Reference values for thrombotic markers in children

Abstract

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.

Increased tissue factor activity promotes thrombin generation at type 1 diabetes onset in children

“…TFPI is an inhibitor of coagulation with a strong influence on thrombin generation, particularly in the early phase of thrombin generation. We found levels above the pediatric reference range at the onset of the disease and a significant reduction after the beginning of treatment 24 . A similar result was found by Rigla et al, who tested young adults with insufficiently controlled T1D and demonstrated reduced TFPI levels after optimization of the treatment.…”

“…We found levels above the pediatric reference range at the onset of the disease and a significant reduction after the beginning of treatment. 24 A similar result was found by Rigla et al, who tested young adults with insufficiently controlled T1D and demonstrated reduced TFPI levels after optimization of the treatment. However, this finding is contradictory to a shortened lag time/time to peak since a heightened TFPI level is supposed to elongate lag time and time to peak.…”

Population pharmacokinetics of human antithrombin concentrate in paediatric patients

“…The normal values of AT in paediatric patients are not well defined, and range from 85-130% in paediatric patients, with decreases in patients under 3 months of age [18]. In our clinical experience, a goal of 120% is often recommended, although this varies for each clinical scenario.…”

The clinical presentation and genotype of protein C deficiency with double mutations of the protein C gene

“…The anticoagulant activities of PC were determined using the Staclot Protein C kit (Diagnostica Stago, Asnieres, France). The reference ranges (Rr) of the PC activity/antigen levels for term and preterm infants and other subjects were based on those reported in previous studies . In our cohort study, the plasma PC activity was determined using repeated coagulation tests (including factor VII activity) at the time of diagnosis and during the disease course.…”