RESUMO
BACKGROUND: The routine D-dimer quantification to exclude venous thromboembolism has led to the development of many assays, the usefulness of which depends on their reliability and performance. OBJECTIVE: We evaluated the analytical performances of the immunoturbidimetric Yumizen G DDi 2 assay (HORIBA Medical, Montpellier, France) performed on the Yumizen G800 analyzer and compared it with other available D-dimer assays. METHODS: Within-run and between-run imprecision were evaluated using low- and high-level quality-control plasma samples. Interference due to hemolysis, icterus, lipemia, rheumatoid factor (RF), or heterophilic antibodies (human antimouse antibodies [HAMAs]) was evaluated by spiking plasma samples with hemolysate, bilirubin, Intralipid, RF, or HAMAs. The measurements obtained with the different D-dimer assays were compared using Passing-Bablok regression analysis and Bland-Altman plot method, using fresh citrated plasma samples collected from 66 consecutive routine patients with a wide range of D-dimer concentrations. RESULTS: Within- and between-run variation coefficients for the Yumizen G DDi 2 assay ranged from 1.7% to 5.8% and from 2.8% to 5.5%, respectively. Hemolysis and icterus did not have any effect up to 10 g/L hemoglobin and 300 mg/L bilirubin. Lipemia seemed to generate an underestimation of D-dimer concentration when the Intralipid concentration was >5 g/L. RF and HAMAs did not have any effect. The Passing-Bablok and Bland-Altman analyses showed small differences with other available D-dimer assays, which were more pronounced with increasing values. CONCLUSIONS: Its analytical performances and main technical features indicate that the new Yumizen G DDi 2 assay is suitable for the rapid quantification of D-dimer in clinical hemostasis laboratories.
RESUMO
Exploring coagulation in newborns and children is a challenge due to the low levels of both procoagulant factors and inhibitors. Conventional coagulation tests might be inadequate to explore all of these changes. The aim of the study is to evaluate the thrombin generation assay, a global test to explore coagulation, in a pediatric population (n=586) compared to an adult population (n=166). The thrombin generation assays were performed using Calibrated Automated Thrombography with two different tissue factor concentrations (1 and 5 pM), with and without thrombomodulin (TM). In the absence of TM, the endogenous thrombin potential (ETP) is significantly lower in the pediatric population, reflecting the decrease in procoagulant factors. In the presence of TM, ETP values in pediatric subjects are within the reference range of adult values. The thrombin generation assay demonstrates that coagulation balance is maintained in the pediatric population.
