Pediatric thromboembolism: a national survey in Japan

Area of Science:

• Pediatric Hematology
• Thrombophilia Research
• Epidemiology

Background:

• Thromboembolism (blood clots) is increasingly diagnosed in children.
• The prevalence of pediatric thrombophilia varies globally and was previously unquantified in Japan.

Purpose of the Study:

• To investigate the incidence and characteristics of symptomatic thromboembolism in Japanese children.
• To identify the prevalence of congenital thrombophilia and associated risk factors in this population.

Main Methods:

• A nationwide survey was conducted among pediatric departments and specialists in Japan.
• Data were collected on pediatric patients diagnosed with symptomatic thromboembolism between 2006 and 2010.
• Eligible cases were analyzed for congenital and non-congenital causes of thrombophilia.

Main Results:

• Congenital thrombophilia was identified in 19.3% of cases (n=54), primarily involving defects in protein C, protein S, and antithrombin.
• Unlike in Caucasians, mutations in factor V Leiden and prothrombin G20210A were absent.
• Children with congenital thrombophilia experienced earlier thromboembolism onset, higher consanguinity rates, and increased recurrence and post-thrombotic syndromes.
• Non-congenital causes included congenital heart disease, central venous catheters, nephrotic syndrome, antiphospholipid syndrome, and malignancy.

Conclusions:

• This study presents the first comprehensive data on pediatric thromboembolism and thrombophilia in Japan.
• Congenital thrombophilia significantly impacts disease presentation, recurrence, and long-term outcomes in children.
• Optimized management strategies are crucial given the high rates of recurrence and sequelae.