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    Poster Networking

    Diagnostics and OMICs

    Poster Networking Session

    PB1144 - Choice of reference plasma for intraassay thrombin generation normalization.

    Tuesday, June 27, 2023
    18:30 – 19:30 ET
    Room: Exhibition
    Background: Calibrated thrombin generation (TG) assaying is limited by a wide intra- and inter-assay variation as well as wide variation in TG between normal individuals. This has limited widespread clinical use of TG. TG intraassay (“with each run”) normalization using a suitable normal plasma could possibly bring this tool closer to clinical use.

    Aims: Our aim was to identify a suitable pooled normal plasma (PNP) for TG normalization.

    Methods: Double centrifuged plasmas from 20 healthy adults were collected and individually stored frozen as well as pooled to make in-house PNP (LSH). Two separate lots of frozen pooled normal plasmas (PNPs) and one lot of lyophilized PNP were obtained from manufacturers. PNPs were compared by measuring extended DIC panel assays, thrombin generation and by flow cytometry.

    Results: While extended DIC panel assessment showed no difference in the PNPs´ coagulation parameters, in-house double centrifugated PNP generated less thrombin than commercial plasmas (Fig. 1). Furthermore, the commercial plasmas generated similar amount of thrombin as the median TG of the 20 normal individuals whereas 18 out of 20 individual normal samples generated more thrombin than the in-house pool. It was observed that the commercial PNPs were more turbid than the in-house PNP suggesting possible remaining cellular debris. However, flow cytometry showed only trace platelet debris (CD61+) and other cellular debris (CD36+) in the GK plasmas and neither were present in Stago PNP or the in-house PNP. Nevertheless, ultracentrifugation of the PNPs cleared the turbidity and reduced TG significantly in all types of plasmas suggesting other forms of non-cellular thrombinogenic particles are present in all PNPs (Fig. 2).

    Conclusion(s): For the selection of PNP to be used as a “normalisator”, we suggest using a series of at least 20 normal plasmas to identify a suitable PNP that generates an amount of thrombin close to the midrange of the normal population.