| Primary
Name |
Factor
VIII Assay |
| Synonym |
Factor
VIII Functional Assay |
| Synonym |
-- |
| Contraction |
FVIII |
| Contraction |
-- |
| Contraction |
-- |
| UAB
Procedure Number |
2500480 |
| CPT
Code |
85240 |
| Specimen |
Collect
one (1) blue-stopper tube (3.2% sodium citrate), filled to specified
volume. Do not underfill or overfill.
|
| Specimen
Management |
Note
time of collection and time of last treatment if applicable.
Centrifuge blue-stopper tube within 1 hour of collection,
separate plasma and test or quick-freeze at -70°C. |
| Specimen
Accepted |
Daily
including weekends |
| Times
Available |
0730-1600;
deliver to lab by 1300 for same-day results |
| Test
Performed |
Monday-Friday. |
| Available
Stat? |
Pathologist's
approval required. |
| Description |
Congenital
factor VIII deficiency, termed hemophilia A, is inherited as a sex-linked
recessive and is seen in 1 in 5000 males. Factor VIII deficiency is also
seen in some cases of von Willebrand disease. Rare inhibitors cause acquired
factor VIII deficiency. Factor VIII deficiency is associated with mild
to severe bleeding. Chronic elevated factor VIII confers a 2- to 3-fold
risk of venous thrombosis. Because factor VIII is an acute phase reactant,
a single elevated result may not alone indicate a risk of thrombosis. |
| Reference
Interval |
50-186% |
| Critical
Value |
-- |
| Therapeutic
Range |
-- |
| Follow-up
Test |
*If
von Willebrand disease is suspected, the ristocetin cofactor (vWF activity)
and von Willebrand factor antigen assays are recommended.
*If an anti-VIII inhibitor is suspected, an inhibitor titer (Bethesda
titer) is recommended |
| Associated
With |
Bleeding
disorders |
| Associated
With |
Venous
thrombosis |
| Associated
With |
Von
Willebrand disease |
