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.