When this type of vascular damage occurs, fats in the blood, inflammation cells and calcium deposit themselves on the walls of the vessels. These deposits are known as atherosclerotic plaques. When these plaques break up, a blood clot can form in the affected places due to activation of the blood clotting mechanism, resulting in the vessel becoming closed off. Arterial thrombi such as these can develop in the coronary arteries around the heart, but also in the carotid arteries in the neck.
The MedUni Vienna researchers have now discovered that monocytes (cells from the immune system that circulate in the blood) are not only involved in the body's defences, but can also play a key role in the formation of thrombi. “We have been able to see that they can trigger and activate clotting,” explains Wojta on the occasion of the Annual Conference of the Society of Thrombosis and Haemostasis Research (GTH), being held from the 12th to the 15th of February in Vienna, which the MedUni Vienna researcher will be attending in his role of Vice President.
The researchers have also demonstrated that monocytes are not a single, homogeneous group of cells, but rather that there are three sub-types that it may be possible to exploit in order to determine the risk of future thrombotic events. In patients who already have vascular calcifications, it has been possible to demonstrate that, where increased evidence is found of a certain sub-type of monocyte, there is a markedly increased risk of a future atherothrombotic event.
Says Wojta: “We have been able to show that this special sub-type of monocyte can increase the activation of thrombosis development. This is a completely new aspect of thrombosis research.” It is not yet known, however, whether monocyte sub-types are also involved in the development of venous thrombi, or whether they can be used as prognosis markers here too. Around 15,000 Austrians are affected by such venous thromboses each year.
Feasibility of surgery can be estimated in patients with narrowing of the carotid arteries
It may also be possible to use monocyte sub-types as markers for the development of carotid stenosis, a narrowing of the neck blood vessels supplying the brain. Cardiologists at the MedUni Vienna are in the process of investigating another marker for this condition: the so-called micro-RNAs.
These short, highly conserved RNAs (ribonucleic acids) have already been identified as bio-markers for various conditions. In a research currently getting underway, researchers want to use these micro-RNAs from patients’ blood to determine whether the diagnosed plaques will remain asymptomatic, i.e. will not produce any symptoms, in the future and therefore do not need to be removed surgically, or whether the subsequent development of symptoms, i.e. a stroke, is likely and whether surgery will be needed with its attendant risks in order to prevent a stroke from happening.
Cardiovascular medicine – one of five research clusters at the MedUni Vienna
Thrombosis research is a specialist area of cardiovascular medicine, one of five research clusters at the MedUni Vienna. These specialist areas are increasingly focusing on fundamental and clinical research. The other four research clusters at the MedUni Vienna, alongside cardiovascular medicine, are cancer research / oncology, immunology, neurosciences and imaging.
Date for the diary: Annual Conference of the Society for Thrombosis and Haemostasis Research (GTH) from 12 – 15 February in Vienna, Wiener Hofburg, Heldenplatz, 1014 Vienna.