Thrombosis in childhood
At the time of this surveillance study, symptomatic thrombotic events (venous and arterial) were rare in childhood, particularly after the neonatal period, and the incidence in the United Kingdom was unknown. The study objectives were as follows: to determine the incidence and epidemiology of thrombosis in children aged between 1 month and 16 years in the UK, determine which risk factors predispose to thrombosis in childhood, and in particular, the role of thrombophilia, both inherited and acquired, determine diagnostic and therapeutic practices for childhood thrombosis and assess whether sufficient information was available on which to develop management guidelines.
Lead investigator
Dr B Gibson
About the study
At the time of this surveillance study, symptomatic thrombotic events (venous and arterial) were rare in childhood, particularly after the neonatal period, and the incidence in the United Kingdom was unknown. A Canadian Registry of DVT/PE in children (age 1 month to 18 years) prospectively identified 137 patients, giving an incidence of DVT/PE of 5.3/10,000 hospital admissions, or 0.07/10,000 children in Canada.
Infants under 1 year of age and teenagers predominated (18% and 50% respectively). Two retrospective reviews reported an incidence of clinically symptomatic DVT in children and PE in adolescents/young adults of 1.2 and 7.8 cases per 10,000 hospital admissions. Advances in tertiary care paediatrics (with its accompanying increase in invasive procedures and a growth in organ transplantation) may have contributed to an increase in incidence.
Management decisions for children with thrombosis were directly extrapolated from treatment recommendations for adults with no further validation. For recommendations for adult patients as optimal management for paediatric patients, these two patient populations and their thrombotic problems needed the basic features in common. These parameters included the primary underlying disorder, the distribution of vessels involved, the interaction of anticoagulant and thrombolytic drugs with the haemostatic system, the pharmacokinetics of these drugs and the risk of serious complications of the disease and treatment. Available data suggested there were important differences.
DVT involved the upper system in between 26-36% of children (due to the use of central venous catheters) compared to 1-2% of DVT in adults. Idiopathic DVT was rare (4% in the Canadian Registry and 2% in the literature), in contrast to approximately 30% of adult DVT. More than 95% of children with DVT/PE had one or more predisposing factors.
The role of acquired and inherited thrombophilia in children remained unclear. There had been no comparative studies evaluating the sensitivity and specificity of diagnostic procedures in children. Given differences in the size and location of vessels involved, it was unlikely that results from comparative studies in adults could be extrapolated to children.
There was a profound effect of age on plasma concentration of coagulation proteins, with secondary effects on the regulation of thrombin and plasmin. This subsequently influenced the pharmacokinetics of anticoagulants, which strongly suggested that optimal therapy for children with thrombo-embolic disease and its complications may have differed significantly from that of adults.
Objectives:
- To determine the incidence and epidemiology of thrombosis in children aged between 1 month and 16 years in the UK.
- To determine which risk factors predispose to thrombosis in childhood, and in particular, the role of thrombophilia, both inherited and acquired.
- To determine diagnostic and therapeutic practices for childhood thrombosis
- Assess whether sufficient information was available on which to develop management guidelines.
Duration
February 2001 – February 2003
Published papers
Gibson, B.E.S. & Chalmers, E.A. & Bolton-Maggs, Paula & Henderson, D.J. & Lynn, R.. (2004). Thromboembolism in childhood: A prospective two year BPSU study in the United Kingdom. February 2001-February 2003. British Journal of Haematology. 1. OC422
Chalmers EA. Epidemiology of venous thromboembolism in neonates and children. Thromb Res. 2006;118(1):3-12. doi: 10.1016/j.thromres.2005.01.010. Epub 2005 Feb 24. PMID: 16709473.
BPSU 17th Annual report 2002 – 2003
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