September 2024 - Dino Mehic

Dr. Dino Mehic

MedUni Wien RESEARCHER OF THE MONTH September 2024

Increased bleeding tendency is a serious medical issue, particularly during surgeries, postpartum hemorrhages, or increased menstrual bleeding in women.2,3 Only in the last decade, several groups including our prospective data from the Vienna Bleeding Biobank have proven that for a majority of patients with mild to moderate bleeding tendencies, no cause can be found.4,5 This complicates the management of bleeding events as well as the planning of surgeries and childbirth, since targeted therapy cannot be recommended. Patients with bleeding disorder of unknown cause hardly differ in their bleeding phenotype and the severity from those with other known bleeding tendencies, such as von Willebrand's disease (VWD) or platelet function defects.6 The general risk of bleeding and risk factors for bleeding have not been thoroughly investigated.7,8 For the first time, we could show in a prospective study that patients with bleeding  disorder of unknown cause generally have a high future risk of bleeding and a persistent presence of almost all bleeding symptoms.1 Moreover, we found that a high bleeding score and a long observation period are associated with an increased risk of bleeding. Blood group O,9 previous postoperative bleeding, and the presence of a definitive diagnosis (such as VWD or platelet function disorders) were associated with an increased risk for bleeding after surgeries, dental extractions, and childbirth. Based on our data, hemostatic prophylaxis in patients with bleeding of unclear cause, for example using tranexamic acid or desmopressin, should be considered before surgical interventions or childbirth.10 Our publication and the data from the Vienna Bleeding Biobank have received much recognition and were acknowledged in an editorial by Prof. Will Thomas (University of Cambridge) in connection with our published data.11

Selected Literature

1. Mehic D, Neubauer G, Janig F, et al. Risk factors for future bleeding in patients with mild bleeding disorders: longitudinal data from the Vienna Bleeding Biobank. Journal of Thrombosis and Haemostasis. 2023;21(7):1757–1768.

2. Mehic D, Pabinger I, Gebhart J. Investigating Patients for Bleeding Disorders When Most of the “Usual” Ones Have Been Ruled Out. Research and Practice in Thrombosis and Haemostasis. 2023;102242.

3. Mehic D, Gebhart J, Pabinger I. Bleeding Disorder of Unknown Cause: A Diagnosis of Exclusion. Hamostaseologie. 2024;

4. Gebhart J, Hofer S, Panzer S, et al. High proportion of patients with bleeding of unknown cause in persons with a mild-to-moderate bleeding tendency: Results from the Vienna Bleeding Biobank (VIBB). Haemophilia. 2018;24(3):405–413.

5. Quiroga T, Goycoolea M, Panes O, et al. High prevalence of bleeders of unknown cause among patients with inherited mucocutaneous bleeding. A prospective study of 280 patients and 299 controls. Haematologica. 2007;92(3):357–365.

6. Gebhart J, Hofer S, Kaider A, et al. The discriminatory power of bleeding assessment tools in adult patients with a mild to moderate bleeding tendency. European Journal of Internal Medicine. 2020;

7. Veen CSB, Huisman EJ, Romano LGR, et al. Outcome of Surgical Interventions and Deliveries in Patients with Bleeding of Unknown Cause: An Observational Study. Thromb Haemost. 2021;121(11):1409–1416.

8. Castle D, Desborough MJR, Kemp M, et al. Outcomes and management of pregnancy in women with bleeding disorder of unknown cause. J of Thrombosis Haemost. 2022;jth.15871.

9. Mehic D, Hofer S, Jungbauer C, et al. Association of ABO blood group with bleeding severity in patients with bleeding of unknown cause. Blood advances. 2020;4(20):5157–5164.

10. Baker RI, O’Donnell J. How I treat. Bleeding Disorder of Unknown Cause (BDUC). Blood. 2021;blood.2020010038.

11. Thomas W. The natural history of bleeding disorder of unknown cause. J Thromb Haemost. 2023;21(7):1747–1749.

12. Mehic D, Tolios A, Hofer S, et al. Elevated levels of tissue factor pathway inhibitor in patients with mild to moderate bleeding tendency. Blood advances. 2021;5(2):391–398.

13. Mehic D, Kraemmer D, Tolios A, et al. The necessity of repeat testing for von Willebrand disease in adult patients with mild to moderate bleeding disorders. Journal of Thrombosis and Haemostasis. 2023;S1538783623007122.

14. Mehic D, Machacek J, Schramm T, et al. Platelet function and soluble P-selectin in patients with primary immune thrombocytopenia. Thromb Res. 2023;223:102–110.