Høiland II, et al. - Whether the activity of the complement pathways, the level of mannose-binding lectin (MBL) and tissue-factor (TF) induced thrombin generation was correlated with risk of unprovoked venous thromboembolism (VTE) was investigated. Participants in the study were patients with unprovoked VTE (n=24) and age- and sex-matched healthy controls (n=24). MBL was quantified by ELISA. CAT-assay was used to measure plasma TF-induced thrombin generation. Results obtained from this case-control study suggested that, independent of activation of TF-induced coagulation, high activity of the classical complement pathway and MBL deficiency could be correlated with an increased odds of unprovoked VTE.