ARUP's Laboratory Test Directory

Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII : 0030026

Mnemonic: F8 BETHR

Ordering Recommendation: Order to diagnose factor VIII deficiency, detect factor VIII inhibitors, and monitor factor VIII replacement therapy.
Methodology: Clotting
Performed: Mon, Wed, Fri
Reported: 1-4 days
Specimen Required: Collect: Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation: Transfer two 3 mL aliquots of platelet-poor plasma to ARUP Standard Transport Tubes. (Min: 2 mL/each)

Storage/Transport Temperature: CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Remarks:

Unacceptable Conditions: Serum. Non-frozen and hemolyzed specimens.

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20°C: 3 months; Frozen at -70°C: 6 months
Reference Interval:
 
Test Number Components Reference Interval
0030095Factor VIII, Activity 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%
 Bethesda Quantitative, Factor VIII No inhibitor detected.

Note: If Factor VIII activity is 20 percent or less, then Bethesda Quantitative, Factor VIII will be added.  Additional charges apply.
CPT Code(s): 85240 Factor VIII; if reflexed, add 85335 Bethesda Quantitative
Cross References: Bethesda Quantitative Factor VIII, Inhibitor (Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII) , Coagulation Factor VIII Inhibitor Panel, Plasma (Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII) , Factor VIII Inhibitor Profile (Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII) , Hemophilia A (Factor VIII Activity with Reflex to Bethesda Quantitative, Factor VIII)