Multicenter Interlaboratory Study of Thrombin Generation Assay in Healthy Adults Using the ST Genesia Analyzer With the STG‐ThromboScreen Reagent (With and Without Thrombomodulin)

Introduction Fully automated thrombin generation (TG) assays facilitate the transition from research to clinical application. We conducted a multicenter inter‐laboratory study using the ST Genesia analyzer to evaluate assay performance and establish reference intervals in healthy adults from Spain and Portugal. Methods In this multicenter study, plasma samples from healthy adult volunteers were analyzed across 12 laboratories following a harmonized protocol. TG was measured using the STG‐ThromboScreen reagent in the presence and absence of thrombomodulin (TM). Analytical performance and reference intervals were assessed. Results Within‐run and intra‐day precision were excellent (coefficient of variation < 10%) for all TG parameters except velocity index. Normalization reduced interlaboratory variability for amplitude‐based parameters such as endogenous thrombin potential (ETP) and peak height, whereas its effect was less pronounced for velocity index. Satisfactory interlaboratory performance (| z | ≤ 2) was achieved in 96%–98% of results, and normalized parameters showed minimal bias across centers. In 252 healthy adults, median normalized values were: ETP 131% (IQR 118–142), peak height 116% (IQR 104–127), lag time 2.6 min (IQR 2.3–2.8), and time‐to‐peak 5.5 min (IQR 5.0–5.9). Median ETP inhibition in the presence of TM was 47.2% (IQR 35.1–61.8). Age had a modest influence on TG parameters, whereas sex differences were observed. Conclusions This multicenter interlaboratory study in the Iberian Peninsula demonstrates high reproducibility of TG measurement using the ST Genesia platform with the STG‐ThromboScreen reagent. These findings support its use for standardized TG assessment and provide reference intervals for clinical and research settings.