Factor IX Activity, Clotting

Overview

  • EPIC Code:
  • LAB308
  • Soft Test Code:
  • FACT9
  • Send Out Test Code:
  • 352X
Alternate Names
  • Christmas Factor
  • Factor IX Activity
  • Factor IX Assay
  • Hemophilia B
Clinical Significance

This test is useful to evaluate a prolonged aPTT. The second most common form of hemophilia is caused by deficiency of factor IX. Hemophilia B is an x-linked disorder affecting between 1 in 25,000 to 30,000 males.


Specimen Collection & Preparation

Specimen Requirements

1.0 mL platelet poor plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial


Transport And Storage

Unacceptable Ambient
Unacceptable Refigerated
14 days Frozen


Collection Instructions

Centrifuge light blue-top tube for 15 minutes at approximately 1500 x g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid WBCs/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (< 10,000/uL). Freeze immediately and ship on dry ice.


Minimum Volume

0.5 mL Platelet Poor Plasma


Neonatal Volume

Clinical Interpretation

Reference Range:

60 -160% of normal


Methodology:
  • Photometric Clot Detection
Clinical Significance

This test is useful to evaluate a prolonged aPTT. The second most common form of hemophilia is caused by deficiency of factor IX. Hemophilia B is an x-linked disorder affecting between 1 in 25,000 to 30,000 males.


Documentation

Limitations: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: Decrease; Heparin (UFH or LMWH): no effect to inhibitor pattern; Dabigatran or Argatroban (Thrombin Inhibitors): no effect to inhibitor pattern; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect to inhibitor pattern.


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Tuesday
Thursday
Saturday
Departments
  • Sendouts - Clinical
Turn Around Time

5 to 7 days


Coding & Compliance

CDM

01453629


CPT Coding

85250