Related Experiment Video
Updated: May 5, 2026
13:08
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
19.4K
Evaluation of Autoimmune FVIII Inhibitor Using Clot Waveform Analysis in Emicizumab-Treated Patients
Shigehisa Tamaki1, Hideo Wada2, Naoki Shinke1
1Department of Hematology, Japanese Red Cross Ise Hospital, 471-2 Hunae-Ichome, Ise 516-8512, Mie, Japan.
Journal of Clinical Medicine
|January 10, 2026
Summary
Autoimmune factor VIII deficiency (AiFVIIID) monitoring is challenging. Clot waveform analysis with thrombin (CWA-sTT) aids AiFVIIID diagnosis and emicizumab treatment monitoring by reflecting residual FVIII activity.
Area of Science:
- Hematology
- Clinical Coagulation
- Autoimmune Disorders
Background:
- Autoimmune factor VIII deficiency (AiFVIIID) is a rare, severe bleeding disorder.
- Emicizumab shows promise for AiFVIIID treatment, but standard coagulation tests face monitoring challenges.
Purpose of the Study:
- To evaluate Clot Waveform Analysis (CWA) methods for diagnosing AiFVIIID.
- To assess CWA's utility in monitoring emicizumab treatment in AiFVIIID patients.
Main Methods:
- Utilized CWA-activated partial thromboplastin time (APTT), CWA-small tissue factor activation assay (sTF/FIXa), and CWA-small thrombin time (CWA-sTT).
- Compared CWA-sTT with standard tests like APTT, FVIII activity, mixing studies, and inhibitor assays for diagnosis and monitoring.
Main Results:
- CWA-sTT effectively reflects residual factor VIII activity in AiFVIIID patients.
- APTT reagent sensitivity varied for AiFVIIID detection.
- Emicizumab treatment was effective for major bleeding; CWA-sTT measured anti-FVIII antibody activity during treatment.
Conclusions:
- CWA-sTT offers potential for AiFVIIID diagnosis and monitoring.
- Emicizumab is a viable treatment for AiFVIIID.
- Anti-FVIII antibody activity measurement is feasible with CWA-sTT during emicizumab therapy.
