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Factor VII activity and antigen in a patient with abnormal factor VII
O Takamiya1, S Funahashi, S Kinoshita
1Department of Clinical Pathology, Osaka National Hospital, Japan.
Clinical and Laboratory Haematology
|January 1, 1988
Summary
A patient presented with abnormal factor VII activity, varying with thromboplastin source. This suggests a specific factor VII abnormality, potentially similar to factor VII Padua 1.
Area of Science:
- Hematology
- Clinical Coagulation
- Biochemistry
Background:
- Coagulation factor VII is a vitamin K-dependent protein crucial for the extrinsic pathway of hemostasis.
- Abnormalities in factor VII can lead to bleeding disorders, but some variants present with mild or no symptoms.
Observation:
- A female patient exhibited an abnormal clotting time unresponsive to vitamin K.
- Factor VII activity varied significantly based on the thromboplastin source used for measurement (rabbit brain, human brain, human placenta, ox brain).
Findings:
- Factor VII antigen levels were normal, with normal electrophoretic mobility and molecular weight.
- The patient's factor VII exhibited reduced activity with certain thromboplastins, suggesting a functional defect rather than a quantitative deficiency.
Implications:
- This case highlights a potential novel or rare variant of factor VII deficiency.
- Understanding such variations is critical for accurate diagnosis and management of coagulation disorders.
- The differing activity based on thromboplastin source may indicate specific structural abnormalities in the factor VII molecule.