Prothrombotic conditions in an unselected cohort of children with venous thromboembolic disease

Abstract

Please see also Sutor A.H. Screening children with thrombosis for thrombophilic proteins. Cui bono?. This issue, pp. 886-888.Summary. Venous thromboembolic events (VTEs) in children are usually associated with underlying clinical conditions. The added contribution of prothrombotic conditions to the occurrence of VTEs in children is not clear. This study reports the prevalence of prothrombotic conditions in 171 consecutive children with VTE followed in the Hospital for Sick Children Thrombosis Outpatient Clinic. The median age of the children at the time of VTE was 2.3 months (range 1 day to 16.5 years). An underlying medical condition and a central venous line (CVL) were present in 156 (91%) and 132 (77%) of 171 children, respectively. A positive family history was present in 8% of children. The prevalence of factor V Leiden was 4.7%, prothrombin G20210A polymorphism was 2.3%, protein S deficiency was 1.2%, protein C deficiency was 0.6% and increased plasma lipoprotein (a) concentration (>30 mg dL À1 ) was 7.5% (tested in 107 children). The overall frequency of inherited prothrombotic coagulation proteins was 13% (95% confidence interval 7 to 19%) and the frequency was not significantly different between neonates and older children with VTE. Inherited prothrombotic coagulation proteins were not associated with gender, CVL-related VTE, a positive family history of thrombosis or spontaneous VTE in neonates. Increased frequency of inherited prothrombotic coagulation proteins was, however, found in older children with spontaneous VTE (60%) compared with older children with VTEs secondary to an underlying medical condition (10%) (P ¼ 0.02). In conclusion, this study indicates that inherited prothrombotic coagulation proteins do not contribute significantly to the pathogenesis of VTEs in neonates and children, in whom the most significant etiological factors are the presence of a CVL and/or other medical conditions.

Manifestations and clinical impact of pediatric inherited thrombophilia

“…Thrombophilic disorders were present in no more than 13% of the total number of patients, but in 60% of the adolescents with unprovoked thrombosis. 30 In a prospective cohort study of 100 children with VTE, family history of VTE appeared to be the only predictor for the presence of inherited thrombophilia (OR, 14.9; 95% CI, 1.9-113) after multivariate analysis. 31 Likewise, in the cross-sectional study by Ruud et al, family history of VTE increased the RR of a child having inherited thrombophilia to 2.35 (95% CI, 1.1-5.2).…”

Lipoprotein (a) as a cause of cardiovascular disease: insights from epidemiology, genetics, and biology

“…However, in a study including 109,169 individuals from the Copenhagen City Heart Study and the Copenhagen General Population study combined, we found that high Lp(a) concentrations of venous thromboembolism, with conflicting results (232)(233)(234)(235)(236)(237)(238)(239)(240)(241)(242).…”

Aspects of anticoagulation in children

“…In a cohort of children with a first VTE, the presence of a prothrombotic factor increased the risk of recurrence and was independently significant by multivariate analysis (single defect: OR, 4AE6, 95% CI 2AE3-9AE0; combined defect: OR, 24AE0, 95% CI 5AE3-108AE7) (Nowak-Gottl et al, 2001). However, Revel-Vilk et al (2003) showed that most recurrent events occur in those with acquired risk factors, such as a CVL. It is notable that children with CVLs and cancer were excluded from the study reported by Nowak-Gottl et al (2001).…”