Sorted By Test Name - Mayo Medical Laboratories

F5IS
7807
F_7
9055
Useful For). Congenitally deficient homozygotes generally have levels < or =10% to 20%. Congenitally
deficient heterozygotes generally have levels < or =50%. Congenital deficiency may occur in combined
association with factor VIII deficiency.
Reference Values:
Adults: 70-165%
Normal, full-term newborn infants may have borderline low or mildly decreased levels (> or =30% to
35%) which reach adult levels within 21 days postnatal. Healthy premature infants (30-36 weeks
gestation) may have borderline low or mildly decreased levels.*
*See Pediatric Hemostasis References in Coagulation Studies in Special Instructions.
Clinical References: 1. Girolami A, Scandellari R, Scapin M, Vettore S: Congenital bleeding
disorders of the vitamin K-dependent clotting factors. Vitam Horm 2008;78:281-374 2. Brenner B,
Kuperman AA, Watzka M, Oldenburg J: Vitamin K-dependent coagulation factors deficiency. Semin
Thromb Hemost 2009 Jun;35(4):439-446 3. Asselta R, Peyvandi F: Factor V deficiency. Semin Thromb
Hemost 2009 Jun;35(4):382-389 4. Lippi G, Favaloro EJ, Montagnana M, et al: Inherited and acquired
factor V deficiency. Blood Coagul Fibrinolysis 2011;22(3):160-166 5. Spreafico M, Peyvandi F:
Combined FV and FVIII deficiency. Haemophilia 2008 Nov;14(6):1201-1208
Coagulation Factor V Inhibitor Screen, Plasma
Clinical Information: Factor V inhibitors can occur in patients with congenital factor V deficiency
after transfusion of fresh frozen plasma, however, more commonly, they occur spontaneously in
previously healthy older patients who have no underlying diseases. Topical bovine thrombin or fibrin
glue, which contain bovine thrombin and factor V, are commonly used in surgery for topical hemostasis,
can result in development of anti-bovine thrombin/factor V inhibitors that cross-react with human
thrombin and factor V. Other associations include antibiotics, transfusions and malignancies.
Useful For: Detection and quantitation of inhibitors against coagulation factor V
Interpretation: Normally, there is no inhibitor, ie, negative. If the screening assays indicate the
presence of an inhibitor, it will be quantitated and reported in Bethesda (or equivalent) units.
Reference Values:
FACTOR V ACTIVITY ASSAY
Adults: 75-165%
Normal, full-term newborn infants may have borderline low or mildly decreased levels (> or =30-35%)
which reach adult levels within 21 days postnatal.*
Healthy premature infants (30-36 weeks gestation) may have borderline low or mildly decreased levels.*
*See Pediatric Hemostasis References in Coagulation Studies in Special Instructions.
FACTOR V INHIBITOR SCREEN
Negative
Clinical References: 1. Feinstein DI: Acquired inhibitors of blood coagulation. In Hematology:
Basic Principles and Practice. Edited by R Hoffman, EJ Benz Jr, SJ Shattil, et al. New York, Livingstone
Press, 1991, pp 1380-1394 2. Kasper CK: Treatment of factor VIII inhibitors. Prog Hemost Thromb
1989;9:57-86
Coagulation Factor VII Activity Assay, Plasma
Clinical Information: Factor VII is a vitamin K-dependent serine protease synthesized in the liver. It
is a component of the extrinsic coagulation scheme, measured by the prothrombin time. Plasma biological
half-life is about 3 to 6 hours. Deficiency may result in a bleeding diathesis.
Useful For: Diagnosing congenital deficiency of coagulation factor VII Evaluating acquired
deficiencies associated with liver disease, oral anticoagulant therapy, and vitamin K deficiency
Determining degree of anticoagulation with warfarin to correlate with level of protein C Investigation of a
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