Photo-optical clot determination with Factor VII deficient substrate.
Detection of specific coagulation factor VII deficiency.
Increased in patients taking oral contraceptives. Interpretation of results may be limited if patient is receiving anticoagulant therapy.
- Factor VII Assay
- Factor VII:C Assay
- Factor 7 Activity
- Factor 7 Assay
Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.
Factor VII may be increased in patients with nephrotic syndrome and in burn patients and decreased in patients with vitamin K deficiency, factor VII deficiency, liver disease, warfarin therapy, and occasionally in patients with chronic renal failure. Normal levels of factor VII may be present in patients with congenital dysfibrinogenemia.