Differences in the mechanism of blood clot formation and nanostructure in infants and children compared with adults

- This is the first study to demonstrate.
- Age-specific differences in mechanism of thrombin generation and blood clot formation
- Age-specific differences in the blood clot, as the final product of coagulation
- Age-specific differences in response of the blood clot to thrombolytic therapy

IntroductionInfants and children have a lower incidence of thrombosis compared with adults. Yet, the mechanism of blood clot formation and structure in infants and children, as the end product of coagulation, has not been studied. This study aimed to establish differences in the mechanism of thrombin generation, fibrin clot formation and response to thrombolysis in infants and children compared with adults.Materials and methodsWe studied thrombin generation, fibrin clot formation, structure and fibrinolysis in healthy infants, children and adults.ResultsYounger populations had a decreased potential to generate thrombin, at a slower velocity compared with adults, correlating positively with age. Clot formation at venous shear rate was decreased in infants and children compared with adults, with increased time for fibrin formation, decreased fibrin formation velocity, resulting in decreased tendency for fibrin formation in younger populations. These differences were less pronounced at arterial shear rate. Studies of the fibrin clot structure in paediatric age groups showed a significantly larger pore size compared with adults, suggestive of a clot that is less resistant to fibrinolysis. The presence of tissue plasminogen activator (tPA) resulted in a significant decrease in the pore size of infants and children, but not in adults.ConclusionsThis is the first study to suggest that the mechanism of blood clot formation and nanostructure, as well as response to thrombolytic therapy is different in infants and children compared with adults.