ARUP's Laboratory Test Directory

Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX : 0030032

Mnemonic: F9 BETHR

Ordering Recommendation: Order to diagnose factor IX deficiency, detect factor IX inhibitors, and monitor factor IX 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 two ARUP Standard Transport Tubes. (Min: 2 mL/each)

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

Remarks: For hemophiliacs: Note dose, date, and time of last factor IX concentrate infusion.

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

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: 4 hours; Frozen: 2 weeks
Reference Interval:
 
Test Number Components Reference Interval
0030100Factor IX, Activity 1-4 days: 15-91%
5-29 days: 15-91%
30-89 days: 21-81%
90-179 days: 21-113%
180-364 days: 36-136%
1-5 years: 47-104%
6 years: 63-89%
7-9 years: 70-133%
10-11 years: 72-149%
12-13 years: 73-152%
14-15 years: 80-161%
16-17 years: 86-176%
18 years and older: 78-184%
 Bethesda Quantitative, Factor IX No inhibitor detected.

Note: If Factor IX activity is 20% or less, then Bethesda Quantitative, Factor IX will be added. Additional charges apply.
CPT Code(s): 85250; if reflexed, add 85335
Cross References: Bethesda Quantitative Factor IX (Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX), Coagulation Factor IX Inhibitor, Plasma (Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX) , Factor IX Inhibitor, Quantitative (Factor IX Activity with Reflex to Bethesda Quantitative, Factor IX)