Bleeding of Unknown Cause: a Swiss Case-control Study

The goal of this prospective cohort is to identified specific biological patterns in patients with a bleeding of unknown cause and to study the specific mechanisms of the bleeding disorder for each subset of patients.

Inclusion Criteria:Man with ISTH BAT>3. If the calculated score includes a surgical bleeding, then two other items of the score should be >0Woman with ISTH BAT >5 points. If the calculated score includes a surgical or a postpartum bleeding, then two other items of the score should be >0Exclusion Criteria:Ongoing pregnancyIntake of antithrombotic treatment or non-steroidal anti-inflammatory drugs for least 10 days at time of blood collectionIntake of antifibrinolytic or blood product administration (factor concentrate, frozen fresh plasma, prothrombin complex concentrate) for least 14 days before blood collectionActive cancer (defined as cancer diagnosis within the last five years or treatment within the two last years before study inclusion)Active autoimmune diseaseActive chronic inflammatory diseaseSevere liver disease (cirrhosis > Child A)Renal insufficiency stage 3Active or recent infection (within the last 30 days)Recent hospitalization (<3 months)Recent surgery (<3 months)Recent trauma requiring medical intervention (<3 months)