Is mannose binding lectin of the lectin complement pathway associated with risk of venous thromboembolism (VTE)?

The complement system, a fundamental part of humoral and innate immunity, has gained considerable attention for its interplay with coagulation and potential role in the pathogenesis of VTE. Mannose-binding lectin (MBL), a pattern recognition molecule circulates in complexes with MBL-associated serine proteases (MASPs) in blood. The MASPs are activated when MBL bind to specific carbohydrate patterns on pathogens or altered host cells and lead to downstream complement activation. In the present population-based study, we found that individuals with high plasma MBL levels had 79% higher VTE risk than those with low MBL levels, and that activated MBL-MASP complexes facilitated thrombin generation independent of downstream complement activation.  The results suggest that high MBL levels are a risk factor for VTE partly mediated by direct thrombin generation at the site of venous thrombosis formation. Our findings were recently published and highlighted as a featured paper in Arteriosclerosis Thrombosis and Vascular Biology.

The first author of this study, Christabel Esi Damoah, is a PhD-student at TREC and the study included collaborators from Norway, Denmark, Hungary and USA.

Reference:

Damoah CE, Valderhaug SM, Snir O, Hindberg KD, Braekkan SK, Grover SP, Nost TH, Gal P, Pal G, Jonasson C, et al. Elevated Plasma MBL Levels Are Associated With Risk of Future Venous Thromboembolism: HUNT. Arterioscler Thromb Vasc Biol. 2025. doi: 10.1161/ATVBAHA.124.322052

Prizes to TREC at ECTH2025

TREC submitted 15 abstracts to the conference (total number of abstracts were >300), and of these, 12 were elected for oral presentations, one for “Science fast and furious”, and the remaining two were presented as posters. The “Science fast and furious” is a scientific presentation in a TED-talk format, and the eight highest ranked abstracts are elected for this session. Mathias Haugmo Storvand did a great job on the fast and furious stage, presenting results on a newly discovered protein which is linked to obesity-related VTE. Together with Solveig Marie Valderhaug he received a young investigator award, while Maryam Hosseini won the prize for best poster presentation!

The TREC members held presentations within the sessions on venous thromboembolism (VTE), recurrent thrombosis, platelets, cancer-related VTE and obesity-related VTE. Anna Arntzen, Camilla Langholm, Celina Cathro, Christopher Antoun, Eduarda Guerreiro, John-Bjarne Hansen, Nikolai Eide, Magdalena Johansson, Maryam Hosseini, Melliane Olsen, Lukas Konecny and Solveig Valderhaug all did an excellent job presenting their work!

The scientific program of the conference was truly inspiring, and it was nice to meet colleagues and researchers in the field of thrombosis and hemostasis from all over Europe.

We had a great time in Prague!

People with high content of omega-3 fatty acids in blood have lower risk of venous thrombosis

Blood clots formed in the veins of the leg and lungs, collectively named venous thromboembolism (VTE), is a common disease with severe complications. The occurrence of VTE has increased during the last decades, and it is important to find out whether lifestyle factors can lower the risk of VTE. We therefore investigated whether a high content of  omega-3 fatty acids in blood was related to risk of VTE in the general population. We found that persons with high content of omega-3 fatty acids in blood had a 28% lower risk of VTE. Our findings were recently published in the American Journal of Clinical Nutrition and highlighted by an editorial commentary in the same journal.

Omega-3 fatty acids are essential fatty acids, meaning that they cannot be synthesized in the body and that the content in blood reflect the dietary intake of seafood or omega-3 enriched supplements (e.g. cod liver oil). Fatty fish, such as salmon, trout, and mackerel, has a high content of omega-3 fatty acids, while lean fish, such as cod, has a low content of omega-3 fatty acids. Studies have shown that omega-3 fatty acids can have beneficial effects on key mechanisms involved in blood clot formation.

Previous studies on the relationship between omega-3 fatty acids and VTE have estimated dietary omega-3 intake based on self-reported intake of fat fish and supplements. Since this estimation is not completely accurate, the true effect of omega-3 can be underestimated in such studies. Consequently, these studies have reported mixed results on the link between omega-3 fatty acid intake and VTE risk. In our recent study, we have for the first time studied whether omega-3 levels measured directly in blood were linked to VTE risk.

In our study of omega-3s and risk of venous thromboembolism, about 17,000 persons living in Nord-Trøndelag County in Norway participated. They went to a health examination and donated blood samples in 2006-08. The amount of omega-3 fatty acids in blood samples from each participant was measured, and all VTE events among the participants were registered until 2020. During 12-years of median follow-up, 340 participants experienced a VTE event. We found that those with high omega-3 levels (upper tertile) in blood had 28% lower risk of venous thromboembolism compared to those with low levels (lower tertile).

Our findings suggest that a high dietary intake of omega-3 fatty acids derived from seafood is associated with lowered risk of future VTE. However, our original findings needs to be validated in other populations and ultimately tested in randomized clinical trials.

The first author of this study, Magdalena Johansson, is a haematologist and researcher from Umeå University, Sweden. She collaborated with TREC on this study when she was a visiting researcher in Tromsø during spring 2024.

Reference:

Johansson M, Brækkan SK, Giskeødegård GF, Wade KH, Hindberg KD, Timpson N, Davey Smith G, Hveem K, Åsvold BO, Brumpton BM, Hansen JB. High concentrations of polyunsaturated n-3 fatty acids in serum are inversely associated with risk of future incident venous thromboembolism – the HUNT cohort study. Am J Clin Nutr. 2025 Nov;122(5):1195-1203.

John Bjarne Hansen  –  Professor

Sigrid Kufaas Brækkan  –  Professor

Omri Snir  –  Associate Professor

Thor Ueland  –  Professor II

Kristian Dalsbø Hindberg  –  Researcher

Vania Maris Morelli  –  Researcher

Nadezhda Latysheva  –  Research technician

Samantha Xavier  –  Doctoral Research Fellow

Christabel Esi Damoah  –  Doctoral Research Fellow

Eduarda Mazagao Guerreiro  –  Researcher

Maryam Hosseini  –  Doctoral Research Fellow

Christopher Antoun  –  Doctoral Research Fellow

Lisa Jakobsen  –  Doctoral Research Fellow

Celina Janene Cathro  –  Doctoral Research Fellow

Ellen-Sofie Wulff Eilertsen  –  Doctoral Research Fellow

Birgitte Gladsø Tøndel

Oda Gabrielle R. Leknessund  –  MD PhD student (Forskerlinja)

Vårin Eiriksdatter Wikan  –  MD PhD student (Forskerlinja)

Asbjørn Lund Onsaker  –  MD PhD student (Forskerlinja)

Nikolai Hagensen Eide  –  MD PhD student (Forskerlinja)

Camilla Langholm  –  MD PhD student (Forskerlinja)

Anna Yang Arntzen  –  MD PhD student (Forskerlinja)

Mathias Haugmo Storvand  –  MD PhD student (Forskerlinja)

Solveig Marie Valderhaug  –  MD PhD student (Forskerlinja)

Inga Røstvold  –  MD PhD student (Forskerlinja)