Infants face high thrombosis risk

Russian scientists have carried out tests to compare the process of blood coagulation in adults and newborns and discovered that the latter face an increased risk of thrombosis. The researchers also compared this process in infants carried to term and in preterm babies. The work was carried out as part of a project funded by the Presidential Program of Research Projects of the Russian Science Foundation (RSF), with the results being published in Pediatric Research.

Damage to the blood vessel wall triggers the haemostasis system: an insoluble clot forms at the site of injury, preventing blood loss. The key role in haemostasis is played by blood plasma proteins and platelets, which form the framework of a thrombus, cross-linked with growing filaments of a fibrin clot. These filaments are produced during the clotting process by a cascade of enzymatic reactions, which yield the proteinaceous polymer.

Coagulation system disturbances are one of the leading causes of infant death or disability. Moreover, the risks of bleeding disorders or thrombosis are greatly increased in the presence of complications in newborns, with preterm birth being one of the most significant. No effective methods for diagnosing haemostasis disorders in infants are currently available in clinical practice. On the one hand, the incidence of clinical complications associated with haemostasis system disorders in infants is generally low, making mass screening impractical. On the other hand, such tests could be recommended for high-risk groups, such as in preterm infants or infants with congenital systemic infections. This, however, brings us to another problem: laboratory test instruments are not sensitive enough to detect disorders at the early stages.

"Our work consisted of applying innovative haemostasis tests, which are based on an understanding of the principles and mechanisms by which a thrombus is produced. The tests were carried out to evaluate the condition of the coagulation system in infants carried to term (the control group) and preterm infants (the test group)," explained the author of the article, Anna Balandina (Ph.D. in Biology), RSF Project Leader and Deputy Director for Scientific Affairs at the Center for Theoretical Problems of Physico-Chemical Pharmacology of Russian Academy of Sciences.

The researchers compared the condition of the coagulation system in adults and newborns (carried to term and preterm). The scientists used laboratory tests for haemostasis evaluation, including innovative methods. Deviations in plasma coagulation were analyzed, and the "working" state of platelets was investigated, which involved studying individual cells using light scattering and fluorescence signals (flow cytometry). The scientists noted that all laboratory tests, especially in clinical practice, are expensive, and the RSF grant allowed a wide array of methods to be used.

The work demonstrated that haemostasis in newborns, i.e., the ability to maintain blood in a liquid state while controlling bleeding in the event of damage to vessel walls, is substantially different from that in adults. Newborns face an increased risk of thrombosis, i.e., the formation of thrombi inside blood vessels, which impedes the free flow of blood. Additionally, platelets in newborns exhibit a reduced ability to activate. Moreover, the differences were even more pronounced in the test group of preterm babies. Based on this, the researchers concluded that, during the first days of infancy, haemostasis exists in a unique state of balance that is radically different from the balance in adults: it is more delicate. Any complication, such as preterm birth, upsets this balance and, consequently, results in the increased incidence of thrombosis and bleeding.

"We are now continuing our work and recruiting a group of extremely preterm infants. Additionally, we are trying to understand the underlying causes of such dramatic differences between the haemostasis of adults and infants. We hope that the work will ultimately result in a protocol of infant screening for detecting latent disturbances in the functioning of the haemostasis system," concluded Anna Balandina.