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Updated: Sep 28, 2025
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Retrospective examination of coagulation parameters in 33 patients with autoimmune coagulation factor deficiencies in
Tsukasa Osaki1, Masayoshi Souri1, Yoshiyuki Ogawa2
1Japanese Collaborative Research Group (JCRG) on Autoimmune Coagulation Factor Deficiency (AiCFD) supported by the Japanese Ministry of Health, Labor and Welfare (MHLW), Yamagata, Japan; Department of Molecular Patho-Biochemistry and Patho-Biology, Yamagata University School of Medicine, Yamagata, Japan; Department of Public Health and Hygiene, Yamagata University School of Medicine, Yamagata, Japan.
Insights
Chromogenic assays improve diagnosis of autoimmune coagulation factor deficiencies (AiCFDs) by distinguishing true deficiencies from pseudo-deficiencies. Detecting autoantibodies helps avoid misdiagnosis in complex cases.
Area of Science:
- Hematology
- Immunology
- Clinical Diagnostics
Background:
- Autoimmune coagulation factor deficiencies (AiCFDs) present diagnostic challenges due to pseudo-deficiencies and pseudo-inhibitors.
- Common one-stage assays can cause confusion by showing reduced coagulation factor activity.
Purpose of the Study:
- To evaluate the utility of chromogenic assays in diagnosing AiCFDs.
- To differentiate true deficiencies from pseudo-deficiencies caused by autoantibodies.
Main Methods:
- Retrospective analysis of 33 AiCFD patients with confirmed autoantibodies.
- Examination of coagulation factor activities (FX, FVIII, FIX) using chromogenic substrates.
- Comparison of chromogenic assay results with conventional one-stage assays.
Main Results:
- Chromogenic assays identified pseudo-deficiencies in 4 (FX), 9 (FVIII), and 22 (FIX) patients.
- Specific activities of FX, FVIII, and FIX were higher in chromogenic assays compared to one-stage assays.
- High titers of FV inhibitors correlated with pseudo-deficiencies and misidentification of other factor inhibitors.
Conclusions:
- Chromogenic assays are superior to one-stage assays for measuring coagulation factor activity in AiCFD.
- Detecting anti-coagulation factor autoantibodies is crucial to avoid overlooking non-neutralizing antibodies and misdiagnosis.
Background:
The early diagnosis and prompt treatment of autoimmune coagulation factor deficiencies (AiCFDs) are challenging for physicians when patients present with pseudo-deficiencies or pseudo-inhibitors of multiple coagulation factors. A reason for this is the diagnostic confusion caused by the apparent reduction in coagulation factor activity when using common one-stage coagulation factor measurement assays.
Methods:
After confirming the presence of autoantibodies against each coagulation factor, we retrospectively examined the activity of factors X, VIII, and IX (FX, FVIII, and FIX, respectively) and each coagulation factor inhibitor using their chromogenic substrates among 33 patients with AiCFD.
Results:
Because the apparent coagulation factor deficiency was completely or partially restored in the chromogenic assay, 4, 9, and 22 patients with AiCFD were suspected of having pseudo-FX, pseudo-FVIII, and pseudo-FIX deficiencies, respectively. Moreover, in the chromogenic assay, the specific activities of FX, FVIII, and FIX (determined by their antigen levels) were higher than those in the one-stage assay. The titers for FV inhibitors showed negative correlations with the ratios of FX, FVIII, and FIX activities measured via the one-stage assay and the chromogenic assay. An especially high titer of one coagulation factor inhibitor tends to either cause pseudo-deficiencies or get mistaken for being a pseudo-inhibitor of other coagulation factors.
Conclusion:
Chromogenic assays appear to be superior to conventional one-stage assays when measuring coagulation factor activity in AiCFD cases. Detection of anti-coagulation factor autoantibodies is recommended to avoid overlooking the presence of non-neutralizing autoantibodies.
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