and coefficient of variations were all within the acceptance criteria according to CLSI H59 and French Group of Hemostasis and Thrombosis Study guidelines.

Conclusion(s): These RI values determined for the aforementioned coagulation assays will provide an aid to the laboratories during the RIs local verification at system implementation on the sthemO 301 analyzer.