Ordering Recommendation

Order to diagnose hemophilia A, acquired factor VIII deficiency, or as part of a diagnostic workup for von Willebrand disease (VWD). Also useful for monitoring treatment in patients with factor VIII deficiency or VWD. Not recommended when screening for thrombophilia.

Mnemonic
F8
Methodology

Electromagnetic Mechanical Clot Detection

Performed

Mon-Sat

Reported

1-3 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Serum. EDTA plasma, clotted or hemolyzed specimens.

Remarks
Stability

Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20° C: 3 months; Frozen at -70° C: 6 months

Reference Interval
Age Reference Interval
0-6 years 56-191%
7-9 years 76-199%
10-11 years 80-209%
12-13 years 72-198%
14-15 years 69-237%
16-17 years 63-221%
18 years and older 56-191%

Interpretive Data



No compliance statements are in use for this test.

Note
Hotline History
N/A
CPT Codes

85240

Components
Component Test Code* Component Chart Name LOINC
0030095 Factor VIII, Activity 3209-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • AHF
  • Antihemophilic Factor (AHF), Factor VIII:C (Coagulant Portion)
  • Coagulation Factor VIII Activity Assay, Plasma
  • Factor VIII Activity Assay
  • Intrinsic Factor Proteins
  • Intrinsic Factors
Factor VIII, Activity