Reference values for thrombotic markers in children

Thromboembolic events are an increasingly common problem encountered in children. The laboratory diagnosis of thrombotic disorders in children differs from that in adults. To establish the normal reference of natural anticoagulant parameters in children of different age groups, plasma from healthy children between the ages of 2 months and 16 years (n = 127) and adults (n = 30) were assayed for a disintegrin-like and metalloprotease with thrombospondin type 1 domain 13 (ADAMTS-13), von Willebrand factor collagen-binding activity (vWF:CB), tissue factor pathway inhibitor (TFPI), homocyteine and natural anticoagulants. Children were divided into four age groups: less than 1 year, 1-5 years, 6-10 years, and 11-16 years. The reference values for ADAMTS 13, homocysteine, and protein C activity were significantly lower in children of all age groups compared with those in the adults. Similarly, those for protein C antigen, total protein S, free protein S and antithrombin III (AT III) for children less than 1 year were significantly lower than in the adults. On the contrary, TFPI levels were significantly higher in the children for all age groups when compared with the adults. vWF:CB levels were comparable across all groups. There are age-related physiologic differences in ADAMTS-13, TFPI, homocysteine and natural anticoagulants between children and adults. Our data will provide physicians with a useful reference guide in interpreting test results of inhibitors of hemostatic parameters in children suspected of thrombotic disorders.     

Activation of endothelial cells, coagulation and fibrinolysis in children with Dengue virus infection

Dengue virus causes a febrile illness: Dengue fever (DF), and less frequently a life-threatening illness: Dengue hemorrhagic fever (DHF). Although severe bleeding remains a major cause of death in DHF, the pathogenesis of bleeding is poorly understood. This prospective cohort study was designed to determine the extent of activation of endothelial cells and the hemostatic system in correlation with clinical severity, and also to detect the best prognostic factor(s) for DHF. Endothelial cell activation, coagulation, anticoagulant and fibrinolysis parameters were measured in 42 children with Dengue infections (20 with DF and 22 with DHF) during three phases of illness. In DHF patients, during the febrile phase, von Willebrand factor antigen (vWF:Ag), tissue factor (TF) and plasminogen activator inhibitor (PAI-1) were significantly elevated, while platelet counts and ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin repeats) were significantly low compared to DF patients. During the toxic phase, soluble thrombomodulin (sTM), tissue plasminogen activator (t-PA) and PAI-1 were also significantly increased, while ADAMTS 13 and thrombin activatable fibrinolysis inhibitor (TAFIa) were significantly low compared to DF patients. Abnormal vWF multimers were seen only in DHF patients. For endothelial cell injury and release of procoagulant components, activation of the coagulation cascade with thrombin generation, increased antifibrinolytic factors and consumption of natural anticoagulants, each appeared to play an important role in the development of hemorrhage in Dengue patients. Using logistic regression analysis, we found plasma VWF:Ag to be the best indicator of progression to DHF.     

Xanthogranulomatous adrenalitis in a neonate: CT and US findings

We report a 46-day-old female infant with xanthogranulomatous adrenalitis. Ultrasonography showed a complex, solid-cystic right suprarenal mass with poorly defined margins. Colour flow Doppler revealed the solid portion of the mass to be vascular. CT demonstrated a heterogeneous cystic and solid mass with some contrast enhancement in the inferior part of the lesion. There was compression of the adjacent upper pole of the right kidney and the lateral aspect of the inferior vena cava. The mass was completely removed; histological examination revealed xanthogranulomatous adrenalitis. At the time of this report she remained well 3 years following surgery.     

Pediatric primary central nervous system tumors registry in Thailand under National Health Security Office schemes

Journal of Neuro-Oncology - Few epidemiological studies of pediatric central nervous system (CNS) tumors have been performed using data from Southeast Asian national registries. Therefore, we aimed...     

Pediatric reference values for molecular markers in hemostasis

BACKGROUND: The hemostatic system is a developing and changing process relative to age. OBJECTIVES: To distinguish the differences in hemostatic parameters between children and adults, and to establish the normal range of these parameters in children of different age groups. DESIGN/METHODS: Blood was obtained from healthy children aged 1 to 18 years (n=70) and adults (n=26). Children were categorized into 3 age groups: 1 to 5 years, 6 to 10 years, and 11 to 18 years. Several coagulation and fibrinolysis parameters were determined. RESULTS: Children in all age groups showed no significant difference in mean levels of von Willebrand factor antigen and activity, activated partial thromboplastin time, fibrinogen, activated factor VII, tissue plasminogen activator, plasminogen activator inhibitor-1, and thrombin activatable fibrinolysis inhibitor compared with adults. However, children aged 1 to 5 years had significantly higher mean values of soluble thrombomodulin (P=0.001), prothrombin time (P=0.03), tissue factor (P<0.001), thrombin-antithrombin complex (P<0.001), and D-dimer (P=0.009) whereas they had significantly lower mean levels of protein C activity (P=0.02) than did adults. CONCLUSIONS: These data indicate physiologic differences in the hemostatic system between children and adults and should serve as a useful reference guide in interpreting test results for children with suspected bleeding disorders.