Platelets: more than a band-aid
Some processes in our body might seem obvious to us. If you cut your finger, the bleeding will stop shortly and form a scab. Behind that seemingly simple process hides a sophisticated system of platelets and clotting factors. By now, we know that platelets do much more than halt bleeding: they function as information carriers and regulators of disease processes.
A delicate balance
“Evolutionary speaking, it is very useful to have a well-working haemostatic system with active platelets: when we used to fight and hunt, the chance of injury was higher, and it was important that bleeding stopped quickly,” says Judith Cosemans, Professor of Platelet Biology and Pathophysiology at Maastricht University. That same process also has a negative side. When the haemostatic system becomes too active, thrombosis can occur, a blood clot that blocks a blood vessel. About 1 in 4 people die of thrombosis, and a similar number die from bleeding. Platelets are central in this delicate balance: too little activity can lead to bleeding, while too much activity can lead to thrombosis.
To better understand where the balance is disturbed, research institute CARIM developed the Maastricht flow chamber at the end of the 90s, which can mimic blood flow in healthy and diseased vessels. Cosemans has been working with this technique for nearly 25 years. “We can change the flow speed, add constrictions and see how the platelets are involved in clot formation.” This adds an important aspect that is often missing in other lab models: flow. Maastricht was one of the first places in the world to perform research in this way.
Inhibiting, not thinning
With the help of the flow chamber, it is possible to look at platelet inhibitors, such as aspirin, from a different perspective. These medications are often called blood thinners, but that is not correct: they don’t thin the blood; instead, they inhibit the formation of clots.
“Years ago, I thought that we would mainly be discovering new medications, but I think that less and less: it is incredibly difficult to develop a new inhibitor.” This is why Cosemans focuses on the personalisation of existing medicine, and on the question of why certain medications work well for one patient, but not for another. An important open question in this area is the difference between men and women, and how this affects haemostasis and how medication works.
From coagulator to information carrier
Although platelets are mainly known for their role in haemostasis, they seem to have many more functions. In the past few years, it has become clear that they are involved in inflammatory and immune responses. Therefore, they are at the crossroads of several diseases. As a kind of postal service, they can take up packages from organs and blood and deliver them elsewhere later. This makes them an interesting option as a diagnostic marker, for instance to help detect cancer or heart failure, and that is less invasive than a biopsy or a scan.
To understand in which diseases platelets play a role, patient cohorts are of great importance. With such large amounts of data, AI is able to play a growing role in Cosemans’ research. “It is something new and complex, which I really enjoy. Currently, we have too much data to extract everything. AI helps us discover patterns that would otherwise stay hidden.”
Looking ahead
With her position, Cosemans hopes to contribute to personalised interventions for thrombosis and bleeding, and a better understanding of the role that platelets play. She also sees many opportunities in prevention to reduce the risk of thrombosis: for instance, early research is already underway into how exercise and good nutrition lead to fewer reactive platelets in the elderly. She is also interested in climate- and environment-related research, for example, the effect of heat or microplastics on the risk of thrombosis. “I look at what we have here within the UM and try to find my niche in this research field, to make a difference.”
Text and photography: Liline Fermin
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