Optimization of the detection of inhibitory autoantibodies against the VWF-cleaving protease ADAMTS13 with an automated chemiluminescent ADAMTS13 activity immunoassay.

Introduction: Acquired thrombotic thrombocytopenic purpura is a rare disease associated with the production of autoantibodies against the VWF-cleaving protease ADAMTS13. The detection of these antibodies is made difficult by the instability of ADAMTS13 in citrated plasma and the time-consuming ADAMTS13 assays. The aim of our study was to evaluate the optimal conditions for detecting anti-ADAMTS13 inhibitory antibodies with the novel automated chemiluminescent immunoassay HemosIL AcuStar ADAMTS13 Activity assay.

Accurate measurement of extended half-life and unmodified factor VIII low levels with one-stage FVIII assays is dependent on the matrix of calibration curves.

Introduction: The monitoring of factor VIII (FVIII) replacement therapy relies on the accurate measurement of FVIII activity over a large concentration range. However, unexplained overestimation of low FVIII levels has recently been reported with extended half-life recombinant FVIIIs.

Aim: The objective of this study was to confirm previous publications indicating that the reagents used to generate the calibration curves determine the accuracy of the measurement of low FVIII levels.