Performance characteristics of the AxSYM D-dimer assay

BackgroundD-dimer testing is used to exclude thromboembolic disease in outpatients suspected of having deep venous thrombosis and pulmonary embolism.MethodsWe evaluated 4 D-dimer assays for imprecision and method comparison and evaluated the AxSYM® method for interference, linearity, and reference interval. Method comparison testing was performed using the following methods: Abbott AxSYM, bioMérieux mini VIDAS®, Diagnostica Stago STA Compact®, and Biosite Triage® Meter Plus.ResultsTotal CVs for all methods ranged from 3.7% for the STA Compact to 17.3% for the Triage Meter. The AxSYM showed good agreement with the other methods with slopes ranging from 1.17 to 1.22 by Passing–Bablok regression and correlation coefficients ≥ 0.96. Interference from hemolysis, icterus, and lipemia had < 7% deviation from the intended D-dimer concentration. Linearity had ≤ 11.5% deviation from target values.ConclusionsThe AxSYM D-dimer assay provides a precise, rapid, and user-friendly method for D-dimer testing with good correlation to other methods.